What is causing this lack of sharpness?

So, two pictures, same exposure settings, just imported into Lightroom with Camera Standard profile applied (it's an 80D)

To the left, you see the picture, to the right 1:1 zoom on the face.

On the first image, there's a lack of sharpness that is not shown on the second. I've noticed this happens perhaps every 1 out of 10 images, where although focused correctly, the image will look blurry. I've seen this happening before on back lit situations but this was not the case.

So I'd like to ask: what causes this (the correct term) and how can I avoid it?

Other pictures were sharp as they can (sample below).






indoor shoot, same lens, sharp

Hard to say from the way you posted, but looks to me like missed focus.

Can you post the uncropped versions separately?

Gato

What about the exif on the first images? Are the settings the same as on the second studio shot?

Krav Maga said:

What about the exif on the first images? Are the settings the same as on the second studio shot?

--
I feel more like I do now than I did before ...
https://danielmedley.smugmug.com/

Click to expand...

The exif was not the same as I was using F2.8 externally to blur the environment a little.

Here's another example, from inside the studio at 1/400s f/3,2 40 mm:


1/400 s f/3,2 40 mm soft image

Focus point always set on the eye/face. Still got a really soft image. The next image was on the same spot (camera was on a tripod, 2sec timer to shoot) and same settings and turned out better:


1/400 s f/3,2 40 mm but sharp

I've posted more samples below, from the same environment/light/settings.

Could be about a number of things, but the most likely reasons are probably the lens and the camera combo, and how you're using it.

The lens may be soft wide open, as many zoom lenses are. To fix that is the easiest, avoid shooting wide open, and test which aperture works the best.

The lens may not be properly calibrated for the particular camera body in use, and dSLRs have a tendency to back or front focus at times, which sometimes results in photos slightly out of focus. Even when focusing manually via the OVF.
To (partially) fix that you should calibrate the lens using a focus pyramid or have it calibrated by a professional. That won't remove the inherent tendency of dSLRs to back or front focus, but it'll help.

It can also be about how you're using the camera, possibly relying too much on some fancy AF mode that gets confused time to time, hunting ever so slightly and missing focus at times. Or maybe you've got continuous AF on by accident?
To fix those, try some other, simpler AF mode and in general, use a small enough aperture, at least F4 or 5.6 for portraits with an APS-C or FF camera. It won't affect focusing, which happens at wide open aperture, but it will affect the depth of field, which in turn helps in keeping things in focus.

Otto Sporteman said:

Krav Maga said:

What about the exif on the first images? Are the settings the same as on the second studio shot?

Click to expand...

The exif was not the same as I was using F2.8 externally to blur the environment a little.

Here's another example, from inside the studio at 1/400s f/3,2 40 mm:


1/400 s f/3,2 40 mm soft image

Focus point always set on the eye/face. Still got a really soft image. The next image was on the same spot (camera was on a tripod, 2sec timer to shoot) and same settings and turned out better:


1/400 s f/3,2 40 mm but sharp

Click to expand...

Are you using a single focus point, or are you using group? If not, I would suggest using a single focus point. The top image looks like it's back focused.

--
I feel more like I do now than I did before ...

Otto Sporteman said:

Krav Maga said:

What about the exif on the first images? Are the settings the same as on the second studio shot?

Click to expand...

The exif was not the same as I was using F2.8 externally to blur the environment a little.

Here's another example, from inside the studio at 1/400s f/3,2 40 mm:


1/400 s f/3,2 40 mm soft image

Focus point always set on the eye/face. Still got a really soft image. The next image was on the same spot (camera was on a tripod, 2sec timer to shoot) and same settings and turned out better:


1/400 s f/3,2 40 mm but sharp

Click to expand...

Even the sharper one appears to be slightly back-focused. The hairs at the top of her head are sharper than her eyelashes. Unfortunately, you stripped all the Maker notes from the EXIF, so we can't see your focus point or settings. But, with these two shots from a tripod with the same settings, there is enough variation that I would suspect a lens focusing issue and not a user or camera problem.

Krav Maga said:

Otto Sporteman said:

Krav Maga said:

What about the exif on the first images? Are the settings the same as on the second studio shot?

Click to expand...

The exif was not the same as I was using F2.8 externally to blur the environment a little.

Here's another example, from inside the studio at 1/400s f/3,2 40 mm:


1/400 s f/3,2 40 mm soft image

Focus point always set on the eye/face. Still got a really soft image. The next image was on the same spot (camera was on a tripod, 2sec timer to shoot) and same settings and turned out better:


1/400 s f/3,2 40 mm but sharp

Click to expand...

Are you using a single focus point, or are you using group? If not, I would suggest using a single focus point. The top image looks like it's back focused.

Click to expand...

Single focus point. I couldn't find exactly where it focused tbh, but it seems the lens is missing focus from time to time, kinda unreliable.

gscotten said:

Otto Sporteman said:

Krav Maga said:

What about the exif on the first images? Are the settings the same as on the second studio shot?

Click to expand...

The exif was not the same as I was using F2.8 externally to blur the environment a little.

Here's another example, from inside the studio at 1/400s f/3,2 40 mm:


1/400 s f/3,2 40 mm soft image

Focus point always set on the eye/face. Still got a really soft image. The next image was on the same spot (camera was on a tripod, 2sec timer to shoot) and same settings and turned out better:


1/400 s f/3,2 40 mm but sharp

Click to expand...

