Help with out of focus pictures

[Bruce Miller]

Please Help me figure out what is wrong here and what to do different.

If this is in the wrong forum, please move it or tell me. I did not see where else to put it.

I went to one of my favorate places in southern Ohio to shoot spring warblers. I found what was the best bird of the day, but did not get a good photo. I'm really lost on what happened. Just about everything was right. I took 26 pictures of him on this perch. During that time I refocused a couple times. The bird appeared in the viewfinder as being in focus. I am shooting a Canon 40D and my brand new Canon 400 f5.6! I have been shooting a 100-400 and pretty good sucess, but wanted to try the prime, especially since I am now shooting mostly off a tripod.

Here is the Photo, cropped in a little so you can see how badly the focus missed.

[Bruce Miller]

To show my focus point is square on the bird, here is the screen print from DPP showing it.

Please let me know what caused this and how I can do better. I did get some decent photos from the day. The first 12 here are from yesterday:
http://redtail.smugmug.com/Feature/2...994442_XNPkgzF

[Matthew Pimm]

I am not sure but from the metadata it looks like the shutter speed was only 1/500 at 5.6.

A 400 on a 40D is a 640mm lens so you are under the "normal" minimum for hand holding that focal length So maybe it's not focus but movement - was there a bit of wind and the branch was swaying ever so slightly? He also looks like he is singing - that could do it too.

[Kerry Perkins]

Hello Bruce, Matthew has a good point about your shutter speed here but I think there is something else going on. You have some very sharp images on your web site (and nice captures too!), so you know that your equipment is working well. What is different in this shot from the others is that there is very little light on the bird. In the standard mode of auto focus (as opposed to live view), the camera relies on local (edge) contrast to determine where the focus should be. If you don't give the camera enough information to work on, it won't be very effective. Also note that just because the camera picked the center point for focus does not mean that it actually achieved good focus there. Note that your camera manual will tell you that low light, low contrast, and back-lit subjects will result in decreased auto-focus reliability.

I am curious about a couple of points... What did you meter in "spot metering" mode? What did the meter tell you? The subject is underexposed, so I don't think spot metering did a very good job here. The scene is exposed pretty well for the background, but not the bird.

[Bruce Miller]

Matt, thanks for replying. I was using a tripod. If there was any problem with that, I would say it would be a little vibration. I also used a flash on about every 5th picture. I have some pictures that look a little soft and I am sure there is a little vibration or wind movement, but not like this.

Bruce

[William Malacarne]

Bruce

Along with what others have suggested you might want to check and make sure the new 400mm lens is not front or back focusing.

Bill

[Bruce Miller]

Kenny, This was on spot meter. No exposure compensation. The sun was right behind me, so this was not backlight at all. It was pretty bright out to get 1/500 with iso 400, f5.6.

One of the things I'm hoping for with the 400 f5.6 over the 100-400 is faster more accurate focus. So this has me a little concerned...

Bruce

[Bruce Miller]

Bruce

Along with what others have suggested you might want to check and make sure the new 400mm lens is not front or back focusing.

Bill

Yea, how do I do that? I've wondered about that with my 100-400.
Bruce

[Stan Cunningham]

I'm no expert so can only make an observation.
It appears the tree branch to the left is in perfect focus, which is in the light.
The bird, that from what I can tell, is 6 inches closer and soft.
I feel your frustration, still have that happen to me some times and mainly chalk it up to the 100 -400.
Your photos on smug mug are gorgeous, and I'd love to know how you got that close or I'm misusing my 400mm.
But what Kerry said is true, all the very sharp photos on your site are in better light.

[William Malacarne]

As a quick test tape a dollar bill on a wall or fence where you have good light and use tripod and take some photos paying attention that you have the target and camera square to each other. For a little more precision you can look up lens micro adjust and try that method.

Bill

[Kerry Perkins]

Kenny, This was on spot meter. No exposure compensation.

You needed some, at least +1 1/3 or so. Your camera obviously exposed for the background. The tree branches in the direct sun are overexposed and the bird is underexposed.

The sun was right behind me, so this was not backlight at all.

I don't see how that could be, since the right side of the vertical branch is completely in shadow. It doesn't really matter anyway, if the bird is in shadow (which it is) and the background is bright, that would be back-lit.

