AF Issues among other things with BIF

[Robert Dreeszen]

I ended up with three marginal keepers out of 60 BIF of a Bald Eagle taken from my front deck about an hour ago. I used a Canon EOS 1D MKII with a 100-400 L and no extenders or filters and it was handheld with IS on Mode 1 and 6.5 to infinity selected. Not the best of conditions with overcast/low light and wind. Having been burned several times with slow shutter speed I overdid the ISO and shutter speed but will remember next time. The marginal keepers were shot at approximately 250 yards and were heavily cropped. The OOF's were as close as 150 yards as the eagle flew upstream in front of my upper deck in a right to left direction. Given my inexperience with this there were the expected amount of images with center AF missing the mark but when I load the images with Breeze Browser the active AF point in a couple cases was centered on the white head and others center mass on the body and they were total OOF's. All of the OOF's were against a dark background and anything that remotely focused was against a light sky or something light. I realize the variations possible on the MKIII so have attached the expanded exif data from the Breeze Browser Pro image with the center mass position of the active focus point. Is there a way to convert the raw image and include the active focus point in a image I could post?
ile: 3N1G8579.CR2
File size: 12.2MB
Image Serial Number: 000-8579
Image counter: 8578
Camera Model: Canon EOS-1D Mark III
Camera serial number: 0000526151
Firmware: Firmware Version 1.3.0
Date/Time: 2011:12:03 11:02:49
Shutter speed: 1/3200 sec
Aperture: 5.6
Exposure mode: Av
Exposure compensation: -1/3
Flash: Off
Metering mode: Evaluative
Drive mode: Continuous
ISO: 1250
Lens: EF100-400mm f/4.5-5.6L IS USM
Focal length: 370mm
Subject distance: 655 m
AF mode: AI Servo AF
Lens micro-adjustment: 0
Image size: 1936 x 1288
Image quality: Raw
White balance: Color temp=6500K
Picture style: User Def. 1 (Landscape)
Color space: sRGB
Saturation: Normal
Sharpness: 4
Contrast: Normal
Tone: Normal
Custom Functions:
CFn I-3: ISO range enabled
CFn I-4: Bracketing auto cancel OFF
CFn I-7: Spot metering linked to active AF point
CFn I-8: Safety shift enabled (Tv/Av)
CFn I-11: Use evaluative metering with manual exposure
CFn II-1: Long exposure noise reduction: AUTO
CFn II-2: High ISO noise reduction: ON
CFn II-7: Viewfinder info during exposure: enabled
CFn III-2: AI Servo tracking sensitivity: fast (+1)
CFn III-6: Lens AF stop button function: switch to registered AF point
CFn III-7: AF Micro-adjustment: adjust by lens
CFn III-8: AF expansion: left/right assist points
CFn III-10: Switch to registered AF point: enabled
CFn III-11: AF point auto selection: rear dial enabled/top dial enabled
CFn III-12: AF point display during focus: ON when focus achieved
CFn III-13: AF point brightness: brighter
CFn III-16: Registered continuous shooting speed enabled
CFn IV-2: AF-ON/AE lock button switch enabled
CFn IV-16: Simulate exposure during Live View shooting

I just registered and is says I can start threads and post but can not do attachments. Is there something else I need to do to post a image. All input appreciated.
Ugashik Bob

[Roger Clark]

Bob,

Welcome!

A significant factor may be: Subject distance: 655 m
655 meters is a long way.

Roger

[Robert Dreeszen]

Roger: wish I could of posted the image and it would of been clearer( No pun intended). I saw the 655 meters and that is the Mountain/river bank in the background that is focused well but the active red focus point is center mass on the eagle. The eagle with the focus point center mass was less than 200 yards and several images that did focus were much further than that. Appears as if anything that isn't a constrasting background is a problem. The image right after the one documented in my post had a light colored patch of grass behind the black body of the eagle and it focused on the eagle and the active focus indicator was barely on the head.

[Doug Brown]

It'd be very helpful if you could post a full frame shot scaled down to 1024 pixels so that we have an idea of how large the Eagle is in the frame. It'd also help if you could post a 100% crop that shows us the detail in the bird.

[Roger Clark]

Robert,

As a forum participant, you'll need to put the image on another web site and then you can post a link to it here. If the hosting site allows hot linking, you can hot link it here so it appears as if it in on this site.

