Archive for the ‘Technical’ Category

Meridian 2

Wednesday, August 26th, 2020

Continuing with pictures from my walk along the Greenwich Meridian in Greater London in 1984-6.

Stratford Bus Station – Peter Marshall, 1995

My walks took me as close to the line of the Meridian I had pencilled on my 1983 1:25000 OS map as possible, though that line may not have been quite exact. I think it goes through the area at the extreme left of the picture above, here just a few yards east of the roadway. My series of walks kept as close as possible to the pencil line, but it often runs through private property, buildings, across rivers etc and many detours, some quite lengthy were required.

Barge carries contaminated earth from Poplar gasworks site, Peter Marshall, 2011

One of those fairly lengthy detours was north from Poplar, where the line ran through the gas works site and across Bow Creek. It wasn’t until 2011 that I was able to go onto the former gas works site, having been engaged to photograph the use of a barge to carry away the heavily contaminated soil from the site. The line crosses the river here, going through the left end of the large shed close to the opposite bank, near to Cody Dock. This is also part of a private business estate, though you can now walk along the roadways in it. There are several such areas I have been able to photograph in later years, but I won’t add any other later pictures to these posts.

Stratford Station – Peter Marshall, 1995

The line continues through the east end of Stratford Station.

Thinking of the line of the Meridian, I had decided it was appropriate to use a panoramic format, and these pictures were all taken with a swing lens panoramic camera. I think at the time I owned two such cameras, an expensive Japanese model and a cheap Russian one. The Russian was a little more temperamental and it was sometimes difficult to wind on the film, but had a much better viewfinder and I think was probably used for most of these. Both give negatives which are roughly the width of medium format film – 55-58mm – but only 24mm high, the limit of 35mm film, giving a roughly 2.3:1 aspect ratio. There is no discernible difference in image quality.

Langthorne Rd, Leyton – Peter Marshall, 1995

Both used 35mm film and curve it in the horizontal plane around a little over a third of the outside of a circle, with the lens pivoting roughly 130 degrees around the centre of that circle during the exposure. This keeps the distance between the centre of the lens and film constant, avoiding the distortion produced by using flat film, where the edges of the film are further from the lens node. This gives a very noticeable distortion with ultra-wide lenses, limiting them to an angle of view (horizontal) of roughly 100 degrees.

St Patrick’s Cemetery, Leyton

Swing lens cameras are limited in angle of view only by the mechanical limitations and can generally cover 130-140 degrees. But the curvature of the film does produce its own unique view. Assuming you keep the camera upright, straight vertical lines remain straight as the film is not curved vertically, but non-vertical lines show curvature, increasingly so as you move away from the centre of the film. You can see this clearly in the shop window in Langthorne Rd.

Whipps Cross – Peter Marshall, 1985

To be continued…

Against Facial Recognition

Sunday, August 16th, 2020

I’m not sure if you need this. But for some people in some countries it could be very important, assuming that it works. I’ve always been very open on-line, posting only under my real name and everything I post is public. I’ve been careful though only to post things that I don’t mind everyone knowing about me.

As a journalist I’ve had some advice and training on privacy issues, particularly on messaging and e-mail, but haven’t ever felt I was in a situation where I needed to put this into practice. But I do sometimes worry a little about my pictures on line and how these might be used to build up profiles of some of those present by legal or illegal groups, including the police who are already making use of facial recognition in various city environments.

There have been various attempts to block facial recognition, both through the courts and through various subterfuges, including the use of masks and special makeup. Covid-19 has surely added to the problems faced by Dynamic Neural Networks in recognising individuals and whereas wearing a mask was often a criminal offence now you may be fined for not doing so.

What is new about Fawkes (it gets its name from the ‘Anonymous’ mask) developed by a team of students at the SAND Lab at University of Chicago is that it is the first tool to enable us to “protect ourselves against unauthorized third parties building facial recognition models that recognize us wherever we may go” that “gives individuals the ability to limit how their own images can be used to track them”, able to defeat the tools used by systems such as https://www.vice.com/en_us/article/5dmkyq/heres-the-file-clearview-ai-has-been-keeping-on-me-and-probably-on-you-too clearview.ai using deep learning to identify individuals.

The team explain how Fawkes works (and for the technical there is a publication and source code available on the site)

At a high level, Fawkes takes your personal images and makes tiny, pixel-level changes that are invisible to the human eye, in a process we call image cloaking.

They go on to state that “if and when someone tries to use these photos to build a facial recognition model, “cloaked” images will teach the model an highly distorted version of what makes you look like you.”

