Sigma APO 150-500mm F5-6.3 DG OS HSM - Bigmos

malndobe wrote in post #12136017
I have been, that's why I tried to do a focus test, because I'm not getting the results I was hoping for shooting outside.

These are some photos I took today. They aren't the best, aren't the worst, but are a pretty good sampling of some of the better ones.

The bird photos were taken back to back, the focal point did not change (birds cheek) between snaps. Most of my photos were closer to the one on the right than the one on the left.

The next photos are the entire photo resized for the 1024 limit, then the focal point at 100%. For the horse trailer the focal point was on the rope right above the white diamond shape, for the butterfly it was in the middle of it's wing.

Tripod? Were these at 500mm too? EXIF data would be useful.

malndobe

After looking at the EXIF data embedded in your photos the most immediate recommendation is shoot in Av and set to f8. This is the sweet spot for my bigmos.

DreDaze wrote in post #12136071
what focusing mode are you using?...i couldn't see why the focus would go from spot on to off in back to back shots...i mean that one bird shot looks nice, and sharp...

AF, single-point

If I got more shots like that left bird I'd be a very happy user. But it seems like those are just the occasional accidents, and ones like the right bird are more common. Since I'm getting them, I know the lens/camera combination can do it, I just need to figure out how to make a higher precentage of my shots like that one.

Allan.L wrote in post #12137112
Tripod? Were these at 500mm too? EXIF data would be useful.

Hand held

Birds - ISO 200, F/6.3, Exposure 1/1000, focal length 370
Horse Trailer - ISO 1000, F/5.6, Exposure 1/1600, focal length 150mm
Butterfly - ISO 640, F/7, Exposure 1/1600, focal length 500mm

wingandaprayer72 wrote in post #12137136
malndobe

After looking at the EXIF data embedded in your photos the most immediate recommendation is shoot in Av and set to f8. This is the sweet spot for my bigmos.

I've done a lot of shooting in AV, set to F8, also played with F9 and F10, I'm not seeing much difference in the results.

These were both cropped to show the main focal area of the photo, and get them down to 1024. The focal point in each was the head.

F8, ISO-500, 500mm, Exposure 1/640

hi..first time with my bigmos...

Hmmm something isn't right here. It could very well be the lens, have you tried shooting over 1/1000 (f8) with NO OS on? Have you micro adjusted it? If you do micro adjust, remember it will affect the entire zoom range not just one instance of it. I still think with such a big lens that lens/camera shake could very well be the culprit.. Im just giving you idea's im no pro and i cant pinpoint exactly what is wrong! This is probably pretty frustrating...

malndobe wrote in post #12137322
AF, single-point

If I got more shots like that left bird I'd be a very happy user. But it seems like those are just the occasional accidents, and ones like the right bird are more common. Since I'm getting them, I know the lens/camera combination can do it, I just need to figure out how to make a higher precentage of my shots like that one.

Hand held

Birds - ISO 200, F/6.3, Exposure 1/1000, focal length 370
Horse Trailer - ISO 1000, F/5.6, Exposure 1/1600, focal length 150mm
Butterfly - ISO 640, F/7, Exposure 1/1600, focal length 500mm

aerideata wrote in post #12137454
hi..first time with my bigmos...

Very nice, sharp images for such low shutter speeds! (the first 3 anyways) Where these hand held?

malndobe: maybe swing over to the 7d thread and ask what AF settings are most appropriate? (if you havent already) I highly suggest back button focus too (for any camera).

Allan.L wrote in post #12137605
I highly suggest back button focus too (for any camera).

What is back button focus? How does it work on the XSi?

Inspeqtor wrote in post #12137640
What is back button focus? How does it work on the XSi?

On my t2i its in custom functions, and i set it to "AE/AF, no AE lock". On the back of the camera you use the * button to focus. It allows you to focus independently of pressing the shutter. IE without it, if you fully release the shutter button and depress it again, it will re-focus which can be a big hindrance to getting the shot.

malndobe wrote in post #12137322
AF, single-point

I meant what mode...AI focus, Ai servo, or One-shot

for all your shots, i think one shot should've been used...if it was any of the other modes, the lens is always kinda hunting in those...servo is good for moving subjects...ai focus is just plain crap...

Not that combination of shutter and f-stop with OS off. There are some photos earlier in this thread, on page 154, that I took with OS off, AV mode, F8, but the shutter speed was slower.

I'll try that this afternoon, and post some results.

DreDaze wrote in post #12137831
I meant what mode...AI focus, Ai servo, or One-shot

for all your shots, i think one shot should've been used...if it was any of the other modes, the lens is always kinda hunting in those...servo is good for moving subjects...ai focus is just plain crap...

Probably Al focus, I switch back and forth between that and One shot depending on if I'm trying to get still subjects or moving subjects. The birds were probably in Al Focus, since I was actually trying to catch them in flight. Not very successfully LOL They are small and FAST, but it's good practice.

malndobe wrote in post #12138051
Probably Al focus, I switch back and forth between that and One shot depending on if I'm trying to get still subjects or moving subjects. The birds were probably in Al Focus, since I was actually trying to catch them in flight. Not very successfully LOL They are small and FAST, but it's good practice.

i'd recommend not using AI focus...i've never gotten good results with it with any lens...

my saying is...if it's not moving One-shot, if it's moving AI servo, and if you want nothing in focus AI-focus

DreDaze wrote in post #12138064
i'd recommend not using AI focus...i've never gotten good results with it with any lens...

my saying is...if it's not moving One-shot, if it's moving AI servo, and if you want nothing in focus AI-focus

x2, i never use AI-focus

DreDaze wrote in post #12138064
i'd recommend not using AI focus...i've never gotten good results with it with any lens...

my saying is...if it's not moving One-shot, if it's moving AI servo, and if you want nothing in focus AI-focus

I mistyped. I am using one-shot or al servo. The one that follows the subject as it's moving.

It's good to know AI Focus doesn't work well though, I just read my manual and the Al Focus actually sounds like it would be useful, if it worked.

MUCH happier with the results, thank you AllanL, DreDaze and everyone else who gave tips. I upped my shutter speed, set F-stop to f8, and also after reading a number of threads on Focus in the 7D changed the Al Servo tracking sensitivity, putting it 1 notch to the slow side.

No processing done except to crop and resize to meet the 1024 rule. These were "average" for what I got, only a few had that soft look the right side bird had in my previous post.

F8, ISO 800, Shutter Speed 1/2000, focal length 500mm