Regarding the 655 meters, the AF system clearly locked on to the background. This is happen more often if the background is brighter than the foreground. Note also that the active AF area is larger than a single AF rectangle (probably 2x larger) and its boundary is fuzzy. So unless the subject (eagle) is much larger than an AF rectangle, there is a chance the AF will lock onto the background. If you can get lock on the subject, one way to reduce the chance of losing lock is to set the custom function regarding AF speed to slow (CFn III-2: AI Servo tracking sensitivity to slow). Tracking sensitivity means only how fast it will change and lock onto another subject, and not how it will track while locked. If you have it on slow, once locked, you can slip off the subject and it will take a second or so to lock onto the background. If you do slip off, take your finger off the shutter, get back onto to bird, then half press to get AF tracking back. There are discussions on this in the gear forum over the last year.

See also (though it sounds like you already know this):
http://www.clarkvision.com/articles/...ith.autofocus/

Even 200 meters is a very large distance to image birds in flight.

You might also get more responses to BIF technique by posting in the gear forum (or maybe a moderator can move it there?).

Roger

[Daniel Cadieux]

Another thing to watch for is that for panning that lens should be either on IS Mode 2, or off, not Mode 1 (which is for static subjects). I know this does not affect AF, but just something else to keep in mind.

Hope you can get some examples up so we can better help you...

P.S. Moved to "General Photography Discussion" forum...

[Robert Dreeszen]

The first link is unaltered except for the conversion to jpeg image I detailed with the earlier data. The active red af rectangle was precisely center mass of the bird. The second link was several frames earlier when the eagle happened to have the light colored grass as a better contrasted background. The active red af rectangle was on the trailing edge of the wing and rear area of the bird. The third link was many frames later and at least 200 yards but had a very light contrasted background. The active red af rectangle has his entire head in the upper 1/3 of the rectangle and the image is heavily cropped.
What I think I am hearing is 200 yards is to far for the short lens I am using but there are times like this where it was that or nothing and I was just trying to make the best of it. Is there some reason why you can not post your own images on here directly?
Thank you for help with this.
http://img.photobucket.com/albums/v1...3-3N1G8579.jpg
http://img.photobucket.com/albums/v1...3-3N1G8574.jpg
http://img.photobucket.com/albums/v1...3-3N1G8586.jpg

[Jeff Cashdollar]

Bob,

Welcome, this is a great place to learn. We have an Educational and Tutorial Forum as well with several nice simple reads to improve technique. There is a thread at the top of this forum that spells out the detail for posting. Send me a PM if you need further assistance.

Regarding your narrative, I had a 100-400 and IMO that is too far away for any quality images. Maybe a lucky one here and there but with the large crop they will not be critically sharp. Yes you are hearing correct, 200 yards is too far away. I have a 500MM and a 1.4 TC combined with a 3530 LS tripod and a quality head mount and do not usually try anything beyond 75/125 feet, but that is me. As a general rule, the subject should be at least 15% of the image more is better. If the bird is something insignificant like 5% of the total picture, you need to get closer via equipment or legs. The third link above is best in the group, keep moving in that direction.

Thanks for the message, we will get this sorted out and your shots will improve fast. Practice and more practice is the key. Get out early, find a good light angle and use a tripod if possible.

[Daniel Cadieux]

From the third link you posted that is about the best you'll get from 200 yards away...the image is properly focussed but you're simlpy running out of pixels to put on the subject from that distance and once significantly cropped this is what you get. In this situation I just don't press the shutter button...

The first image is just focussed on the mountain. That happens as it may not taske much for the focus point to jump back there. I'd try Roger's suggetion of switching CFn III-2: AI Servo tracking sensitivity to slow. This is how I have my camera setup (a 7D) and works well for me. You can also try centre point with expansion with subjects smaller in the frame.

