Zeiss ZE is for Canon!

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DanPBrown
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p.7 #1 · Zeiss ZE is for Canon!

edwardkaraa wrote:
This Farkas guy doesn't seem to know what he's talking about. I understand that the optical formula needs to be slightly modified to account for the difference in register and the lens will definitely perform better than with an adapter. But what the heck the low pass filter has to do in the lens design? Canon have changed their low pass filters practically with every new model. Some with strong AA filters, others with very weak almost non existent ones. Did they make special glass for each camera model?

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When light enters the aa filter, or any glass whether it's flat or not, it slows down and gets bent. As you can see by the diagram the light strikes the sensor at a different position than if there were no filter. The thickness of the filter will cause the light to be offset more. It is more pronounced near the edges of the sensor and non existent in the center.
It's the some reason why you shouldn't remove the clear glass drop in filters from lenses like the Canon 300mm f/2.8, the lens is designed to have glass in it's optical path.

Dan
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Sep 28, 2008 at 11:51 PM

angeloks
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p.7 #2 · Zeiss ZE is for Canon!

What would this mean if you use it on a film camera? It should be back focussing since the optical path will be shorter (without the AA)? Obviously, the lens will work on film and digital cameras just like all the other lenses. It must be a really slight tweak...

Sep 29, 2008 at 11:08 AM

DanPBrown
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p.7 #3 · Zeiss ZE is for Canon!

Here is an interesting read,
http://diglloyd.com/diglloyd/free/CoastalOptics60f4/index.html
Read the paragraph titled sensor cover glass.
Dan
www.danbrownphotography.com

Sep 29, 2008 at 11:59 AM

edwardkaraa
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p.7 #4 · Zeiss ZE is for Canon!

But Canon admittedly use filters of different thicknesses on different models. They will be removing the filter altogether in next generation cameras as they have announced themselves. Doesn't make sense to me.

DanPBrown wrote:
edwardkaraa wrote:
This Farkas guy doesn't seem to know what he's talking about. I understand that the optical formula needs to be slightly modified to account for the difference in register and the lens will definitely perform better than with an adapter. But what the heck the low pass filter has to do in the lens design? Canon have changed their low pass filters practically with every new model. Some with strong AA filters, others with very weak almost non existent ones. Did they make special glass for each camera model?

This image is copyrighted by the owner

Sep 29, 2008 at 03:53 PM

DanPBrown
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p.7 #5 · Zeiss ZE is for Canon!

Where did you hear that Canon would be removing AA filters?
Dan

edwardkaraa wrote:
But Canon admittedly use filters of different thicknesses on different models. They will be removing the filter altogether in next generation cameras as they have announced themselves. Doesn't make sense to me.

DanPBrown wrote:
edwardkaraa wrote:
This Farkas guy doesn't seem to know what he's talking about. I understand that the optical formula needs to be slightly modified to account for the difference in register and the lens will definitely perform better than with an adapter. But what the heck the low pass filter has to do in the lens design? Canon have changed their low pass filters practically with every new model. Some with strong AA filters, others with very weak almost non existent ones. Did they make special glass for each camera model?

This image is copyrighted by the owner

Sep 29, 2008 at 08:54 PM

Xavier Rival
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p.7 #6 · Zeiss ZE is for Canon!

edwardkaraa wrote:
But Canon admittedly use filters of different thicknesses on different models. They will be removing the filter altogether in next generation cameras as they have announced themselves. Doesn't make sense to me.

I never noticed such a statement. Where did you see that ? I cannot see Canon making such an announcement a long time in advance, by the way (or maybe I totally misread your post; in that case please accept my apologies).

Sep 29, 2008 at 08:56 PM

edwardkaraa
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p.7 #7 · Zeiss ZE is for Canon!

It must have been on RG website talking about the 50D "almost gapless" sensor that allows Canon to use a very weak AA filter. Canon said that in future models they will achieve truly gapless sensors and they will be removing the AA filter altogether. It could be as soon as the next upgrade of the 50D. Unfortunately the article I read seems to have been changed and this info removed, or it could be that I didn't find it. Sorry about that.

Sep 30, 2008 at 02:40 AM

Xavier Rival
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p.7 #8 · Zeiss ZE is for Canon!

I see. But was the 50D sensor not supposed to be really gapless already ? I had understood so.

<sarcasm>That is very fortunate though; it means those who get 50D already have a reason to want to upgrade it to the next generation.</sarcasm>

Sep 30, 2008 at 07:07 AM

RalphJ
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p.7 #9 · Zeiss ZE is for Canon!

The new 50D has gapless microlenses; it is the new 5D2 that does not, apparently because of issues relating to orienting the edges of a full-frame sensor to reduce light falloff. I believe Canon hopes eventually to make all of their full-frame sensors gapless as well.

Sep 30, 2008 at 01:45 PM

edwardkaraa
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p.7 #10 · Zeiss ZE is for Canon!

RalphJ wrote:
The new 50D has gapless microlenses; it is the new 5D2 that does not, apparently because of issues relating to orienting the edges of a full-frame sensor to reduce light falloff. I believe Canon hopes eventually to make all of their full-frame sensors gapless as well.

Yes, I might have misunderstood the article. I think what they said is that the gapless sensor allows them to use a very weak AA filter. And I believe they said that when they increase the pixel density in future models, there will be no need for the filter. Now I'm confused

Sep 30, 2008 at 03:24 PM

formula4speed
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p.7 #11 · Zeiss ZE is for Canon!

I apologize if this has been covered, but I've been looking and can't find it. Are there any precise release dates for specific lenses? I'm curious to see the 25mm f/2.8 as a landscape lens.

Sep 30, 2008 at 04:22 PM

edwardkaraa
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p.7 #12 · Zeiss ZE is for Canon!

formula4speed wrote:
I apologize if this has been covered, but I've been looking and can't find it. Are there any precise release dates for specific lenses? I'm curious to see the 25mm f/2.8 as a landscape lens.

50 and 85 in November. 21 in early 2009.

Sep 30, 2008 at 04:35 PM

shiwan
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p.7 #13 · Zeiss ZE is for Canon!

Sep 30, 2008 at 06:51 PM

Andi Dietrich
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p.7 #14 · Zeiss ZE is for Canon!

Soso, Zeiss finaly decided to make some good money

Oct 02, 2008 at 09:44 PM

Xavier Rival
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p.7 #15 · Zeiss ZE is for Canon!

RalphJ wrote:
The new 50D has gapless microlenses; it is the new 5D2 that does not, apparently because of issues relating to orienting the edges of a full-frame sensor to reduce light falloff. I believe Canon hopes eventually to make all of their full-frame sensors gapless as well.

Ok! I knew the 5D2 did not get the gapless microlenses but did not know the reason behind that choice (I was actually just suspecting they did not want to put a much better sensor in the 5D2 than in the 1Ds3). I guess the gapless microlenses will need to happen in the next 1Ds version, if they want to increase the resolution again (well, in that case, not only the microlenses will be useful, but the lenses may also need some serious work too

Oct 02, 2008 at 09:59 PM

crazeazn
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p.7 #16 · Zeiss ZE is for Canon!

bumping this.

Oct 14, 2008 at 04:14 AM


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