EF 400mm f/5.6L USM image quality

Started 2 months ago | Questions thread
kristian1 Senior Member • Posts: 2,889
Re: EF 400mm f/5.6L USM image quality

Octopuss wrote:

So I bought the lens and am really perplexed: I just refuses to focus. Almost literally.

When I watched videos and read articles about it, it was praised to no end about its autofocus speed, but that seems to be the exact opposite of what I'm experiencing.

I slapped it on my 80D and it was nothing short of ridiculous. Focusing on things within say 10m distance was ok (not particularly fast but it just worked), but anything in distance flat out didn't work. There was a red crane maybe 50m away. The lens just didn't focus on it at all. I kept the shutter half pressed for three or so seconds and virtually nothing happened. I had to repeat that two or three times before the damn lens finally focused. I tried other random stuff and fairly contrasty stuff (like some black poles on blue sky background) as well with the same result.
The focus limiter didn't seem to make any difference.

I tried it on the guy's 1Ds with almost the same result and he told me it was simply an old lens and that simply was the way it worked. I didn't know any better so I bought it anyway, because it's really in absolutely mint condition as if it was just brough from a store with all the paperwork. It was manufactured in 2010.

Any ideas?

This is really strange , lens has very fast focus speed , not far away from best newest Canon lenses , it can be slow in low light or when the subject is completely out of focus but this is the way those lenses work even new 500mm f4 II is slow when it loose focus completely.

Luckily when you know how to use the lens it almost never happens.

All the best


 kristian1's gear list:kristian1's gear list
Canon EOS R Fujifilm GFX 100 Canon EF 500mm f/4.0L IS II USM Fujifilm GF 32-64mm F4 Fujifilm GF 23mm F4 +4 more
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