Adventures with a Changing Bag

For the last few days I’ve been working on an article about using a Minox camera. I’ve managed to prove two things conclusively:

1. You can 3D print a light tight cassette to hold Minox film.

2. You do need to put something in the light trap to stop light getting onto the film.

This means I’ve been spending a while with my hands in a light-proof bag, rolling up film and putting it into tiny cassettes. I was happily doing this the other day when the doorbell rang. I was alone in the house at the time and half-way through a rather tricky cassette load, so I had to walk to the door with my hands in the black bag, find the keys and then open it to reveal two people who asked me if I wanted them to save my soul. Or something. I replied politely that I’d settle for having the films in the dark bag saved and bade them farewell.

I’m kind of hoping they will go back to base with tales of a strange, wild-eyed man who lives at our address and answers the door with his hands in a large black bag. With a bit of luck they’ll skip our house next time.

Minox Cartridges - take 2

Last time I tried to print some cassettes for the Minox camera it didn’t end well. Never one to give up (see Canon Dial 35) I’ve today returned to the fray. I’m using my secret weapon; this time I’ve made my own design for the lids. The one I was using turned out to have a hole too small for the winder so I’ve made a new lid and spool which fits. I’m printing at a much slower speed too. And this time the cartridges seem to have worked - at least I can get them off the build plate without them disintegrating. Next thing is to pop some film in one and see how it works in a camera.

Heading for the Photography and Video Show

NOTE THE LOVELY BEVELS on the top of the holder. I’m very proud of those.

We’re heading to the Photography and Video Show today. So I spent the morning 3D printing some prototype Minox film holders. As you do. Each of the five holder is a slightly different height, so that you can pick the one that works the best for your scanner.

3D Printing Minox Cassettes: Fail

A few attempts and the camera I’m trying to use

I’ve been trying to print Minox film cassettes for a while now with no success. I love the Minox system for its tinyness and amazing design, not to mention the nice pictures you can get with it. But I’ve only got a few film cassettes and I’m too mean to buy any more. So I thought I’d print some with my lovely new printer. It kind of works. The finished articles are almost useable. But not quite. Even if I use the high resolution 0.2mm nozzle. The problem is that some of the sides of the cassette lids are just one strand of filament wide. The printer can print these just fine, but they haven’t got enough strength to stay attached to the lid for very long, as you can see above.

I’d be happy to trace printability for film length: in other words a 24 shot exposure film held in a cassette that has double thick walls would be just fine with me. Unfortunately I’ve not found a way to tweak the design just yet. If anyone reading this can point me at designs I can work with I’d love to have another go.

Minox Scanning Report

The height steps are in .2mm because that’s the print layer height

The story so far: “Rob has become mildly obsessed with getting the best possible results scanning the tiny negatives produced by his Minox camera. He’s 3D printed a holder for his scanner which had different negative heights. The idea is to scan a negative and determine which height works best”. Now read on…

It wasn’t taken for testing, but it works really well

I took the picture above down at “the dock” in Hull. It is of the C4DI building and a tiny bit of the tidal barrier. The railings going off into the distance are a very good test for resolution. I used my “different height scanner thingy” (really must think of a better name) and got the following results:

A print of the entire image at this magification would be around 24 inches or so across

It was interesting to see the difference that 0.2mm height makes to the image quality. The best way to see it is to look at the lamppost at the end of the walkway. That is better defined against the background in the -0.2mm height scan. The next thing to do is to print a complete scanning frame for that height.

Adventures in Minox Scanning

I do like working in OPENSCAD

I’ve been investigating the scanning of Minox films. These films are a mere 9mm or so wide and the negatives are teeny tiny. I’ve been wondering if the distance of the negative from the scanner affects quality. To test the theory I made the film holder above. Each holder is a different distance from the scanner base. I’m 3D printing the holder, so I’ve made each one print layer (0.2mm) different from the other. I got the original height by measuring a PENSO holder I already had. It will be interesting to see if the different negative heights make a difference.

Scanning Minox negatives

The film got a bit scratched as I was loading it

I love my little Minox camera. It takes tiny pictures on 9mm wide film. I make the film by slicing 35mm film into strips and then loading it into Minox cassettes. Then, once I’ve developed the film I scan the negatives. I use an Epson V750 scanner that I got a while back. It’s quite an old device, but the good news is that scanners age quite well (or at least I hope they do). To hold the negatives on the scanner I use a 3D printed PENSO mask. When I started scanning I got spectacularly bad results, with black streaks everywhere.

I’ve discovered that if I rotate the holders through ninety degrees on the scanner glass, so that they are in a “portrait” rather than a “landscape” orientation they work just fine. This must be due to the way that my scanner shines the light through the film when scanning.

I have no idea why this works, but I’m rather glad it does

Spying on c4di

I need to clean the film a bit

I took this picture up town today using a Minox B “spy” camera. Considering that the film had been sliced down to 9mm wide, rolled into a Minox cassette (twice because the first time didn’t work) and then unrolled and processed, it hasn’t come out too badly.

If you are ever lucky enough to get one of these to play with (they are great fun) make sure that you set the frame counter to zero before you load the film. The camera has a very clever mechanism that changes the amount the film winds on as the number of pictures increases. This compensates for the change in thickness of the take-up spool as more film is wound on. However, if you set this wrong (like I did) you end up with a bunch of overlapping frames (where the camera didn’t wind on as much as it thought it needed too) followed by a bunch of “spaced out” frames. Worth knowing for next time…

Developing Minox film

I think the light meter on the camera got this about right. There is some detail in the dark parts of the shot.

