What did you fix today? (part 2)

Kino · Dec 5, 2023

Mr Flibble said:
Thanks! 88E30M50 & Kino, I'll look into this.
Did you strip the whole mirror coating off before respraying or just the black backing?

Speaking from my experience; take the affected areas down to clear glass.

if you do not remove all the existing sliver coating it is very distracting to have patches of different colored reflections in the viewfinder and the outlines of the filled "holes" are very apparent (at least to me).

I tried just removing the black, feathering the holes in the sliver coating and spraying the surface, but that looked really bad to me through the viewfinder. I felt compelled to tear it all apart again and take off all the existing sliver surface before respraying.

It's a very messy job and you have to mask off the rest of the prism very carefully to keep the acetone off all other surfaces. Take care to not abrade the prism surface; it's quite easy to do. After it was all said and one, I wondered if a gel-based paint stripper, carefully applied might not have worked better for removing the black and sliver on the prism. All the rubbing with acetone and soft cloths did leave a few faint abrasions on the prism surface.

Next time, if there is one, I will try the paint stripper.

If there is a possibility to manually change them out from a donor, that's probably a better solution. However, if you have no alternatives in the matter, this does work.

Mr Flibble · Dec 5, 2023

Cheers,
In my two Contaxes it's mainly the top edges of the prism that have de-silvered and shows up as lines in the viewfinder. It would probably be less noticeable if I just fix those areas than if it were bigger areas.
Good idea on the paint stripper ....I'm not sure if or how it would react with Canada Balsam or other Optical cements between multi-part prisms.

Kino · Dec 5, 2023

Mr Flibble said:
Cheers,
In my two Contaxes it's mainly the top edges of the prism that have de-silvered and shows up as lines in the viewfinder. It would probably be less noticeable if I just fix those areas than if it were bigger areas.
Good idea on the paint stripper ....I'm not sure if or how it would react with Canada Balsam or other Optical cements between multi-part prisms.

Yes, I would only try the paint stripper on solid prisms or singular surfaces.

88E30M50 · Dec 5, 2023

On mine, I just stripped the black off of the copper coating but left the remaining copper/silver intact. I have cleaned up the prism on the old FX and on that one, I didn't respray it at all. I just cleaned the bad areas with acetone and naphtha and reassembled with new foam under the prism bracket. It looks every bit as good, if not a bit better than the mirror finish. I don't know how that will age, but if it does not age well or otherwise introduces a new issue, I can always just spray it as I did with the FT.

Donald Qualls · Dec 5, 2023

88E30M50 said:
It looks every bit as good, if not a bit better than the mirror finish.

Some pentaprisms have angles that provide Total Internal Reflection (TIR) -- which is better than silvering, by about half as much loss. The reason they're silvered (or aluminized, I presume, in newer cameras) anyway is that anything that gets into close contact with the glass (that isn't air) will spoil that high reflectivity and leave a dark spot, patch, streak, etc. Then the overcoat protects the metallic coating (until it doesn't).

88E30M50 · Dec 6, 2023

Donald Qualls said:
Some pentaprisms have angles that provide Total Internal Reflection (TIR) -- which is better than silvering, by about half as much loss. The reason they're silvered (or aluminized, I presume, in newer cameras) anyway is that anything that gets into close contact with the glass (that isn't air) will spoil that high reflectivity and leave a dark spot, patch, streak, etc. Then the overcoat protects the metallic coating (until it doesn't).

That makes a lot of sense. What would work for removing the copper and silver plating? I don't know if paint stripper would remove it.

Helios 1984 · Dec 6, 2023

I've yet again cleaned the aperture mechanism of my CZJ Tessar 50mm f/2.8. Just like last time, helicoid grease separated and crept under the aperture guide ring.

Donald Qualls · Dec 7, 2023

88E30M50 said:
What would work for removing the copper and silver plating? I don't know if paint stripper would remove it.

Paint stripper certainly won't work. For silver, I'd use nitric acid, but it can be a little exciting on copper (volumes of red nitric oxide vapor, do it under a fume hood or outdoors with the wind at your back). Sulfuric acid (sold as high powered drain cleaner) might work well on copper. Neither one will touch the glass, but I can't say how they might affect balsam or epoxy bonding layers if it's a two-piece prism. If the prism is new enough to be aluminized instead of silvered, you'd want hydrochloric acid -- which might also work on copper, but won't be good on silver (silver chloride is insoluble). You could also use tray cleaner or extra strength Farmer's reducer to remove silver, of course (halogenate, then dissolve with fixer).

Obviously, all of these are more hazardous to handle than most photographic chemicals...

88E30M50 · Dec 12, 2023

Donald Qualls said:
Paint stripper certainly won't work. For silver, I'd use nitric acid, but it can be a little exciting on copper (volumes of red nitric oxide vapor, do it under a fume hood or outdoors with the wind at your back). Sulfuric acid (sold as high powered drain cleaner) might work well on copper. Neither one will touch the glass, but I can't say how they might affect balsam or epoxy bonding layers if it's a two-piece prism. If the prism is new enough to be aluminized instead of silvered, you'd want hydrochloric acid -- which might also work on copper, but won't be good on silver (silver chloride is insoluble). You could also use tray cleaner or extra strength Farmer's reducer to remove silver, of course (halogenate, then dissolve with fixer).

Obviously, all of these are more hazardous to handle than most photographic chemicals...

When I get to the next prism that needs refinished, I'll take a deeper look into these. I have a couple of parts cameras that might be worth pulling a prism on to see what works. We're heading into winter here in Indy and since this sounds like something to be done outside, I'll most likely ponder the issue until spring

Donald Qualls · Dec 13, 2023

88E30M50 said:
this sounds like something to be done outside,

Farmer's Reducer or tray cleaner are intended for darkroom use. Nitric or hydrochloric acid at the least call for a vent hood.

Kino · Dec 15, 2023

Had some spare time today, so I installed my new bellows on the 1909 (?) Korona 5x7 I purchased from @AnselMortensen. The process was not without some errors, (like having to install the rear frame 3 times), but it worked out in the end.

Need to make a lens board for this camera and a few other minor things before I can shoot, but this was a major hurdle.

AnselMortensen · Dec 15, 2023

Looks great!

mshchem · Dec 16, 2023

Kino said:
Had some spare time today, so I installed my new bellows on the 1909 (?) Korona 5x7 I purchased from @AnselMortensen. The process was not without some errors, (like having to install the rear frame 3 times), but it worked out in the end.

Need to make a lens board for this camera and a few other minor things before I can shoot, but this was a major hurdle.

View attachment 356775 View attachment 356776

Looks fabulous. 5x7 is so perfect. Makes great contact prints, plenty big.

fiddle · Dec 16, 2023

After a few months of tinkering, going back and forth with ideas, I have finally finished my rotary base thingamabob.
Had gotten a cheap Jobo Expert 3010, had to build something to use it on.
Built the water bath tub out of plexi, arduino running a motor. Pretty much a filmomat clone, where i got the idea from. Will run some film through it this weekend.

Kino · Dec 16, 2023

fiddle said:
After a few months of tinkering, going back and forth with ideas, I have finally finished my rotary base thingamabob.
Had gotten a cheap Jobo Expert 3010, had to build something to use it on.
Built the water bath tub out of plexi, arduino running a motor. Pretty much a filmomat clone, where i got the idea from. Will run some film through it this weekend.

Looks great and a lot smaller than a ATL machine!

Would love to see a video of it running.

Trademark that name: Rotary Base Thingamabob.

fiddle · Dec 16, 2023

Kino said:
Looks great and a lot smaller than a ATL machine!

Would love to see a video of it running.

Trademark that name: Rotary Base Thingamabob.

Here ya go.
Have it running at about 45 , rotates two revolutions in each direction. I heard 50rpm was the recommended speed by Jobo, Ill adjust if needed.
Way smaller thatn a ATL yes, and waaaaayyyyyy cheaper than anything on the market. Not as nice, refined as something bought, but should work just as well.

Kino · Dec 16, 2023

fiddle said:
Here ya go.
Have it running at about 45 , rotates two revolutions in each direction. I heard 50rpm was the recommended speed by Jobo, Ill adjust if needed.
Way smaller thatn a ATL yes, and waaaaayyyyyy cheaper than anything on the market. Not as nice, refined as something bought, but should work just as well.

Looks great! My ATL 2500 can rotate at 25, 50 and 75, but you can probably rotate at any speed you like and not have to have a machine that takes up the space of a refrigerator.

Is that a Sous Veid cooker you are using for temperature control?

Quite nice!

fiddle · Dec 16, 2023

Kino said:
Looks great! My ATL 2500 can rotate at 25, 50 and 75, but you can probably rotate at any speed you like and not have to have a machine that takes up the space of a refrigerator.

Is that a Sous Veid cooker you are using for temperature control?

Quite nice!

Thank you!
Yes I set it at 50 because I read that was the recommended. I have it programmed to run 2 speeds on a 3 way switch, one for the 3010 and the other If I want to do 35 at some point, set a second speed with less rotations for that. I can also add a potentiometer to control the speed at some point if i need it, but figured Id make it as simple as possible.
Yes its a Sous vide, does a decent job maintaining temps, if was the cheapest one found on Amazon...

88E30M50 · Dec 19, 2023

This was a good evening for me at the workbench. A little while back, I purchased 3 Canon A-1s as parts cameras. The first is truly a parts camera as it came with missing bits and was used to practice disassembly/assembly on. The second was locked up somehow and had an inop shutter once I was able to get things moving. I don't know what the issue really was but some cleaning and a tiny bit of oil here and there got things going again. I found the second shutter magnet corroded and replaced that. There was a corroded spring in there too indicating the camera got wet at some point. With a couple of parts robbed from the practice camera, I got it shooting quite well with the only remaining issue is that it displays the error message when a lens is rotated into auto mode. Other than that, the meter is accurate and with new light seals and a touch of oil to cure the cough, it now sounds and functions well manually.

The third camera seemed to be functional in all respects other than the display was dead. The camera was really dirty too. Tonight, I took a detailed inventory of what it needed and got to doing it. The light seals are still pretty good, but I'll replace them since I have spare A-1 kits on hand. Once I removed the top cover, there was nothing obvious wrong except I found signs of previous work in there that had not been done with the right tools. Since everything looked ok, I was thinking that whomever put it back together may have screwed something up. I decided to pull the ribbon cable connector to see how the cable was attached and found the connector less than tight. Not loose, but not tight either. All looked OK, so I replaced the connector with just a bit more torque and don't ya know, the display now functions again. All bits were scrubbed and waxed before reassembly and it looks like a new camera again (aside from the usual scuffs of life).

So, another A-1 has been revived and the collection is growing. I'm up to 5 now, including one bought new in 1980 by me. The parts camera will be disassembled again a couple of times while I try to learn how the auto exposure functions mechanically. I don't expect to have as much luck as I did tonight, but it's fun to try.

Andreas Thaler · Dec 19, 2023

@88E30M50

Congratulations!

The A-1 is one of the most beautiful and technically impressive cameras of this time! It's also good to know who I can contact with questions about Canon A

Andreas Thaler · Dec 19, 2023

Andreas Thaler said:
@88E30M50

Congratulations!

The A-1 is one of the most beautiful and technically impressive cameras of this time! It's also good to know who I can contact with questions about Canon A

What is your experience with the A-1 regarding repairs? Are there any particular weak points?

mshchem · Dec 20, 2023

88E30M50 said:
This was a good evening for me at the workbench. A little while back, I purchased 3 Canon A-1s as parts cameras. The first is truly a parts camera as it came with missing bits and was used to practice disassembly/assembly on. The second was locked up somehow and had an inop shutter once I was able to get things moving. I don't know what the issue really was but some cleaning and a tiny bit of oil here and there got things going again. I found the second shutter magnet corroded and replaced that. There was a corroded spring in there too indicating the camera got wet at some point. With a couple of parts robbed from the practice camera, I got it shooting quite well with the only remaining issue is that it displays the error message when a lens is rotated into auto mode. Other than that, the meter is accurate and with new light seals and a touch of oil to cure the cough, it now sounds and functions well manually.

The third camera seemed to be functional in all respects other than the display was dead. The camera was really dirty too. Tonight, I took a detailed inventory of what it needed and got to doing it. The light seals are still pretty good, but I'll replace them since I have spare A-1 kits on hand. Once I removed the top cover, there was nothing obvious wrong except I found signs of previous work in there that had not been done with the right tools. Since everything looked ok, I was thinking that whomever put it back together may have screwed something up. I decided to pull the ribbon cable connector to see how the cable was attached and found the connector less than tight. Not loose, but not tight either. All looked OK, so I replaced the connector with just a bit more torque and don't ya know, the display now functions again. All bits were scrubbed and waxed before reassembly and it looks like a new camera again (aside from the usual scuffs of life).

So, another A-1 has been revived and the collection is growing. I'm up to 5 now, including one bought new in 1980 by me. The parts camera will be disassembled again a couple of times while I try to learn how the auto exposure functions mechanically. I don't expect to have as much luck as I did tonight, but it's fun to try.

View attachment 357294

That's great!!

Mr Flibble · Dec 20, 2023

Getting closer to completing my US Army PH-261 Photographic Set, a.k.a. the Darkroom-in-a-box.

The original control unit had been yanked out when it was demilitarized. So I've been collecting parts for a replacement.
A friend made the housing.

Test fitting it to the case.

After this I wired it all up and assembled it properly. Only for it to fail the circuit test.
I think the main power lead has a break in it....Something to fix this evening.

88E30M50 · Dec 20, 2023

Andreas Thaler said:
What is your experience with the A-1 regarding repairs? Are there any particular weak points?

I really wish I could claim to have some good experience or insight, but I'm still new to the platform. I've got 5 of them on hand right now, 4 of which are functional. Last month, I picked up 3 parts cameras. One of those has been used to practice disassembly and reassembly processes. I've not got a lot of experience in soldering flexible circuit boards, so that's what I've been doing a bunch of on that poor old abused camera. The 2nd camera was gritty and tight and once I was able to lube a couple of spots, it started to mostly work. Slow motion video showed an issue with the second shutter curtain magnet. I replaced that and the camera is mostly working. It still has an issue with auto exposure modes though. The third camera, I just got lucky on. I pulled the top cover and when there was nothing obvious, I decided to check the LED panel connection since that's where the problem was centered. The screw was buggered up a bit so I pulled the connection clamp and reinstalled it with a bit more torque because it was on the loose side when I removed it. That worked. Like I say, lucky.

The biggest issue with the A series for me is that they are intimidating when you pull the top cover. There's an amazing amount of stuff going on in there. But, when you start looking at it systemically, patterns emerge. At this point, I am limited to mechanical corrections. If the display was dead because of a bad chip or board, I'd had to have written it off as a parts camera. That's pretty much where that parts camera is. It's simply dead and nothing I've done has changed that in any way.

I've not really detected any weak points yet. There are some plastic bits in the rotary dials that may be getting brittle being over 40 years old, but I've yet to break anything while disassembling it. When you remove the mirror box, be really, really careful of the display ribbon. If that hangs up, it can possibly damage the LED display if it pulls it from the prism area. Make very good notes and mark wires if needed to make it easy to remember what went where. I'm sure that you know all of that already but I'm still learning on that abused body

88E30M50 · Dec 20, 2023

Mr Flibble said:
Getting closer to completing my US Army PH-261 Photographic Set, a.k.a. the Darkroom-in-a-box.

The original control unit had been yanked out when it was demilitarized. So I've been collecting parts for a replacement.
A friend made the housing.

Test fitting it to the case.

After this I wired it all up and assembled it properly. Only for it to fail the circuit test.
I think the main power lead has a break in it....Something to fix this evening.

That's really cool.

What did you fix today? (part 2)

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