carstenw wrote:
I'm sorry to hear about your dog, Wayne, that must be very difficult for you.
Thanks Carsten very much! Yes, as I have no kids, he was my closest loyal buddy who slept next to me every night.
But lots of great memories and photographs and stories I have to remember him by and he was well loved by a lot of people.. Luckily, he didn't suffer long and we got to comfort him with our hugs, caresses, and kisses as he was put to sleep. Yes, a very hard moment for me.
Sorry about your loss, Wayne. 12 years is a long time.
I can see the difference in the highlights at the white cars, as you say. Even before brightness alignment. Not sure what to make of it. I don't see it in the bright tree trunk in the center crops you posted.
Wayne, I wish I could say something effective, but I can't. I believe it was Dr Seuss who wrote: "Don't cry because it's over. Smile because it happened."
@Alundeb, I also checked the RGB values for the white cars and found that they are neutral, equal values for both shots despite the grasses looking more bluish in the 25/2 shot.
I read this thread and checked all images from this lens in Z* thread and zeissimages.com. After spending some hours searching for the right sample image I gave up and ask here: It seems that 2/25 has some issues in extreme outer corners, is the issue just softness of is it like in 2/28 that vignetting causes effective aperture to be smaller (=DOF larger in corners)?
I would have loved the 2/28 but the vignetting + smearing on corners would force me to crop every photo to 10:8 ratio. Here is what I'm talking about:
I'm just wondering if 2/25 is no better than 2/28 (in this specific thing asked, it seems better on other aspects), it might be better that I keep using 2.8/25 C/Y and save my money for something else.
Samuli, I have a ZE 25 f:2.0. First, it vignettes heavily wide open. More, for example, than ZE 21. But that is easy to clean up, and has no consequence on corner sharpness AFAIK. Second, it has an issue with extreme corner softness at infinity below f:8.0. It is only if those 3 conditions (extreme corners, infinity, open wider than f:8.0) are combined, but then it is there. I tried to see if it is field curvature of some kind, and think it is just that: softness. I have given this feed-back to Zeiss, and they haven't objected, which IMHO they would have if I had been wrong in their opinion.
That doesn't stop me from thinking that this lens is the best ZE out there, not because it doesn't have weaknesses, but because of its superlative qualities. But you know me, and how my requirements are not incompatible with flawed but delightful lenses...
For overall rendering under most conditions, the 25 f:2.0 is very close to the 35 f:1.4, but I feel its colour accuracy is even slightly better, as is spatial placement.
Rcicala of LensRentals published some MTF curves of lenses he felt might have the highest resolution for the new Nikon D800, and the ZE 25 f:2.0 at f:4.0 came out tops, ahead of all Nikon G and other Zeiss lenses.
I mean how objects are correctly placed spatially, within both the in-focus and out-of-focus zones. Some lenses give a great sense of spatiality, while others are desperately flat. The 25 is outstanding at this IMHO, and, AFAIAC, this is connected to how well it resolves very fine detail.
philber wrote:
Samuli, I have a ZE 25 f:2.0. First, it vignettes heavily wide open. More, for example, than ZE 21. But that is easy to clean up, and has no consequence on corner sharpness AFAIK. Second, it has an issue with extreme corner softness at infinity below f:8.0. It is only if those 3 conditions (extreme corners, infinity, open wider than f:8.0) are combined, but then it is there. I tried to see if it is field curvature of some kind, and think it is just that: softness. I have given this feed-back to Zeiss, and they haven't objected, which IMHO they would have if I had been wrong in their opinion.
That doesn't stop me from thinking that this lens is the best ZE out there, not because it doesn't have weaknesses, but because of its superlative qualities. But you know me, and how my requirements are not incompatible with flawed but delightful lenses......Show more →Philippe, I'm not worried about corner softness, it's obvious it's there, plenty of proof of it in samples available. Only think I worry is that the lens barrel causes effective aperture on corners to be much smaller than in center (causing the ugly corners I linked image above).
In Z* thread I asked if kururu could post 100% crop of the top left corner of his environmental portrait image:
philber wrote:
I mean how objects are correctly placed spatially, within both the in-focus and out-of-focus zones. Some lenses give a great sense of spatiality, while others are desperately flat. The 25 is outstanding at this IMHO, and, AFAIAC, this is connected to how well it resolves very fine detail.
An interesting observation - I think I see what you mean.
kururu wrote:
here is 100% crop 12mp from photo above. 102_5094_LRe
Kururu, top left corner please. The bottom left corner doesn't seem to have more DOF due to mechanical vignetting, but very hard to say since it's very dark due to vignetting. On top left corner the branches seem to get more contrast even on the web display size and that is what I'm worried. Just similar as I explained above.
The sign photo; I really want this lens to work if it draws this way. Nice color contrast between blue signs and red bricks.
At infinity distance I could not get the extreme corners to be sharp at f8 on a planar church wall, even if adjusted focus using liveview on the corners. So I don't think it is just field curvature.
At close distances it is fine. It doesn't' take too many meters away before you hit the infinity stop.
I think this lens is better for city and portrait shooting,closer distance stuff.
