andre_reinders Posted May 21, 2008 Share Posted May 21, 2008 I have just purchased a Rebel XT - which I really like, but when I use my Micro- Nikkor n/ai 55mm lens with adaptor on it, the meter over exposes by one stop. It does not do this on my Canon 20D, where it all works as expected. Any thoughts? Link to comment Share on other sites More sharing options...
digitmstr Posted May 21, 2008 Share Posted May 21, 2008 This sometimes happen with Manual lenses. I have used many from Nikon, Pentax, etc... I have never had as much as one stop of difference but, 1/2 stop can be common. Link to comment Share on other sites More sharing options...
jason_hall4 Posted May 21, 2008 Share Posted May 21, 2008 This is normal, the smaller the aperture the more it over exposes. Set your camera to Av mode and start at the lowest (largest) aperture of the lens. Take one shot at each stop of the aperture ring. YOu should see a proportional increase in over exposure as the aperture gets smaller. That was my experience any way. Jason Link to comment Share on other sites More sharing options...
yakim_peled1 Posted May 21, 2008 Share Posted May 21, 2008 1. Why should a manual lens be any different from a Canon one? After all, the metering is TTL. 2. Why should it happen in one body but not the other? Happy shooting, Yakim. Link to comment Share on other sites More sharing options...
shambrick007 Posted May 21, 2008 Share Posted May 21, 2008 "1. Why should a manual lens be any different from a Canon one? After all, the metering is TTL." - A manual lens lacks all those neato electrical contacts and processors. <p> "2. Why should it happen in one body but not the other?" - Because they are different bodies. Either way, as mentioned, this is par for the course. Link to comment Share on other sites More sharing options...
jason_hall4 Posted May 21, 2008 Share Posted May 21, 2008 I hate it when this happens. I did not read the OP as well as I should have. I have no idea why the 20D is not affected, unless you shot at different apertures on each camera. At the widest aperture, my experience with several manual lens (two are non AI Nikkor) is meters pretty darn well. I only see an issue when I stop down, but it is predictable and easily compensated for it. So with that, my question would be, are you trying the same aperture setting on both cameras? If not try that and compare shots at different f stops on each camera to see how they each respond. Jason Link to comment Share on other sites More sharing options...
yakim_peled1 Posted May 21, 2008 Share Posted May 21, 2008 >> A manual lens lacks all those neato electrical contacts and processors. I know that but how does it relate to this specific issue? >> Because they are different bodies. I don't see how that fact relates to this specific issue. >> Either way, as mentioned, this is par for the course. My English is not my native language. Please re-phrase this sentence. Happy shooting, Yakim. Link to comment Share on other sites More sharing options...
donald_weston1 Posted May 21, 2008 Share Posted May 21, 2008 Yakim "par for the course" means approximately that this does happen from time to time in these situations and no one really knows why most likely, I find that I always have to check and adjust exposure accordingly on both my 5D and 40D when I mount MF lenses, even with an AF confirm mount...short form of translation I guess is "shit happens"...best thing is be aware that it can happen and be ready to deal accordingly, but then I do the same thing with AF EOS lenses too, jmho....ymmv... Link to comment Share on other sites More sharing options...
bjscharp Posted May 21, 2008 Share Posted May 21, 2008 I can imagine the metering not working properly with an adapted lens, but the difference between the 400D and the 40D is weird. Other layout of the TTL-zones maybe? Have you tried setting the camera to another metering mode? Link to comment Share on other sites More sharing options...
jason_hall4 Posted May 21, 2008 Share Posted May 21, 2008 >>>"Either way, as mentioned, this is par for the course. My English is not my native language. Please re-phrase this sentence."<<< -Its normal It comes from Golf as when you get "par", it means you took the average number of strokes(swings), non over or under what it should take to sink the ball. So the phrase is "Par for the (Golf) course". So if par is 3 and you shot 4, It is said you are 1 over par. I hope I did not over do my answer. :o) Jason Link to comment Share on other sites More sharing options...
yakim_peled1 Posted May 21, 2008 Share Posted May 21, 2008 Thanks for the English lesson. I love this forum. You learn so much more than photography here... :-) BTW, my only manual lens is the Nikon 1000/11. It meters well on 40D and 1D Mk III. No bias to either side. Happy shooting, Yakim. Link to comment Share on other sites More sharing options...
yakim_peled1 Posted May 21, 2008 Share Posted May 21, 2008 >> My English is not my native language. Please re-phrase this sentence. Ouch. Someone please delete the first word... :-( Happy shooting, Yakim. Link to comment Share on other sites More sharing options...
jason_hall4 Posted May 21, 2008 Share Posted May 21, 2008 >>>"Ouch. Someone please delete the first word... :-( "<<< LOL...but I think the sentence explains itﾒs self! :o) Jason Link to comment Share on other sites More sharing options...
tommyinca Posted May 21, 2008 Share Posted May 21, 2008 The body choose "center weighted average" metering when a manual lens (aka: no signal) is attached. This explain some metering delta between EOS and manual lens. On some camera body (don't know if XT is one of them), the sensor may not be placed exactly where the focus plane lies for one reason or others (ie: cost). I think when that happen, it is possible for the metering to be off if the on camera computer made a certain assumpion about the lens attached but turn out not to be true. Link to comment Share on other sites More sharing options...
kitaphoto Posted May 21, 2008 Share Posted May 21, 2008 I have the same issue...not a problem except the the XT and 30D meter differently and so I have to remember which body I'm using...what I do is take a few test shots to remind me...I find that in many situations I must "underexpose" by one 3 lines...in bright situations I sometimes have to go all the way to the left to get the LED to blink, and then increase the exposure and fully press the shutter when the LED stops blinking...at least it's consistant... This is like the focus confirmation LEDs...the LED stays through a lot of turning of the MF ring...I find that focus in spot-on just at the point when the light comes on as I turn the focus ring inwards from infinity. If I keep turning the ring towards a closer distance the LED may stay on, but the point of focus will be closer than I intend... Canon is not designed to work with my Nikons, but I'm designed to make them work together.... Link to comment Share on other sites More sharing options...
yog_sothoth Posted May 21, 2008 Share Posted May 21, 2008 I shoot MF Contax lenses on a 20D, and it often overexposes the shots as well. I just set the exposure compensation any time I mount an adapted lens. Link to comment Share on other sites More sharing options...
andre_reinders Posted May 21, 2008 Author Share Posted May 21, 2008 After I noticed the issue in the 'field' - I did some testing at home. I shot both lenses (Canon EF-S 18-55 and Micro-Nikkor 55) on both bodies. I shot all 4 shots at f8 and the shutter speed varied by a stop only when comparing the 2 lenses on the XT. I tried each in Matrix mode and center-weighted avg mode. Same thing - one stop out. I did not try it at different apertures to see if there was a gradual change from 'open' to 'closed' Thanks for all the answers! I guess I will just chimp - but realistically the manual focus is easier on the 20D - so I will most likely be using that for my Nikkor lens. Link to comment Share on other sites More sharing options...
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