MTF curves for new 21/2.8 Distagon
/forum/topic/711268/1

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cogitech
Registered: Apr 20, 2005
Total Posts: 10967
Country: Canada

hubsand wrote:

The old CZ21 is the resolution king, by far, all over the frame, at all apertures.


Exactly. And here we have MTFs that show the new one convincingly beating the old one. It is so obvious to me. Can you see it too, Mark?

For instance:

Zone A wide open on the new one will kill Zone A wide open on the old.

Zone C at 5.6 on the new one is considerably higher resolution than Zone C at f5.6 on the old one!

Anyone who has owned and shot a lot with the old version must find this as remarkable as I do. Some recent lenses have come close (sort of) to the original CZ21, but this one is better, and by a very significant margin, and where it really matters.



Lotusm50
Registered: Sep 26, 2005
Total Posts: 6050
Country: United States

thrice wrote:
I'd say they will be optically very similar, quite an accomplishment given ROHS. If you don't want distortion the Leica 19/2.8 ROM is the way to go (with modification). The Leica beats the distagon from 5.6 smaller in all but extreme corners (at least going by MTF's, I don't have either... yet).



But you can't go by the MTF's. They were created by different companies using different methodologies. In order to accurately compare MTF's, they have to be consistently created using the same procedures, methodology and equipment. If you just compared lens based on the manufacturers' own MTF charts, you would probably never by a Zeiss lens becuase on the surface the manufacturer produced charts just don't look as good. I would be however, an apples or oranges comparison becuase the charts were produced in very different ways.

You can, however, compare Zeiss' MTF's for the old Contax 21mm Distagon with the Zeiss MTF's for the new ZF/ZE 21mm Distagon. And in doing so, as described immediately above, you will see that there are noticeable improvements ove rthe old Contax design.



dcmiller
Registered: May 21, 2002
Total Posts: 3643
Country: United States

mark1958 wrote:
Well i am selling my Nikon 14-24 with the 16-9.net EOS adapter... it is in Buy and Sell forum


Mark, were you not impressed with the performance, or you just don't like how it works in your system?



brianc1959
Registered: Feb 24, 2007
Total Posts: 44
Country: N/A

EB-1 wrote:
brianc1959 wrote:
It appears to me that the new lens is slightly better than the original Contax version, both in MTF and distortion.


Results are pretty similar as if they were aiming for the same design goal. Distortion is disappointing.

EBH


Distortion in the new design really does look better, judging from the curve. You want the curve to bend back in toward the edge of the field because that improves straight line rendition. The problem with the old design is that the curve bent almost all the way back to zero, which is really an amateurish design mistake. The new lens is better in this regard.

If you're thinking the distortion curve should be zero at all field points: forget it, at least for the near term. That would require large diameter aspherics near the front end, and the cost would probably go well beyond $4k.



dcmiller
Registered: May 21, 2002
Total Posts: 3643
Country: United States

brianc1959 wrote:


Bear in mind that actual tests have shown the old 21/2.8 to be better than the 14-24.


I do remember that. And that the 14-24 is best at the wide end. I guess I find a wide zoom so useful for landscape that I would have a hard time using a prime. I would be constantly trying to zoom with the Zeiss.



thrice
Registered: Jul 10, 2008
Total Posts: 3035
Country: Australia

Well I got told I'm a noob to understanding MTF's, I sorta get them, just not the subtleties.

Guess I should save my pennies and stop buying Leicas the 5D-II is calling my name though, I really want that higher-res screen on the back and the high iso performance.

So many toys, so little money haha



cogitech
Registered: Apr 20, 2005
Total Posts: 10967
Country: Canada

dcmiller wrote:
mark1958 wrote:
Well i am selling my Nikon 14-24 with the 16-9.net EOS adapter... it is in Buy and Sell forum


Mark, were you not impressed with the performance, or you just don't like how it works in your system?


I can only imagine that he has made the decision based on how obvious it is that the new CZ21 will simply stomp the 14-24.



Steve Spencer
Registered: Nov 08, 2006
Total Posts: 6145
Country: Canada

cogitech wrote:
hubsand wrote:

The old CZ21 is the resolution king, by far, all over the frame, at all apertures.


