Dear Members, If I take a photo with my Canon DSLR camera's viewfinder and the focal length is over 100mm(with a Tamron 18-270mm), nothing can be seen in the pictures, only blackness. Everything is fine if I take photos with the LCD display or viewfinder under 100mm focal length. Do you have any tips as to why this might be? The same error occurs in all modes/programs (e.g. automatic, P, AV). It's completely black, like the cap is on, so it's not underexposed. I appreciate your assistance.
Have you examined if the exposure settings being tried and recorded in the image file are as you would expect, meaning that it thinks its shoot at say f8 1/00 of sec or whatever would be appropriate in that situation? This seems very much like a lens failure issue, intermittent issues can be caused by a bad connection to the camera at the sensors, but i suspect there is something worse happening if the aperture is sticking completely shut as you zoom out. Do you have other lenses you can test to confirm that its just this lens when zoomed that is a problem?
Hi Johnsey, Thank you for your answer! I don't think the problem is with the lens, because if I take a picture not with the viewfinder, but with the LCD display, it takes perfectly good pictures, there is no blackness. On the other hand, the same lens works well in another camera (50D). Furthermore, the Canon 250D does not produce this problem with another lens (18-55mm). I noticed a larger grain of dust is also visible in the viewfinder, which is located on the mirror of the machine. It is not even visible in the LCD display and in the pictures. Could this have anything to do with it?
So your saying now that 200mm works in live view, I was operating on the info given that it stops working after 100mm zoomed. You could have the camera full of dust ...or spiders for that matter, wouldn't stop it from taking an image. Dust is only annoying and can be a pain to clean out or remove in post. I have yet to clean any of my 5d cameras, but have cleaned with wands and solution my 20 prob 5-10 times during the 6 years it got a lot of use, it was a dust magnet. The sensor is behind the mirror and a shutter The mirror flips up the shutter opens and the lens stops down to the fstop selected. If it works as expected the image is captured, the lens working in the first half of the zoom already tells me it should be lens related, this is also supported by the other lens. This whole process is very mechanical in nature, however the communication between the lens and camera is now electrical sensors and not mechanical as it was in older lenses. It is very very peculiar that you only have i happening on half a zoom range of a lens on one body only during viewfinder shooting and not during live view. Live view does make a small difference as it flips up the mirror and opens the mechanical shutter so your using the sensor to provide the LCD image rather than view finder, so it takes care of two steps that happen in a fraction of a sec during the viewfinder shooting. I guess there could be a failure of the shutter, but it should not be a camera shutter issue if it is only happening on that lens in that zoom range. Again I go back to the camera lens failing to speak properly, have you cleaned your connections on/between the lens and camera?
I agree with Johnsey, it must be a lens fault. I would suggest it is possibly a broken ribbon cable within the lens, these can cause all sort of intermittent faults but normally show up most when then zoom is at a particular position where the cable is flexed.
If the problem is not with the lens then it could be autofocus or the diopter adjustment may not be set correctly. You can try switching to manual focus or ensure that the diopter adjustment is set correctly for your eye. Black photos can be fixed easily with some photo repair software and checking the focus settings could be the first priority.
