Exposure Simulation With Adapters and Old Lenses?

[CBImages]

I have a Contax 35-70mm f3.4 lens that I love for landscapes, when I used it with my old Canon 50D I was able to use 'Exposure Simulation' in 'Live View' to estimate the correct exposure. Now I have upgraded to the 5D Mk III 'Exposure Simulation' doesn't work at all, all I get is a black live view screen. If I drop the shutter speed right down I can use 'Live View' to focus my composition but its useless for estimating the exposure. I find myself having to resort to my digital spot meter which slows down the whole image making process.

I currently use an adapter made by SRB Griturn, it doesn't have a chip in it, I would be willing to buy another brand if anyone knows if it will allow 'Exposure Compensation' to work on a 5D Mk III.

Does anyone have any ideas - is it possible to get 'Exposure Simulation' working with non Canon lenses on a 5D Mk III?

Does anyone know of any tech gurus who might be able to solve the problem?

Thanks - Chris

[ajohnw]

There are a number of EOS to this and that converters including Contax with AF confirm on Ebay. I have used one on a 5D Mk1 but for my use on a microscope the AF confirm wasn't accurate enough. It's sort of like moving a camera lens to focus except positioning has to be better than 0.001mm at times and the available depth of field isn't all that many of those either so it's a bit critical.

What the adapters with the chips do is make the camera think it has a 50mm F1.4 Canon lens on it. A Russian reverse engineered the lens communications. You shouldn't have any problems using your Contax in any way on it unless Canon state that the camera doesn't support certain lenses. That should include live view and metering. Metering certainly wasn't a major issue on my microscope but I have never used one of these adapters on a manual lens.

These 2 links might help

http://www.northlight-images.co.uk/r...s_on_dslr.html

and lenses on a 1Ds

http://www.northlight-images.co.uk/r...s_on_dslr.html

There does seem to be a problem on 5D MKIII's however there also seems to be adapters that have been adapted to work on these as well. eg Ebay No 271290756617, under £15 so no import duty. I have bought several types of adapter from the far East direct and they really aren't any different to what is sold in the UK. Sometimes better in fact.

John
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[CBImages]

There are a number of EOS to this and that converters including Contax with AF confirm on Ebay. I have used one on a 5D Mk1 but for my use on a microscope the AF confirm wasn't accurate enough. It's sort of like moving a camera lens to focus except positioning has to be better than 0.001mm at times and the available depth of field isn't all that many of those either so it's a bit critical.

What the adapters with the chips do is make the camera think it has a 50mm F1.4 Canon lens on it. A Russian reverse engineered the lens communications. You shouldn't have any problems using your Contax in any way on it unless Canon state that the camera doesn't support certain lenses. That should include live view and metering. Metering certainly wasn't a major issue on my microscope but I have never used one of these adapters on a manual lens.

These 2 links might help

http://www.northlight-images.co.uk/r...s_on_dslr.html

and lenses on a 1Ds

http://www.northlight-images.co.uk/r...s_on_dslr.html

There does seem to be a problem on 5D MKIII's however there also seems to be adapters that have been adapted to work on these as well. eg Ebay No 271290756617, under £15 so no import duty. I have bought several types of adapter from the far East direct and they really aren't any different to what is sold in the UK. Sometimes better in fact.

John
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Sorry it has taken me so long to reply - I have just moved home and my new internet connection is very 'flaky', another job to add to my ever growing list!

Thanks for the reply and the info John, I took a look at the links - the adapters you mention all seem to relate to 'focus confirmation' chips. This is not a problem for me as I nearly always focus manually using live view.
My problem is that my camera doesn't display Exposure Simulation accurately (it is enabled in the menu and works fine with Canon lenses but not with my Contax lens).

In my investigation I have found that my 5D MkIII and Contax lens combination does provide a close 'exposure simulation' if I set the camera in Av mode and set the lens to f8 or f11. As I said it is a close approximation but not exact but close enough to correct in Lightroom. However if I open the aperture up or close it down from f8/f11 the 'exposure simulation' is way off.

[ajohnw]

Sorry I assumed you would use the camera meter for setting exposure. The other reason for mentioning them apart from AF confirm is that you may find that your camera behaves more "normally" with one on in either shutter priority or maybe full manual mode.

I suspect the exposure simulation is similar to something available on some m 4/3 cameras. The view can be set to boost / maintain the same level of illumination or simulate the exposure setting. The latter looks like it might be ok for HDR type things if each shot is adjusted but it's not terribly accurate.

John
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[tao2]

Hi Chris,

don't know a lot about Canon cameras but some other cameras retain, in memory, settings for the last (AF) lens used. Mebbe your camera has that facility? If so there should be a method tae clear details - exposure simulation itself?

Try switching that mode off, before mounting the Contax, then switching it back on. It'll probably not work on the old lens but the reset may enable the Contax without the problems you're having?