Even the sharper one appears to be slightly back-focused. The hairs at the top of her head are sharper than her eyelashes. Unfortunately, you stripped all the Maker notes from the EXIF, so we can't see your focus point or settings. But, with these two shots from a tripod with the same settings, there is enough variation that I would suspect a lens focusing issue and not a user or camera problem.

Click to expand...

I think the lens (Sigma 17-50 2.8) doesn't mark the focus point. On the 85mm it is there on both the camera and lightroom but with this lens, it's not.

I'll probably get a prime (35mm IS 2.0) to do these kind of shots, it's frustrating. Thanks for the input.

Otto Sporteman said:

Single focus point. I couldn't find exactly where it focused tbh, but it seems the lens is missing focus from time to time, kinda unreliable.

Click to expand...

You might want to set up on a tripod and shoot something stationary; perhaps even a chart, and see if it replicates.

Krav Maga said:

Otto Sporteman said:

Single focus point. I couldn't find exactly where it focused tbh, but it seems the lens is missing focus from time to time, kinda unreliable.

Click to expand...

You might want to set up on a tripod and shoot something stationary; perhaps even a chart, and see if it replicates.

Click to expand...

I already did it when I bought the lens and couldn't find it was back or front focusing. It seems to be something like the lens hunting intermittently. I guess that's the price to pay for non branded lens.

I only recently started doing this studio photoshoots, was getting more external/event photography gigs before and for that purpose the lens always served me well but on these internal shoots it's showing its weaknesses.

Otto Sporteman said:

Krav Maga said:

Otto Sporteman said:

Single focus point. I couldn't find exactly where it focused tbh, but it seems the lens is missing focus from time to time, kinda unreliable.

Click to expand...

You might want to set up on a tripod and shoot something stationary; perhaps even a chart, and see if it replicates.

Click to expand...

I already did it when I bought the lens and couldn't find it was back or front focusing. It seems to be something like the lens hunting intermittently. I guess that's the price to pay for non branded lens.

I only recently started doing this studio photoshoots, was getting more external/event photography gigs before and for that purpose the lens always served me well but on these internal shoots it's showing its weaknesses.

Click to expand...

Maybe try setting your fstop to at least 8 and setting up a back button focus in servo mode. Might be worth experimenting with.

Krav Maga said:

Otto Sporteman said:

Krav Maga said:

Otto Sporteman said:

Single focus point. I couldn't find exactly where it focused tbh, but it seems the lens is missing focus from time to time, kinda unreliable.

Click to expand...

You might want to set up on a tripod and shoot something stationary; perhaps even a chart, and see if it replicates.

Click to expand...

I already did it when I bought the lens and couldn't find it was back or front focusing. It seems to be something like the lens hunting intermittently. I guess that's the price to pay for non branded lens.

I only recently started doing this studio photoshoots, was getting more external/event photography gigs before and for that purpose the lens always served me well but on these internal shoots it's showing its weaknesses.

Click to expand...

Maybe try setting your fstop to at least 8 and setting up a back button focus in servo mode. Might be worth experimenting with.

Click to expand...

Yeah, you're completely right, I should've set the aperture way smaller but now the damage is done

Will do it on the next session!

Definitely stop down when you're shooting people for money, unless they specifically ask for no depth of field. Start at f/5.6 it's usually one one of the twi sharpest apertures on any lens, f/4 is the other sharp one.

Here's a link to a video on how to adjust your autofocus. Sorry I couldn't find one in Portuguese.

MrBrightSide said:

Definitely stop down when you're shooting people for money, unless they specifically ask for no depth of field. Start at f/5.6 it's usually one one of the twi sharpest apertures on any lens, f/4 is the other sharp one.

Here's a link to a video on how to adjust your autofocus. Sorry I couldn't find one in Portuguese.

Click to expand...

English is fine. Thabkyou very much!

Otto Sporteman said:

So, two pictures, same exposure settings, just imported into Lightroom with Camera Standard profile applied (it's an 80D)

To the left, you see the picture, to the right 1:1 zoom on the face.

On the first image, there's a lack of sharpness that is not shown on the second. I've noticed this happens perhaps every 1 out of 10 images, where although focused correctly, the image will look blurry. I've seen this happening before on back lit situations but this was not the case.

So I'd like to ask: what causes this (the correct term) and how can I avoid it?

Other pictures were sharp as they can (sample below).




indoor shoot, same lens, sharp

Click to expand...

Focus is not synonymous with sharp.

--
dw

I'd start by taking fresh pictures, I would pay attention to aperture and depth of field, and I'd look at the focus mode (one shot or servo) and time between focusing and actually shooting.
BAK

I moved your thread here, because I think your issue may be related to limitation of the camera. I haven't had a camera in this series since I moved from the 10D to the 5D, so I'm not up on the recent changes. I think it's probably still true, though, that a camera in spec is meant to focus within 1/3 DOF if using a high precision focus point, less if using one of the others. So there will be some variation from shot to shot. By moving the thread here, I hope someone can address this more carefully.

Also note that the focus point indicated does not necessarily align with the image. First, the focus sensors don't exactly line up with the indicators in the viewfinder. Second, you may have recomposed between the time focus was achieved and when the shutter was released. The indicator in EXIF will show the correct focus point, but the subject may have shifted. If you set up a controlled test, you should be able to control for this so that what appears in the image reflects the situation you were shooting.

I suspect your issue is a combination of: 1) normal shot-to-shot variation within spec, 2) camera/lens being out of calibration. That's just a guess, though.

ISO 100 and f3.2

You have no depth of field.

Try ISO 200 and maybe shutter speed of 1/320 though I prefer 1/400.

And not just lack of depth of field. You are out of the sweet spot of that lens by far.