User error or gear fail?
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Discussion

Davi

Original Poster:

17,153 posts

249 months

Wednesday 29th June 2011
quotequote all
What's the best way to test a lens for mechanical issues and can a lens be the cause of poor focus? I assumed that as the focus was handled by the body no matter what was going on with the lens the body would either get focus, or not say it had.

Basically shot my first wedding as 'the' tog a couple of days ago and got a lot of pics that are not that sharp or badly focussed. I was nervous, conditions were not great so could believe it was just me were it not for the fact that some of the nerves were caused by the fact either the body or lens kept making an odd noise!!! It's knocked my confidence a touch to day the least.

itsnotarace

4,685 posts

238 months

Wednesday 29th June 2011
quotequote all
Davi said:
got a lot of pics that are not that sharp or badly focussed
What flash were you using


rasputin

1,449 posts

235 months

Wednesday 29th June 2011
quotequote all
Can you post an example including EXIF?

Davi

Original Poster:

17,153 posts

249 months

Wednesday 29th June 2011
quotequote all
Nissin di622 was in use some of the time but outside it was reasonably bright so didn't need it too much. I'll post a pic in a mo.

andy-xr

13,204 posts

233 months

Wednesday 29th June 2011
quotequote all
Were you on continuous with 51 point AF? I tried that once on a 50mm 1.4 and quickly turned it off

Davi

Original Poster:

17,153 posts

249 months

Wednesday 29th June 2011
quotequote all
LOL no I've had the same experience of that, that you obviously had tongue out

I tend to shoot in spot focus 90% of the time, not sure why I just like to feel (under the vague illusion of) control!

I can't get hold of the client so I'm not really sure about sticking a "full" example shot up without their say so as they haven't even seen them yet, so instead this is a 100% crop of one of the ones I feel shows it quite well (and was destined for the bin anyway due to copious quantities of crapness!)

Am I asking too much? I dunno, I just don't think this is very sharp at ALL! Hmmmm - just thought, I presume you can see exif data on thumbsnap stuff? it's SOC just raw - jpg converted so is intact.






Dogsey

4,301 posts

259 months

Wednesday 29th June 2011
quotequote all
Davi said:
LOL no I've had the same experience of that, that you obviously had tongue out

I tend to shoot in spot focus 90% of the time, not sure why I just like to feel (under the vague illusion of) control!

I can't get hold of the client so I'm not really sure about sticking a "full" example shot up without their say so as they haven't even seen them yet, so instead this is a 100% crop of one of the ones I feel shows it quite well (and was destined for the bin anyway due to copious quantities of crapness!)

Am I asking too much? I dunno, I just don't think this is very sharp at ALL! Hmmmm - just thought, I presume you can see exif data on thumbsnap stuff? it's SOC just raw - jpg converted so is intact.





No idea on an answer but I thought I'd add the EXIF fr those that can't access it straight away.

Exposure Time - 1/125
F Number - 6.3
Exposure Program - Aperture priority
ISO Speed Ratings - 200
Metering Mode - Spot

Hope it helps.


itsnotarace

4,685 posts

238 months

Wednesday 29th June 2011
quotequote all
What focal length was that shot at 1/125th

People move, you move. Generally shoot with as fast a shutter speed as you can get away with. If that means upping the ISO from 200 then so be it.


andy-xr

13,204 posts

233 months

Wednesday 29th June 2011
quotequote all
Whats the focal length on this one? I know I cant get the same sharpness hand held on my D700 against my D300 and have to use a tripod for anything lower than 1/200th

Simpo Two

92,710 posts

294 months

Wednesday 29th June 2011
quotequote all
I was going to download that and see what PS Unsharp Mask would do - but I can't download the image.

I'm sure a bit of Shoppery will crisp it up - and remember that images are rarely viewed at 100%.

Davi

Original Poster:

17,153 posts

249 months

Wednesday 29th June 2011
quotequote all
That was at shot at 52mm using my 24-70 f2.8

You're right, PS certainly crisped it up a bit, just to me it looked a bit soft and I'm trying to work out how to get things spot on (as best I can). My biggest problem is being self taught I have no base line, so when I look at pro's pics I'm not sure how they would look SOC at 100% crop.

rasputin

1,449 posts

235 months

Wednesday 29th June 2011
quotequote all
It does look a bit blurry to me, but I think the focus is fine (you can see individual hairs and details like that).

