Making a Leather Lens Cap

A few weeks ago, I got myself a nice, cheap, big brass lens. Originally, it must have come from a magic lantern projector – however, I betcha I can make it work for me!

The lens seemed OK, the focusing pinion was present and working, and the iris smooth and operational with only the glass being really really dirty. After a good clean it turned out that the lenses were actually in pretty good shape with only a few minor scratches.

Seeing I’d like to keep it that way, but also because the lens comes without any form of a shutter mechanism, I set out to make myself a lens cap. And it’s easy! I followed the instruction as written up by Alex Timmermans in 2010 – you can find his description here.


What you need:

  • thin cardboard, about A4 in size (depending on the size of your lens)
  • a piece of thin leather in a colour of your choice
  • some water in a bowl
  • (wood)glue
  • cling film
  • clamps or clips
  • (clear) tape
  • a ruler
  • pencil
  • Emery board or sanding paper
  • sturdy rubber band/ tie wrap
  • a sharp blade
  • a pair of scissors
  • a cutting mat
  • Oh yes, and the lens you are making the cap for!


Step 1: Cut a spacer. Take your cardboard and cut a strip long enough to wrap around your lens once. It should be about 2 cm wide, max. Make sure it fits well, tape the ends together and cover in (clear) tape. Let the tape cover the ridge of your lens as well, this will protect against the glue we’ll use later on. My cardboard was really thin, so I used two layers of strips as spacers.


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Step 2: Cut the sides of your lens cap. You will take your cardboard again and cut 2 strips to fit around the spacer. First cut the one, wrap it round and make sure it fits exactly. Secure with a bit of tape, then cut the second one to fit snugly on top. The width will depend on your lens, but again, should be max 2 cm.

Now take those last two strips off and glue them together, slightly overlapping at the ends to be able to secure them into a ring. Use the edge of the lens as your mold and use clamps/ clips to keep them in place till dry. Remove the ring from the lens.




Step 3: Again, taking your bit of cardboard, glue the ring from step 2 onto that (make sure to wipe the edges of excess glue) and, once dry, cut it out using a sharp blade. smooth down the edges using an emery board or sanding paper.


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Step 4: Take a piece of thin leather, large enough to cover the cap. Soak it in (tap) water for at least 30 minutes as wet leather is much easier to shape.

Pull a large piece of cling film over your lens and put the lens cap on top. Cover the cap in glue, squeeze out the excess water from the leather (don’t wring it) and cover the lens cap with it. Pull it tight – slowly and gently – as to not tear the leather. Make sure it’s smooth on top and as well as it gets round the edges, then secure with a rubber band/ tie wrap. Leave the dry overnight.


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Step 5: Take the cap off the lens and cut off the excess leather. Be smarter than I was and make sure you’ll leave enough the cover the inside of the cap! If you’re familiar with some tailoring techniques, you can cut away some of the excess in V-shapes on the insides of the cap as well, to smooth it out nicely. Put glue on the inside, and clamp the leather down to dry. Put a strip of cardboard between the leather and the clamps, or you may be left with some permanent marks on your cap.


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Step 6: Try the cap on your lens. Is it a snug fit? Great! You now have the option of covering the inside of the cap front and you’re done. Mine was a little loose so I had two options:

  1. cover the inside rim with more leather / a cardboard strip, giving it a tighter fit and a better finish.
  2. put another kind of space filler in.

I was (dare I admit it?) a little lazy and didn’t really want to mess about too much with the interior finish. I decided on a non-classic feature: a handle, the provide a better grip on the lens as it’ll serve as my shutter too.

I cut another strip of cardboard, folding it over and taping it with clear tape, leaving only the outer edges bare. I folded it round the cap and secured the ends on the inside with a bit of glue. I put some clamps on it whilst it dried and presto! I was done too 🙂


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Making an – inkjet printed – digital negative

Last time I talked about salt printing, and how I used a inkjet printed digital negative to use for the contact print. Today I’ll show you how I made the negative and the printout.


This is the first time I tried making one of these negatives to use in my first salt-printing attempts, so I am not claiming this to be the best, most accurate or most technically insightful of tutorials – but it seemed to do the trick.

