why am I getting inconsistant results?

Cobra

Cobra

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The real Chris
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Guys my 70-200 IS f/2.8 seems to be giving inconsistant results
one minute its sharper than a sharp thing the next its about as sharp as a wet sponge

2 images below taken on the same day with EXIF intact
briefly the Blackbird 1/800th f/5.6 ISO 200 @ 140mm
The peacock 1/100th f5.6 ISO 200 @ 200mm
both hand held ( IS engaged) and yes the s/speeds are the right way around!
now if I had made an opperator error the peacock would ( should) be the one blurred
other focal lengths and speeds are also inconsistant
They have both been re-sized nothing more

Any suggestions?
Cheers
IMG_2572.jpg


IMG_2646.jpg
 
Is the IS in the lens and does it need to be powered, I guess so, if so but could it be a power supply issue to the lens ?
 
1st one the background looks to be in focus-so maybe you had the focus on this by mistake and at 5.6 would be very shallow dop with a 140mm lens.

Dont know about canons but could happen with my nikon if focus sensor is moved due to being in wrong setting
 
I doubt that its a power supply issue, but even if the IS is not working I should be able to hand hold at 1/800th (even after a few bottles of wine :D)
 
digitalmaniac said:
1st one the background looks to be in focus-so maybe you had the focus on this by mistake and at 5.6 would be very shallow dop with a 140mm lens.

Dont know about canons but could happen with my nikon if focus sensor is moved due to being in wrong setting
Click to expand...

Thats also a bit of an inigma the Camera read-out shows the single dot focal point on the eye of the BB
 
the blackbird shot is pretty sharp, just nowhere near the subject. At the top of the frame it looks fairly well focused but unless it's a fairly heavy crop, or you're focusing manually, it makes little sense as that's nowhere near a focus point.

Also, something looks a tad odd about the way the focus falls off from the top down. Could the IS be faulty and somehow the glass is moving in the wrong way?:thinking:
 
dazzajl said:
the blackbird shot is pretty sharp, just nowhere near the subject. At the top of the frame it looks fairly well focused but unless it's a fairly heavy crop, or you're focusing manually, it makes little sense as that's nowhere near a focus point.

Also, something looks a tad odd about the way the focus falls off from the top down. Could the IS be faulty and somehow the glass is moving in the wrong way?:thinking:
Click to expand...

Cheers Daz No crop & Auto focus :shrug:
 
Is it the first time its happened or many.

Anyway why would you want to frame the blackbird right out of the frame-centralise it or at least fill the frame with it.
 
digitalmaniac said:
Is it the first time its happened or many.
Click to expand...

It happens occasionally but seems to be getting worse / happening more often:(

digitalmaniac said:
Anyway why would you want to frame the blackbird right out of the frame-centralise it or at least fill the frame with it.
Click to expand...

Oh thats easy operator error :D I did get it right several times but that was just the one I picked on as an example as I thought it was the worst of the bunch
 
Does it ever happen with the IS turned off?
 
Cobra said:
Thats also a bit of an inigma the Camera read-out shows the single dot focal point on the eye of the BB
Click to expand...

Was it active though?
Or was a focus point along the top active instead?

Looking at the shot, the centre focal point isn't where the eye is. The eye is above centre.

What camera?
 
Assuming these are full frame shots and you are using the centre AF spot...

If you draw a vertical and horizontal line to mark the centre of the shot, that gives you your AF point, and just judging it by eye, it looks like it's fallen just under the eye of the Blackbird on an area of black feathers with no highlight detail for the AF system to key on. I'm pretty sure that's it - happens to me regularly with Blackbirds. :shrug:

Had to check it.

AF_Point.jpg
 
This is why i try to manual focus all the time :thumbs:
 
Just need to be aware of it and always try to use a detail like the edge of the bird to contrast for the af sensor to detect.

Manual focus No autofocus is my karma-just have to know what to watch out for
 
Well that's a bit of a challenge with birds hopping around TG. I get it with Maggies too especially when they're in the shade or backlit.

If you'd focused on the the wing cobbers it would have locked onto those highlights no probs, but then the head would have been oof anyway! :D

It looks like you could have focused on that area behind the eye where there seems to be enough detail, but you did the right thing going for the head, and that blank area will change from having detail to none as the bird moves around - so it's just bad luck really.
 
Right, I'm going to get a proper bird shot tomorrow :lol:

Just emagen a fairly big man in camo gear grawling along the park you are walking in :lol: With a camera in hand

Could be past as a stump though :D
 
Marcel said:
Was it active though?
Or was a focus point along the top active instead?

Looking at the shot, the centre focal point isn't where the eye is. The eye is above centre.

What camera?
Click to expand...

Thanks Marcel 40D It was the center point if thats what you are asking

CT said:
Assuming these are full frame shots and you are using the centre AF spot...

If you draw a vertical and horizontal line to mark the centre of the shot, that gives you your AF point, and just judging it by eye, it looks like it's fallen just under the eye of the Blackbird on an area of black feathers with no highlight detail for the AF system to key on. I'm pretty sure that's it - happens to me regularly with Blackbirds. :shrug:

Had to check it.

AF_Point.jpg
Click to expand...

Thanks for that CT Its begining to look like opperator error then :bang:
A lot cheaper than a lens replace / repair :thumbs:
I hadn't given any thought to "not locking on" as it didn't seem to be hunting around though.

BTW I have just been checking a few more EXIFS from the day and it looks like the best ones are 1/320 @ f/8 does this have any bearing on anything?
 
