In this article I want to give some information about my effort on creating an optical viewinder adaptor for Contax II and Kiev 4 cameras. The intention is to be able to use different focal lengths on the internal viewfinder so that no more extra viewfinder – like the turret viewfinder – is needed.
I had the idea in creating one since I read about the Leica M3 (?) and it’s special version of a Summicron 35 mm lens that comes with attached lenses that change the angle of view of the viewfinder. You can see an example on this great Leica-Fan-Site (which is in german only – sorry about that).
I am using a Kiev 4 for budget reasons so I was looking for a rather inexpensive solution and thought about fixing an adaptor on the tripod mount because I did not wanted to make the lightmeter on my Kiev 4 obsolete.
About the same time I bought my Kiev 4a – the one without light meter – I found an article about cheaply creating a finder mask for tele lenses on rick olesons great site. This gave me the idea to create a simple mask made of adhesive tape that can be used on the Kiev 4 and Kiev 4a without blocking the light meter.
Btw.: it is a bit hard to read on Ricks notes – the size of the mask is calculated the following way:
mask size = RF size · 50 ÷ f
The problem about this finder is that even tiny changes in the position of the mask have huge impact on the framing of the picture. My first roll had real problems with cut off parts in the pictures.
I thought if I put two lenses in front of the viewfinder windows in front of the camera with the proper dioptre my problems could be solved. So I went to a local optician and asked if this is technically possible. He explained that this might be no problem as long as I deliver him a frame in which he could put the cut out lenses. The lenses itself will be rather cheap (approximately 12 Euros each if I remember correctly).
Since then a few years are gone, I was really busy raising the kids and work wise. So I restarted this project and found a place that cuts out aluminium plates from an uploaded CAD-File – or even they deliver a software where you can manipulate the CAD file and instantly check the price upload and order. Sorry – for this software again is in german only.
So I designed a frame already, if the budget allows I will order it next month and see if I can get the lenses attached to it. I will continue this article if anything new happens here.
I will also share the FrontDesign-CNC-File in case you would like to do development on this on your own. Only thing I demand is that you leave a comment here if you did any development on this:
Download: Kiev IV Brille optisches Glas.bak
After playing around with this masking idea I figured out that there are big problems with parallax. It would be needed to add some marks for close up focus since the magnification gets bigger if you focus closer adding with the growing effect of parallax which gets bigger the closer you focus either.
Since these are too big technical problems I actually do not focus on this project in the moment any more but bought me a turret finder for the Kiev 4 camera. Anyway the mask can work fine if you bear these limitations in mind.