Blurry or soft full body photos when using canon 50mm f1.8 stm

muhdhumamkhan wrote:

Alastair Norcross wrote:

muhdhumamkhan wrote:

scrup wrote:

muhdhumamkhan wrote:

scrup wrote:

Best to post a sample image. It could be subject movement, DOF too shallow, miss focus or a number of other things.

50mm f2 ISO500 Flash 1/2

here if you zoom on his face you wil see that is soft focused.

That is the sharpness, I would expect at F2 for that lens. What I see is noise/grain. You need more light to reduce the noise. Get a stronger flash, go FF or lower the ceilings.

I see Thank you.

I would actually expect a bit better sharpness than this. I sold my 50 STM when I got the Sigma 56 F1.4, which gives much better sharpness than this, even at F1.4. But my 50 STM still performed better than this, I think. Have you tried the lens in other conditions?

Thinking about what you said about the conditions, this could be a combination of hand shake and subject movement. If the ceiling is really 30 feet high, I'm pretty sure you're not getting much, if any, benefit from the flash (that's much too high for an effective bounce). What color is the ceiling? If what we're really seeing is the exposure from available light, 1/100 is just not fast enough to freeze even slight subject movements or hand shake. Take a shot with the lens in bright light at a fast shutter speed (at least 1/250) of a flat detailed surface at the same distance as this shot, and check how sharp it is at 100%.

Yes when I take medium or closeup shots the sharpness is excellent but not when trying to take full body shots.

I some time wonder because the 50mm is a FF lens and because of that their is a distance limit for its focus to work accurately and if i am using it on crop frame i am exceeding that limit.

The focus should work accurately all the way out to infinity on crop or full frame. I've never heard of a focus limit for accurate focusing with full frame lenses on crop cameras. I've mostly shot with crop cameras for the past 18 years (only adding the R a couple of years ago), and mostly with full frame lenses on those cameras.

I looked up your flash, and it just isn't anywhere near powerful enough to bounce of a 30 foot high (or more) ceiling (even a white one) and freeze movement. So, both subject movement and camera shake will be determined by your shutter speed. Your shutter speed of 1/100 is definitely too slow for handholding an unstabilized 50 on a crop camera. That gives you a FF equivalent field of view of 80mm. The old rule of thumb for handholding was 1/focal length for full frame, but that was based on acceptable looking sharpness from a 35mm film negative printed no larger than 10" X 8" (or 12" X 8" without cropping). If you view a 24MP image (6000 pixels X 4000 pixels) at 100% on a modern monitor, you're probably looking at an image that is anywhere from 27 inches wide to about 80 inches wide, depending on your monitor resolution (my iMac uses about 220ppi, but older monitors were more like 72ppi). For sharp looking shots from a 24MP sensor at 100% view, you need much faster than 1/FF-equivalent focal length. At a minimum, I'd say 1/2*full frame equivalent focal length, which would be 1/160 with the M50 II, and preferably a bit faster. Of course, this is just a rule of thumb, and some people have much steadier hands than others. Also, you didn't say whether this was shot on a tripod (I'm assuming it wasn't).