Exactly. And here we have MTFs that show the new one convincingly beating the old one. It is so obvious to me. Can you see it too, Mark?

For instance:

Zone A wide open on the new one will kill Zone A wide open on the old.

Zone C at 5.6 on the new one is considerably higher resolution than Zone C at f5.6 on the old one!

Anyone who has owned and shot a lot with the old version must find this as remarkable as I do. Some recent lenses have come close (sort of) to the original CZ21, but this one is better, and by a very significant margin, and where it really matters.


I agree but to me the most noticeable improvement seems to be in Zone B at f/5.6. The old version has a bit of a Zone B dip something like the 17-35 Contax N shows. They seem to have brought that dip up to a flat line. The Zone A and C increase may be more important, but I see improvements in all three of the zones that Mark talks about.

Take care,

Steve



Ed Sawyer
Registered: May 08, 2007
Total Posts: 1991
Country: United States

It's nice to see some improvement in the MTFs, though I would say they are more on the order of 0-15%, so not GIGANTIC improvements as seem to be implied...

overlay the curves - in some places there's nearly no change vs. the older one. Seems more pronounced the further out from center you get.

-Ed



shirozina
Registered: May 22, 2006
Total Posts: 1655
Country: United Kingdom

This lens is going to blow all others out of the water - I'm going to sell all my other lenses to get my hands on one. From those MTF's it 's not just going to blow every other wide out of the water but when it's done that it's going to rip them apart and eat them for breakfast. This lens is going to be so awsome that it's going to produce more resolution than any sensor out there can handle and beyond what can actualy be measured by MTF analysis - so sharp infact that it could well damage some sensors esp those below 21mp. With this much resolution to play with it's going to produce better results to just crop into the image instead of using any narrower lenses. I'm going to become a new 21mm fanboy and create a website with a forum totaly dedicated to this lens. I'm about to smash my 5D up with a big hammer as I know it won't be able to handle this totaly awsome lens and I've also deleted my last 3 years worth of work as the image quality is now obsolete and I'm saving myself the pain of viewing them and their inferior quality again.



Paul Yi
Registered: Dec 10, 2004
Total Posts: 4583
Country: United States

shirozina wrote:
This lens is going to blow all others out of the water - I'm going to sell all my other lenses to get my hands on one. From those MTF's it 's not just going to blow every other wide out of the water but when it's done that it's going to rip them apart and eat them for breakfast. This lens is going to be so awsome that it's going to produce more resolution than any sensor out there can handle and beyond what can actualy be measured by MTF analysis - so sharp infact that it could well damage some sensors esp those below 21mp. With this much resolution to play with it's going to produce better results to just crop into the image instead of using any narrower lenses. I'm going to become a new 21mm fanboy and create a website with a forum totaly dedicated to this lens. I'm about to smash my 5D up with a big hammer as I know it won't be able to handle this totaly awsome lens and I've also deleted my last 3 years worth of work as the image quality is now obsolete and I'm saving myself the pain of viewing them and their inferior quality again.


Wow...that's some strong words....
I was about to buy Contax N17-35/2.8, and you kinda put a break on it.
I have a deal where I can get the Contax N17-35/2.8 for about $1050.
Should I wait fot the new Contax 21/2.8?



cogitech
Registered: Apr 20, 2005
Total Posts: 10967
Country: Canada

@ shirozina



Ed Sawyer
Registered: May 08, 2007
Total Posts: 1991
Country: United States

shirozina, it sounds like this lens is the lens-embodiment of http://www.realultimatepower.net/ ;-)



