Canon 400mm L 5.6 .. So what's changed in 19 years?

[Edwin Herdman]

Funny that the latest (so it would seem) reference available to Canon techs about the lens is dating from the original 1D.

IS aside, and maybe some lens production aside, Canon doesn't seem to have a big reason to update this lens. I still see lots of people mentioning they use it here and there, and it seems a pretty good bang for the buck.

What's changed since the lens was released is the advent of Diffractive Optics...oh, nevermind. (The 200-400mm DO IS USM and the 500mm f/2.8 are still AWOL, and nothing else has come of the technology, still, besides the 70-300mm DO.)

Something I thought was interesting was the 400mm f/4 comparison lens (a mockup? or a rival prototype?) Canon used in its early promotional material (still available around the web where the press release is mirrored, i.e. DPR) which looked identical to the DO lens but just longer. I would think that moving from f/5.6 to f/4 would be highly worthwhile and would add some speed to AF without quite reaching f/2.8L prices - but realistically, Canon only needs to have the f/5.6 for people who are really pressed for cash but need a 400mm option (usually those who would rather have a 500mm f/4 or longer, I suspect). People who want AF speed and better background blur have at least two newer-than-the-5.6L choices in f/2.8L lenses. The f/4 DO is probably not as good as a non-DO f/4 but they have little reason to create another lens with that focal length and aperture. I think the 400mm f/5.6 is going to be played out until it becomes really embarrassing to the line in terms of sharpness - somewhat like the 100-400mm L which is still selling like crazy and has no replacement in sight (even thought the new 70-300mm L shows it's quite possible to better it optically).

 

[kubelik]

I like edwin's comment about a 400 f/4 ... I'd like that, which I could then stick a 1.4x on top of to get a cheap-ish, easy 560 f/5.6, or just a straight 500 f/5.6 ... which would definitely save some cost and probably also some weight.

 

[Mt Spokane Photography]

I like edwin's comment about a 400 f/4 ... I'd like that, which I could then stick a 1.4x on top of to get a cheap-ish, easy 560 f/5.6, or just a straight 500 f/5.6 ... which would definitely save some cost and probably also some weight.

Which 400mm f/4 are you discussing? The existing one is not cheap, and does not take TC's particularly well. A new 400mm f/4 would certainly be in the $7,000 range.

 

[kubelik]

I wasn't discussing the existing 400 f/4, whose price is blown way out of line because of the DO. I think a 400 f/4 L IS could easily fall into the $5K or $6K range (even $7K would mean plenty of people would buy this over a 400 f/2.8 monster) ...

I'll get back on my favorite topic: as I've stated a number of times before, I think the ideal lens for telephoto prime in the prosumer range would be a 500mm f/5.6 L IS. you could do that for probably around $2K to $3K, meaning it would be a great entry-level supertelephoto L lens for the prosumer crowd. it would be a relatively light and cost-effective means of getting to 500mm and still be able to have it AF with any body ... which right now, simply doesn't exist. you have to go to sigma and buy an optically poor zoom to get you to 500mm for the time being on a non-1-series body.

 

[WarStreet]

A 400mm f4 non DO would be great. We have the 300mm 2.8 + TC for this, but if we need 400mm, getting the native FL is better. The price of the 400mm f4 would be similar to the new 300mm 2.8 IS II, about $7000 release price.

I did considered The 400 DO since the low weight was a great advantage, but the reason for such a lens for me would be to get more background blur quantity, but unfortunately, this lens has horrible bokeh, so it defeats the purpose.

 

[Edwin Herdman]

Random guess about a possible reason Canon avoids a 500mm f/5.6: Canon would want to avoid cheapskates (like me) from buying such a lens and then complaining about its "poor autofocus performance" when they use it on cheap Rebel (#00D) bodies. The 500mm f/4 is expensive, but I bet that stop of light gained would be a big benefit. I know that my cheap-o Sigma 120-400mm has a tough time focusing on stuff at 400mm (where it is f/5.6).

And on the other hand, while the price savings would probably be substantial, I wouldn't be surprised if it still wasn't enough to really satisfy cheapskates, and pros would generally rather stick to their f/4 aperture.

 

[kubelik]

@edwin: I don't know much about lens optics. would a 500 f/5.6 be darker than a 400 f/5.6? from what I've heard, the 400 f/5.6 is a pretty good lens as far as AF speed and accuracy go, so would keeping the same max aperture really hurt that? I do understand we're dealing with shallower depth of field because of the focal length, how big of a deal is that?

 

[Loswr]

@edwin: I don't know much about lens optics. would a 500 f/5.6 be darker than a 400 f/5.6? from what I've heard, the 400 f/5.6 is a pretty good lens as far as AF speed and accuracy go, so would keeping the same max aperture really hurt that? I do understand we're dealing with shallower depth of field because of the focal length, how big of a deal is that?

