MTF curves for new 21/2.8 Distagon
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brianc1959
Registered: Feb 24, 2007
Total Posts: 44
Country: N/A

I saw these on another forum, and they do look official, even though I haven't seen them on the Zeiss site yet:

http://forums.dpreview.com/forums/read.asp?forum=1030&message=30124570

It appears to me that the new lens is slightly better than the original Contax version, both in MTF and distortion.



cogitech
Registered: Apr 20, 2005
Total Posts: 10909
Country: Canada

Nice!



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Tariq Gibran
Registered: Oct 01, 2006
Total Posts: 5849
Country: United States

B&H Price = $1749. Ouch!



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

It's very good, but from my limited understanding of these charts, not better than the 14-24. (I assume if we had a f5.6 MTF for the 14-24 the corners would sharpen up a bit) And the 14-24 comes with a "free" 14mm lens.

But I do understand the exciting news here for Zeiss fans.



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

Tariq Gibran wrote:
B&H Price = $1749. Ouch!


Sounds like a steal compared to prices for second hand Contax 21/2.8's in recent years!



Tariq Gibran
Registered: Oct 01, 2006
Total Posts: 5849
Country: United States

brianc1959 wrote:
Tariq Gibran wrote:
B&H Price = $1749. Ouch!


Sounds like a steal compared to prices for second hand Contax 21/2.8's in recent years!


Obviously, Zeiss has taken into consideration the going price of the Contax 21 2.8. I bet this lens would be much cheaper otherwise. Probably closer to what the original 21 sold for when new. Those Contax 21's which sold for $1300-1400 on ebay in recent months were pretty good deals and I suppose the new lenses will keep the price of the older one in that range. I have never read of any sample variation with the older version. Curious if that will be the case with the new one.



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

dcmiller wrote:
It's very good, but from my limited understanding of these charts, not better than the 14-24. (I assume if we had a f5.6 MTF for the 14-24 the corners would sharpen up a bit) And the 14-24 comes with a "free" 14mm lens.

But I do understand the exciting news here for Zeiss fans.


Its tricky to compare Nikon and Zeiss charts because:
1) Nikon uses 10 and 30 lp/mm whereas Zeiss uses 10, 20, and 40 lp/mm

2) Nikon shows calculated geometrical MTF. Zeiss shows diffraction-based MTF that might actually be measured (I'm not entirely sure about the measurement part). In any case, geometrical MTFs such as those shown by Canon and Nikon can be very misleading. In my view, a published MTF curve *must* include diffraction effects.

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



mawz
Registered: Sep 11, 2005
Total Posts: 4631
Country: Canada

Tariq Gibran wrote:
brianc1959 wrote:
Tariq Gibran wrote:
B&H Price = $1749. Ouch!


Sounds like a steal compared to prices for second hand Contax 21/2.8's in recent years!


Obviously, Zeiss has taken into consideration the going price of the Contax 21 2.8. I bet this lens would be much cheaper otherwise. Probably closer to what the original 21 sold for when new. Those Contax 21's which sold for $1300-1400 on ebay in recent months were pretty good deals and I suppose the new lenses will keep the price of the older one in that range. I have never read of any sample variation with the older version. Curious if that will be the case with the new one.


Wasn't the C/Y version around $1500 when new in 2004? IIRC it was $1475. A $250 increase in MSRP in 4-5 years is completely understandable, especially when the new lens is likely to be low-rate production.



Tariq Gibran
Registered: Oct 01, 2006
Total Posts: 5849
Country: United States

mawz wrote:
Tariq Gibran wrote:
brianc1959 wrote:
Tariq Gibran wrote:
B&H Price = $1749. Ouch!


Sounds like a steal compared to prices for second hand Contax 21/2.8's in recent years!


Obviously, Zeiss has taken into consideration the going price of the Contax 21 2.8. I bet this lens would be much cheaper otherwise. Probably closer to what the original 21 sold for when new. Those Contax 21's which sold for $1300-1400 on ebay in recent months were pretty good deals and I suppose the new lenses will keep the price of the older one in that range. I have never read of any sample variation with the older version. Curious if that will be the case with the new one.


Wasn't the C/Y version around $1500 when new in 2004? IIRC it was $1475. A $250 increase in MSRP in 4-5 years is completely understandable, especially when the new lens is likely to be low-rate production.


It was $1099 at one point while it was still available/not discontinued.

Perhaps you can buy this one but don't hold your breath for it to show up!

http://www.hotbuyselectronics.com/contax_carl_zeiss_distagon_21mm_f28_slr_lens.htm



phuang3
Registered: Feb 09, 2005
Total Posts: 747
Country: Taiwan

Look at the disortion curve. The infamous moustache distortion is still there! With a right adapter, I guess I'd choose Nikon 14-24. A WA zoom is much more convenient.



StevenPA
Registered: Jan 05, 2004
Total Posts: 2803
Country: Korea, South

Well it looks good to me. Look what Canon is charging for Mark II version of their lenses. It seems only natural to up the price, not that I'm happy about it. Even without seeing it in action, I'd chose the new 21 over the Nikon 14-24. If I shot Nikon, that might be another story though.

New on top, old on the bottom.


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Tariq Gibran
Registered: Oct 01, 2006
Total Posts: 5849
Country: United States

The Sony Zeiss 16-35mm 2.8 AF will sell for about the same price though its performance is a big question mark. For a fixed wide angle lens at that price, it really should be an F2 OR perhaps made in house by Zeiss.



EB-1
Registered: Jan 09, 2003
Total Posts: 18217
Country: United States

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



Cableaddict
Registered: Jun 10, 2008
Total Posts: 3704
Country: United States

phuang3 wrote:
Look at the disortion curve. The infamous moustache distortion is still there! With a right adapter, I guess I'd choose Nikon 14-24. A WA zoom is much more convenient.


Fingers crossed that DxO will make a correction module for this lens, since it's sort of an "official" Canon lens. -Or maybe some one will be able to make an accurate manual fix in one of the other correction programs? (was that ever accomplished for the CZ?)

If so, then this lens may be a no-brainer. If not, gotta' consider the Nikon zoom. (once I'm financially back on my feet, that is! )



mark1958
Registered: Jan 27, 2002
Total Posts: 8021
Country: United States

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



Xavier Rival
Registered: Jul 21, 2004
Total Posts: 3855
Country: France

These diagrams look pretty nice to me...
Now, regarding to the price, I remember reading references to a 1.3k to 1.4k expected price, a couple of months ago. Might be a no deal for me, at least for some time then... Or would you expect prices to be higher in the begining and go down a little bit in a few months ? or to be lower in ZE/ZF mounts ?
(well, actually I notice the 85 ZE is priced higher than the ZF/ZK versions on B&H)



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

Well I have be one for the 14-24, I shot it at the coast (more on his later) last night and the results are absolutely awesome. I have to say in my line of work there is no way I would want limit myself to 21mm at that cost when the Nikon is so much more versatile.



thrice
Registered: Jul 10, 2008
Total Posts: 2934
Country: Australia

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).





cogitech
Registered: Apr 20, 2005
Total Posts: 10909
Country: Canada

Cableaddict wrote:
-Or maybe some one will be able to make an accurate manual fix in one of the other correction programs? (was that ever accomplished for the CZ?)



Bibble has had a distortion correction profile for the CZ21 for quite some time now. There will be a profile for the new version as soon as someone sends them a test shot with it.

As far as I can tell from the MTFs, the new one is considerably better than the old one. Anyone who doesn't see that needs to learn more about reading MTF graphs. This easily puts it far beyond anything else available.



hubsand
Registered: Dec 17, 2004
Total Posts: 2014
Country: United Kingdom

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 not in practice! The old CZ21 is the resolution king, by far, all over the frame, at all apertures. The Leica 19mm suffers localised but quite severe resolution fall-off in the outer limits of Zone C.



cogitech
Registered: Apr 20, 2005
Total Posts: 10909
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: 5901
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.



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