Large Format, Paper Negative, DIY Camera Project

[Pete Askew]

Now the viewing screen is equipped with it's translucent layer (again, only the finest tissue paper from a box of shoes has been used - and the shoes at least were made in Italy!) and spring clips have been added. Also now some hand-tooled Gaffa Tape has been added to the outside of the screen holder. The 'film back' can be seen behind with a sheet of paper in to get the spacing for the slide correct. Just the dark slide to make now to enable the loaded holder to be transported from the darkroom to the camera. With this setup the camera has a frame rate of about 10 frames an hour!!

Checking the focusing screen.

Yes, it works.

 

[Hamish Gill]

its faulty Pete the image is upside-down

 

[Pete Askew]

And the film holder with paper inserted and a Mk I dark-slide (pre-production only - 'cos it's the wrong size!!).

 

[Pete Askew]

its faulty Pete the image is upside-down

I'm working on it! But all the flowers fell out of the vase when I tried out one idea I had!!

 

[Hamish Gill]

A shame ... you shall have to tackle those pesky laws of physics ... I dont envy you, I have heard they are quite stubourn!

 

[Paul Lange]

This is starting to look pretty good Pete. You could save yourself a fortune form now on by making all your new cameras yourself.

How did you light seal the sliding faces between the two halves?

 

[Brian Moore]

Looks like you might have some difficulty sticking it up through the car sunroof for snapshots, Pete.

 

[Pete Askew]

This is starting to look pretty good Pete. You could save yourself a fortune form now on by making all your new cameras yourself.

Hmm, maybe.

How did you light seal the sliding faces between the two halves?

I'm relying on a fairly close fit and a very long overlap. I might have to add some extra if it's a problem - but I think it should be OK.

 

[Pete Askew]

Looks like you might have some difficulty sticking it up through the car sunroof for snapshots, Pete.

Yes I thought about that. I'm planning to point is through the side window and then use controlled slides / handbrake turns to fine tune the positioning. Will have to get a longer cable release and bigger black cloth though I think and some of those magnifying glasses that dentists use to save having to hold the loupe, cable release and steering wheel at the same time!

 

[Pete Askew]

Well the camera is now complete and ready for its first shots. Here it is in all its glory!! This is the Mk Ib with additional reinforcing and external frame ready to take the Mk2 fine focus system!!

Front view showing lens and cable release fitted.

Side view.

Rear without back (showing inner bracing).

And angled showing the reinforcing frame.

With focus frame fitted.

With 'film' holder - dark slide in closed position.

And in open position (exposure mode).

Underside showing reinforcing for tripod mount.

Focus screen outer.

And inner.

Film holder - closed, outer.

Film holder - closed, inner.

Film holder - part open, inner

Film holder - fully open, inner

The camera takes A4 photo paper (Ilford Multigrade IV RC Gloss at the moment) and the 'film' holder and viewing screen are designed to be par-focal. Focus is achieved by sliding the lens frame box into the outer chassis although I have plans to add a more sophisticated system at a later date (if it actually takes a decent photo!).

First 'road' test tomorrow I hope.

 

[Hamish Gill]

Awesome ... In the true sense of the word!
Can't wait to see the first results!!

 

[Chris Dodkin]

Just stunning Pete - but you forgot the red dot on the front!

 

[Pete Askew]

Coming with the Mk II Chris!!

 

[Pete Askew]

As promised, here are the first test shots from the DIY camera. Focus is tricky and I need to improve the screen I think but with practice I am pretty sure I can do better than with these shots. The main objective was to work out the approximate speed of MGIV and try out the film holder. It works pretty well but a bit of 'velvet' at the bottom where the dark slide goes would help - as soon as I find my double-sided tape I'll add that. The first test exposure was done in the same way one would do a test print in the darkroom. The shutter was tripped for 1 second. The darkslide was then closed a bit and then another 1 second exposure was made. This was repeated in doubling steps to give the following image. The camera moved a bit during sliding the dark-slide in but that was not a problem for determining the approximate speed of the paper. The developed 'negative' (in MG developer - I then discovered the RC dryer that I haven't used for about 3 years was full of dust despiet having a cover on it!) was scanned and then inverted in SilverFX via Lightroom. Text was added in PS.

The 'correct' exposure looked to be about 4 - 6 seconds which gives a film speed of approximately ISO 2.

So a test exposure was made giving the following 'negative'...

and print.

I'm having a few problems with the cable release on the old lens and will need to address this as it is unreliable and results in the camera being moved. I also need to fiddle with the focus screen to improve its clarity a bit. But for a first couple of shots I'm pretty pleased.

 

[Kev Pugh]

I should say so Pete, good result

 

[Pete Askew]

Now with the Mk II focusing screen (piece of translucent document wallet sandwiched in front of the glass). Focusing is much easier as the screen is vastly brighter (I am focusing on the seeds). However, the coarse texture of the plastic precludes fine focus with a loupe. The Mk III will probably be a piece of glass coated with hair spray. I think I was about 1 stop under exposed here too - must have counted wrong (I'd given up with the cable release and was using a lens cap and counting 'seconds' with an elastic band holding the shutter in the 'T' position)!

 

[Paul Lange]

Pete, Paperchase sell clear frosted polypropylene in various grades and the thinnest might just do the trick for your focus screen. Alternatively I think I have some grinding compound in the loft that will cut glass. I could post you some if you're interested.

 

[Pete Askew]

Thanks Paul. It needs to be frosted on one side only - they have frosted acrylic in the DIY store here in Potsdam as well but is a bit too thick. I was going to try either grinding paste or fine wet and dry paper if the lacquer didn't work.

Making a Ground Glass Focus Screen

 

[Hamish Gill]

This is very impressive!
Certainly providing some inspiration for me!

 

[Pete Askew]

Thanks Hamish. I need to fine tune the exposure and sort out the focusing but, overall, I'm quite pleased. I will also try some Maco-Lith paper I have in the drawer although I might just use the MG developer for it for now.

I'm also going to have to strip down and clean the paper dryer properly I think - i've cleaned it twice while is is running but the rollers are still adding some fine dust to the prints. It is hardly ever used and got dusty during the last phase of the building work here I suspect. I only use it if I tone RC paper as the main development and drying is done in an Ilford 2150 RC dry-to-dry machine. Fibre based paper is dried on mesh racks although I do have a glazer / dryer in the basement, but FB won't work so well in the camera.