melcat wrote in post #14449663
You have proven you don't know how to do it properly. It works for me on multiple bodies. I have looked at your "results" in the past, and the only ways I can see of getting the 5 stop error you do are:
- metering wide open instead of stopped down.
- setting a chipped adaptor to the shooting aperture, stopping down, and then metering. Of course the camera thinks the nonexistent auto aperture is going to stop down again and you get a metering error.
My guess is it's the second, but you have never been clear on your methodology.
The only "error" I see is the camera not correcting for fall-off in the lens becauae it doesn't know what lens it is, the same "error" I see in my Canon lenses newer than the bodies and my Zeiss lens....I don't know what combinations of stock screen and chipped adaptor work, but for sure Ee-S + unchipped adaptor + OM lenses works on my 5D. I got this straight out of the Fred Miranda Alt forum, where there were *numerous* people doing it. How did you suppose the adaptor people had a business otherwise?
I have over 45 years experience with TTL cameras, some of which used stopped down metering (Pentax, Mamiya, Yashica), most of which use wide open metering. My methodology, in tests with 40D with EF-D screen focus screen...
I meter stopped down to shooting aperture, and (in Av or M -- the results are identical) then set the shutter speed according to the meter.
With an unchipped adapter. :
- I meter stopped down to shooting aperture, and (in Av or M -- the results of metering mode are identical) set the shutter speed according to the meter.
- Import RAW files into LR and have all Exposure and all other settings set to +0.0, with Brightness = +50 and Contrast set to +25.
For reference, incident meter indicates ISO 100, 1/30 f/1.4 for all of the following...
Here are the results with unchipped
adapter 40D meter in Av mode, using Olympus OM50mm f/1.4
, starting at f/1.4 and progressing down the apertures to f/16 (note: exposure #9 is not part of this test series):
The results with chipped
adapter (set to f/1.8). , 40D meter in Av mode with Olympus OM 50mm f/1.4
, starting at f/1.4 and progressing down the apertures to f/16:
While this appears better at f/1.4, it still is NOT accurate. The in-camera meter asked for 1/15, 1/8, 0"4, 1'3, 2", 4", 6", 10"
rather than 1/30, 1/15, 1/8, 1/4, 1/2, 1 (which the incident meter asked for)
Same procedure repeated unchipped
adapter, but using OM50mm f/1.8
Same procedure repeated with chipped
adapter (set to f/1.8). , but using OM50mm f/1.8
While this appears accurate at f/1.8, it still is NOT accurate. The in-camera meter asked for 1/15, 1/13, 1/6, 0'5, 2", 4", 6", 8"
rather than 1/20, 1/15, 1/8, 1/4, 1/2, 1 (which the incident meter asked for). Yet the chip is set for f/1.8, and the lens is an f/1.8
These result reflect my warnings that the meter is not necessarily accurate! While it does seem that using a chipped adapter which is set match to the physical max aperture (e.g. f/1.8) is close, what point it is to want to shoot at f/16 but have to first meter at f/1.8 and then count down -7EV to f/16 and then also count shutter clicks up +7EV to suit?! And what happens when you want to mount a 135mm f/2.8 lens using the same adapter...re-program it in the field before shooting and then have to reprogram it back to f/1.8 when switching back to the 50mm?!
I wish you would stop posting this repeatedly.
Why stop giving advice when the advise can be shown to be true? Using my 5D which has the EE-D focusing screen in it, the results are better with the same lens and same chipped adapter...Why any difference? I'm not supposed to use stopped down metering?...then why these much better and much more consistent results (not perfectly consistent, though) with the 5D?!
With chipped and unchipped adapters out there, and with folks trying to use the same adapter on multiple lenses, one has to be very careful and follow very, very explicit procedures or risk getting wrong results!!! Yet there is NO ACCURATE result in the above 4 series, even with a chip matching the max aperture of the lens used!!! Yet a different model camera can work better, with the same adapter and lens.
So how will anyone know if their combination will be right, without testing? And that is the reason to use a handheld meter with these adapters.
PS: For folks reading this thread...ALL frames in any single series should have IDENTICAL density values, and NOT differing ones, all of them about mid-tone density. If you do NOT get identical tones, you are experiencing variable meter exposure values and not uniform metering.