[Robert Dreeszen]

Roger:
I changed III-2 to slow as it makes sense. I just went through the rear button focus thing and it is still somewhat confusing to me. What would be a normal sequence of events when using rear button focus on a BIF and the biggie to me is what confirmation of focus lock do you recieve in the process. Any hope for an old guy that can't hear the beeps?
Thank you for your help.
Doug:
Hope the additional links helped. Thank you for your help.
Jeff:
I've suspected exactly what you have said regarding distance and preordered the 500mm II about 6 weeks ago. Received two messages regarding the order. One was a price increase and the other said in effect they don't have a date when they will know the date. Have a Wimberly II head for my heavy tripod and 1.4x and 2.0x III extenders in the village downstream which is the closest place we can get mail in. Because of the unsafe river ice can not travel to get them yet. Have found the 100-400's limitations in both low light and distance but other than the 70-200 II with extenders it is the only real reach I have so far. The dust pump isn't a 500 or bigger but I'm still impressed with it. The 125 foot max with a 500/1.4/tripod got my attention. I do 90% of my shooting from my front upper deck this time of year and do my share of tundra pounding but 125 feet or less is a very low odds thing even here in our target rich environment. Even lower odds this time of year when ice/snow conditions further limit travel. We have lived out here over 25 years so I know the patterns of the wildlife but this time of year 125 feet isn't impossible but its not easy. Yours is the first detailed response I have received in terms of distance and equipment and it is appreciated.
Daniel:
I just flat missed the mode 2 IS thing you pointed out. I've been burned with the IS switch left on from taking the pump off from the tripod and need to put it on the check list along with Mode 2 for BIF. I've been in a lot of forums lately and one thing I haven't seen is a checklist of things for BIF along with a button sequence and how to confirm focus. I agree that in the first image it is focused on something other than what the red active focus rectangle implies. If I could find a way to do a screen capture I could show you the red rectangle perfectectly centered on center mass of the eagle in this particular case. I'm sure the issue is the low light background against a dark object(other than the small white head) but my question is why does the red active focus rectangle show its entire boundry around the center mass of the eagle then focus on something else? I could understand it if there was just a small portion of rectangle without a part of the eagle in it but in this case there is not. I've done Roger's III-2 change and think it will help. I also have a new 7D but am concentrating on BIF's with my MKIII first because I'm a long ways from feeling comfortable with it. Regarding the III-8 expansion setting that was in effect (left/right) in the above data I know wonder if that could be a contributer to missing focus at times? I set it thinking it would help my sloppy tracking but now wonder if doesn't increase your odds of missing focus by providing additonal avenues to the background? Also agree with the 200 yard running out of pixels thing with a heavy crop. Have used both 1.4 & 2.0x II extenders and there seems to be more to the loss of light issue than the reach gained. With the additional reach it seems like I couldn't get out of the deadly embrace of low light/shuttter speed and the high iso to deal with it. Was considering a MK IV for a higher pixel count for the heavy crops.
Gentlemen:
The common theme I'm seeing here is get closer and I got it. The other theme is get more reach. Haven't got that along with the experience to use it yet. I've found BIF to be very challanging in terms of technique but unless it is intentional if you don't have focus you are done right there. Very impressed with the amount and detail of advise given. It is very much appreciated.
Bob

[Daniel Cadieux]

Bob, the normal sequence for using back button is simply focus with your thumb and once focus is attained fire away with the shutter button. Focus for BIF can be tricky and may need lots of practice. Having siad this (and possibly making it sound very easy) focus is not meant to be mashing the button and keeping it pushed and hoping for the best. Check out this great tutorial on "bumping" the focus by Jim Neiger:

http://www.birdphotographers.net/for...=bumping+focus

Be aware that focus confirmations do NOT activate when using AI SERVO... (neither the audible beep nor the visible green dot in the viewfinder)

For me the "expansion" points around the AF point make it easier to get something on the small subject as these assist the main point rather than act independantly...it is different than selecting multiple points (that's from my understading and experience anyhow).

About the highlighted red rectangle on the subject even if focus is on the BG: that red rectangle simply simply indicates which focus point was the one used and active at the moment of capture...if the lens hunted and you pressed the shutter as the BG was in focus you will still see the red focus point on the subject itself.

[Doug Brown]

Thanks for posting the image links Robert. Here's my take on your problems. First and foremost, the bird is small in the frame and flying against a varied BG in low light. This is a challenging AF situation for even experienced BIF photographers. Practice your BIF skills against a sky BG at first, and then try your hand at varied BGs. .o with larger and slower-moving subjects initially and take on new challenges as you become more and more proficient

Generally speaking, for BIF the IS mode isn't all that important in terms of getting sharp frames. Once you get above about 1/1000, its only real benefit is stabilizing what you see through the viewfinder.