Original
Cloaked

I’ve downloaded the software (a small file available for Mac and PC) and run it on a picture or two. It was rather slow – but my first files were large. I tried it again on a couple of 600×400 pixel images to post here, and it took around 100s to convert the pair.

The differences are real but pretty subtle – easier to see if you right click to download the files then view them one after the other in your image viewer. The change between the two in each pair then gives me a slightly weird feeling

But these were both images of a single person and I thought I’d try it on something rather more complex but the same size. Although it said it would take about 1 minute, 5 minutes later I was still waiting, and waiting…. I went away and did something else and I think it took around 7-8 minutes. There were small differences to most of the larger faces in the image but many appeared completely unchanged.

Original
Cloaked

The input files were all jpegs, but the output files are png, and have roughly five times the file size in bytes. They had also lost their various keywords and presumably other metadata. The files went back to a similar size to the originals when saved from Photoshop as jpg at an appropriate quality level, and it is these I’ve used here. Saving as jpg perhaps very slightly diminishes the differences.

I have of course no way of knowing whether the ‘cloaked’ files would – as the inventors say their trials show – provide at or near 100% protection “against state of the art facial recognition models from Microsoft Azure, Amazon Rekognition, and Face++”, but can only accept their assurances – and presumably their paper gives more details on their testing.

Fawkes is at the moment more a demonstration of concept rather than usable software, and you would have to be very concerned about your on-line privacy to treat pictures with it. But it does show that there are technical ways to fight back against the increasing abuse of personal data and its commercial exploitation by corporations.

Recently we’ve seen complaints being made by protesters about photographers putting their pictures online, with some arguing that their permission is needed or that they should be pixellated. While photographers rightly argue their right to photograph and publish public behaviour as a matter of freedom of speech – and the idea of claiming privacy seems to negate the whole idea of protest, I can see no objection to minor alterations in images which retain the essential image while frustrating AI-assisted data acquisition. It would I think be rather nice if Adobe could incorporate similar technology as an optional ‘privacy mode’.

Images used above are from My London Diary No War With Iran protest on 4th Jan 2020 opposite Downing St.


My London Diary : London Photos : Hull : River Lea/Lee Valley : London’s Industrial Heritage : Flickr

All photographs on this and my other sites, unless otherwise stated, are taken by and copyright of Peter Marshall, and are available for reproduction or can be bought as prints.


Fuji or Olympus?

Wednesday, December 4th, 2019

This is the question I’ve been asking myself for some weeks or months. For a year or so I’ve been finding a camera bag full of Nikon gear too heavy to carry for the length of time needed to cover events in London. It’s mainly standing around that I find a problem so far as my health is concerned, and I have to remember to either sit down or to keep moving to stop my ageing veins becoming inflamed. Walking is a little better, though I do get tired much more quickly, and while I used to walk for the length of a working day and perhaps cover ten or a dozen miles, now I get tired and give up in half the time.

I can still run when I need to, though not quite as far or as fast as when young. Last Saturday when I saw a march going down Whitehall from in front of the National Gallery I ran to catch up with the front of it, around 600 yards in the fastest time I’ve done for some years. But still slow compared to my youth, when before smoking took its toll I recorded some decent but not outstanding times. I once won a quarter mile at the local youth sports in a world record time and at least fifty yards ahead of the next runner. The timekeepers ran up to me pointing at the time on their watches, and in a perhaps stupid fit of honesty I told them that the race officials had put the finishing tape in the wrong place. I was very annoyed as the conditions had been perfect and I would surely have recorded a personal best on the day over the full distance.

But no I feel a great need to cut down the weight I carry, and the Nikons are only for special occasions (the D810 is now my slide scanner – more about that one day in another post.)

For some years my holiday cameras have been Fujis. I started with the fixed lens Fuji X100, then went on to an X-E2, followed before too long by an X-E3. I swapped my Leica M8 with a friend for an X-Pro1 because I wanted to work in colour without all the fuss that the M8 needed. All of these Fujis were good in their way – and if I could be satisfied with just a say 28, 35 and 50mm equivalent lenses I would have been happy with the X Pro1. But I really got serious with Fuji with the X-T1.

I tried working with the X-T1 and one of the Nikons. It was still a fairly heavy combination, but the X-T1 was pretty good (if occasionally mystifying.) Its 10-24mm wideangle zoom was an improvement optically than the Nikon 18-35mm that I’d bought when the 16-36mm gave up the ghost (it remains on my desk with an equally almost certainly beyond economic repair D700 as an expensive paperweight) though sometimes a little slow to focus. It was good to have the extra wide angle that its 15-36mm equivalent provided – I sometimes found the Nikon’s 18mm not quite wide enough.

