The New Canon 400mm f/2.8, IS II lens --BIF - Looking for suggestions

Hi,

I was fortunate to receive the new Canon 400mm f/2.8 lens yesterday. It is unbelievably sharp even with a 2x III TC on it. That's the good news. The bad news is that especially with the 2x TC, the autofocus is quite slow. It will work fine for birds that are perched or are moving short distances at a time, but for BIF I was having problems with it. For example, I had a short-eared owl flying right towards me and as it came closer, it moved off of the center focus point long enough for the camera to lose focus (not the lens's fault, my own) but attempting to regain focus was painfully slow and the bird was already overhead by the time the focus recovered. The speed to regain focus was just too slow. It is faster with a 1.4x TC and much faster without any TC, but I thought it would perform better than this considering it is a f2.8 lens.

I have many years worth of experience with BIF using Canon 500mm and 600mm lenses and both are fast with 1.4x TCs on them and not too bad with 2x's either.

Can anyone offer any suggestions? I had heard that the first version of this lens had similar problems but thought the newer lens with the new 2x TC would work better. 800mm @ f/5.6 should not be a problem for a Mark IV or 7D.

Thanks,

Alan

I may have found the answer to my own question...According to Chuck Westfall, the 1.4xTC reduces autofocusing speed by 50%, 2.xTC by 75%. I never really noticed the reduction with my 600mm with a 1.4, but 75% reduction on the 2x is substantially more.

I found this information on the-digital-picture.com website:

http://www.the-digital-picture.com/R...II-Review.aspx

According to Chuck Westfall (Canon USA): "As with previous EF Extenders, usage of Series III EF Extenders lowers AF drive speed to improve AF performance. When Extender EF 1.4X III is used, AF drive speed is reduced by 50%. When Extender EF 2X III is used, AF drive speed is reduced by 75%. This may seem like a drawback, but in reality subject tracking performance remains quite high when Series III Extenders are used with IS II lenses. This is due to improvements in AF precision made possible by the new microcomputer in the extenders."

I guess it doesn't matter if it's a 2.8 lens or not. It appears the TC purposely slows down the autofocus speed for accuracy's sake. As they say... no free lunch!

Alan

I had a chance to use the new 400mm f/2.8 II with a 2x III at the Bosque last week, and my experience matches yours. A poor choice as a flight lens combo at 800mm IMO, although the results are optically very good. Here's a 100% crop of a flight shot with default LR sharpening only.

Attachment 104494

Thanks Doug,

I'm glad to learn it isn't "just me". Interestingly, I plan to photograph sandhill cranes tomorrow with it and I'm going to see if I can do anything to increase the keeper rate. What are your thoughts with using a 1.4x? Did you get a chance to try that combo?

Thanks again,

Alan

Quote:

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Originally Posted by Alan Stankevitz

What are your thoughts with using a 1.4x? Did you get a chance to try that combo?

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Performance is much better with the 1.4x III. Have a good time!

I had the same experience with the new 300mm f/2.8 II lens. With the 2X TC, the AF module gets really slow.
I tried setting the focus limiter to 6m-inf though and the response seemed much better. Hope it helps...

Quote:

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Originally Posted by Doug Brown

I had a chance to use the new 400mm f/2.8 II with a 2x III at the Bosque last week, and my experience matches yours. A poor choice as a flight lens combo at 800mm IMO, although the results are optically very good. Here's a 100% crop of a flight shot with default LR sharpening only.

Attachment 104494

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Doug,

Your intentions are admirable, but you know as well as i do that posting images like this will not really benefit anyone trying to discern whether a lens is sharp or not.

Best,

Chas

How about a non-Canon TC? Do they suffer the same speed issues?

Alan,

What are your thoughts overall on the lens aside from the slow focusing with the teleconverters? I have been salivating over a 400mm lens, and am wondering if it is worth aspiring for this version or picking up one of the older, less expensive versions. I am particularly interested in the lighter weight of this lens as I tend to shoot handheld. I have seen some reviews that this lens is less sharp with 1.4x and 2.0x extenders than the previous verions, but my plan would be to primarily use it standalone in which case it seems that the optical quality of this lens are superior. What is your opinion on cost vs. performance?

Hi Rhys,

I never had owned the previous version, but I can't imagine it being not-as-good as the previous version with TC's as far as sharpness is concerned. I found the sharpness of this lens unbelievably sharp! Even with a 1.4x and 2x TC. I also found the weight just wonderful. I felt quite comfortable hand-holding this lens. Quite a few times that I was testing this lens out from my car, I lifted it off of the bean bag and hand-held it to photograph BIF. I quickly fell in love with this lens.

I can't tell you how often I thought about not returning this lens. But...my wallet is only big enough for one of these version II lenses. I felt that too often I would be kicking myself for buying this lens instead of waiting for the 600mm II to become available. Every time I would miss a shot due to slow autofocus, I'd be wishing I would have waited.

As far as cost...all of the new lenses are overpriced as far as I'm concerned but I really want a hand-holdable 600mm lens and I'm willing to pay the premium for it. I do believe the dollar vs the yen has something to do with the lens prices nowadays. If the current trend was ever to reverse, maybe the prices would drop a bit on these lenses, but I don't see that happening any time soon.

Hope this helps,

Alan