I'm a back button focus shooter, but it's really a matter of personal preference; I know Jim Neiger uses the shutter button for AF. AF expansion points can help, but they can also make it harder to get sharp frames. When the bird is small in the frame, an expanded AF zone is more likely to be drawn off the subject than the center point alone.

Just out of curiosity, why are your pixel dimensions in your EXIF data so small? A Mark III RAW file should be 3888 x 2592. Are you shooting in sRAW?

[Robert Dreeszen]

Daniel:
Thanks for the link I will use it. I've read Art Morris's write up on using back button to in effect switch between AI Servo and One shot AF and can see that as plus in some cases. Other than that I just don't see any advantage over the shutter button unless its a physical location preference. You confirmed my suspicions about what you have for focus confirmation in AI servo- post processing. Good explanation of the AF expansion feature. I think I will go back to it based on your experience because I need all the help I can get on target acquisition.
If your target is in a low contrast enviorment and especially in a low light case I think you are saying the red box you see may not be what you get regardless of accuracy of placement. Understandable. Thanks again for your help..

Doug:
I think you have outlined a good strategy. I wanted to do the images with the mountains in the background but will wait till I have more experience and try it on a clear day first. What you are saying about the expansion points just adds to the get closer advice I think. Untill I started this post I had no idea what the practical ranges of my equipment were. You see a lot of things discussed in the forms but distance boundries isn't one of them. Good eye on the pixel dimensions as I never noticed that. The 1 portion of my image size setting was on the raw box and it showed as you noted at 3888x2592. I moved it up to L and it still shows as 3882x2592 but will see if it makes a difference.
Thanks again for your help.

[KurtWecker]

Daniel:
Thanks for the link I will use it. I've read Art Morris's write up on using back button to in effect switch between AI Servo and One shot AF and can see that as plus in some cases. Other than that I just don't see any advantage over the shutter button unless its a physical location preference. You confirmed my suspicions about what you have for focus confirmation in AI servo- post processing. Good explanation of the AF expansion feature. I think I will go back to it based on your experience because I need all the help I can get on target acquisition.
If your target is in a low contrast enviorment and especially in a low light case I think you are saying the red box you see may not be what you get regardless of accuracy of placement. Understandable. Thanks again for your help..

Doug:
I think you have outlined a good strategy. I wanted to do the images with the mountains in the background but will wait till I have more experience and try it on a clear day first. What you are saying about the expansion points just adds to the get closer advice I think. Untill I started this post I had no idea what the practical ranges of my equipment were. You see a lot of things discussed in the forms but distance boundries isn't one of them. Good eye on the pixel dimensions as I never noticed that. The 1 portion of my image size setting was on the raw box and it showed as you noted at 3888x2592. I moved it up to L and it still shows as 3882x2592 but will see if it makes a difference.
Thanks again for your help.

I have been shooting Birds for many years and have gone through the process of how to get sharp images... Here is my 2 cents.

Always use AI servo doesn't matter how fast you tracking is set to if your only shooting one bird, I keep mine right in the middle.
AF expansion in your body is not for AI servo, but one shot. I beleive.
Distance shooting is a challenge and in bad light you fight the air it self, and in hot weather you fight heat vapors but if the conditions are right you will get a good shot.
When you are in bad light and have a busy background the focus will jump and not lock on as it cannot tell what you are trying for.
I have used the body you own and its not the best AF system Canon makes but you can get what you want with practice.
Never use a shutter speed lower then 1600 and never shoot wide open and do all this keeping your iso down.
If you have any questions i'd be glad to help, shoot me a note.
Here is my website http://www.thrukurtslens.com/ its a bit jumbled right now I'm reworking it but I do post to flickr http://www.flickr.com/photos/thrukurtslens/ almost everyday and here is that link.

Good luck.. Practice will get you there.. and keep reading and learning. You will everyday.

Kurt

[Robert Dreeszen]

Thanks for taking the time to reply. You added some issues to the distance thing and I understand. I'm starting to get a better feel as to what range produces acceptable images. Struggling to get 1600 shutter speed smaller than wide open without bumping the ISO. Thankfully I have a target rich environment from my front deck that allows me daily practice. Enjoyed your photos on your flickr site.