It was pretty bright out to get 1/500 with iso 400, f5.6.

My whole point is that the incident light is irrelevant if your subject is in the shade. If this bird had been in direct sun you would have been shooting at more like 1/1600 at ISO 400.

One of the things I'm hoping for with the 400 f5.6 over the 100-400 is faster more accurate focus. So this has me a little concerned...

I've been shooting with this lens for three years and I find it to be amazingly fast and accurate. Accuracy is more a function of the camera body. Unfortunately, the 40D does not offer micro-adjustment for lenses, but the fact that you take very sharp images like the ones on your web site tells me that there is nothing wrong with the lens or the body.

[Bruce Miller]

Kenny,
No doubt the bird is under exposed. I didn't see it as being that drastic in the field. I need to get a better handle on this. +1 1/3 is a lot (for me), that is just telling me how bad I am at getting the exposure right.

...
I see your point totally and although it doesn't matter, I'm still pretty sure the sun was right behind me. Hummm. Maybe it moved on me! :)

...
One of my biggest complaints is not getting decent shutter speeds. I did notice this lens "seems" to be letting in more light. Yes, this make no sense. All 400, f5.6 should let in the same amount of light.

...
What body are you using? I am considering getting a 7D, but as you can see, it's not like the 40D sucks... This is a brand new lens. Only the last 21 pictures are with the 400/5.6. All the rest are with the 100-400.


Thanks for your help. I have taken from your comments a lot of info to consider with the exposure, but still confused on why this focused so bad (on this series of photos). It's a especially frustrating because this is a tough bird to get a shot of. This may very well be the only chance I get at one this year.

[Matthew Pimm]

Sometimes the focus just doesn't work. I can't begin to explain it but Kerry is probably on the right track. Your web site images are spectacular and if done with the same equipment it's not a lens problem.

I have had the same experience. Tack sharp images and then soft ones even though I have tried to do everything the same way. Anytime the background is brighter than the bird I have problems though so Kerry is on to something. I also wonder about distance to subject. I have had focus points dead on the eye with a 7d on a tripod but come away with a soft image if the bird was far away even without a lot of enlargement. The distance must magnify even the smallest focus error as well as any movement.

All I know is that the closer I am and the better the exposure the sharper the image.

Don't give up on that lens - looks like you have done really really good work with it despite this snafu.

[Kerry Perkins]

Bruce, you can call me Kenny but my name is Kerry.

Sorry I didn't realize that your web site images were taken with your 100-400mm. I can see how you would be concerned, but unless you got a bad copy, this is a great lens from Canon. It's perfect for people like me who just can't afford the big guns and like to hand-hold. I love the light weight and extremely fast focus. Getting exposure right under these conditions requires a little bit of adjustment, but practice will get you there for sure. Artie's "Art of Bird Photography" is a great reference.

My main body right now is the 7D and I also have a 50D. I love the 7D - it does a fantastic job for the money and, while it does suffer a bit from noise at high ISOs, the noise granularity is very small so the NR software has a better time of it than it does with the 50D noise. Definitely not suggesting that there is anything wrong with the 40D, but if you need to make a micro-adjustment to the new lens you won't be able to with that body. You can do the test that Bill suggests though and see what might be going on. You can also use a page of a newspaper for a bigger target.

For sure don't give up on the lens. It has reputation as one of Canon's sharpest lenses!

[Geoff Warnock]

Hi Bruce,

It looks to me like you have clear evidence for 'back focus', which unfortunately I know about all to well too.

Shutter speed is certainly not a major issue as the branches in your pic are sharp enough to tell you that the focus is behind the bird. The hard part now is being sure that it is a consistent back focus problem.

Arthur Morris wrote an article around microadjusting your lenses with a suitable body, but the target (or home made version of) is a good way to reveal your back focus:

http://www.birdsasart-blog.com/2011/...justing-magic/

This article is also interesting:

http://www.lensrentals.com/blog/2008...nd-other-myths

Are all of the photos you've taken with the new lens like your example? I saw the problem with my Sigma 120-400 zoom on my D90, and it hasn't even been satisfactorily fixed after the lens spend more than a month going back to Sigma. It is 'within specifications' apparently. The second link above seems to explain this - i.e. my D90 may have a tendency to back focus, and while all my other lenses are neutral or front focus a little to balance the D90, the Sigma back focuses more, multiplying the problem. If you can build clear evidence that it is a back focus problem you may find that your dealer can exchange the lens directly (Sigma - Europe anyway - don't exchange...). I face problems at 400mm at close range where the DOF is so narrow, but can have some keepers if I fire several frames. Since I'm not selling my pictures I'm basically now waiting to make a lens upgrade (and/or microadjustable body).