What you need to make a digital negative:

  • digital image
  • printer
  • (Pictorico) OverHead Projector Film (OHP)


Step 1: Choose an image. Select a file that is large enough for the size of the print-out you intend to make.

Step 2: Open up your image in your image editing software (Lightroom, Photoshop, GIMP) and edit it as you would normally do. I usually stick to spotting for any dust that may have gotten onto the film whilst scanning and adjusting the levels in Lightroom. Save your image.

Hong Kong, 2012


Step 3: With your image opened, save the file under a different name, so you won’t accidentally save over your original. I’ve done the next few steps in Photoshop.

Step 4: Make the image 16 bit & RGB. You can do this under Image > Mode > 16 bit / RGB in Photoshop.

RGB conversion 16 bit conversion

Step 5: Apply a ratio curve to the image, invert the image and flatten. Don’t worry too much about how messed up your image is looking right now – but try to judge the contrast that it will provide to your print. The contrast I’m showing here is actually not that great, but it’s a good example of a 1:1 image conversion.

Ratio curveinvertinginverted, flattened


Step 6: Add a new layer, set to ‘screen’ mode.

add new layer, screen mode


Step 7: Using the colour picker, set the foreground colour to:

Platinum printing (density 1.6) R: 127 G: 255 B: 0

Palladium Printing (density 1.9) R: 70 G: 140 B: 0

(some) Palladium printing (density 2.2) R: 50 G:100 B:0

Salt and Albumen printing (density 2.5) R: 25 G: 50 B: 0

color picker


Step 8: Fill the new layer with this colour. The idea is, that some colours block out UV light better than others and you’ll see in a cyanotype printing video I’ve linked below, that red is their colour of choice.



Step 9: (optional) Taking the advise from another website (see links below) I added a step tab, so judge my exposure times. You can find a few via Google, but you could also opt for a classic exposure test by making a test strip.

Printer Calibration Image

Step Tab

Step 10: You are now ready to print your negative! Fire up the printer and insert one of your OHP sheets. The ‘sticky’ or non-slippery side is the one taking the image. Insert it with the paper strip first so your printer has something to hold on to. Print with the following settings if you have the option:

Working space: adobe RGB / US web coated (SWOP) Gamma Grey 2.2, Dot Grain 20%

Policies: Convert to working (all) – tick all boxes

Conversion: Adobe (ACE), perceptual – tick all boxes

Leave your print to dry for at least 24 hours.



As I did not believe that the above negative would have made a great print, I went back and made some changes in the original to bring out more detail in the shadow areas. Other than that, I followed the same steps as outlined above, resulting in quite a different negative!

Hong Kong Switches



Should you like to learn more about making a digital negative, I can recommend having a look the following sites and articles:

Article by Dan Burkholder on

Article by Robert Hirsch on

Article by Christina Anderson on


Making a salt print

When I started diving into the various printing varieties, the salt printing immediately caught my eye. Not only do I adore the slightly romantic feel of salt printing, it’s also fairly safe and affordable to try.


Hong Kong, 2012salt printing

This is what you need – it will seem like a long list, but you’ll find you already own most of these items:

1. An image to print. We will be contact printing the image, meaning that you will get a 1:1 copy of the negative. I have tried contact printing some of my wet plate collodion clear glass plates with some encouraging results but not everyone will have some of those lying around. We’ll be using a digital image – this specific image of the light switches has been taken in Hong Kong in 2012.

2. A digital negative from said image. I’ll explain how to make one in my next blog post. You’ll need a computer, a printer with sufficient ink and one/ several sheets of Over Head Projector (OHP) Sheets. You can buy these online or at an office supply store. I am using some I bought in Germany to try, but it seems that Pictorico is widely used and recommended. Make sure you leave your negative dry for at least 24 hours, or it can stain your print!

