AF Sharpness at 100%

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Clonetrooper

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Basically I want to know If I'm expecting too much or if there's a problem with my equipment or more likely me.

I've taken quite a few pictures recently single af point over the nearest eye. The look fine and when I view them at 100% they are not pin sharp. This is hand held indoor mostly at high apertures 2.8 with a 17-55 and 2.8 to 1.8 with a 1.8 50mm.

Normally use with a speedlite as well.
 
Have you got any any examples?
 
Any lens wide open is going to be slightly soft.
Try stop the lens down a bit, say f3-f4 and you may see a difference.

The DOF is crazy at wide apertures like 1.8 and 2.8, and a pin sharp shot is going to be tough going!
 
keirik said:
stop pixel peeking!
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You know what I think I have OCD, whenever I buy something I assume it's broken and try to find whats not working first ;)

I think It's the engineer in me, trying to find why everythings happening. I hate not knowing :D
 
Have you applied any "unsharp mask"?
 
barrypriddis said:
Have you applied any "unsharp mask"?
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I will be honest I don't really know what that is, the images are completely unprocessed. I'm new to that side of it, so far I've been shooting in both RAW and Jpeg so I can revisit ones I like later when I have a clue about PP :)

Those I posted came out of the camera.
 
Flippin eck mate, they are bloody good!
Anyway, the first one, according to the EXIF data says it was taken at f4 :thinking:

And the second one f1.8!!!! If that's the case, you've nailed it!

Relax pal, they are super shots, and very sharp when viewed at normal size.
(How often do you look at shots cropped 100%???!!!)

Stop pixel peeping, enjoy your hobby.

Smashin lad btw :thumbs:
 
The 17-55 shot is focused on the child's shoulder, not his eye. You can see the texture clearly in the fabric of his t-shirt, but it's going out of focus by the time you get to the plane of his face.

You're also seeing some halation-like effects with the lens being wide open that are softening the image.

The 50mm shot is about as sharp as I'd expect with that lens at that aperture. Maybe just a dab of USM would help.
 
I'm struggling to see a problem.
First seems bang on, second may be a tiny touch front focussed, look at the enter key on the keyboard.

But if you're comparing these to stuff you've seen after processing you'll drive yourself nuts, a bit of USM on the eyes will bring them right out.
 
Musicman said:
The 17-55 shot is focused on the child's shoulder, not his eye. You can see the texture clearly in the fabric of his t-shirt, but it's going out of focus by the time you get to the plane of his face.
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Yep, first thing I saw was the keyboard, but the fabric weave is clearly visible on the shoulder.
 
That's your first port of call then. Here's one for the engineer :)

The sensor has something called an anti aliasing filter in front of it. It means that your shots in RAW are always going to be soft! They are unsharpened because RAW allows you to decide how much rather than the camera applying it for you.

Some reading for you!

http://en.wikipedia.org/wiki/Anti-aliasing_filter

http://www.dpreview.com/learn/?/Glossary/Digital_Imaging/Aliasing_01.htm

Now sort out your PP and stop thinking your kit is broken. :)
 
dannyjo22 said:
I've taken quite a few pictures recently single af point over the nearest eye.
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BTW, with reference to my comment about it being focused on the shoulder. Kids move, and you're working with very fine tolerances at those apertures ;)
 
andy_fozzy said:
Flippin eck mate, they are bloody good!
Anyway, the first one, according to the EXIF data says it was taken at f4 :thinking:

And the second one f1.8!!!! If that's the case, you've nailed it!

Relax pal, they are super shots, and very sharp when viewed at normal size.
(How often do you look at shots cropped 100%???!!!)

Stop pixel peeping, enjoy your hobby.

Smashin lad btw :thumbs:
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Thanks he certainly keeps me on my toes and probably like a lot of people here the reason I picked a camera up again and has got me the bug to learn more and more and take different types of shots.

Your right I posted the wrong image for the 50mm will link another at 1.8 :)

http://img241.imageshack.us/img241/9136/img0108o.jpg

Musicman said:
The 17-55 shot is focused on the child's shoulder, not his eye. You can see the texture clearly in the fabric of his t-shirt, but it's going out of focus by the time you get to the plane of his face.

You're also seeing some halation-like effects with the lens being wide open that are softening the image.

The 50mm shot is about as sharp as I'd expect with that lens at that aperture. Maybe just a dab of USM would help.
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The AF point when I look back at it with the grid overlay, the AF point is bang on the eye. Is it worth having corrections made to the front focusing of the lens?

cyclone said:
I'm struggling to see a problem.
First seems bang on, second may be a tiny touch front focussed, look at the enter key on the keyboard.
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As above really, does it need any adjustment or just get on with it and stop worrying :)

Thanks for the input guys, appreciated.
 
