# why has canon converted to 82mm filter size?



## RGF (Apr 22, 2016)

The newest version of the 16-35 and 24-70 F2.8 lenses have 82mm filters. Previous versions had 77mm filters.

5mm is not a lot of distance (0.5 cm or 0.2 inches). The additional barrel size is not due to added IS - neither the 16-35 II F2.8 or 24-70 II F2.8 have IS.

Wonder if Canon made the front of the lens just a tiny bit smaller than the barrel to allow 77mm filters. With the 24-70 would not have vignette, perhaps a challenge for the 16-35?


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## cdang (Apr 22, 2016)

The newest version of the 16-35 is 77mm. The older 16-35 F2.8 is 82.


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## neuroanatomist (Apr 22, 2016)

The newer 16-35 has a slightly larger front element, not 5mm worth but perhaps enough to bump to 82mm filters. The 24-70 was a major redesign, particularly going to the 'normal' zoom direction. 

In both cases, I suspect the filter size increase was to improve vignetting with a filter in place. I rather think they should have also increased the filter thread of the 70-200/2.8 IS II, since that lens has a 77mm filter and shows increased vignetting with a standard UV filter. 



cdang said:


> The newest version of the 16-35 is 77mm. The older 16-35 F2.8 is 82.



He's talking about original vs. MkII versions of the 16-35mm and 24-70mm f/2.8 lenses, not the f/4 versions.


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## slclick (Apr 22, 2016)

Sales of course! But seriously, larger front elements require a larger filter. It's easy.


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## RGF (Apr 22, 2016)

slclick said:


> Sales of course! But seriously, larger front elements require a larger filter. It's easy.



but how many people buy Canon filters? No many, and the few sales they would get is not worth the bad vibes from the user base.


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## slclick (Apr 22, 2016)

RGF said:


> slclick said:
> 
> 
> > Sales of course! But seriously, larger front elements require a larger filter. It's easy.
> ...



I never said anything about Canon brand filters. Partnerships, marriages, businesses aligning....nothing new here.


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## neuroanatomist (Apr 22, 2016)

slclick said:


> Sales of course! But seriously, larger front elements require a larger filter. It's easy.



Except that the 24-70/2.8 front element seems to be essentially the same diameter, and the 16-35's is only very slightly larger (1-2mm, probably could have been accommodated in the original front housing).


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## romanr74 (Apr 23, 2016)

I honestly believe you read way too much into that... To me it feels like the filter size is just a result of the optical design. I don't think they melt their brains over that topic...


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## retroreflection (Apr 23, 2016)

Any design is a compromise of competing concerns.

- Lens customers want to use their existing stock of filters.
- Lens customers want edge to edge sharpness.
- Lens customers want minimal vignetting.
- Lens customers want to show off great test charts and reviews while they are not shooting.
- Trolls want to obsess over test charts and reviews.

Prioritize that list according to real customer behaviors, conservation of existing filters loses every time. Hell, we'll even buy a lens with no filters available.


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## JonAustin (Apr 23, 2016)

I was mildly curious about this, as well, when these lenses were first announced. I appreciate the information provided in the responses above. (And I agree with *neuroanatomist's* observation about the 70-200 II.)

I don't own either of these lenses, nor do I use filters very often, so it's only of passing interest to me. Lightroom does a great job of using lens profiles to adjust for vignetting (and do other apps, I'm sure), and rarely is there anything of much interest in the corners of the frames.

Still, I would be irritated if I were striving for corner sharpness and minimal vignetting, and realized that the filter I was using was inhibiting either, and there was nothing I could do about it. Good filters are expensive, but still minor, relative to the price of these lenses. I have a small collection of 77mm filters, but wouldn't hesitate to buy some good 82's, were I to buy a lens that required them.


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## RGF (Apr 28, 2016)

dilbert said:


> RGF said:
> 
> 
> > ...
> ...





Perhaps Canon decided to use the same filter size across both lenses? the 82mm filter may have been necessary for the 16-35 (unless thin filters were used).


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## kaihp (Apr 28, 2016)

neuroanatomist said:


> I rather think they should have also increased the filter thread of the 70-200/2.8 IS II, since that lens has a 77mm filter and shows increased vignetting with a standard UV filter.



I have long suspected that a 70-200/2.8 IS III will have a 82mm filter.

Only time (and Canon) will tell!


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## slclick (Apr 28, 2016)

We adapted to different cards, we adapted to different batteries, filters are no different. They all start out at egregious prices and come back down to earth after a bit. Same as it ever was.


