Yashica Electro 35 GSN Rangefinder Replacement

My first attempt at finding a working copy of one of these fabulous but mechanically and electronically finicky cameras landed me a fine looking example of electronics that were way beyond repair. Still, the $30 price of admission was well worth the entertainment value of trying to fix it up. 🙂

The second attempt was an eBay buy that was maybe a 9.5 cosmetically and sound mechanically but had one major flaw which made it a pain to use… The rangefinder spot in the viewer that is used to focus was almost non-existent. It had just the barest ghost of an overlapping image which made focusing difficult even on bright days.

Since I had the parts from a whole other camera, (happily the focusing mechanism on the broken GSN was in stellar shape) I decided it was high time to perform a little surgery and build… a Frankie.

You can see in the photo on the right just how bad shape the old rangefinder mechanism was in… The top one was the mechanism I replaced and you can see how the diagonal piece of glass there is nearly transparent. This gold coated piece of glass is basically a beam splitter that superimposes the focusing area on the view through the lens. With the coating nearly gone as in the top photo, very little was being reflected and consequently the focusing area had pretty much disappeared.

There are other sites with instructions on disassembly of the GSN so I won’t go too much in to that here. This photo shows the camera with the top-plate already removed and the rangefinder mechanism exposed. The screws circled in green hold the whole unit in place and are all that need to be removed. When removing it, lift out the left side first (where the film rewind crank is) and be careful of the Over / Under lights and other electronics on the right.

When replacing the rangefinder mechanism, tuck the right side under the electronics and it should just drop in to place. Don’t screw it down yet, as you will need to make sure the focusing lever is set in the lens tab in the next step. Note the location of the vertical focus adjustment screw circled in the photo on the right.

This photo shows the metal tab that keeps the lens indexed with the rangefinder mechanism. Underneath the rangefinder mechanism is a focusing lever that moves the mirror assembly back and forth. This lever needs to rest in a tab that is attached to the lens. (Both are circled in the picture.) Once this is set, move the lens from close to far focus and back a few times to make sure no wiries are obstucting the movement or worse, getting pinched somehwhere in the process.After this step, you can screw the rangefinder mechanism in place and proceed with the final adjustments.

The final and most complicated step is adjusting focus so the lens is in register with the rangefinder mechanism. The method I found easiest was to set the lens to infinity and then adjust the rangefinder to that.

To adjust the rangefinder, there are 2 screws that control horizontal and vertical registration of the focusing square. The photo on the right shows the location of the horizonal 45° adjustment screw. [It was pointed out to me (thanks Alfredo!) that the horizontal adjustment is the cross-like screw located next to the moveable rangefinder lens, labelled as “infinity adjustment” on page 36 of the GSN service manual.] The vertical adjustment screw is shown two photos back. I was lucky and actually didn’t have to touch the verical registration at all.

Mount the camera on a tripod and point the it at a distant object. I actually found it easier to do this step at night with the camera trained on a street light in the distance. Set the lens to infinity marking – it should be right against the stop and not go any further. When you look through the viewfinder you’ll see whatever object you’ve trained on is “out of focus.” Just adjust the horizontal (and verical if needed) until the images register exactly. Go back and verify that the lens is still set to infinity and check focus again.

Before putting a roll of film in the camera I wanted to be reasonably sure that focus was good.

To do so, I used an old roll of film that I accidentally fixed but didn’t develop (Oops! A couple of pieces of electrical tape would have worked just as well though…) to hold in place a square of material I cut from a soft CD sleeve.

I like the CD sleeve material for this as it is cheap, lint-free and the thinness and perforations make it easy to tell where focus is. A good alternative would be tracing or rice paper but this is what I had on hand and it worked well for me. Basically, the thinner the better…

Here you can see what it looks like focusing on a desk-lamp at closest-focus on the GSN which is about 80 cm (or 2.5 ft). Looking through the viewfinder and looking at the back of the camera, the focus seemed to match well and focusing at a distant street light with the lens set to infinity showed an equally sharp image.

This is not meant to be a definitive test of focus, just a quick preview before putting everything back together in case something is really off… A true test of focus can only really come from a test roll. (At least with the gear I have on hand!)

This should be it! To keep focus from slipping, brush some clear nail polish on the adjustment screws and let it dry before assembling the camera.

The surgery worked! My GSN is still in focus and the “new” focusing mechanisim is an astounding improvement.

When putting the camera back together I used the newest looking bits from both and now the camera looks great along with working great.

It’s also nice to know I have parts to replace nearly anything on this camera should anything else ever break…

Here are a few links to sites and manuals that were very helpful in figuring all this stuff out:


Here are a couple of shots from my GSN set on flicker:

House of Shields

wet paint

Darkroom Timer Android App by Chicken of the Web

There is a great Darkroom Timer application by Chicken of the Web for Android devices on the Android Market that is really worth a look at. It is a super useful and flexible application that lets you enter your own development recipes and accounts for things like agitation intervals, pour time etc.