But things were still too heavy. And when I saw an Olympus OMD M5 II selling new for just over £400, Micro Four Thirds seemed to be the answer (as one of my colleagues had been telling me whenever we met.) Along with the body I bought the absurdly small and light Olympus 18- 150mm, also going cheap. Just over 3 inches long and only 10 oz. I don’t own the Nikon equivalent, but it is half as long again, weighs almost three times as much and costs over twice what I paid for the OM lens.

And using the M5 II usually turned out to be a great experience, except for a few quirks – the most serious of which was perhaps the ease with which the main control dial could be inadvertantly moved. Working in shutter priority it is far too easy to find yourself taking pictures at 1/8th rather than the 1/250th you have consciously selected. Though with its effective in-camera stabilisation the pictures were still usually sharp unless anyone moved.

I don’t make a great deal of use of long lenses, but this August I spent some time testing the Nikon telephotos I do have, an elderly 70-300 and a couple of shorter zooms (one a DX) against the Olympus. Despite the much smaller 4/3 sensor, this gave the sharpest images and I could see no difference in the amount of detail.

For the past months I’ve been working almost all the time with the Fuji X-T1 and the Olympus M5 II. I’ve bought an expensive Panasonic Leica wide angle zoom for the Olympus, and can chose either camera for wide-angle or telephoto use, and can’t quite decide which I prefer. Both cameras have their quirks and neither is as straightforward to use as the Nikons. And winter weather and working in poor light have made some limitations felt, particularly with the noise in Olympus images at ISO over 3200. The D750 gives noticeably better results at ISO 6400 and focuses better in low light.

Of course the X-T1 is quite an old model by now – and the M5 II is now being updated as the M5 III. It would be easier to work with two cameras from the same marque, and I’ve been wondering which way to go. The M5 III seems only a minor upgrade on the II, and annoyingly takes slightly different batteries. I’ve been thinking of getting a second M5 II instead of waiting for the III, and the price is now even slightly lower. The X-T30 looks much more of an upgrade on the XT1, and is even lighter than the Olympus, but is not weatherproof, and I have more Fuji lenses… With some special offers and rebates the difference in cost isn’t great…


Long lenses

Wednesday, August 14th, 2019

Last Friday I was testing out equipment for an event I was hoping to photograph the following day. For the last few months I’ve seldom used the two working Nikon DSLRs I own, working instead with a Fuji XT1 and an Olympus OMD EM5 MKII, and I wasn’t confident that they could cope.

I knew I would need a fairly extreme telephoto lens for some pictures. The longest I own for the Fuji is the 18-135mm F3.5-5.6, equivalent to a 27-203mm, and for the Olympus, the lightweight 14-150mm (28-300mm equiv) f4-5.6. Would either of these be good enough or should I take the larger and heavier Nikon D810 with the 70-300mm Nikkor zoom?

I was worried about the weight as I was expecting to have to walk some distance, so would have preferred not to have to carry the Nikon, as along with another lens to cover the mid-range it would roughly double the weight I was carrying for around four or five hours. But if it really gave better results I’d have to put up with it.

I could get greater magnification from the Nikon, as I don’t need the full image size, but could switch it to DX mode, making it at its long end a 450mm equivalent lens, while still retaining roughly the same pixel count as the Fuji or Olympus, and I thought before looking at the results that this would make a vital difference.

So I got out the gear and took pictures of a subject at roughly the same distance as I would be working – around 200 metres and compared the results. I used more or less the same shutter speed and aperture as I expected to need on the following day, around 1/500 f8 at ISO640, and made sure the image stabilisation was on for the Fuji lens and Olympus body.

I got a couple of surprises from these simple tests. The first was that the two mirrorless systems both focused at least as fast as the DSLR, with the fastest usually being the OM5 (though both the Nikon and the Olympus occasionally went in for a little hunting.)

It took a little fussing around to view the images with the subject roughly the same size on my screen, but the results were interesting. The pictures themselves are pretty boring (and as I was photographing a window in a nearby flat perhaps an invasion of privacy) so I won’t include them here; the differences between the 3 camera/lens setups would in any case probably barely show even on enlarged small sections.

I’d expected the Nikon with its larger sensor and longer (equivalent) focal length to have a distinct advantage, but this wasn’t the case. The clear winner in these tests was Olympus, though the differences were not huge. It seemed a little sharper and to give just a little better gradation. Details in highlight and shadow seemed a little clearer. Even though I had to magnify it more it still more than matched the Nikon. The Fuji lens gave a nice sharp image, but the extra magnification it needed just about showed. But at any size I was likely to need to use the pictures any of the three systems would have done the job.