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## seamonster (Apr 28, 2016)

Its the way lens design is going in general. Minimum exit pupil diameter (true front element size) is defined by focal length divided by maximum aperture. 

A 50mm 1.4 only "needs" a front element diameter of 36mm but doing that is going to result in a crappy lens that is going to vignette like crazy and probably only have a very small center area of usable resolution. Look at how much bigger a front element the Sigma 50mm ART uses. If you've got the rest of the elements in the lens sorted out then you NEED a big(ger than the minimum required) front element to complete the package. Its all about light gathering.


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## ahsanford (Apr 28, 2016)

neuroanatomist said:


> The newer 16-35 has a slightly larger front element, not 5mm worth but perhaps enough to bump to 82mm filters. The 24-70 was a major redesign, particularly going to the 'normal' zoom direction.
> 
> In both cases, I suspect the filter size increase was to improve vignetting with a filter in place. I rather think they should have also increased the filter thread of the 70-200/2.8 IS II, since that lens has a 77mm filter and shows increased vignetting with a standard UV filter.
> 
> ...



The only beef I have with the two new f/4L zooms (I own + love both) is the 24-70 f/4L IS, which vignettes with a _standard_ B+W 77mm CPL, something I never experienced on my prior 24-70 f/2.8L I. It's not a show stopper so much as a head-scratcher -- the 16 end of the 16-35 f/4L IS doesn't vignette with the same filter.

- A


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## GMCPhotographics (Apr 29, 2016)

ahsanford said:


> neuroanatomist said:
> 
> 
> > The newer 16-35 has a slightly larger front element, not 5mm worth but perhaps enough to bump to 82mm filters. The 24-70 was a major redesign, particularly going to the 'normal' zoom direction.
> ...



I've used a 77mm polariser on my my 16-35IIL (82mm thread) using a step down ring...worked fine and no mechanical vignetting seen at 16mm


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## ahsanford (Apr 29, 2016)

GMCPhotographics said:


> ahsanford said:
> 
> 
> > The only beef I have with the two new f/4L zooms (I own + love both) is the 24-70 f/4L IS, which vignettes with a _standard_ B+W 77mm CPL, something I never experienced on my prior 24-70 f/2.8L I. It's not a show stopper so much as a head-scratcher -- the 16 end of the 16-35 f/4L IS doesn't vignette with the same filter.
> ...



Sorry, perhaps I've misstated the situation. The 16-35 f/4L IS takes a standard (not 'slim') CPL and the vignetting is nonexistent at 16mm. It's totally fine with a 77mm standard CPL.

_That same CPL_ on the 24-70 f/4L IS vignettes at 24mm. 

It's like Canon nailed the filter thread distance to the front element on the 16-35 f/4L IS and completely pooched it on the 24-70 f/4L IS. Very, very odd.

- A


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## J.R. (Apr 29, 2016)

RGF said:


> how many people buy Canon filters?



I do ... slightly expensive in my country, but they are quite good. 

That being said, if B+W were available, I probably would have gone for those.


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## LDS (Apr 29, 2016)

ahsanford said:


> It's like Canon nailed the filter thread distance to the front element on the 16-35 f/4L IS and completely pooched it on the 24-70 f/4L IS. Very, very odd.



Not odd. Look at the size of the front elements of both lenses and you'll understand why it happens.

Sometimes keeping a constant filter size for a group of lenses probably going to be used together may lead to some compromises.


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## ahsanford (Apr 29, 2016)

LDS said:


> ahsanford said:
> 
> 
> > It's like Canon nailed the filter thread distance to the front element on the 16-35 f/4L IS and completely pooched it on the 24-70 f/4L IS. Very, very odd.
> ...



In this case, it wouldn't be the size of the front element (77mm should work absolutely fine at 24mm on FF), it's something about the *design* of the threads.

I just pulled both lenses out. Turns out there isn't much of a difference in the two lenses' elevation/distance of the front filter ring to the front element -- it's about the same to my eye (I lack the height gauge to check that properly/safely). But interestingly, it appears that the filter threads on the 16-35 f/4L IS are far thinner / offer less turns of thread engagement. That would lead to a thinner filter ring than the 24-70 f/4L IS, which has at least two more turns to my eyes. 

This very well may explain why that 16-35 is vignette free with a standard CPL and also  impressively vignette free with a Lee 4x4 / 4x6 filter setup -- it appears this 16-35 was 'optimized' for the filtering crowd in a way the 24-70 f/4L IS was not.

- A


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