55 1.8

[pozzello]

Level isn't the same as parallel. Measuring parallelism to a planar surface is more difficult than ensuring the camera is level. That's one of the flaws in most "brick wall" lens tests. If slightly out of parallel with a wide open aperture, the apparent "plane of focus" could look skewed.

I'm sure Tim does his magic to set up as parallel to these subjects as possible.

Joe

Would be nice if Tim could share some of his magic

I was thinking of adapting my old versalab Parallel for my camera but would probably need to mount it to a wooden board first.

Any one done this before ?

 

[pozzello]

Absolutely right for the level on its own - but, assuming the level is accurate, then if there are perfect horizontal lines in the subject, then the level will tell you exactly that.

good point...

 

[tashley]

aint no magic, sorry!

But there is a feel to the technique. For example, when I shot the Olympus 12-40 F2.8 recently, it was immediately clear from my brick walls that it had no centering issues and that it was sharp all over - and sure enough, all other shots (mid and far distance) showed no problem. You get a feel for what DOF is available per sensor size/focal length/aperture/subject distance and whether your accuracy of alignment is within it or at the edge of it or risks being out of it. Sure one can make mistakes, but that's why one is looking for a part of a pattern of behaviours.

Once I have the rig set up as close to perfect as I can, I always shoot at least three series. One with AF, one with MF and no re-focus from wide open, and one with re-focus for every aperture up to F8 and then shoot F11 and 16 at the same focus point because by then DOF is so deep and diffraction so present that you can't critically focus any more even at full mag.

 

[Duane Pandorf]

I don think it's much larger than a telephoto or super fast specialty M lens like the newer (Noctilux, 75 Lux, 35 Nokton etc.) The hood makes it look larger.

The Leica lenses you mentioned are not as big (size wise, weight maybe) but they are faster.

 

[turtle]

Decentering is infuriating and all too commonly encountered. I've had a Leica lens (new 75 Summarit that did not remotely focus, but never decentering with Leica).

Its a shame if this is decentering with Zeiss, because none of my ZMs have even a whiff of decentering. Its commonplace with CV lenses and would be very disappointing to find $1000 Zeiss lenses with the problem. You pay that money NOT to have to send the first few copies back....

 

[Duane Pandorf]

I have a feeling many folks have my thought of having at least one native lens on board. This maybe it. Not sure why they did not have the 24-70 ready at launch, that would be a big seller for them.

I wish they did a 28 prime and this 55. Perfect setup

Do you think a fast 28 prime may be a challenge as we've seen with other third party lenses on this 36mb sensor?

Then how big will it be?

 

[pozzello]

Regarding parallelism…

Some people favour the mirror technique. It is a clever idea but frankly, unless the mirror is set perfectly flush with the target plane, it won't work. Look at a tiled bathroom wall and see how subtly different all the reflective planes are.

Sp what I do is to choose a subject that has the sort of horizontal lines that are plumb-lined, then line it up by eye and by level. The eye is informed by experience and the level by my knowledge of whether that camera has a half accurate level or not, and whether it is sensitive.

But even that is an approximation: we all know that. So I ensure that I do several sets with different targets and at different distances and if a pattern emerges, I know I have 'an issue'. But actually, I think the brick wall shots I posted are pretty close.

Is there anything else you test for ? Are there variations in MTF between the same lenses ? How do you know when a lens is good enough ?

 

[cunim]

Tim, I downloaded 7142 and at f4.0 I think that things should pretty much snap together. If my lens shoots the same as yours it will be history.:thumbdown:

Victor

I have to agree. I had real hopes for this lens but my Summicron R looks better at f4.

 

[tashley]

Is there anything else you test for ? Are there variations in MTF between the same lenses ? How do you know when a lens is good enough ?

It's a royal pain in the you know what to test thus, but I always do it in detail because the return window is small and the reject rate high.

First off I go for a walk and shoot some very familiar subjects that I have shot with lots and lots of other lenses. That usually arouses suspicions if there's a problem. I knew with the Olympus 12-40 even from that walk that there was no problem.

