100-400 with IS or 400 5.6 without IS??

I'm having a very tough time deciding between these two. They are the only 400mm within my price range. The things that im most concerned with are the 100-400's "push/pull" system. I have heard that it can suck in dust to your sensor? Has anyone had a problem with this? Also, how is the sharpness on either end? Lastly, My concern with the 400 5.6 is the lack of IS. How has this lens played out for you without having IS? So with that being said, which would you choose and why?

I went through this recently and got the 100-400 (actually got two of them by accident )

At 400, IS becomes really, really useful. I hear the 400 focuses much faster though, so if you are just looking for a birding lens, I'd lean more that way, but the 100-400 is much more versatile. The push pull zoom doesn't bother me and the whole package is smaller than a 70-200 2.8. Mine is really sharp too.

I don't personally own either lens, but have used a L lens with the push-pull system. Personally, I LOVE that aspect of it. Haven't done much research on it, therefore I haven't heard of the dust issue.

What are you primarily shooting? I had the 100-400 but sold it and moved to the 400 prime. But I shoot birds with it and can count on one hand the number of times I truly wanted anything *less* than 400. Also, it's not as heavy, and it does seem to focus quicker. For me anyway, many sharper pics from the prime.

After you have the 100/400 for a few weeks, you will not have a problem with the push / pull. It really works good when you first start tracking BIF. I started with the 100/400 and thought I would do better with the 400... after spending alot of time reading and looking, I kept my 100/400... there are many times that I used it at less then 400mm and was glad I had it.

I will be mainly shooting wildlife, such as birds and other animals. Also shooting sports occasionally.

I'd get the 400 without IS, better IQ.

I much prefer the ability to zoom, and the IS, over the flat speed of the prime. Recommended highly for general wildlife use. The prime is a monster for birds in FLIGHT, specifically, due to the faster AF performance...but so far, I haven't found the LENS to be lacking when it comes to that.

The zoom doesn't move any more dust through than any, other zoom; and the sensor is covered by the shutter whenever the exposure isn't actively being taken (in which case, the lens isn't being zoomed anyway).

I've had both and prefer the 100-400L. Between the two lenses I had difficulty finding any difference in image quality or sharpness. In fact, I found the images from my 100-400L to be sharper and, at the end of the day, had more keepers.

I purchased the 400L brand new and returned it after about 3 weeks. It does have much faster AF, so if BIF is your thing, it may be a better choice for you. I did like the build quality of the 400L and the built in hood was a very nice feature.

Don't forget about the Sigma 150-500mm OS and 50-500mm OS.

Does the 400 have a significantly faster autofocus than the 100-400?

katodog wrote in post #13911374
Don't forget about the Sigma 150-500mm OS and 50-500mm OS.

The 50-500 is more expensive and has worse IQ, and has potential misfocusing issues. Why would anyone choose it over the 100-400?

Also 500mm on the sigma is more like ~470mm

blakeG! wrote in post #13911530
Does the 400 have a significantly faster autofocus than the 100-400?

According to many a birding photographer I chatted with prior to purchasing the 400mm f/5.6 ... its very fast!

I think I have read just about every post in the last 12 months comparing these two lenses plus other lenses with a tc to get to 400

I think if you where mainly shooting birds in flight the prime would be the best way to go , but if like me you want to shoot birds in flight and up trees plus other animals , zoos etc then the zoom is the way to go ( I am saving up for the zoom now ) .

But if I had a huge wad of spare cash just laying around doing nothing then I would be hanging out for the new 200-400 , maybe if I sold some body parts that i don't use much I might be able to afford one .

I honestly don't know how good or bad the 50-500mm is, I've not used it. I can speak for the 150-500mm however, and in my experience it's on the same level or better than the 100-400mm.