HTH, Geoff.

[Geoff Warnock]

BTW I can provide plenty of examples like yours....

and the best evidence I got that it was the Sigma lens and not operator error (to convince my dealer) were shots taken on a demo Nikon 600 f4 that were perfect.

[Bruce Miller]

Bruce, you can call me Kenny but my name is Kerry.

Sorry I didn't realize that your web site images were taken with your 100-400mm. I can see how you would be concerned, but unless you got a bad copy, this is a great lens from Canon. It's perfect for people like me who just can't afford the big guns and like to hand-hold. I love the light weight and extremely fast focus. Getting exposure right under these conditions requires a little bit of adjustment, but practice will get you there for sure. Artie's "Art of Bird Photography" is a great reference.

My main body right now is the 7D and I also have a 50D. I love the 7D - it does a fantastic job for the money and, while it does suffer a bit from noise at high ISOs, the noise granularity is very small so the NR software has a better time of it than it does with the 50D noise. Definitely not suggesting that there is anything wrong with the 40D, but if you need to make a micro-adjustment to the new lens you won't be able to with that body. You can do the test that Bill suggests though and see what might be going on. You can also use a page of a newspaper for a bigger target.

For sure don't give up on the lens. It has reputation as one of Canon's sharpest lenses!

Hey Kerry! Sorry for the name mix up. I have considered getting a body with micro adjustment. Maybe I should just order the lens alienment tool so I can see if my lenses are focusing properly.

I don't think this lens is bad. I just can't figure out why this focus was so off. I refocused multi times while this bird perched there. It never locked on the bird. However, it looked good through the viewfinder.

All the pictures taken on Friday and Saturday are from this lens. The Wild Turkeys are the first pics taken with this lens.

BTW, what is your goto f-stop? On my 100-400, 7.1 is the sweet spot. Noticablely better than 5.6 and seems even better than f8.

[Bruce Miller]

Hi Bruce,

It looks to me like you have clear evidence for 'back focus', which unfortunately I know about all to well too.

Shutter speed is certainly not a major issue as the branches in your pic are sharp enough to tell you that the focus is behind the bird. The hard part now is being sure that it is a consistent back focus problem.

Arthur Morris wrote an article around microadjusting your lenses with a suitable body, but the target (or home made version of) is a good way to reveal your back focus:

http://www.birdsasart-blog.com/2011/...justing-magic/

This article is also interesting:

http://www.lensrentals.com/blog/2008...nd-other-myths

Are all of the photos you've taken with the new lens like your example? I saw the problem with my Sigma 120-400 zoom on my D90, and it hasn't even been satisfactorily fixed after the lens spend more than a month going back to Sigma. It is 'within specifications' apparently. The second link above seems to explain this - i.e. my D90 may have a tendency to back focus, and while all my other lenses are neutral or front focus a little to balance the D90, the Sigma back focuses more, multiplying the problem. If you can build clear evidence that it is a back focus problem you may find that your dealer can exchange the lens directly (Sigma - Europe anyway - don't exchange...). I face problems at 400mm at close range where the DOF is so narrow, but can have some keepers if I fire several frames. Since I'm not selling my pictures I'm basically now waiting to make a lens upgrade (and/or microadjustable body).

HTH, Geoff.

Geoff,

Thanks for the links! I will read those right away. I think this might have been an isolated incident.

Here is another picture I took in great light at the end of the day (same setup)...

[Geoff Warnock]

Looks like you can get great results then!

Perhaps it was just down to contrast in the image tricking the AF sensors then. This thread:

http://www.birdphotographers.net/for...hp/81766-Focus

contains discussion of how backgrounds with good contrast might draw focus. I suppose the well lit branches in your first example might have caused the problem.