Tariq Gibran
Registered: Oct 01, 2006
Total Posts: 6608
Country: United States

shirozina wrote:
This lens is going to blow all others out of the water - I'm going to sell all my other lenses to get my hands on one. From those MTF's it 's not just going to blow every other wide out of the water but when it's done that it's going to rip them apart and eat them for breakfast. This lens is going to be so awsome that it's going to produce more resolution than any sensor out there can handle and beyond what can actualy be measured by MTF analysis - so sharp infact that it could well damage some sensors esp those below 21mp. With this much resolution to play with it's going to produce better results to just crop into the image instead of using any narrower lenses. I'm going to become a new 21mm fanboy and create a website with a forum totaly dedicated to this lens. I'm about to smash my 5D up with a big hammer as I know it won't be able to handle this totaly awsome lens and I've also deleted my last 3 years worth of work as the image quality is now obsolete and I'm saving myself the pain of viewing them and their inferior quality again.





bobbytan
Registered: Feb 03, 2004
Total Posts: 5597
Country: United States

This is great news. If the performance of the new ZE lens even matches the old Contax version we are already way ahead. If it exceeds it in performance, then it is theoretically worth a lot more than what the old 21 was selling for at it's peak about a year ago .... because now you are getting a brand new lens with a dedicated Canon mount with focus confirmation and auto exposure for about half the price of the old Contax version! I think I might pass on the Canon 24L Mk II.

Lotusm50 wrote:

You can, however, compare Zeiss' MTF's for the old Contax 21mm Distagon with the Zeiss MTF's for the new ZF/ZE 21mm Distagon. And in doing so, as described immediately above, you will see that there are noticeable improvements ove rthe old Contax design.




bobbytan
Registered: Feb 03, 2004
Total Posts: 5597
Country: United States

Careful when you use this lens with the 5D Mk II. You may get an orgasmic reaction.

shirozina wrote:
This lens is going to blow all others out of the water - I'm going to sell all my other lenses to get my hands on one. From those MTF's it 's not just going to blow every other wide out of the water but when it's done that it's going to rip them apart and eat them for breakfast. This lens is going to be so awsome that it's going to produce more resolution than any sensor out there can handle and beyond what can actualy be measured by MTF analysis - so sharp infact that it could well damage some sensors esp those below 21mp. With this much resolution to play with it's going to produce better results to just crop into the image instead of using any narrower lenses. I'm going to become a new 21mm fanboy and create a website with a forum totaly dedicated to this lens. I'm about to smash my 5D up with a big hammer as I know it won't be able to handle this totaly awsome lens and I've also deleted my last 3 years worth of work as the image quality is now obsolete and I'm saving myself the pain of viewing them and their inferior quality again.



David Clapp
Registered: Sep 03, 2007
Total Posts: 359
Country: United Kingdom

My girlfriend and I were thinking of getting married in a camerashop on the day of its release, Robert Whites looks like a great venue and they are UK distributors.

I have also written to Gordon Brown to ask him whether he will consider making the 21st December a bank holiday.



DanPBrown
Registered: Nov 21, 2005
Total Posts: 636
Country: United States

Let's not forget about flare resistance, hopefully the new one is much improved. Another point is that the new version will have a much better hood.
Dan
www.danbrownphotography.com



wayne seltzer
Registered: Dec 22, 2007
Total Posts: 3201
Country: United States

Brianc1959,

Thanks for the post and giving us some of your extensive lens design and MTF knowledge.

Can you compare the distortion of the new 21ZF with the 14-24 Nikon and the 18ZF?
From test shots with the 18, it seemed to have alot more distortion than the 14-24 at 18.

Also, can you suggest a couple of good books on lens design and MTF graph reading?

Thanks!
Still saving up for the Coastal Optics 60mm lens. Hate to see what Shirozina might do if he got his hands on one of those!



DanPBrown
Registered: Nov 21, 2005
Total Posts: 636
Country: United States

wayne seltzer wrote:
Brianc1959,

Thanks for the post and giving us some of your extensive lens design and MTF knowledge.

Can you compare the distortion of the new 21ZF with the 14-24 Nikon and the 18ZF?
From test shots with the 18, it seemed to have alot more distortion than the 14-24 at 18.

Also, can you suggest a couple of good books on lens design and MTF graph reading?

Thanks!
Still saving up for the Coastal Optics 60mm lens. Hate to see what Shirozina might do if he got his hands on one of those!

Wouldn't it be nice if Coastal Optics would make a wide angle on par with their 60mm?
Dan
www.danbrownphotography.com



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