Danny, go and read those articles I posted. They are important if you are going to be pixel peeping and it's important to know what your files actually are and what you need to do to them. Shoot in RAW and no PP, you will always have a problem!
 
dannyjo22 said:
Your right I posted the wrong image for the 50mm will link another at 1.8 :)

http://img241.imageshack.us/img241/9136/img0108o.jpg
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That looks bang on for focus. It'll take a bit of sharpening in Photoshop, but I think you're just hitting the limitations of that lens at f/1.8.

You might try taking a hit on either the shutter speed (the last example was at 1/250 so you had some room for manoeuvre) or ISO and knocking down to f/2.8, where the 50mm f/1.8's sharpness and contrast improves considerably. Keeping focus-critical elements toward the centre of the frame will help too.

You can see the difference it makes here.

http://www.the-digital-picture.com/...CameraComp=9&SampleComp=0&FLIComp=0&APIComp=2
 
AliB said:
Danny, go and read those articles I posted. They are important if you are going to be pixel peeping and it's important to know what your files actually are and what you need to do to them. Shoot in RAW and no PP, you will always have a problem!
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Thanks Ali I will do, I probably wasn't clear enough. Those shots are Jpeg not raw, I just have it selected to do both at once so I can post process them at a later date if there are any I like enough some time in the future :)
 
Musicman said:
That looks bang on for focus. It'll take a bit of sharpening in Photoshop, but I think you're just hitting the limitations of that lens at f/1.8.

You might try taking a hit on either the shutter speed (the last example was at 1/250 so you had some room for manoeuvre) or ISO and knocking down to f/2.8, where the 50mm f/1.8's sharpness and contrast improves considerably.

You can see the difference it makes here.
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Ah interesting great link, will look at that also :)

I was limited on the 1/250 because all of those shots have the speedlite on as it was lowish light and that was my max speed available :(
 
Both of the images linked to are taken with the 50mm lens (from the exif).

The first is in manual mode, 1/250, f4, ISO 800 with one shot AF selected. One shot AF is good for static subjects and a static camera i.e. tripod mounted. The focus is obtained on half-press of the shutter and doesn't move, so you've been pretty lucky to get the focus as close as it is.

The second shot is in Tv mode (shutter priority) 1/250, f1.8, ISO 200 with AI Servo AF selected. AI servo AF is reasonably good at predicting movement on close up subjects where the movement relative to the focal plane is at a constant speed. (Rarely the case with moving children.)

You might want to try the shots again with AI focus AF selected, and if you're going for a narrow DOF use Av mode with ISO set to obtain a suitable shutter speed. Other AF modes are going to be pretty hit & miss at such wide apertures.
 
dannyjo22 said:
Ah interesting great link, will look at that also :)

I was limited on the 1/250 because all of those shots have the speedlite on as it was lowish light and that was my max speed available :(
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With a speedlight on your actual effective shutter speed is WAY faster than 1/250 though. Unless you're letting massive amounts of ambient in and getting motion blur your effective flash exposure is at around 1/10000. that's why shots taken with flash are so much sharper as a rule.
 
The first pic is excellent, the second one just misses the eye for focus but a touch of sharpening would probably solve that - either unsharp mask or High Pass.

TBH once you start serious pixel peeping you could lose the enjoyment of taking photographs and become obsessed with the technicalities.
 
It's all about the PP...here's an example straight from the camera and then processed...

4655776008_b55f1faa1f.jpg
4638554248_5545cbe37b.jpg
 
TrevorP said:
Both of the images linked to are taken with the 50mm lens (from the exif).

The first is in manual mode, 1/250, f4, ISO 800 with one shot AF selected. One shot AF is good for static subjects and a static camera i.e. tripod mounted. The focus is obtained on half-press of the shutter and doesn't move, so you've been pretty lucky to get the focus as close as it is.

The second shot is in Tv mode (shutter priority) 1/250, f1.8, ISO 200 with AI Servo AF selected. AI servo AF is reasonably good at predicting movement on close up subjects where the movement relative to the focal plane is at a constant speed. (Rarely the case with moving children.)

You might want to try the shots again with AI focus AF selected, and if you're going for a narrow DOF use Av mode with ISO set to obtain a suitable shutter speed. Other AF modes are going to be pretty hit & miss at such wide apertures.
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Yeah I'm a chimp, I didn't put one up from the 17-55. I think reading what your saying my problem is technique and and expecting too much with a slight moving target at such wide appertures.