My empty 35mm cassettes arrived today. I needed them to transfer the film out of a cassette into cut strips. To do this I had to tape the end of the spool of film to the empty cassette spool and then load the cassette into the splitter. First lesson – the receiving cassette must be “upside down” or it won’t work. After that it all worked quite well.

The yellow block contains the blades that will cut the film

The film splitter is from camerahack. It’s beautifully made and works a treat. The receiving cassette is on the left. You crank the handle to pull film out of the cassette on the right, over the cutting block which has blades fitted in it. When I’d finished I had two lengths of 9mm film in the receiving cassette.

Anyone need any spare sprocket holes?

Then I just had to load one sliced film into a Minox cassette in a dark bag. Slightly complicated by the doorbell ringing as I was doing this. But it passed off OK. I had to answer the door with a huge black bag on the end of my arms. I then hand wound the film into a little roll and then popped it into the Minox cassette with the tongue protruding and put the cover onto that side of the Minox cassette. Then I could tape the tongue to the takeup spool and pop that spool in the other side of the Minox cassette in normal lighting. Ended up with a Minox cassette with a length of film in it.

I went outside and took some pictures, but this was slightly complicated by the way I’d not advanced the film counter on the camera to zero before I loaded the film so I had no idea when the film ended. I really didn’t want to run all the film off and back into the cassette so I gave up early. Then I got the cassette out of the camera, punched a hole in the end of the film and loaded the film into the Minnox daylight tank. This worked mostly OK. I used a 25ml measure to work out 53ml of liquid. Did the 1+50 develop which was rather hard to measure. I think I need a syringe.

Developing was OK but I didn’t let the developer fill up the tank as well as I might. Same for the wash and the fix. I did get some pictures though, but the film has opaque deposits which I think are silver from where the fixer didn’t reach. Scanner had real problems with some of the film too. Some of the pictures came out quite well though. A bit grainy but no evidence of problems with the splitting and the cassette transfer. Things to remember for next time:

• Zero the counter on the camera before you put the film in. Also set the film speed – although the exposure was generally pretty good.

• Fill the tank properly and give the liquid time to go into the tank. Especially important during fixing.

• Hopefully the old cassette will dry out (it gets immersed in developer during processing) and I can reuse it.

• The Minox thermometer that came with the tank is badly broken, but the tank itself is properly watertight and works a treat – although I need to get better and agitation and making sure that all the film is covered. I think for the fixing process I didn’t cover the top part of the film properly.

• There were some issues with frame spacing but these might be to do with me not opening and closing the camera firmly enough.

• Use “Film (with film holder)” as the Document Type for scanning. Don’t click “thumbnail”. Scanning works best if you select the entire length of film and then chop these up afterwards – I think. Use 3200 dpi for maximum detail.  

Everyone should get a Minox Camera

The pen and the dust on the camera are there for scale….

The Minox camera is very interesting. A while back; if you were caught carrying one you were assumed to be a spy. Because you probably were. The camera model above even made an appearance in a Bond film. In “On Her Majesty’s Secret Service” James is seen using one to take clandestine shots to a background of suitably tense music. The chain attached to the camera has little lumps in it (you can see them above) which correspond to distance settings on the super sharp lens. One of the lumps is pre-set to take perfectly focused pictures of A4 documents if you hold the camera that distance from the page. However, you can also use the camera to take pictures of less secret things and they come out surprisingly well. I’ve just added a Minox to my camera collection because I’ve always fancied one and I look great in a tuxedo.

Minox cameras first appeared in the 1930s and continued to be made up until just after the turn of the century. The Minox B (the one above) has a mechanical shutter and a little light meter you can use to set the exposure. Later ones had battery powered meters and shutters. It might look a very exclusive and expensive thing, but you can pick the cameras up quite cheaply because they were made over many years and there are lots about. Taking pictures is fun, you open and close the camera to wind the film on, and the shutter makes a very satisfying whirring sound when you press the tiny release button.

The camera takes tiny pictures onto film loaded into a cartridge that fits inside. My camera came with a roll of 20 year old film which I took out on Sunday to take some shots. Every single one came out completely black, which I hope is a comment on the age of the film and not on the camera or my technique. To process the pictures I printed a spiral film holder for use in my developing tank at home.

I also printed a piece of “test film” that I could use to practice loading the spiral

Minox film isn’t made any more. But there are folks out there who are refilling cartridges and selling them. I’ve ordered a bunch of films from here. They also do processing and scanning if you just want to live out your spy dreams and not spend any time in the darkroom.

I really like the camera. I find the whole design ethic and the way it is used very pleasing. You get the impression that the designer (a chap with the wonderful name of Walter Zapp) thought extremely hard about the best way of doing everything when he set out to make it. I know that the pictures it makes will not be super high quality (even when I manage to get some that come out) and I’ll have to set the exposure and focus myself. But that adds to the appeal to me. The shots will be plenty good enough for small prints and screen viewing. There is a huge range of accessories available, including an awesome home developing tank and a lovely little tripod.

If you like owning devices that are just nice to have around, actually do something and have a properly interesting history you should try to find a way to get yourself a Minox. If you shop around it won’t cost you much more than a triple A video game and I think you’ll find it very pleasing. One tip if you do decide to splash out: the selenium light meters in the B model degrade, particularly if the camera has spent a lot of time in the light. So if you are making a purchase you should make sure that you have a working one.