3. Paper to make your salt print on. You can really use whatever paper you like, but do consider ease to work with and archival values. Watercolor paper gives the images a beautiful classic look and there’s tons of brands to try, including acid-free brands. Lighter, thinner papers like Japanese tissues can give interesting effects but might be harder to smooth down after they’ve been soaked with a salt solution. Again, try looking online, a hobby/ craft or art store or a stationary supplier. I got a super cheap batch of 300 grams watercolour paper from to give this process a try.



4. Tape and boards to tape your paper to. The tape should be low-tack as not to damage your paper, like a paper painters tape. The boards should be at least somewhat sturdy, but in all fairness, I have used cut pieces of a cardboard box which seem to do the job perfectly well for 1-5 uses.




5. You will need some stuff to prepare your paper to take the image:

  • distilled water (1600 ml)
  • table salt a.k.a. Sodium Chlorine (10 grams)
  • silver nitrate (10 grams)
  • hypo a.k.a. Sodium Thiosulfate (100 grams)
  • sodium bicarbonate (2 grams) or ammonia (2 ml)



6. Then there are your tools:

  • trays for the (chemical) baths – these can be darkroom trays if you have them, or alternatively a couple of glass dishes or washing up tubs will do just fine – just don’t put any chemicals into a tray you’ll want to use for food in the future.
  • a small pan and a heat source to warm up some of the water. Using a non-metallic stirring rod is advised.
  • brushes to coat the paper, alternatively use a glass pushing rod or a piece of a washing up sponge.
  • an eyedropper (optional)
  • a washing line, pins and a place to hang up your paper to dry. I put mine in our tiny shower cabin.
  • a piece of clear glass, larger than your intended print, or if you have one, a printing frame. Make sure the glass you are using is clean and not UV coated!
  • a source of UV – the sun, a sunbed, UV lamps – all will work. I use a small Philips face tanner, picked up from a local charity shop for under a fiver.
  • a source of running water.


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7. Do remember to use protection kids:

  • protection for your eyes (glasses)
  • protection for your hands (disposable rubber gloves)


8. A space to work in:

  • a room that you can black out completely, a closet or bathroom – with a red safety light. you will need this during and after sensitizing your paper. I’m using my portable darkroom I normally use for wet plating.


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That’s a lot huh?

Well, here comes how to use it.

  • Take a couple of sheets of paper that you want to use for your salt printing. Take your pan and heat up 500 ml of distilled water and mix in the 10 grams of salt. Stir until it is dissolved. Pour it in the tray and now dip in your sheets of paper one by one. Leave then in a few seconds and turn them over till they’re drenched. Now pin them up somewhere to dry.
  • Next, warm up 100 ml of distilled water. When it is warm, put it into a (dark brown) glass container and go into your darkened room, put on your protective gear and mix in 10 grams of silver nitrate. Stir it with a glass rod until dissolved and put the mixture into an eyedropper. Be careful with this mix – it is extremely corrosive and will stain everything it touches. It could even make you go blind if it gets into your eyes! This mix is what will make your paper light sensitive.
  • (optional) I use a 10 ml eyedropper bottle to coat my paper. A full bottle will coat approximately 5 full A4 sheets. I have added a few drops of a 5% mix of potassium dichromate (1-2 drops to 12 drops of silver) to increase contrast and the image does seem to turn more into a blueish grey than the normal yellow / reddish-brown. It does increase exposure times, so keep that in mind if you’re adding this step.
  • Once your paper has dried completely, tape it to a support. In the darkroom, use the eyedropper to form a liquid line on one edge of the paper. Take your brush or glass rod (a glass rod is harder to control, but a brush will use more fluids) and spread the solution over the paper. You can coat it once, twice, as many times as you like – as long as you coat the paper evenly and your paper is sturdy enough to take the strain. Leave to dry in the dark. If light hits the paper, it will fog over and start to darken; your whites won’t be white and you’ll lose contrast overall.
  • When this stage is completely dry, place the paper, with your negative on top (emulsion side down when using an original, protect your image by using a thin sheet of Mylar) under the sheet of glass. Place it in a spot where the sun can hit it, or use your UV light. You can check on the progress from time to time by carefully lifting the paper backing – you can see the image appear as you go along! Beware that you’ll need to make it quite dark as fixing and washing will lighten the image somewhat.
  • Once you are happy, rinse the image in water for about 15 minutes to wash any unexposed silver off. Then, place the image in a fixer made from 1 liter distilled water, 100 grams Hypo and either 2 grams of soda bicarbonate or 2 ml ammonia for about a minute. Leave it a little longer if you want the print to be lighter.
  • Finally, move the print to a tray with (running) water. This can be tap water, and you should leave it in there for about 30 minutes. Hang to dry, and you’re done!