The D810 in full-frame mode gives images 7360 × 4912 pixels, compared to 4896 x 3264 for the Fuji and 4608 x 3456 for the Olympus. All more than enough for an A4 print – and if the images are sharp you can go considerably larger. Those extra pixels that the Nikon has to offer are very seldom needed.

Of course Nikon has newer and better telephoto lenses than the old model I own, the 70-300mm f/4-5.6D ED AF Nikkor. The Fuji lens weighs 490g, not particularly heavy for its specification, but almost twice as much as the Olympus at 285g. Both essentially replace two of my Nikon lenses, and of course both Olympus and Fuji bodies are considerable lighter than the D810.

My Nikon 70-300 was made for film and is not really up to the demands of high-pixel digital cameras, particularly at its longer focal lengths, so I shouldn’t be too surprised at the result. It weighs 520g, only a few grams more than the Fuji 18-135, but its modern replacement, the AF-P NIKKOR 70-300mm f/4.5-5.6E ED VR is noticeably heavier at 680g – and reviews show it to be a rather better performer. I don’t do a great deal with long focal lengths and got my lens second-hand at a bargain price, around a fifth of the cost of the newer model.

The tests showed me that the Olympus would do the job well and so I packed my bag ready for the following morning. But the following day gale force winds meant I had to cancel my journey. But at least I know for the future that I don’t need to carry the extra weight to use a long lens.

Debunking digital myths

Monday, August 5th, 2019

You may like to view the 30 minute video in which Tony & Chelsea Northrup discuss what they say are 12 common myths about digital photography, which was recently posted on Petapixel.

But to be frank, I find their presentation pretty nausea-inducing, and even scrolling through on fast-forward with the occasional pause to listen to the answers seemed like 10 minutes of my life wasted. There are some things video is an appropriate format for, but this was just not one of them.

So, what were the myths? I’ll paraphrase, and give my own answers which sometimes differ slightly from Tony Northrup.

Q: Should you fully discharge batteries to avoid a memory effect?
A: Cameras now use lithium batteries and full discharge should be avoided.

Q: Will your memory card be corrupted by deleting pictures in camera?
A: No.

Q: Will using a UV filter improve image quality?
A: No. Adding extra glass may even very slightly degrade IQ, though seldom noticeably. But it can protect the front lens element in tough conditions.

Q: Do higher megapixels sensors have greater noise?
A: Not necessarily, although very high megapixel small sensors on some phones do.

Q: Do medium format lenses give better “compression”?
A: This is just marketing talk. In general larger formats have more limited depth of field which may give a different look to the image, but at apertures that give similar depth of field the pictures will be identical so far as “compression” is concerned. Of course larger sensors generally have more megapixels and lower noise and their larger pixels can give them greater dynamic range. If you want to make giant prints a MF camera will be at an advantage

Q: Does your PC do a better job of Raw processing that your camera?
A: The PC – and viewing your image larger allows you much more control over how Raw processing is carried out. But modern cameras do a very good job in producing jpegs.

Q: Can you edit jpegs?
A: Well, of course you can, and Lightroom in particular seems to do it very well. But avoid repeated saving and later reloading to re-edit them as every jpeg save loses information.

Q: Do you need to turn off Image Stabilisation when using your camera on a tripod?
A: You don’t need IS when your camera is on a tripod, but it may well not make any difference. But it’s probably best to read what the camera manual says and follow its advice.

Q: Are lenses at their sharpest at f8?
A: Probably not. A better rough guide suggests two stops down from wide open, but a stop or two either way is almost never critical. Never be afraid to stop down more if you need greater depth of field or open up if you need a faster shutter speed. Remember many great pictures are not particularly sharp and the great majority of sharp images are not worth a second look.

Q: Is manual focus more accurate than auto-focus?
A: Manual focus is as sharp as you make it, but it is difficult to get focus more accurate than with modern autofocus systems, though you can match this using ‘focus peaking’. Manual focus does have the advantage that the photographer is aware exactly where in the subject focus is – all too easy for autofocus to be somewhere different.

Q: Do Canon cameras give the best colour?
A: Probably only so far as Canon’s marketing guys are concerned. If you shoot RAW, then you (and your raw processing software) make the choices on colour. I’ve used Fuji, Nikon, Olympus and Canon digital cameras. All can produce great colour from RAW files. I usually prefer Nikon, or, if I want a more vibrant look, Olympus, but the others are fine.