Thanks guys again for all the input, I've learnt a lot again this morning and it's only 10 oclock :D

This was one of a near static shot on the 17-55 and you can see it's pretty much where I wanted the focus at 2.8 so in hindsight it's me and my choices of settings rather than anything equipment based. Which I'm happy with, I can work on my failings :thumbs:

http://img241.imageshack.us/img241/8786/img0371at.jpg

Musicman said:
Only if it's clearly doing it consistently.
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Yeah I don't think it's consistent, more ability :lol:

The23rdman said:
With a speedlight on your actual effective shutter speed is WAY faster than 1/250 though. Unless you're letting massive amounts of ambient in and getting motion blur your effective flash exposure is at around 1/10000. that's why shots taken with flash are so much sharper as a rule.
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Didn't know or understand that completely, another example why Flash use is the next topic on my learning agenda. Cheers :)

petersmart said:
TBH once you start serious pixel peeping you could lose the enjoyment of taking photographs and become obsessed with the technicalities.
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Yeah point taken, advice I could probably do with taking for most aspects of my life :D
 
dannyjo22 said:
Yeah I'm a chimp, I didn't put one up from the 17-55. I think reading what your saying my problem is technique and and expecting too much with a slight moving target at such wide appertures.
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Technique - yes. Read and UNDERSTAND the manual regarding AF modes.
 
Arkady said:
It's all about the PP...here's an example straight from the camera and then processed...
Click to expand...

Amazing results, post processing is the one item of photography that daunts me the most. I know it's a skill I should learn and embrace but it's just making the first steps...

TrevorP said:
Technique - yes. Read and UNDERSTAND the manual regarding AF modes.
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My mistake I think it's in how much movement I percieve needing before going from one shot to servo. So most of the shots I've taken of my son have been im one shot.
 
TrevorP said:
You might want to try the shots again with AI focus AF selected, and if you're going for a narrow DOF use Av mode with ISO set to obtain a suitable shutter speed. Other AF modes are going to be pretty hit & miss at such wide apertures.
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my thoughts too, almost
with one shot AF a tiny bit of body sway (either you or the subject) or the often used focus and recompose manoevre and suddenly what was focused on is at a significantly different distance when the dof is so small.

however my understanding of the AI systems differs:
- AI Focus expects an approaching or receding object to pass from centre AF point to outer AF points - I avoid it, there's too many criteria and it requires a specific focus tracking technique by the user for it to work properly.
- AI Servo continually tracks the active AF point :thumbs: it does expect motion and will try to be predictive, so will hunt if the movement is very small and overshoots when subject reverses direction but its pretty fast to haul it in when dealing with small motions on close "static" subjects

but the 2 AI systems are badly named and difficult to remember which one is which, on my 400D I just remember never to use the option in the middle of the screen.


best to get it from the horse's mouth, have a look through all 3 of the canon official lectures on the focussing system here: http://www.video.bhphotovideo.com/ and search for "A Look at The Canon Autofocus System", it's a lecture in 3 parts

it also explains about the focussing sensors, their orientation (some are horizontal, some vertical, and some crossed) and how far they extend (often beyond the box)
 
As an engineer, you'll love playing with the depth of field calculator on this link www.dofmaster.com

First pic you posted looks pretty good, second one is just front focused, which is user error (see keyboard).

Common problem with this kind of subject is camera shake due to low light (though that doesn't seem to be a problem here) so bone up on that and the hand-holding focal length rule of thumb. Did you use flash for the second (keyboard) pic? It's very subtle and works extremely well - I guess the camera balanced that up for you but it's done a great job and will have lifted the image a lot :thumb:

The other danger area is shallow depth of field, which is measured in fractions of an inch when you're close and at low f/numbers. I'm guessing that the reason the keybaord pic is mis-focused is because you've used focus-recompose technique and either you or the subject (or both) have moved between focusing and shooting. The AF point indicator only tells you which point was used, not what was focsued on, which is obviously different with focus-recompose.

I think you just need to learn a little more about your camera and a bit of basic technique. But those pics are a heck of a good start! :) And nothing ever looks very good at 100%...
 
HoppyUK said:
I think you just need to learn a little more about your camera and a bit of basic technique. But those pics are a heck of a good start! :) And nothing ever looks very good at 100%...
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Cheers Hoppy, Yes the picture of him and keyboard used flash, they all did, 430exII.

I didn't use the recompose is any of my shots, It's something I practiced once but from reading alot on this forum and a few books people seem to discourage at high apertures. So I've avoided that for now as most of my shooting with the little man has been indoors. Also the canon autofocus videos mentioned the pitfalls so I haven't bothered with it so far :)
 
dannyjo22 said:
You know what I think I have OCD, whenever I buy something I assume it's broken and try to find whats not working first ;)
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I'm the same! Find fault with everything! My D5k 'needs' to go back to Argos......becasue I can see a thin white strip of light on the left of the LCd about 7 hairs width!:D:p


Regards the Anti whatjamacallit Bouncy Mellons, I've not read up on it, but thats what makes me hate the Canon's softness.:D:p
 
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