super ikontas weakness... opacified viewfinder

[photovdz]

I have got some problem with Super-ikontas A,C, and D with ALbada viewfinder :

There are some tiny plastic frames in the view finder that reflects on the albada mirrors, those tiny plastic frames tends to go dull and opacify...

Does anyone have a solution ? new bits and pieces somewhere... ?


Stephan

[literiter]

I have no solution but I have bits of information. Hopefully this may encourage others to give us their thoughts and advice.

The problem is in the front lens, as well as the plastic frames. The front lens is composed of two lenses. The inside of one of the lenses has been partially silvered and they were glued together with "Canada Balsam".

Something happened over time to make the "Canada Balsam" darken. It looks like the silvering didn't do so well either.

I've been trying to find a replacement for the plastic with the frame lines. I think the solution may be to print the lines using a inkjet or laser printer on clear plastic. (can be done using those overhead projector transparency sheets) But the lines are white and printers don't use white, in my experience.

I have three Super Ikonta C's that would benefit from this.

[Windscale]

I have got rid of the original finders in a couple of folders and replaced them with various 35mm finders for the 135 format.
I would remove the original finders and fix an assessory shoe in their place. Then find some bright 35mm finders and shade the unnecessary areas. And there you have it.

[Keith]

Interesting thread ... I stopped using my Super Ikonta because it's a bit hard to use in poor light for this reason. It's also not too well aligned with what the lens is seeing I discovered ... It's currently lurking in the back of the cupboard in the 'too hard basket" for these reasons. It's a shame because it has a beautiful lens and would be one of the prettiest cameras I own.

[literiter]

I am considering heating the front element (carefully!) to perhaps remelt the Canada Balsam. I could then take the lens apart, clean, resilver and re-cement. It maybe possible that just reheating this element and refusing the Balsam may help. This makes me a little nervous but I do have an extra old Ikonta.

The issue then, would be to fabricate the plastic frame lines.

[jan normandale]

Originally Posted by photovdz

I have got some problem with Super-ikontas A,C, and D with ALbada viewfinder :

There are some tiny plastic frames in the view finder that reflects on the albada mirrors, those tiny plastic frames tends to go dull and opacify...

Does anyone have a solution ? new bits and pieces somewhere... ?


Stephan

Stephan are you talking about your 'rangefinder' or the 'albada viewfinder' I'm a little confused here. The albada is a pop-up viewfinder that permits a 'quick framing' of a subject and using a predetermined f stop that catches the subject in focus due to them being within the DoF for that f stop.

The rangefinder is the small finder that you look through and align overlapping images to ensure accurate focus without relying on DoF to cover you off.

The albada often has a plastic front, inside a frame. Pop it out and replace it with a home made replica if necessary. Not nice but it will work. Obviously it's better if you can find a replacement to pop in. Sometimes you don't even need the plastic and you can estimate the framing inside the two metal viewfinders.

The rangefinder has mirrors to align the split/overlapping image. If there is an issue there you might take the camera to someone who can re align and re silver the mirrors. If you are very 'dextrous' you could go to some sites like Matt Denton's and read about doing this on your own. It's not easy as a DIY project in my opinon. I leave that to pro's at a camera repair shop.

Post some photos from it when you're done. Good luck!

[photovdz]

I was of course speaking of the albada finder... the rangefinders are usually ok...

I'll try to see if there is a possibility of using a VC viewfinder instead...

but what would be the focal correlation... would a 50mm viewfinder be ok ? with the A (75mm on 4,5x 6) the C and the D

I'm trying to modify my D in order to accept 120 rolls and have a 54,8 / 110 negative... miam...

[literiter]

Originally Posted by jan normandale

Stephan are you talking about your 'rangefinder' or the 'albada viewfinder' I'm a little confused here. he framing inside the two metal viewfinders.

I believe the item in question is the "Albada" viewfinder. The first image is the whole affair, rangefinder and viewfinder.The second image is the front lens. Beneath it is a second lens.

[literiter]

The first image is the front lens by itself. It is composed of two lenses. The lenses are cemented together after one is partially silvered. These lenses can go dark and the silvering can go bad.

The second image is the rear element which has a piece of clear plastic, with frame lines. In front of this is another lens.

The plastic with the frame lines will be a clear nitrocellulose with the frame lines silkscreened on. This material will become dark and distorted over time.

The Albada finder (Van Albada I think) is a fairly complex device. When they work well (and I've never seen it) the frame lines will seem to be projected to the image in the finder. Rather ingenious. There are three lenses in this device.

[photovdz]

I thougth only two lenses... the frame screen is a flat glass... (but even a flat glass is a lens... in this design).


L.E.W. Van Albada (Generaal-Majoor BD) was a dutch miltary engineer who wrote many books on lenses... and designed that devices in the 20ties...

[literiter]

Originally Posted by photovdz

I thougth only two lenses... the frame screen is a flat glass... (but even a flat glass is a lens... in this design).

On my Ikonta the frame screen is behind a lens, not flat glass. (I just checked. )

So, two lenses on front frame, cemented together to form one, one lens on rear frame, behind it the frame screen.