This time from the 20D and the Sigma 80-400 EX.
I am very disappointed with the flare from the lights, compared to the FZ20B
Also the red/blue fringing off centre is annoying.
And the vignetting wide open at 800mm, goes away a couple of stops down.
All in all, disappointing for £780.

Last two shots of the winner are crops from the original. One at about 1/3 size then scaled to 640x480, the last a direct crop at 100%.

Paul,

Looks like pretty standard teleconverter problems. I guess you are using a 2xTC from your post regarding 800mm and from the "star" bursts in your first post which have 18 'points' which looks like a nine-blade aperture times two.

Not that it really usually makes a difference, but are you using a Canon or Sigma TC? There is some serious element to element flaring in a couple of these photos. I hope the 80-400 isn't flaring that badly. If so I'd take it back and get another one.

My understanding is that when you lose AF with these, you also lose OS? Is that true or is the documentation vague enought to warrant emailing Sigma and finding out? Not having used the Sigma OS variant I'm curious. Some of the anomalies in your other post look like to me OS/IS at its extreme and not quite keeping up. There are some pro sports photographers who with the first IS from Canon turned it off if the action was over a certain distance away. Did you use mode 1 or 2 with the "long" shots?

I've seen IS do something strange with the Canon 20D in Auto DOF and having been using either AI Focus or AI Servo AF when rapidly changing camera to subject distance. Say from about 10 feet to 75+feet it almost seems as if the image hops? I don't know how else to describe it. It doesn't seem repeatable. Only on occasion. I do not usually shoot action or switch between moving subjecst either. I've heard some comments and would be curious to know if you've experienced anything similar. I think Single Shot AF is the fix?

I always enjoy your Motor Sports photos. As I've said before, if I only had the time. We sure had a mess here with the F1 at Indy didn't we?

This double posted for some reason? So I erased the second one.

No taleconverter, that is a 80-400 EX Zoom from Sigma.
I couldn't afford the Canon 100-400,. but may try to return the Sigma and upgrade to the Canon.
Depends on the shop though, since the Sigma is now used.

No loss of AF or OS as far as I can tell, it seemed to be working fine.
Hand held with OS in mode 1 on the lens.

The first post was with the Panasonic FZ20 P&S (from the same spot) hand held with IS in mode 1.


>> Some of the anomalies in your other post
Really? What anomalies?
Please post something in the other post thread and we can look at them.

This Sigma lens isn't supposed to look like this according to an aquaintance of mine who uses one. They wonder if the aperture blades are still moving when the camera captures the images. Yes, they report vignetting at 80mm.

The lens is apparently susceptible to dust and will flare rather badly if is dirty. This lens is supposedly not very tightly sealed in some cases.

Definitely needs adjustment or replacement. Glad to see your posts from the 100-400.

I'm not sure if the 100-400 is worth the extra £400
I won't know until the 24h race at Zolder, where our company is sponsoring a team.

Vignetting was at all focal lengths at f5.6
Even the Canon has vignetting, but not as badly.