A 500mm f/5.6 would project the same amount of light on the image and AF sensors as a 400mm f/5.6 - that's solely a function of iris diaphragm diameter (89.3mm for 500/5.6, 71.4mm for 400/5.6).

Random guess about a possible reason Canon avoids a 500mm f/5.6: Canon would want to avoid cheapskates (like me) from buying such a lens and then complaining about its "poor autofocus performance" when they use it on cheap Rebel (#00D) bodies. The 500mm f/4 is expensive, but I bet that stop of light gained would be a big benefit. I know that my cheap-o Sigma 120-400mm has a tough time focusing on stuff at 400mm (where it is f/5.6).

The stop of light is a benefit gained for shutter speed, no effect on AF performance. For anything other than a 1-series body, the off-center AF point sensors are f/5.6-sensitive - an f/4 lens does not provide any additional sensitivity or accuracy - an f/4 lens is the same as f/5.6 for the AF system. The center AF point on recent non-1-series bodies is f/2.8 sensitive, so f/4 doesn't help there, nor does faster than f/2.8. For a 1-series body it would make a difference - the high-precision center AF point on those bodies is f/4-sensitive.

Sorry, Edwin - your Sigma 120-400mm has a tough time focusing on stuff at 400mm (where it is f/5.6) not because it's f/5.6, but because it's a cheap-o lens and the AF system in the lens is not that good.

 

[dr croubie]

Sorry, Edwin - your Sigma 120-400mm has a tough time focusing on stuff at 400mm (where it is f/5.6) not because it's f/5.6, but because it's a cheap-o lens and the AF system in the lens is not that good.

I'll certainly vouch that my 15-85 @ 85mm and 70-300L @ 300mm (both at f/5.6) have no troubles focussing in all but the darkest rooms. 50 f/1.8 isn't so bad (because it's fast), but 70-300nonL @ 300mm occasionally had some troubles in a bit of darkness, lower quality AF than the L-version...

 

[Edwin Herdman]

The stop of light is a benefit gained for shutter speed, no effect on AF performance. For anything other than a 1-series body, the off-center AF point sensors are f/5.6-sensitive - an f/4 lens does not provide any additional sensitivity or accuracy - an f/4 lens is the same as f/5.6 for the AF system. The center AF point on recent non-1-series bodies is f/2.8 sensitive, so f/4 doesn't help there, nor does faster than f/2.8. For a 1-series body it would make a difference - the high-precision center AF point on those bodies is f/4-sensitive.

Sorry, Edwin - your Sigma 120-400mm has a tough time focusing on stuff at 400mm (where it is f/5.6) not because it's f/5.6, but because it's a cheap-o lens and the AF system in the lens is not that good.

It is a cheap-o lens, no argument there! AF is a rather complicated topic, but here is my reasoning:

1.) The "tape trick" enables autofocus, albeit slowly, with apertures slower than the "hard limits" (which are really just soft limits) of the camera. (Though, to be fair, we've gone from a lens-assisted AF to one where only the camera body is guessing at it, so that's not definite proof.)

2.) Even good lenses have trouble autofocusing in low light. (Which would seem analogous to moving up steps in aperture somewhere between f/2.8 and f/5.6 or f/8.)

There are plenty of anecdotes, like this from The Digital Picture:

Another negative aspect to shooting with the Canon EF 1.4x II Extender attached is the resulting reduction in autofocus speed. This can be an issue if you are shooting in low light and/or are using a lens that is not very fast focusing (such as the Canon 180 L lens mentioned above).

That would be a reduction from f/3.5 to f/5 - neither f-number is at or passing any limits in sensitivity of the autofocus system. The problem with that example being used to prove my particular theory is that the teleconverter's AF chip is used, not the 180 Macro's.

More relevant, but gratingly unsourced, this from the Wikipedia article on autofocus:

The speed of the AF system is highly dependent on the maximum aperture offered by the lens. F-stops of around f/2 to f/2.8 are generally considered optimal in terms of focusing speed and accuracy. Faster lenses than this (e.g.: f/1.4 or f/1.8) typically have very low depth of field, meaning that it takes longer to achieve correct focus, despite the increased amount of light.

If true, that's essentially exactly what I'm saying.

I suppose the argument that absolute aperture doesn't matter would be that the AF zone system works like the grid on a default bright focusing screen for viewfinders, which do not demonstrate real DOF effects at apertures wider than around f/2.8, regardless of how much faster the lens really is, and furthermore don't appear to get dimmer until you stop down past f/2.8.

Looking again I see the 120-400mm is a fairly old lens (c. 2001-ish). Sigma has been known to rechip lenses with newer AF parts, and I don't know the date of manufacture. It's probably a fairly recent make though (bought off Amazon at the beginning of 2011).

