I seem to have lucked out. Only time my cap comes off is when I'm pulling it out of a top loader bag. (Pretty much a function of the large diameter of the front of the lens.). Still might try one of those Op/Tech lens hoodies or whatever they are called. I imagine mine will loosen up over time.
Lee Saxon wrote:
One big issue I had is that the cap falls off if you look at it wrong.
Contact Zeiss about the lens cap falling off. They claimed that there were a small number of caps with deviations in manufacturing. They will send you a new one if you explain the situation. Great customer service! All I did was go through their website.
rji2goleez wrote:
Contact Zeiss about the lens cap falling off. They claimed that there were a small number of caps with deviations in manufacturing. They will send you a new one if you explain the situation. Great customer service! All I did was go through their website.
Glad they hooked you up!
In my case it was a rental lens and it'll be a few months before I've saved up the money to buy one, so hopefully I won't have the issue.
The lens has impressive center sharpness and color, however I am slightly disappointed by its corner sharpness. I have done a comparison with the Distagon 21mm and find that my copy of the 15mm is as sharp as the 21 in the center, but not even close when it comes to corner sharpness.
While my Distagon 21mm is more or less sharp from corner to corner allready wide open, my copy of the 15mm must be closed down to f8 or f11 to reach reasonable sharpness in the corners. All corners are equally (un)sharp, but center sharpness holds up well almost to the far corner/ edge where sharpness fall-off is rather steep.
I would be very interested in knowing if this is in line with your experience with the Distagon 15mm. I could post some test shots if necessary.
I am aware that corner-to-corner sharpness is a tough call for a full-frame 15mm, and don´t expect that.
But I see contradicting reports about corner sharpness on the net.
The results here are more or less in line with what I find:
However the only review so far at FM claims corner-to-corner sharpness even wide open, and imatest resolusion test done at ephotozine and lensrentals suggests that corner performance should be better than what I see.
Mine is reasonably sharp in the very extreme corner (last 1 mm) from f/4, but improves marginally to f/8 - f/11. It never gets 21 sharp though. I think this is normal and to be expected also from the MTF charts.
Resolution tests like imatest don't go that far into the corner, I think only to 19 mm image height or so.
twoeye wrote:
While my Distagon 21mm is more or less sharp from corner to corner allready wide open, my copy of the 15mm must be closed down to f8 or f11 to reach reasonable sharpness in the corners. All corners are equally (un)sharp, but center sharpness holds up well almost to the far corner/ edge where sharpness fall-off is rather steep.
I would be very interested in knowing if this is in line with your experience with the Distagon 15mm. I could post some test shots if necessary.
When I look at your (very 3D) picture I only see a little bit less sharpness in the extreme corners. I don't think this is a problem in real world photography.
Examples from Lloyd Chambers show good sharpness in the corners starting at F8 and at F11 it is very good in my opinion.
twoeye wrote:
The lens has impressive center sharpness and color, however I am slightly disappointed by its corner sharpness. I have done a comparison with the Distagon 21mm and find that my copy of the 15mm is as sharp as the 21 in the center, but not even close when it comes to corner sharpness.
While my Distagon 21mm is more or less sharp from corner to corner allready wide open, my copy of the 15mm must be closed down to f8 or f11 to reach reasonable sharpness in the corners. All corners are equally (un)sharp, but center sharpness holds up well almost to the far corner/ edge where sharpness fall-off is rather steep.
I would be very interested in knowing if this is in line with your experience with the Distagon 15mm. I could post some test shots if necessary....Show more →
It would be good if you could post some test shots for discussion. Note that in the one provided, you are not focused at the distance at which the corners are positioned. If you want to compare centre and corner sharpness, you need to make sure that they are at the same distance from the camera.
I have shot a test series at 2-3m distance and will make a compilation later today comparing the 15mm with the 21mm at different apertures. I might even throw in the Canon 24mm TS-E II.
carstenw wrote:
If you want to compare centre and corner sharpness, you need to make sure that they are at the same distance from the camera.
This lens has a lot of field curvature, already not very far from the center. It is an eternal dilemma if you want to test sharpness in the plane of focus, or the amount of field curvature.
I was thinking field curvature too when I started testing, but there is only a very slight refocus necessary when moving focus from centre to corner in liveview so in my opinion this is only part of the explanation.
My testing: tripod, focus in liveview, flash in combination with existing light, there is some difference in lighting between different apertures, (and slightly unevenly lit test setup).
PP: Adjusted exposure and WB to match the shots. Automatic CA removal in Lightroom, no distortion correction, 50% correction of vignetting in LR.
Hmm, the corners look good, but not fantastic... How sharp can you get the corners if you focus for them explicitly?
I wouldn't worry too much about the 21 and 24 being sharper, they are much easier to design. Also, the 21 is known to carry a surprising amount of depth of field for an f/2.8 lens, due to its design.
Looks normal to me. Wouldn't worry about the lens. If it doesn't meet expectations, I would say the expectations for extreme corner sharpness were too high.
I have more or less concluded that way myself, after initial doubts. Most of the frame is really good from wide open and only the far corners a little weaker than the 2.8/21 which should be acceptable for a lens this wide.
I might get slightly better corners if focused by them, but I doubt that they would be significantly sharper.
Thanks again for your opinion, highly appreciated.
It seems that by design the optimal sharpness and depth of field are on F11 with the 15/2.8. I think that is very acceptable since this lens will be used with a tripod most of the time (at least that is what I do).
This is what dr. Nasse from Zeiss has to say about the corners:
"At f/5.6 corners should be quite acceptable, at least the contrast is very high; best detail is rendered from f/8.
At f/11 the curves look like from many macro lenses, except from the tangential loss towards the edges which is caused by the residual lateral chromatic aberration. It is small but not zero in such a very wide one. Tangential MTF is further improved when one measures with a more narrow spectrum – green light with about 80nm bandwidth."
