Industar 26M (focus problem)

[gabrielcik]

Hi,

I recently bought, here in Ukraine, an old Fed 2 + industar 26M (here such things cost much less than on ebay)...

Everything seem to be working correctly... but I am not sure about the lens.
I tried with the help of an adapter (M39 to Nikon F) the Industar on my Nikon d200... result: i can't focus, i turn the focusing ring but nothing change. I can only adjust the focus by moving the camera (coming closer to the object).

Now I have some question (btw I don't have experience of RF camera and lens):
- Is it normal that it doesn't focus on a DSLR camera (maybe the lens is working only with RF)? but then what for they sell the adapter? 😀

- Maybe is missing some component inside my lens... (can you say me how many "glasses" have to be inside it)

I have also an Industar 50-2 "pancake" m44... with this one I can focus without any problem on my Nikon.

Thank you for your help🙂

 

[wolves3012]

There's a pretty simple explanation for this. The FED's I-61 lens is a rangefinder lens, so it's not designed to fit so far from the film as it does on an SLR. In effect, you have put an extension-tube onto the camera and turned it into a macro lens. You should find the focus-ring does have a slight effect but not much. This is normal for putting an RF lens on an SLR, digital or not. Your I-50 "pancake" lens is an SLR lens and should focus properly.

 

[gabrielcik]

Hi, thank you for your reply!
so i believe there is nothing wrong with my lens 😉
Do you know any way for to make the lens work on a DSLR? (without to buy expensive adapters...)

Another question... is there a way for to check the correct speed of the camera? (I mean to know if 1/50 is really 1/50 etc... 😀)

Spasibo!

 

[Ron (Netherlands)]

Like said before: the lens flange to film / sensor distance is shorter with 35mm rangefinder lenses, so it won't work, and you cannot solve this with an adapter.

 

[wolves3012]

You cannot correct the I-61 for SLR use with a simple adapter, no. It is possible, in theory, by adding an adapter with corrective optics but I do not know of one that exists. Such an adapter would not be cheap either.

It is possible to check the speeds with a shutter speed-tester but, in honesty, I doubt they are very accurate on a mechanical camera. Bear in mind that deadly-accurate speeds are not really needed in most circumstances. If the shutter shows no capping or tapering on 1/500th then it's probably about as near as you're likely to get. If 1/500th is ok, the other speeds are unlikely to have problems.

If you don't have access to test gear, take some shots on 1/500th of (say) a blue sky or something of uniform brightness. Take vertical and horizontal shots. Check the results to see that the brightness is uniform and that there is no part of the frame cut off (left or right edges of the frame).

There are a couple of simple tests you can do without film too. If you can find a computer monitor with CRT (not common nowadays), take the back & lens off the body and look through the shutter at the screen (put a white raster on the screen). When firing the shutter, you should see narrow, diagonal white stripes and the sides of the stripes should be parallel. Use 1/500th. The stripes should be wider on 1/250th and very wide on 1/125th. Lower speeds won't give useful results.

The other test you can try is to aim a laser-pointer (not a high-power one!) at the shutter blind, both left and right-hand sides in turn. Take off the lens and back. Fire the shutter on 1/500th and check that you get to see the dot projected through the shutter. This shows that both ends of the frame are getting light through, so it proves there's no capping. It won't prove that there's no tapering though.