Cleaning the other side of the scanner glass

This scanner is almost 10 years old Canon CanoScan 8400F. It began giving showing some strange curly shapes to dark areas in images. Cleaning the glass didn't do anything. The pattern was on the other side of the glass. Dust or moisture seems to get there, apparently causing this.

This is a levels-enhanced scan of a black paper. The swirling shapes of the patinated underside are clearly visible. The top of the glass was not too clean either.

Scanner unplugged:

Lid removed. It comes out quite easily.

There are four screws to be removed.

The first two screws are in the lid's leg holes.

The other two screws are under the front cover. The cover snaps out by pressing from the edges where the clips are, and at the same time turning the front cover up or rown. Here the scanner is upside down:

The two screws on the top need to be unscrewed.

The top cover can now be detached. It is held in place by several plastic clips. A flathead screwdriver or a dining knife helps here. Twisting the frame too much risks shattering the glass.

Top removed, the glass can now be cleaned from both sides.

The dirt and patina was surprisingly persistent. Swiping with a moist cloth didn't really do anything. I first used Mellerud Adhesive and Glue Remover, then finished with lense cleaning liquid. Instead of cloth I used a piece of synthetic chamois. Turning the glass near a lamp helps seeing if it is clean.

Putting the scanner back together. A piece of blu tack helps in getting the screws to the lid's leg holes. These screws seemed to be non-magnetic.

Here's the same piece of black paper scanner again, levels enhanced to reveal any dirt and dust. Now the glass is very clean.

Before & after comparison:

Building the Gakkenflex TLR Camera

Otona no Kagaku (大人の科学) is a Japanese science magazine. Each issue comes with a kit for building something interesting. The vol.25 has a Gakken Twinlens Reflex Camera. It takes photographs on standard 35mm film.

This magazine is a Chinese translation, but is otherwise identical with the original Japanese issue. Wrapped in plastic.

After removing the plastic... it is still wrapped in plastic! There are two layers of it.

Between the kit box and the magazine are sticker sheets for decorating the camera. I decided to not use these. I think a black camera looks nicer. And I won't have to deal with the residue glue from worn-out stickers later.

The kit is well packed in styrofoam. Screws and other small parts come in plastic bags.

The back pages of the magazine have the instructions. For some kits, also for this, the instructions are available in English from the magazine's web site.

All parts out. There are three kinds of screws. It is important to use the correct one as instructed. My kit had an extra washer head screw. There's even a little screwdriver included. Though it might work for the whole kit, I used also a bigger one as in some places the screws get pretty tight.

1.1: Installing the tripod mount (the numbering here follows those in the instructions). I noticed the nut that go inside the mount will be a little loose. I placed a piece of cardboard behind the nut, about the thickness of a playing card. That keeps the nut in place so it won't rattle around when handling the camera.

Tripod mount installed.

1.2: Film rewind knob installed.

2.1: Film advance knob installed to the left side plate.

2.2 and 2.3: Counter and sprocket installed. The sprocket gets rotated by the sprocket holes on side of the film, and the gear moves the counter. That way the advancing of the film becomes visible to the outside of the camera, which in turn makes it easier to advance the film by the right amount.

3. Assembling the body front plate. The shutter mechanism here has to be assembled with care. Three delicate springs go in there. The original magazine may have the springs labeled wrong, so following the instructions or updates from the web site is a good idea. The shutter place, shutter plate feeder and the shutter release lever shaft have to align each other with sub-millimeter accuracy for the shutter mechanism to work well. At first the shutter plate feeder may get jammed over the little knob on the shutter plate, or on the shutter plate screw. Careful adjustments to the screws on the feeder and the lever shafts eventually makes the alignments just right. The screws must not be too tight to prevent the movement, but also not too loose for the levers to slip over or under each other. Some careful testing is all worth it as any adjustments afterwards will require disassembling most of the camera.

Black box installed. For taking square format photographs, black cardboard or other such material can be used to shape the opening to a square.

4: Back cover assembled.

5.1: Assembling the body. The screws are better left loose to make the installing of the mirror and the back cover easier.

Besides the side plates screwed in, they also have a groove for the joints to prevent light leaking to the inside. When the screws are first loose enough, the sides snap together quite easily. Front view:

5.2: Mirror installed to the fixing plate. It is important to have the mirror the right way up. The front of the mirror is covered with blue protective film, but it is very faintly blue. The protective film is best removed after the mirror fixing plate is installed to the camera.