I'm curious...did you have any tests or sources available that confirm what you're saying? I've had limited experience thus far with autofocus but even that little seems enough to confirm my suspions all along.

It will be interesting to see what happens when I get that 2X extender, which will make the maximum aperture of the new 120-300mm f/2.8 OS roughly equivalent to the maximum aperture of the 120-400mm OS. (Would be yet more interesting to compare it with the Sigma version's AF; alas, I have no Sigma version on hand...if I need the Sigma version, that'll mean I have no lens compatible with the Canon 2X III for doing a direct comparison of the two teleconverters and their effects on autofocus, however.)

I would certainly be most comfortable agreeing that the actual AF systems involved can have a sizable impact on AF performance, but when you start gaining or losing a stop or more, even the best AF detection routines are likely to be taxed.

 

[Edwin Herdman]

Update: It's not the lens, it's the camera...the 120-300 f/2.8 still hunts now and then in more or less the same situations that the 120-400mm did. Now I'm interested to see what a better AF sensor would do.

 

[Loswr]

Update: It's not the lens, it's the camera...the 120-300 f/2.8 still hunts now and then in more or less the same situations that the 120-400mm did. Now I'm interested to see what a better AF sensor would do.

Ok, so not a cheap-o lens. But still, a Sigma lens, and Sigma has to reverse-engineer the AF algorithms, plus the fact that Sigma lenses are often reported as having less than stellar AF. So, frankly, I'm still not convinced it's the camera. Does a Canon lens of the same aperture hunt like the Sigmas do?

 

[kubelik]

here's why I believe a 500mm f/5.6 L IS would have pretty good AF speed and accuracy:

1. people have been highly complementary of the Canon 400mm f/5.6 L, which we've noted is the same max aperture

2. my 70-200mm f/2.8 L IS II on a 5DII body focuses pretty quick except in extremely low lighting situations. most people agree that a native f/5.6 lens will AF better than an f/2.8 lens + 2x extender, so if the 70-200 is already pretty good, a 500 f/5.6 would be better.

that's good enough for me, and I suspect for almost anyone interested in buying a 500 f/5.6

 

[Loswr]

most people agree that a native f/5.6 lens will AF better than an f/2.8 lens + 2x extender, so if the 70-200 is already pretty good, a 500 f/5.6 would be better.

The accuracy should be equivalent with and without extender. But using the 2x extender will result in ~50% slower AF, by design, than the bare lens; a 1.4x extender slows AF speed by ~25%, also by design.

 

[autochrome]

On the weather sealing issue, seems all pre-1999 lenses have some basic form of weather sealing:

Chuck Westfall (Canon USA) has provided information about the weather sealing found in some pre-officially-sealed lenses.

According to Mr Westfall, "Pre-1999 white EF lenses such as the 200/1.8L, 300/2.8L, 300/4L, 300/4L IS, 400/2.8L, 400/5.6L, 500/4.5L, 600/4L, 35-350/3.5-5.6L, 70-200/2.8L, and 100-400/4.5-5.6L all lack mount gaskets but have moderate dust and moisture resistance for their switches, focusing rings and zoom rings where applicable."

For example, "The EF400mm f/5.6L USM lens was designed before Canon started offering "dust and drip resistant" lenses, so it does not have a mount gasket or a built-in protective filter. However, it does have seals under the switches and the focusing ring, so it is weather-resistant to a point. For best results in wet conditions, I suggest using a clear filter on the front of the lens and covering the lens barrel with a plastic wrap."

"Canon will not retrofit mount gaskets to EF lenses that were not introduced with that feature." I of course had to ask that question.

(Thanks John!)

http://www.the-digital-picture.com/News/News-Post.aspx?News=996&Title=Partially-Weather-Sealed-Canon-Lenses


The 400mm f5.6L is tempting. Sure the IS would be nice, but the price would jump from 1300 euros to 2500 at least, that's almost certain (if not more, judging by the massive leap in price in the latest super telephotos with the addition of IS mode 3) - and this when Canon decides it's time to update it, which probably won't happen soon. Everything considered it seems the best bargain around, price and optical quality considered. The lack of full weather sealing is another annoyance though. Other ones that also need weather sealing are the 35mm f1.4L, 85mm f1.2L, 200mm f2.8L II, 180mm f3.5L macro and 135mm f2.0L at least, some of which were rumoured to be replaced here (the 35mm and the 135mm if i remember it well).

 

[Loswr]

On the weather sealing issue, seems all pre-1999 lenses have some basic form of weather sealing:

Chuck Westfall (Canon USA) has provided information about the weather sealing found in some pre-officially-sealed lenses.

According to Mr Westfall...

(Thanks John!)

http://www.the-digital-picture.com/News/News-Post.aspx?News=996&Title=Partially-Weather-Sealed-Canon-Lenses

Yep. In fact, it was this very thread that resulted in the news post on Bryan's TDP site. From p.2 of this thread:

I'll do a little more digging...