The Northrups have carried out some experiments with large groups of people and colour images from various cameras and you can find more details on their site. But for me it’s only my opinion that matters, and I think that which gives the best colour depends on the subject and its colours – it can be Fuji, Olympus or Nikon, but seldom Canon.

Q: What causes memory card faults?
A: A few years ago counterfeit cards were common, and the packaging was good enough at times to fool even reputable suppliers. I was supplied with some and they immediately gave problems. I’ve also bought cards direct from reputable manufacturers which turned out to be not entirely compatable with my camera – and again this showed up fairly quickly. Both times I got replacements without a problem. I think that both these things are now much less common.

Card faults resulting in image loss are now uncommon. But it makes sense to take care never to remove a card while it is being written to and not to get the card contacts get dirty. But as the video says everything does go wrong sometimes – fortunately not very often.

Reading this will have saved around 25 minutes of your life and imparted probably slightly better advice than that in the Tony & Chelsea Northrup video. But I’m sure their many fans will still want to watch it, though I hope if you are reading this you will find better things to do with your time. Why not go out and take some pictures?


My London Diary : London Photos : Hull : River Lea/Lee Valley : London’s Industrial Heritage : Flickr

All photographs on this and my other sites, unless otherwise stated, are taken by and copyright of Peter Marshall, and are available for reproduction or can be bought as prints.

There are no adverts on this site and it receives no sponsorship, and I like to keep it that way. But it does take a considerable amount of my time and thought, and if you enjoy reading it, please share on social media.
And small donations via Paypal – perhaps the cost of a beer – would be appreciated.


Neuran

Monday, June 17th, 2019

It’s a little hard to write about image quality in a blog post, because the quality of reproduction, particularly if like me you restrict yourself to posting 400×600 pixel images is hardly great. And although I use images that size, if you simply view them on the blog post you will be seeing them at only 300×450 pixels if they are in landscape format.

Apart from size, there is also a matter of jpeg compression. To allow pages to load at a reasonable speed I post jpegs with a reasonable amount of compression, and the JPEG algorithms introduce their own artifacts, the quality of the image getting worse as compression increases.

There are now better ways than JPEG to compress images, but JPEG has two big advantages. Firstly that it is a set of methods that anyone can use free of charge, and secondly that it has been pretty universally adopted, which almost any software capable of displaying images can read. So until we get another non-proprietary method which becomes universally adopted we are stuck with it.

Neuran are a company which has developed some very smart software that is supposed to address some of the problems of JPEGs (its also an Anticonvulsant drug, but that’s something quite different) using Deep Neural Networks trained on thousands of real images to enable it to reduce jpeg artifacts and also to scale up images without quality loss.

There have been other methods that have been developed, particularly for scaling up images that have made sometimes extravagant claims in the past, and back in the old days I reviewed some of them, but ended up finding the methods already provided by software such as Photoshop and QImage generally worked as well.

But the examples on the Neuran web site and Neuran’s Instagram feed make it look promising (though their Youtube video lacks any real content) and so I decided to give it a free try – and to sign up for its mailing list to get news of when it launches on Kickstarter. And I took advantage of the web site to get one of my small jpegs enlarged.

The original web image:

Here’s a detail, enlarged in Photoshop

And a similar detail from the Neuran enlarged version

The effect is fairly remarkable, particularly for her hair. Comparing the two the out of focus background is little changed but those parts of subject that are in focus are much sharper.

The whole enlarged file is too large to post here, and the 1:1 detail shows the effect better, but I also reduced the whole enlarged image back to the original I sent to Neuran in Photoshop.

As you can see, both Ahed Tamimi‘s eyes and hair are considerably sharper now. The picture (almost all the four thirds frame) was taken with an Olympus 14-150mm lens at 150mm (300mm equivalent) and at 1/250s wide open, and at the extreme end the lens is not quite as sharp as it might be.

Rather than take my word for it, you can log on to their web site and upload your own image to try Neuran’s processing – and the result will be e-mailed back to you.

Of course, most of my images are large and sufficiently detailed not to need the Neuran treatment, and the software will be of more use to those working on camera phones, but I can see occasions when it could be of great use, and I look forward to seeing more about it on Kickstarter.


There are no adverts on this site and it receives no sponsorship, and I like to keep it that way. But it does take a considerable amount of my time and thought, and if you enjoy reading it, please share on social media.
And small donations via Paypal – perhaps the cost of a beer – would be appreciated.