5.3: Installing the mirror fixing plate. The plate goes under the diagonal protrusions on the side plates, not over them, and the front tips of the mirror fixing plate will rest on top of the 'shelve' of the front plate. Now the blue film from the top of the mirror can be removed.

5.5: Film advance shaft installed, visible on the right. The film roll goes to the bottom of the camera (here on the left), and comes from the roll in over 45 degrees angle for the back plate. I think an additional shaft close to the film roll would make the advancing and rewinding the film a bit easier. But now it makes this fairly sharp turn coming from the roll, so I wonder if this will leave the film with noticeable bends, particularly if it is left in the camera for several days.

5.6: Back cover installed. Once this is in place, the screws keeping the side plates in place can be tightened.

6 and 7: Viewfinder and hood installed, side screws in place, and lenses assembled. When handling the lenses, it is important to touch them only from the sides. The two lenses are identical, both will have the groove pointing outwards. The viewfinder lens is inserted from the back of the lens frame, while the imaging lens is inserted from the front of its lens frame. The alignment of the lens frames is important when installing them, else all pictures could be out of focus.

Finished! I had some Fujicolor C200 film to put into this thing. With analogue photography the pictures cannot be seen until after taking the pictures (a full roll, else you're wasting it), having it processed and printed. Though I won't have them printed, I'll just have it developed and then I'll scan it myself.

Stand by for some photographs later on...

Light Box

For quite some time I wanted some kind of setup for taking better pictures of things, bigger or smaller everyday objects. So I built one to my storage. I had some extra pieces of wood, a white desk that I was no longer using, various excess parts from Ikea furniture, small hooks, etc.

I wanted to use the old desk top as a background, and for attaching colored background papers to it. Attaching it to the wall was not going to work since the wall frames and studs were not for anchoring the table quite where I wanted to put it. Plus I wanted it to be easy to disassemble. It wedged nicely behind the workbench but, was way too low. I used three pieces of wood and a cross support from an Ikea Gorm storage shelf for a simple support frame to get the table top a good 60 centimeters off the floor:

Here is a close up of the support frame, with some metal clips on the sides to prevent the table top from moving sideways:

To get some feel of how it all might work, I attached a spare shower curtain to the ceiling and took some test pictures. Besides the little flash on the camera, I had one separate flash and a halogen site light that got really hot and was way too yellow. That aside, things seemed going to the right direction. Here the uplifted table top is on the left:

Ugly and inconvenient as it was, I planned ahead. For one thing, the shower curtain was so not going to stay there:

For a and decent perfectly white backdrop I bought a roll of printing paper. This is nearly 1 meter wide and there's no less than 43 meters of it:

So that had to be attached to something. Anything resembling a 25 millimeter pipe seemed working. This one is from an old laundry rack. But then I found a nice 120 cm long chrome steel tube. That was just the right length as the studs behind the wall boards are that much apart. I bought a couple of strong hooks and attached them to the wall studs.

For the sides I used 110 cm of 60 cm wide drawing plastic. That seems good material for it lets most of the light through, but scatters a lot, making just about any lamp soft and even. I glued two pieces of lath to the ends, for hanging them from the ceiling and for keeping them straight. I then taped a piece of white paper to the ceiling for bouncing off a flash of it.

Here's the completed setup. The sides come off easily and the background paper can be rolled back up or taken out and cut if it gets dirty:

To avoid the thing burning up, I bought a cheap LED site light to light the background. And for some nice highlights I found a simple clip-on reading lamp. Putting a good LED lamp into it made it rather useful.

The whole thing being nearly 1 cubic meter in size, though not quite that deep, I can photograph quite big objects it. Here's a warehouse dolly; I left the background just a bit off-white to show how evenly lit it is:

...and from the smaller end of the scale:

More test shots... a toy car, about 20 cm long:

Headphones, for checking out the black tones:

...and some color:

Transparent objects... I need some practice with this. Turning off all but the background light seems working much better than the regular setup used here:

And then some shiny things. For this I installed the white shower curtain behind the camera to avoid the reflections getting to interesting. Could be interesting to try out some colored backdrops for the reflections.

If the background can be white, it can also be black. With the two shots it is easy to do background removal, even with transparent objects. Here's something on white:

...and the same thing on a black background:

The difference of the two can be then used as a mask to get rid of the background completely:

And that's that. Now to take some pictures...