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Art or ‘Art’?

We have entered February and it seems like the rains never ends. Our newly purchased Toyota Celica already died on us once, which resulted in it having to be carted off to get the battery replaced. I have been inside the house mostly, next to a cozy little fire burning in the living room, looking for work. (Please do share if you know of any cool part-time jobs going in the Cambridge area!)

Apart from that, I’ve taken to actually reading some of my books! One of my newest additions was ‘Art’  by Clive Bell. This little gem from 1923 (6th printing) tells us all about ‘Art’ and what makes it ‘Art’ in the boisterous and somewhat  arrogant tones of Mr. Bell. It’s fairly light and even a little humorous at times and I thought I’d share some of the ideas set out in the book and my view on them.

Art, he says, should be about significant form – and significant form, it turns out, is mostly found in primitive art. In periods of turmoil, man seems to have a preoccupation with the spiritual whereas periods of comfort dull the minds with materialism. Art is about feeling and good design (colour, forms) and does not need to represent reality as we see it all around us or even be beautiful.

Most of us have been brought up with a certain idea of what art is and what art should look like and it’s immensely hard to shake those thoughts. (I too used to believe art should be beautiful, then I believed it should be meaningful.) Bell goes even further to state that all art should be freed from religious, mythological, literary, scientific and intellectual connections and references. A reference might stir an emotion – which is intellectually and culturally dictated and therefore not genuine. And that’s where I really start to struggle. I, like everyone else, have learned to look at art and think about it in a certain way – and despite my academic years (or maybe due to!) – I fail to envision how an image might look that is completely without reference.

Glancing back mostly to the Victorian period (dull grey and drab, without passion) and the Impressionists out of whom he favors Cézanne, the book is clearly written in the early part of the 20th century.  He is overly avert of salon painters or the royal academy and he despises ‘pretty pictures’ that especially the working classes seem to value.

The question is: can his theories be applied to the early 21st century where every person can express their own creativity is so many different ways? The ‘pretty picture’ which he despises, is everywhere. I’m not even talking about pictures of kittens or puppies per se. Some images are going viral over the world, on Twitter and Facebook and ripped off by a sheer mind-boggling number of blogs. Does the creator of that image consider him/ herself an artist? Or a photographer? Or……? Don’t get me wrong, I love seeing fantastic landscapes or creative model shots – and images of kittens – but is it art? There is some amazing sculptural and digital art out there – but since it is referencing to allegory, stories, politics, literature, science, etc – is it art? Is there a real difference between art and fine art? Does the difference only matter for galleries and dollar signs? I recon the line can be drawn but it will be a fine one centering around hefty discussions filled with personal tastes.

It almost seems to me that galleries and museums have not even changed that much over the years, still showing the classic masters whenever they can, making space for but a few newcomers. And who are the newcomers? Bell speaks of plush positions being opened up by the government – artists that would be hired by the government to create art for the nation. Does it still work this way? Does not every person want a plush, well-payed position, even though it means having to create art? The ones with the biggest mouths and the best art-babble-BS will be the first in. How many of these hired artists would be ‘true’ artists, who would pursue the arts even if it meant living like a beggar?

So even though this book is a very interesting read, I find it hard to agree with mr. Bell on all aspects of this theory. From an aesthetic and theoretical point of view he may well be correct, but I find it a tad short-sighted as it very nearly dismisses all modern artworks. The theory is mainly revolved around paintings and antique forms of art such as pottery and tapestry and I found it a great short-coming that photography (even though it was not considered a ‘proper’ form of art yet around this time) is not mentioned in any significant way.

Should you be interested in reading this book for yourself, you can buy it on Amazon as they’re still re-printing it: