Canon 100-400L and Filters

[qwerty]

I have been trying to figure out why I could not get shots in good sharp focus with this lens. I found something interesting this morning on another forum that I hadn't seen here and thought I would pass along. The original poster was having the similar focus issues even on a tripod. Several people asked him if he had a filter on the lens. It got me to thinking so I checked mine and sure enough I had put my UV filter on it as soon as I got the lens. I removed the filter and tomorrow will go test it out.

I believe my issues have been a comedy of errors. 1) Slow shutter speeds- hand held. I think I fixed this by going to Tv and setting the shutter to at least 1/400 but faster when possible. I increase the ISO to alow me to get there when the apeture is full open and needs more.

2) Hand holding in general- I borrowed a monopod which helped and have since ordered both mono and tripods.

3)Focus soft at full extension (400mm)- This I haven't tried yet but it was suggested to pull back maybe 20mm to 380 or so to get sharper focus since the lens is known to be soft at the full 400. I plan to try this tomorrow along with the other techniques. I'll post the results.

[pjt72611]

I rented a 100-400 L before our big summer trip to Grand Teton NP and Yellowstone. I wish I had read this before then. I also found the focus to be soft at 400. Good advice, thank you for sharing.

[newtune3]

Also do not shoot this lens wide open and expect sharp. Stop down one and you should cut your finger, but wide open and 400 mm is not the way to do it. Keep the shutter speed up and the lens stopped down a stop and see what happens. You should be amazed. Good luck!!!

[Tim T]

I use my 100-400 wide open at 400mm most of the time for wildlife shots and get sharp photo's except when I screw up. I'd get rid of the UV filter, keep the shutter speed up when possible and use a tripod. If you are still having sharpness issues, consider sending it back to Canon for calibration. I sent mine in for service a few years ago and it made a big difference.

[qwerty]

I went to BNC yesterday morning to test things out after having removed the filter. These shots are all hand held since my pods didn't make it to the porch yet. I was pleased with the difference and can't wait till I get the tripod. C&C welcome.