Dear members, I've used Canon fixed 50mm F1.8 with my Canon EOS400D with no problems. However on EOS700D it sometimes completely looses focus and overexposes the photos using that lens. This happens quite often like in 1 in 20 photos or so. With 400D still no problems. What is that? Updated software on EOS 700D, no improvement. I have a few other lenses which work just fine. P.S. I reached EOS400's 100.000 shutter limit so I bought 700D.
Well the only difference here is the camera is what i am hearing, so lets a assume the camera meters generally the same but has some nuance to how it handles different lighting. Assuming the lens works fine, because it is a 1.8 it is a very wide aperture lens, and shooting 1.8 is generally pretty wide for sunlight which may be where you are seeing this, so i ask do you have issues if its stopped down to f4? Also does it happen on 1 out of 20 because your doing a lot of burst shooting and maybe the lens /motor frame per second issue is not keeping up? If there is an issue on occasional high speed burst rate the lens may not be stopping down quick enough for 10 shots in a row at fast burst, hard to say without you really digging into exactly how to recreate the situation. I should say if it is a very contrasty scene with dark shade and brightly lit areas the meter can be fooled and look at multiple things and it could range by multiple stops between multiple shots in the same area back to back creating a noticeable exposure variation. Shooting in manual mode and dialing in the exposure you want should solve this if its a metering issue. Without being in your place shooting and testing some of these things and seeing the results as you go its all speculation and difficult to narrow it down to what you are seeing.
My observation is, that 700D is not such a superb quality as 400D. Recenty a friend donated another alsmost unused 400D to me. It was sitting over 15 years. I charged battery, everything worked instantly, even the date battery worked! I was on one big birthday celebration and my 700D didn't want to communicate with my 580EX Flash. Since I was in a desperate situation I shot around 200 pics with donated 400D and my 580EX¨flash. Later I did manage to get 700D to sync with flash. It's like 700D does have some sort of peripherial device issues. I wonder if anybody else noticed that? I don't do burst shots, like never. With 50mm F1.8 it's an embarassement, as it is has no zoom people look at me strangely, since I used it for potraits. But when I have to retake the shots due to exposure and focus issues then it is really embarassing. And exposure is totaly wrong, unsusable. Also on my 700D the build in flash is sticky and won't pop up without help.
Well i would assume something is wrong with the lens itself if other lenses work fine. The 50 1.8 II is a very old lens ... I bought mine 20 years ago when I bought a 20d in college. It was... "OK" it did not have an exposure issue, but had some inconsitent focus when wide open, and between 1.8 and 2.8 f stops images were soft even with good focus. You get what you pay for for under 100$ new. I quickly upgraded to a 17-40 L which was my main lens on that body for the next few years, Great lens.... I do like prime lenses, so over a decade ago I got the 50mm 1.4 which is a very nice lens for the money and I didn't see the need to spend 5 times as much on the 1.2 L. I heard good things about the STM 1.8 which is about as cheap as the original 1.8 nifty 50 if your on a budget. But yeah its a very cheap and very old plastic lens... I would upgrade it and I think you will be fine. The flash shoe may just need to the contacts cleaned, they collect grease and dust over the years and that may be the only real issue there. Either way the 700 is just the same canon rebel camera but 5-6 years newer with a few feature bumps like more megapixels. Both are entry level DSLRs. If you 700 has worse image quality with the same lens on it in a side by side, then you must have a bad copy of the camera, The 700 is definitely an upgrade to a newer better sensor. But again both these are more or less in the 15-20 year old range of cameras.