My London Diary : London Photos : Hull : River Lea/Lee Valley : London’s Industrial Heritage : Flickr

All photographs on this and my other sites, unless otherwise stated, are taken by and copyright of Peter Marshall, and are available for reproduction or can be bought as prints.

To order prints or reproduce images


Catalan evening

Thursday, May 30th, 2019

It was around a quarter past five by the time the Catalan protest got going on the steps around Eros, and in mid-February this was sunset, though it seemed rather darker than this suggests. Of course with the amount of street lighting and lights in shop windows and traffic it never really gets dark, but the contrast between the brightness of the advertising display on one side of Piccadilly Circus and the opposite side of the monument was pretty huge, and the protesters seemed to be in very deep shadow,

Using the Nikon D750 and D810, with both set to ISO 6400 allowed me exposures of around 1/125 at f5.6 without flash, though these were deliberately underexposed by a stop or so to keep something of a night look.

I didn’t have any fast lenses with me – and don’t own anything faster than f2.8 for the Nikons, finding them too heavy to carry and unsuited to most of the work I do where wide apertures mean the depth of field is too limited, though there are times when a fast telephoto would certainly help. But apart from the cost of the lenses I’d probably find myself needing the services of an osteopath. Although the Nikon lenses are remarkably good wide-open, when possible I like to stop down just a little, and most of these were taken at 1/2 to one stop down from the variable maximum.

I used flash for about half of these pictures, with a Nikon SB800 in the hot-shoe, but still worked at ISO 3200 to avoid getting people looking like cardboard cutouts in front of a black background, making sure that areas too far away to benefit from the flash were still getting enough exposure from ambient light. Although normally I work with the cameras on the ‘P’ setting (but often altering the selected shutter speed) Nikon’s flash system doesn’t really work with this, and when using flash I switch to aperture or shutter priority or sometimes full manual.

Flash on camera is always a problem where important parts of the subject are at different distances from the camera, and sometimes I make use of the fall-off of flash away from the centre, angling the flash head away from the closer parts of the subject. But inevitably some, often considerable, burning and dodging is needed when processing the images. Even in those taken without flash the lighting was pretty uneven and some correction was needed. If I can tell which of the images was taken with flash and which without except by looking at the EXIF data I don’t think I’ve got it right.

More at Against political trial of Catalan leaders


There are no adverts on this site and it receives no sponsorship, and I like to keep it that way. But it does take a considerable amount of my time and thought, and if you enjoy reading it, please share on social media.
And small donations via Paypal – perhaps the cost of a beer – would be appreciated.

My London Diary : London Photos : Hull : River Lea/Lee Valley : London’s Industrial Heritage : Flickr

All photographs on this and my other sites, unless otherwise stated, are taken by and copyright of Peter Marshall, and are available for reproduction or can be bought as prints.

To order prints or reproduce images


Simple Cyanotypes

Monday, May 20th, 2019

Congratulations are due to Mike Ware for both his development of a new ‘Simple Cyanotype‘ process and for his generosity in making the details of this and all his other contirbutions over the years to alternative photographic processes freely available to all.

Back in the days when I had time for such things, in the 1980s and 90s, I played a little with most of the methods for photographic print-making using hand-coated paper, largely out of interest in the history of our medium, which was one area of my writing and teaching. I made cyanotypes, along with kallitypes, palladium and platinum prints, gum prints, salted paper prints, carbon prints, photogravure and more, some more successfully than others.

I’ve written before about how I started in this area, together with friends Terry King (and here) and Randall Webb, both sadly no longer with us. Terry went on to make a considerable reputation and something of a living as both a teacher and printmaker using these processes, developing his own tweaks on various of them. He came to alternative processes as a poet and an artist, and occasionally I and later several others helped him out a little with the science.

Mike Ware is a scientist, and approached the processes in a much more scientific way, though that did not stop him making the impressive images you can see on his web site galleries. But it did mean that he was able to develop the chemistry in new ways, notably in his improved cyanotype process, and now with the new Simple Cyanotype.

You can read a discussion of the short-comings of the traditional cyanotype, first invented by Herschel in 1842 (and used most effectively by Anna Atkins the following year) and the advantages of Ware’s new simple and safe method in Towards an Unproblematic Cyanotype Chemistry. I found it particularly illuminating in helping to explain why I never encountered some of the problems so many others had – simply the good fortune of having purchased an excellent sample of the light sensitive but “ill-characterised” ferric ammonium citrate, and chosing the right papers to use it on.

The Simple Cyanotype uses readily available chemicals which are relatively safe, though still need handling with care, particularly ammonia. I once made the mistake of sniffing from a bottle whose label had fallen off (having trained as a chemist I should have known better) which turned out to be concentrated ‘880’ ammonia, and staggered back as if punched with my nostrils cauterized.

