Tack sharp to soft as a wet noodle, lens or operator error?

Whenever I am shooting (birds - most of the time perched) my keeper rate is pretty low. The images are either tack sharp or not. Even during a series of say 10 shots of the same bird in the same spot I may get several keepers or I may end up deleting them all due to not being sharp.

BUT, having images from the lens that are tack sharp I can only think if the lens has done it once, it can do it everytime. I know lighting, stillness of the bird, press of the shutter, steadiness of the camera, exposure, all have a big part in the difference with the outcome of a shot. I am generally shooting the birds at 500mm with this lens (Tamron 200-500 on a 50D) so I can't really compare it to my 70-200. Does it seem to be operator error or must every element be in line to get the perfect shot?

Hopefully this makes sense. Thanks for any input

If your taking pictures from the same spot and same subject then I can only assume it is operator error as the camera should be able to take the same sharp picture over and over again. Are you shooting in manual mode? If not your camera could be changing your settings based on lighting conditions.

Take Care,
Cheers, Patirck

Do you have a couple of samples of one in focus and one that is not?

Take Care,
Cheers, Patrick

What focus mode are you using? If using one shot, and maybe having a slight pause between locking focus and taking the shot, slight movements can be enough to move the bird from in focus, to "somewhere within the DOF" to "out of focus. It may only take a slight breeze to move the branch, or even a slight movement forwards or backwards by the photographer, to turn a tack sharp shot into a soft one.

What are your shutter speeds like? They can make a noticeable difference too, even if you are locked down on a tripod. With long lenses you still need to keep the speed up in order that any motion in the subject is frozen. Again, a perch moving gently in the breeze may not be obvious when looking at the subject, but may be enough to soften the image if the motion isn't counteracted with a fast enough shutter speed.

Either of those could easily be the cause of variation from tack sharp to soft between shots in a sequence, and other potential errors too.

As has been suggested, post some shots (with exif intact) and we can possibly get a better idea of potential causes.

Saint728 wrote in post #15915786
If your taking pictures from the same spot and same subject then I can only assume it is operator error as the camera should be able to take the same sharp picture over and over again. Are you shooting in manual mode?

Usually shoot in AV mode. If not AV, TV. On a tripod (ballhead unlocked) when out in the field or rested on the window sill in the same spot when backyard shooting.

Saint728 wrote in post #15915788
Do you have a couple of samples of one in focus and one that is not?

Take Care,
Cheers, Patrick

I'm going to work on getting one of each. I delete all the images that are not sharp, so will post next time I shoot.

sandpiper wrote in post #15915989
What focus mode are you using?

Center focus point, AI Servo, Back button focusing (BBF). At times I will refocus in between shots or continuous focus (or not) during a burst.

sandpiper wrote in post #15915989
If using one shot, and maybe having a slight pause between locking focus and taking the shot, slight movements can be enough to move the bird from in focus, to "somewhere within the DOF" to "out of focus. It may only take a slight breeze to move the branch, or even a slight movement forwards or backwards by the photographer, to turn a tack sharp shot into a soft one.

This is why I shoot AI Servo, use BBF and most of the time continuously focus.

sandpiper wrote in post #15915989
What are your shutter speeds like? They can make a noticeable difference too, even if you are locked down on a tripod.

That is another thing that really boggles me. I would of never thought a slow shutter speed & wide open would capture one of my sharpest images (1/60 wide open @ 6.3, 500mm, ISO400) with this lens. Of course the lens was resting on the window sill:

IMAGE LINK: http://www.flickr.com …d_photography/8​699758942/

sandpiper wrote in post #15915989
With long lenses you still need to keep the speed up in order that any motion in the subject is frozen. Again, a perch moving gently in the breeze may not be obvious when looking at the subject, but may be enough to soften the image if the motion isn't counteracted with a fast enough shutter speed.

Either of those could easily be the cause of variation from tack sharp to soft between shots in a sequence, and other potential errors too.

As has been suggested, post some shots (with exif intact) and we can possibly get a better idea of potential causes.

I've got to figure out why LR4 is not exporting with the EXIF data. Thanks to all for all the information

I'm going to post sharp and soft examples next time I shoot.

don't save for web if you want exif data to remain intact...

if you're talking a small percentage of keepers, I'd have to guess that it's the person behind the lens

Have you ever tried setting up a shot of a static object with everything in manual, using a remote release (or timer), and then taken a series of images while locked down on your tripod? If everything is exactly the same with your settings, and you take you out of the picture, it should let you know whether it's equipment or operator.

Are you sure you disable the IS when using a tripod, or supported on a window sill? This can make a difference.

AI Servo by its very nature will focus where it thinks is right and any slight movements will push it back or forwards depending on where you point it, slightest movements will mean focus differences shot for shot. Dont forget small animals move all the time, heart beats, beak muscle movements, nothing will ever be perfectly sharp unless shooting 1/8000sec all the time.

Neilyb wrote in post #15917276
AI Servo by its very nature will focus where it thinks is right and any slight movements will push it back or forwards depending on where you point it, slightest movements will mean focus differences shot for shot. Dont forget small animals move all the time, heart beats, beak muscle movements, nothing will ever be perfectly sharp unless shooting 1/8000sec all the time.

This.

Small birds are especially jittery. It's a must for their survival. I find the OP's experience to be pretty much normal.

I wonder.... if neither you nor the subject moves, it would seem to make sense to me to just focus once and let off the button until something changes. I use AI Servo with BBF too, and though I don't shoot birds much, I will use the method I just described when I have a relatively static subject - chimp the first shot to be sure of exposure and focus, then try not to change anything unless my subject moves.

ETS wrote in post #15917629
This.

Small birds are especially jittery. It's a must for their survival. I find the OP's experience to be pretty much normal.

So , the OP underestimated the impact of small DOF ?

Foggiest wrote in post #15918604
So , the OP underestimated the impact of small DOF ?

You know, that's a very good question. Though I don't usually think about it that way. In terms of DOF I'm usually concerned about HOW MUCH of the bird is in focus. But yes, if you have a very thin DOF, a quick moving bird can very easily slip in and out of your focal plane.

I shoot birds and have a 25% to 50% keeper rate. I use program which controls the shutter speeds and aperture size. I use spot metering, center focus point only, A1 Servo, no IS and all hand held. Lens are Zeiss 135mm/2 EF (manual focus), Canon 200mm/2.8 and Canon 400mm/5.6, I use Photoshop with Camera Raw plug in which does keep all the photograph information when converting to jpg for the web. It is far better than Lightbox. So far as I can see it is all a question of focus and distance, recognizing when the subject is in focus and range then pulling the trigger accordingly. I'm getting better at it. I may try changing to single shot only.

I'd say my keeper rate is in the 30-40% range as well, i've found shooting in Av with spot metering and center point focus and AI servo to be the most beneficial of all the settings i've tried, i mess around with the ISO a lot to keep my shutter speed up, i also found shooting is burst mode has helped yield more keepers (3 shot burst i usually get 1 out of 3 spot on)

Definitely agree with ETS on small birds being jittery since i mainly shoot finches and sparrows, they move quick and this equates to a lot of missed shots. An example of a 3 burst shot where only one nailed the mark...

IMAGE LINK: http://www.flickr.com/​photos/lenzfreak/87157​46192/