CT said:
Well that's a bit of a challenge with birds hopping around TG. I get it with Maggies too especially when they're in the shade or backlit.

If you'd focused on the the wing cobbers it would have locked onto those highlights no probs, but then the head would have been oof anyway! :D
Click to expand...

Your right of course-though with the new 3d tracking on my d300 makes it a lot easier now. Wack it on continuous focus and just guage it as it looks in the viewfinder and snap away at 6 fps and it gets one you want lol
 
with the new 3d tracking on my d300 makes it a lot easier now. Wack it on continuous focus and just guage it as it looks in the viewfinder and snap away at 6 fps and it gets one you want
Click to expand...

Cool, pretty soon you won't even need to be there yourself at all. :thumbs:

;):lol:
 
digitalmaniac said:
Just need to be aware of it and always try to use a detail like the edge of the bird to contrast for the af sensor to detect.
Click to expand...
Good point thanks :thumbs:

digitalmaniac said:
....Wack it on continuous focus and just guage it as it looks in the viewfinder and snap away at 6 fps and it gets one you want lol
Click to expand...

Well thanks God for 6FPS and the falling costs of memory cards is all I can say ( but I have to agree :D)
 
Where you using servo though Chris? Because if you had focused on the eye then moved slightly to recompose the servo would have readjusted itself but so slightly you probably won't have heard it or felt it do so :shrug: I had that happen with a few shots of BBs
 
Are you trying to insinuate im a tecno junkie-not a purist. LOL

Actually you can get full remote control now cant you LOL

The art of photography is knowing what setting to use.

If I wanted to manual focus i would still have my richo kr10-m

:wave:
 
Ahhhh, I loved my KR10. :love::love:

Until I passed it over for something better spec'd. ;)
 
Yes was a lovely camera-just wish id had af as the split level focus did my head in lol.

I have a stigmastism and it gave me a headach m,anual focus all the time
 
Cobra said:


BTW I have just been checking a few more EXIFS from the day and it looks like the best ones are 1/320 @ f/8 does this have any bearing on anything?
Click to expand...

Well f8 will always give a bit more DOF which is always welcome with birds. You'd think that 1/320th would be fast enough, but it's a question of luck really, I get so many spoiled shots where they've just twitched their head at the crucial moment, while the rest of the bird is sharp. So really we always want a smallish aperture and the fastest shutter speed we can get, but it rarely happens.

So no operator error mate, if you're using one AF spot and continuous AF which you should anyway, the system can only stay locked onto the bird as long as it has detail to work with. You could shoot a sequence with some sharp and some oof where the AF spot has dropped in the wrong place.

Spoiled shots are a way of life with bird shots. :D
 
Jo said:
Where you using servo though Chris? Because if you had focused on the eye then moved slightly to recompose the servo would have readjusted itself but so slightly you probably won't have heard it or felt it do so :shrug: I had that happen with a few shots of BBs
Click to expand...

Good point Jo, but no :( I think CT may have nailed it, that time at least. I fired a few off from the same position and they are all the ( pretty much) the same.
Its still a bit of a mystery though as Its happened a few times, in the past, unfortunately I can't go back ane check EXIFS etc though as they go in the bin. I will certainly watch for "highlight detail" in the future and see what happens.

 
CT said:
So no operator error mate, if you're using one AF spot and continuous AF which you should anyway, the system can only stay locked onto the bird as long as it has detail to work with. You could shoot a sequence with some sharp and some oof where the AF spot has dropped in the wrong place.
Spoiled shots are a way of life with bird shots. :D
Click to expand...

Thanks CT your help is much appriciated :thumbs:
Now I know what to look for hopefully I can try and avoid it to some extent
 
The last thing I'm thinking about is highlight details when I'm shooting tbh, I'm too busy trying to track the bird and keep that AF spot on or around the eye area. Obviously if you can nail the eye every time that's the answer, but often it's well nigh impossible.
 
CT said:
Spoiled shots are a way of life with bird shots. :D
Click to expand...

Statement of the week,i`m running at about 10% success rate at the moment.........:lol:
 
That's probably about right! :D
 
Although, Chris... didnt you say earlier that in the viewfinder afterwards the red dot that was the focus point in that photo was displayed on the screen?

Mine does that... and if it was on the eye..then surely that is where it would have been focusing at that time? :shrug:


Also... looking at CT's image with the red lines on it.... if you had focused just above or below the eye...........why would that make the leaves in the far background in focus instead?
 
Janice said:
Also... looking at CT's image with the red lines on it.... if you had focused just above or below the eye...........why would that make the leaves in the far background in focus instead?
Click to expand...

The answer there Janice is that as soon as the lens has insufficient detail to focus it starts to hunt, and the bg just happened to be in focus when he pressed the shutter.
 
Cobra, was the focus limiter set to 3m->infinity as opposed to 1.5m->infinity?

If so the lens will pull back to the closest it can focus to, which as luck may have it is just behind the subject in this instance. I've done this before and wondered why I can't get things in focus!
 
Thanks CT. I have a thing somewhere that you can turn on or off to prevent hunting .. in the custom setttings i think ;)
 
i have had something similair to this when trying to snap a very dark wolf(i think) spider.

just thought it was me being rubbish as normal.
 
Janice said:
Thanks CT. I have a thing somewhere that you can turn on or off to prevent hunting .. in the custom setttings i think ;)
Click to expand...

Yep - I think though without looking Janice, it just shuts the lens down to save battery drain - it wont help you get focus if there's not enough detail.
 
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