Apparently, the 400mm f/5.6L is partially sealed. According to Chuck Westfall (Canon's tech support guru)...

My 'digging' consisted of contacting Mr. Westfall, and I forwarded his responses to initial and follow-up questions to Bryan at TDP (John = me, neuroanatomy is part of my day job ), thinking the fact that these 'unsealed' lenses do have partial sealing was pretty interesting and worth disseminating. In particular, the fact that a push-pull zoom like the 100-400mm actually has dust-resistant seals around the zoom ring is worth noting, since that lens is sometimes aka the "dust pump."

Other ones that also need weather sealing are the 35mm f1.4L...

I agree...but remember that for sealing on a lens to be effective, the body must also be sealed, and although some non-1-series bodies have partial sealing, only the 1-series are truly weather-sealed (the rank ordering for sealing is 1-series >> 7D > 5DII = 50D/60D).

 

[autochrome]

On the weather sealing issue, seems all pre-1999 lenses have some basic form of weather sealing:

Chuck Westfall (Canon USA) has provided information about the weather sealing found in some pre-officially-sealed lenses.

According to Mr Westfall...

(Thanks John!)

http://www.the-digital-picture.com/News/News-Post.aspx?News=996&Title=Partially-Weather-Sealed-Canon-Lenses

Yep. In fact, it was this very thread that resulted in the news post on Bryan's TDP site. From p.2 of this thread:

somehow i missed that

I'll do a little more digging...

Apparently, the 400mm f/5.6L is partially sealed. According to Chuck Westfall (Canon's tech support guru)...

My 'digging' consisted of contacting Mr. Westfall, and I forwarded his responses to initial and follow-up questions to Bryan at TDP (John = me, neuroanatomy is part of my day job ), thinking the fact that these 'unsealed' lenses do have partial sealing was pretty interesting and worth disseminating. In particular, the fact that a push-pull zoom like the 100-400mm actually has dust-resistant seals around the zoom ring is worth noting, since that lens is sometimes aka the "dust pump."

I see You're the person that asked about the gasket retrofitting? That would've been great to have, even unnoficially, or even implying voiding the warranty.

Other ones that also need weather sealing are the 35mm f1.4L...

I agree...but remember that for sealing on a lens to be effective, the body must also be sealed, and although some non-1-series bodies have partial sealing, only the 1-series are truly weather-sealed (the rank ordering for sealing is 1-series >> 7D > 5DII = 50D/60D).

At the moment i have a 7D. I thought about a 2nd body, a 5D Mk.II, but resisted the temptation and invested in lenses instead. I'll skip the 5D Mk.II and get a 1D when the time is right.
In fact i just got the 400mm, lack of full weather sealing and all. I thought the lack of IS would make it unusable (since it's a 640mm equivalent on APS-C), but it's not that bad. I'll just have to get some sort of weather protection when using it outdoors, other than this issue, my first impressions are positive. The 100-400mm was too cumbersome, i would be using it at 400mm mostly, and i got the 70-200mm range covered already. I'm not sure the 400mm f4.0 DO is fully weather sealed, but at the price Canon is charging for the DO you can make a bit of extra effort and go straight to the 500mm which is a far better investment (and would be even better if it included a chiropractor ).

 

[Loswr]

I see You're the person that asked about the gasket retrofitting? That would've been great to have, even unnoficially, or even implying voiding the warranty.

No, Bryan asked about the retrofitting. I posed the original question to Mr. Westfall about sealing on the 400/5.6L.

At the moment i have a 7D. I thought about a 2nd body, a 5D Mk.II, but resisted the temptation and invested in lenses instead. I'll skip the 5D Mk.II and get a 1D when the time is right.
In fact i just got the 400mm, lack of full weather sealing and all. I thought the lack of IS would make it unusable (since it's a 640mm equivalent on APS-C), but it's not that bad. I'll just have to get some sort of weather protection when using it outdoors, other than this issue, my first impressions are positive. The 100-400mm was too cumbersome, i would be using it at 400mm mostly, and i got the 70-200mm range covered already. I'm not sure the 400mm f4.0 DO is fully weather sealed, but at the price Canon is charging for the DO you can make a bit of extra effort and go straight to the 500mm which is a far better investment (and would be even better if it included a chiropractor ).

Almost always good advice to invest in lenses more than bodies. The 400mm f/4 DO is fully weather-sealed, yes, but I agree - the reduced contrast with DO is a turn-off, especially in that price bracket.

The 100-400mm is bulky, but one thing I like over the 400/5.6 is that the 100-400mm stores more compactly - I frequently go out with the 7D + 100-400mm in a Toploader Pro 75 AW and it's a perfect fit; the 400/5.6 is too long for that.