We are now much more environmentally conscious, and some of those materials which we handled carefully but perhaps disposed down our drains with too little thought are now often rightly subject to much tighter controls. I was rather pleased a few years ago to dispose of virtually all of my extensive chemical collection collected over the years I worked in alternative processes rather than leave a possibly tricky and expensive problem for my executors. Chemical safety is important – and some of those needed for old processes are now unobtainable by private individuals in some countries.

It also allows control of contrast, something which was always a problem in making cyanotypes, where negatives had to be produced specially for the process. It relies on the production of a relatively newly discovered iron complex, made in solution from the cheap and pure iron(III) nitrate – perhaps coincidentally the same starting material that I had used for many of my later iron process prints, though I used it with the much more toxic oxalates. It wasn’t then an orginal idea, but one I adapted from another source and used the same solution with its excess nitrate ions still present to produce various types of print.

Ware gives full details of how to make the solution, coat paper, expose and develop, and it does really seem to be a useful new process, and I feel quite excited by its possibilities. If I had the time and not so much else I want to do it might be something I would try again, but exactly the same thing that stopped me making cyanotypes twenty or more years ago would do so again.

I didn’t really want blue prints. But if you do, this seems the way to go.

On the train

Thursday, November 15th, 2018

I have mixed feelings about taking pictures thorugh the window on train journeys, though I do it quite often. While I enjoy just sitting and looking as the coutnryside flashes past, and we rush through towns and villages, our Intercity trains now go too fast, often passing through stations at speeds too fast to be able to read their names.

We can of course use our smartphones to tell us our location, though even they have problems keeping up, and its just a little disconcerting to often see on the map that we are in the middle of a field distant from any railway line.

Looking out of the window also seems to be a waste of time, when I could be reading a book or writing a post such as this, or even be reading Facebook or other web sites on my phone or notebook. But I do quite a lot of it, just feeling slightly guilty, and sometimes take a few pictures.

The great majority of them get deleted either on the spot or later,  with line-side posts and bushes having appeared in the fraction of a second between the decision to press the shutter and the actual exposure. Others because my split-second decision was simply wrong – you don’t get long to think at 145mph.  And then there are those spoilt by dirt on the window, though I try to find a clear patch. Or by reflections that are hardly noticeable when you make the exposure but glaringly obvious in the result.

It was much easier back in the old days, when trains went slower had windows you could open, and even lean out of (though there were notices to warn you of the danger of doing so.)

When I took pictures through train windows more seriously, I would travel with a cloth and, having picked my seat would often go outside and give the relevant window a much-needed clean.  Of course it was only really possible if you joined the train at the station it started from and sat on the platform side.

Reflections can be minimised too,  first by holding the front of the lens as close to the window as possible, and then by shielding around the lens. A rubber lens hood was useful for this, as it could be pressed up to the glass without transmitting the vibrations of the window to the camera – and if your cleaning cloth was a dark colour it could also be used to help.

I took hundreds of photographs – if not thousands – in this way through windows,though more often shops than trains, and was pleased to see that someone has come up now with ‘The Ultimate Lens Hood‘, a giant version of the rubber lens hood, though it perhaps looks too geeky for me to use it in public.

The journey from Doncaster to Hull flashed past too fast for me to take pictures,, except for one snatched of Alexandra Palace before we really picket up speed, though rather marred by the power lines across it,  but the service from Doncaster to Hull proceeds at a leisurely pace – and I think like my own local services rather slower than under British Rail as train operators have added a spare minute here and there to cut down the fines for late running – in the same way they now annoying quote the time of the train as anything up to 2 minutes after you can actually board it. The 12.00 is now really the 11.58 so far as passengers are concerned.

Somewhere in Lincolnshire the line goes along the edge of a large windfarm, and since we were jogging along at perhaps 30 or 40mph I was able to take a whole series of pictures, seven of which I’ve put on-line.  There was even time to think a little about composition, though of course I had no control over the running of the train. But I had time to look at what was coming up and thinking where the train would be, looking out of the window as well as at the camera screen.

Of course I didn’t get everything right. Rather more than I’ve shown were discarded, and even those that are on-line aren’t perfect. They’ve also had some tidying up in Lightroom, including some rotation, perspective correction and cropping, something that would have been tricky to get right in pre-digital days.