Hmm, the story continues. I think you will find the root cause is curvature of field and I would have thought that a planar object (wall) will not show what is happening.
CoF will change somewhat by aperture with this lens. The MTF which are at infinity, show the deterioration quite clearly, I reason (maybe incorrectly) that the focal plane curves backwards away and backwards from the focal plane - infinity. If, with a suitable subject (carpet, grass from above, etc) it should show up as clear delimiter at the arc of sharp focus, in whichever direction the design shows. Though of course it may be of a quite different character to how it shows focused at infinity, if this is impractical due to the observable distance of the effect. Really the MTF at f8 would give more data too.
If I'm right, best to focus a bit short of infinity - I do this all the time with the 21mm, seldom use infinity, which in the distance always draws very well with slight defocus with that Distagon, and you get much better middle ground clarity, which in turn shapes image depth better. I seldom use wider than f5.6 though.
From the LC interview of Dr Nasse recently:
'Many fast wide-angle lenses and many wide zooms have a correction style where MTF is high and *field quite flat up to about 15-17mm image height, and then the image surface suddenly curves backwards rapidly*.' Asters mine.
And indeed you see the same change in all their charts, to a lesser or greater extent. 25/2.8, 21/2.8, 28/2...
It's easy to expect too much of this one as it has design characters to suit f2 shooting at short distance (bokeh quality, consistent central contrast already at a high level, focus fade) so a lot of what we see is simply the visual limits of DoF. People are not stopping down enough if high IQ and good DoF is needed.
This one also improves fine detail micro-contrast at mid apertures significantly, like the CY wides but not so great a difference.
Like all pricey lenses, it can do several things acceptably, but I do agree with Wayne re its intended usage. I think it would make a great 35-ish f2 lens on a Canon 7D or Sony A77.
philip_pj wrote:
Hmm, the story continues. I think you will find the root cause is curvature of field and I would have thought that a planar object (wall) will not show what is happening.
CoF will change somewhat by aperture with this lens. The MTF which are at infinity, show the deterioration quite clearly, I reason (maybe incorrectly) that the focal plane curves backwards away and backwards from the focal plane - infinity. If, with a suitable subject (carpet, grass from above, etc) it should show up as clear delimiter at the arc of sharp focus, in whichever direction the design shows. Though of course it may be of a quite different character to how it shows focused at infinity, if this is impractical due to the observable distance of the effect. Really the MTF at f8 would give more data too.
If I'm right, best to focus a bit short of infinity - I do this all the time with the 21mm, seldom use infinity, which in the distance always draws very well with slight defocus with that Distagon, and you get much better middle ground clarity, which in turn shapes image depth better. I seldom use wider than f5.6 though.
From the LC interview of Dr Nasse recently:
'Many fast wide-angle lenses and many wide zooms have a correction style where MTF is high and *field quite flat up to about 15-17mm image height, and then the image surface suddenly curves backwards rapidly*.' Asters mine.
And indeed you see the same change in all their charts, to a lesser or greater extent. 25/2.8, 21/2.8, 28/2...
It's easy to expect too much of this one as it has design characters to suit f2 shooting at short distance (bokeh quality, consistent central contrast already at a high level, focus fade) so a lot of what we see is simply the visual limits of DoF. People are not stopping down enough if high IQ and good DoF is needed.
This one also improves fine detail micro-contrast at mid apertures significantly, like the CY wides but not so great a difference.
Like all pricey lenses, it can do several things acceptably, but I do agree with Wayne re its intended usage. I think it would make a great 35-ish f2 lens on a Canon 7D or Sony A77. ...Show more →
Philip_pj, I tried focusing the corners at f8 the best I could by pulling the focus closer and the corners got only a tiny bit better. If it was just straight FC, I should have been able to get good focus in the extreme corners by focusing slightly closer. This was at infinity distance though.
Hmmm, maybe I have to use tape markers or something in rear LCD (I use only live view, so I don't have to worry about optical viewfinder) to indicate 10 by 8 framing and then I can use D28 and MP50 and in future D25... smiley here so too serious people understand I'm not 100% serious about this
Most of my forest shooting soft corners won't affect (but having large DOF caused by mechanical vignetting resulting to smaller effective aperture in corners will ruin most of my photos), since subjects are usually quite close, however this will cause some limitations to landscape photography.
Even 2/28ZE is not nearly as good (based on MTF etc.) than 2/25ZE I really liked it, but finally gave up due to the corner issues, still using it on "urban" subjects where I rarely find this behaviour distracting. Also 2/28 seems to be stronger on short distances than at infinity, but I haven't done much testing, except against 2.8/28 C/Y, and it always seemed to be "more Zeiss-like" in infinity shots, but when pixel peeping at 100% 2/28 beats it.
Interesting to see how it compares to C/Y 2.8/25, which has it's own corner issues.
Philippe, yes you are right when shooting portrait orientation top left becomes bottom left...however most programs will turn the image based on the sensor on camera body (became common ~2006, I still remember the enormous work to turn images as part of the import process) but if you use dcraw then maybe you have to turn them manually.