I’ve been using it for a while now and have a nice set of presets for black and white film developing for this app that I hope some of you might find handy too.

Below a list of the presets I have so far. All of these have been tested by me but I’m still a noob and learning and tweaking as I go so I’ll probably be updating this list often…

You can download my latest presets file by right-clicking on this link and selecting “save as”

You’ll need to get the text file on your Android device either by mailing it to yourself and saving locally or by copying it to the SD card via USB. Drop the text file on the SD card of your Android device in to the folder named (create the folder if it doesn’t exist). Then fire up Darkroom Timer, hit the Menu button and select Load Presets. On the pop up that appears, just select the preset to load it.

If you have any problems loading the file, please leave a comment.

Updated: 2012-01-12:
30 Minute Timer
30 Second Timer
60 Second Timer
5 Minute Wash
60 Second Timer
Stop & Fix
Arista Rapid E6 @ 40C
Kodak D76 – 1:0 & Ilford Delta 3200 @ EI1600
Kodak D76 – 1:1 & Ilford HP5 @ EI400
Kodak D76 – 1:1 & Ilford PanF+ @ EI50
Kodak D76 – 1:1 & Kodak Tri-X Pan @ EI200
Kodak D76 – 1:1 & Kodak Tri-X Pan @ EI400
Kodak HC-110 – 1:60 & Kodak Tri-X Pan @ EI200
Kodak HC-110 – 1:16 & Kodak Tri-X Pan @ EI200 (Solarization)
Kodak HC-110 – 1:30 & Kodak Tri-X Pan @ EI400
Agfa Rodinal Stand Development 1:100
Agfa Rodinal 1:25 & Ilford Film (HP5, PanF)
Agfa Rodinal 1:50 & Arista Premium @ 100
Agfa Rodinal 1:50 & Arista Premium @ 200
Agfa Rodinal 1:50 & Arista Premium @ 400
Agfa Rodinal 1:50 & Fompan 100 @ EI100
Agfa Rodinal 1:50 & Ilford Film (HP5, PanF)
Agfa Rodinal 1:50 & Kodak TMax P3200 @ EI1000
Agfa Rodinal 1:50 & Kodak Tri-X Pan @ EI400
Rollei / Compard Digibase C-41 @ 25°C
Rollei / Compard Digibase C-41 @ 45°C

Rodinal Developer

I am collecting in this post my experiences developing black and white film with Rodinal developer, now sold as Adox Adonal. I have a little notebook with all of this information that would be a huge pain to loose so I’m transcribing those notes here and adding more as I learn.

For the basics, the wiki post is a great place to start… (Be sure to check those external links!)

Digital Truth has a massive chart of development times for Rodinal with all kinds of film as well as the Rodinal product leaflet. You can find the Adonal Material Safety Data Sheet (the stuff I use) at the site. I ordered my 500ml bottle of Adonal from FreestylePhoto in the USA. In Europe, you can order from SilverPrint.

To check out other great images developed with Rodinal and get feedback from some really knowledgeable people, check out the Flickr Rodinal Group.

If you’ve enjoyed these tips and are in the market for some photo gear, using these links to buy from, or or alternatively using the PayPal Donate button to make a small contribution helps me keep this site going. Thanks!

My handy table of Rodinal Dilutions:
For 300 ml
(ml Rodinal + ml Water)
For 500 ml
(ml Rodinal + ml Water)
For 1000 ml
(ml Rodinal + ml Water)
12 ml / 288 ml
20 ml / 480 ml
40 ml / 960 ml
6 ml / 294 ml
10 ml / 490 ml
20 ml / 980 ml
3 ml / 297 ml
5 ml / 495 ml
10 ml / 990 ml

Examples of development at different dilutions:

Development Type: Stand Development 1:100 Concentration @ 20C
Time: 60 min

60 sec of inversions at start, 10 sec of inversions at 30 min.

Flickr Set:
three chairs

Development Type: Normal Development 1:50 Concentration @ 20C
Time: 11 min

60 sec of inversions at start, 10 sec of inversions at start of every min thereafter.

Flickr Set:
Polaroid 350

Development Type: Normal Development 1:25 Concentration @ 20C
Time: 7 min

60 sec of inversions at start, 10 sec of inversions at start of every min thereafter.

Flickr Set:
floating in a...
16th Ave.


The TurtleCam is unfortunately no more…

I’ve moved a few times since I had the webcam broadcasting live views of San Francisco and while I am now back in the city, my current views don’t really merit the attention. 😉

It was a blast being able to share the view and everything I needed to learn to make that happen.

Maybe one day I’ll have a nice view to share again… In the meantime, I’ll leave you with a time-lapse video of one of the last days the TurtleCam recored in San Francisco – the 2005 summer solstice!

Thanks to everyone for all the visits and feedback.

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