I took a few more at other places on the journey, and also read some of my book. Most of what I took were quickly deleted, but I’ve kept one from Goole and another as we were coming into Hull. I’ve photographed Goole’s famed ‘Salt and Pepper’ water towers before (and better) standing on the ground but the train does give you a different viewpoint.

And although the station in Hull is now just Hull, rather than Hull Paragon, the signal box outside carries a reminder of the past, as does the door into what was once the bedroom shared by my two sons next to where I’m typing this, still adorned by its bright orange-red sticker:

HULL

PARAGON

 

You can see another 6 pictures of the windfarm at On the way to Hull. And should you be sitting on a speeding train frustrated by not being able to read the station names, you can always take a burst of pictures as you go through  – one of the very few uses I’ve ever found for those extremely fast shutter speeds on my mirrorless cameras. When else is 1/4000 (or even faster) useful?

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My London Diary : London Photos : Hull : River Lea/Lee Valley : London’s Industrial Heritage

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Memory Card Failures?

Monday, October 8th, 2018

I’ve generally been lucky with memory card failures over the sixteen years I’ve now been using digital cameras, and I don’t think I’ve lost a single image due to them, though writing this is likely to provoke disaster. A few times cards have simply refused to work when I’ve put them into the camera either on first use (and one batch turned out to be very convincing ‘fakes’ for which I got a refund) or after some time when they have worked without problems. Once or twice I’ve had cards fail with pictures on them (or formatted them by mistake in a camera with dual card slots), but so far I’ve always managed to recover the images, though often it has been a lengthy process.

What I have found is that many ‘recovery’ programs have failed to recover any images, and the only one I’ve found to work reliably has been an old version of Rescue Pro, which came free years ago with SanDisk cards but is no longer supported by them. You now have to pay to get a working version, though a free download will show you whether files can be recovered. I didn’t try every other product on the market, but most I did failed. They may work for some causes of card failure, but didn’t help me. An article recommends some cheaper alternatives to Rescue Pro I haven’t tried (and links to more) that are cheaper and might be worth considering, and I’ve also found Recuva useful – and there is a free version.

That old version of Rescue Pro is slow and rather opaque, but it still works on WIndows 7, though I think it was written for Windows XP and may not run when my next computer is on Windows 10 (or 11.)

I began thinking about this after I put the SD card with all my pictures from last weekend into my card reader. Windows gave an error message asking me if I wanted to format the disk. Fortunately after I declined the offer the card read without problems. I do try to remember to always format cards in camera after I’ve copied the pictures from them and before using the card again, which I think is good practice.

Also when I’m away from home for more than a day or taking pictures I try to back up the cards I’m using on to my notebook computer every day, so that at worst I should only use a day’s work.

Catching up on my reading this morning I came across an article on PetaPixel by photographer QT Luong, Lessons from Losing a Week of Photos to Memory Card Failure, in which he recounts his problem with a corrupted SD card. He tried various software recovery programs without luck, and then some commercial recovery services who again were unable to bring back his files by their normal methods, eventually offering to charge large sums for further detailed examination of the card with no guarantee they could recover any data. At which point Luong decided it was simply not worth continuing.

It is an interesting article and very much a warning to the rest of us not to be complacent about the problem, as well as suggesting some strategies. In particular it might be a good idea to back-up while working using both card slots on dual slot cameras, even though this may slow down the rate at which the camera will work.

As Luong states, not all cameras have dual slots, and when Nikon and Canon recently announced mirrorless cameras with only a single card slot (like the Fuji cameras I sometimes use), there were many comments from photographers that this made them unsuitable for professional use. I’m more inclined to think that way after reading Luong’s article, though I do still wonder how many of those making the complaint actually currently use the second slot in their cameras for back-up.

Luong also quotes some statistics, looking at the star ratings given to several UHS-II cards in Amazon reviews. Although overall ratings are generally high, there were an alarming number of 1-star reviews for some cards from top brands, as high as 17% for the Lexar 2000x, while others were a more reassuring 3%.

Of course people who buy a card that fails are far more likely to contribute a review than those whose cards just keep on working without problems. I don’t think I’ve ever submitted a star rating for any of the cards I’ve used. But these 1-star ratings almost certainly give a good comparative rating of the reliability of the different products.

It also seems likely that the faster the card and the more complex the higher the failure rate is likely to be. My good luck so far may well be because I’ve never bought the fastest cards and I don’t think I have any UHS-II cards.

I’ll keep using that card that gave an error message as I suspect it was itself an error, as it was not repeated when I re-inserted the card into the reader. And I’ll make sure to format the card before next use. It might too be worth carefully cleaning the contacts on the card in case they have picked up some dirt or corrosion.