1/125 seems a bit slow though. ISO to 400 and shutter to 1/250 would have probably improved that.

adamfogerty

144 posts

219 months

Wednesday 29th June 2011
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Some bodies allow AF adjustment (and can store different values for different lenses) because front-focusing or back-focusing from the factory can be an issue.

There are loads of focus test charts available online to see if your AF is 'off'. http://focustestchart.com is one example.

Adam

Davi

Original Poster:

17,153 posts

249 months

Wednesday 29th June 2011
quotequote all
Thanks Adam, I'll get that printed and do some tests.

Basically I don't mind what is wrong as long as I know it's wrong so I can get improving! Doesnt help when I'm not sure if anything actually is wrong lol so I'm glad Rasputin agrees it's a bit blurry biggrin

RobDickinson

31,343 posts

283 months

Wednesday 29th June 2011
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It looks over exposed and under sharpened for one.

Is it a 100% crop?

I would be horrified if at f6.3 the focus system is that poorly aligned its getting it wrong, usualy if there is an isue its apparent at f2.8 or larger.

1/120th should have been fast enough?

Simpo Two

92,710 posts

294 months

Wednesday 29th June 2011
quotequote all
Wot he said. Remember all digital images need 'sharpening', either automatically applied if you shoot JPG; or manually if RAW.

I was going to comment on the overexposure but it might be recoverable from RAW (the sample posted has no corrections).

Davi

Original Poster:

17,153 posts

249 months

Wednesday 29th June 2011
quotequote all
It is indeed 100% crop. I've started shooting raw but I never knew that that gave a requirement for more sharpening in PP! Always used jpg before so that's new to me.

Exposure is a whole other ballgame, never in my life have I had as many issues with exposure as I did that day, it was absolute hell that I was saving for another question thread tongue out

RobDickinson

31,343 posts

283 months

Wednesday 29th June 2011
quotequote all
Raw has nothing done to it at all.

All you see is the debayering. The filters in front of the sensor (aa filter, bayer etc) make the image soft, this is done on purpose to prevent moire.

You have to add the sharpness back in, I do this in two stages. An initial light sharpening to combat the AA filter, then I sharpen the image after resize or before print accordingly.

Over exposure will make it look poorer too. That image is probably very recoverable with the right processing techniques.

As for exposure, if you have people in the shot then typically the key thing is their faces, so one technique is to shoot in manual mode, use spot meter on their face, adjust the exposure (typically with shutter speed) according to their skin colour (+2 for very pasty white, 0 for a mid tan, -2 for a very dark/black person). This should give you a well exposed shot for the important thing, takes a little time to get right.

andy-xr

13,204 posts

233 months

Wednesday 29th June 2011
quotequote all
There's usually a RAW sharpening in your catalogue or converter that gets applied on first view. I'll usually leave that alone, sharpen again in PS locally, sharpen globally as a last action before saving and sharpen again on resize

Exposure wise, a D700 is normally good for just under 2 stops over where you should have been as a Get out of Jail Free card, with what you've got there I'd be considering lowering the exposure, bit of contrast and a black and white hehe

Xerstead

724 posts

207 months

Wednesday 29th June 2011
quotequote all
Davi said:
It is indeed 100% crop. I've started shooting raw but I never knew that that gave a requirement for more sharpening in PP! Always used jpg before so that's new to me.

Exposure is a whole other ballgame, never in my life have I had as many issues with exposure as I did that day, it was absolute hell that I was saving for another question thread tongue out
For jpegs from the camera, the camera has automatically applied it's processing to the raw data to produce the image. This is based on presets and covers sharpening, white balence etc.
Shooting raw, none of this processing has been done so it's not really a case of 'more sharpening' but setting how much you want.

For checking the focus, find a large ruler, put the camera on a tripod. Set it on centre spot focus and focus on the middle of the ruler. This should give an indication of how acccurate it is.