Then I take a look at the MTF to see if it explains anything I noticed.

Then I do a focus shift test using a target at usually about 25x the focal length, insecure in the knowledge that some lenses which seem to have no significant shift at close range, do have it at greater distance.

Then I shoot a far target I know well (distant hillsides) at every aperture. Then I do the harbour scene. Then I do a brick wall or similar. Bracketing my head of all the time of course. By now I know if its great, or a reasonable copy of a not bad lens, or a dud design or de-centered or whatever and if I am uncertain I shoot more to test hypotheses.

If it's good enough to keep I then work out what its field curvature is at different apertures and distances. Takes ages.

Then I buy another lens

 

[jlm]

pozzzello:
i use one of those for shooting artwork. i put the laser box on the wall and a reflective glass across the lens barrel, making the reflected dot nail the crosshair. then i make the assumption that the art will be parallel to the wall

for art it is useful avoids keystoning both ways.

for brick wall at 20'…maybe a board would average out the micro imperfections/

 

[vjbelle]

Shot my first images checking for decentering. My lens is also decentered. My Leica 50mm Summicron doesn't suffer from any decentering but isn't quite as sharp on the edges or center until F5.6....center is the same, edges are a little softer at F5.6. The Sony/Zeiss lens has incredible potential..... so I'll be looking for another one to try.

Victor

 

[vjbelle]

I have two more lenses on order and hopefully one of them will be on the money. This lens has the potential to be the finest lens I have seen in quite some time. Just needs to be centered. I can forgive almost anything else..... Luck of the draw......

Victor

 

[tashley]

I feel you pain, Victor, literally. Buy/test/return/refund/replace/re-test is not something that camera manufacturers should routinely put us through. Lloyd Chambers says his is asymmetric too. There's no point Zeiss making a fine design if the people who commission that design don't assemble the units with due care.

 

[vjbelle]

I feel you pain, Victor, literally. Buy/test/return/refund/replace/re-test is not something that camera manufacturers should routinely put us through. Lloyd Chambers says his is asymmetric too. There's no point Zeiss making a fine design if the people who commission that design don't assemble the units with due care.

Amen.....:thumbup:

Victor

 

[iiiNelson]

The Leica lenses you mentioned are not as big (size wise, weight maybe) but they are faster.

Yes the M-mount 50's are smaller but not by that much. Here's a size comparison between the Leica 50 Summilux ASPH, the Zeiss 55/1.8 FE, and the Sony 18-55/3.5-5.6 kit lens. Sorry for the crappy cell phone quality.

 

[iiiNelson]

I guess this is the first shot I posted of any of my around the house test shots... Straight from the camera to the iPad. No editing. Looks pretty promising to me and I think I'll keep it.

A7r + 55/1.8 FE

 

[tashley]

Has anyone else noted that when you mount the 55mm F1.8 and go to the lens compensation tab in the menu, the Auto option for Lens Distortion is selected and greyed out and can't be turned to OFF whereas when you use the 35mm F2.8, that option is selectable as liked? The other options remain selectable with both lenses.

 

[Deleted member 7792]

Received mine today from Amazon. After a few quick test shots, I'm OK with it. The AF with the A7R is quick and precise. Manual focusing using the EVF is easy. I'll test more outdoors over the weekend.

Test shot, handheld at f/2.8, focused on the middle of the snowman on the right:

100% crop:

Joe

 

[fmueller]

I have two more lenses on order and hopefully one of them will be on the money. This lens has the potential to be the finest lens I have seen in quite some time. Just needs to be centered. I can forgive almost anything else..... Luck of the draw......

Victor

If you don't mind me asking... So, you just order multiple copies and keep the best and return the other?

Not being critical, I've got one on the way and I'm going to wring it our pretty good but I confess I've bought a fair amount (OK, a LOT) of lenses and except for one tech cam lens I've never had to have anything returned or repaired.

 

[Deleted member 7792]

Has anyone else noted that when you mount the 55mm F1.8 and go to the lens compensation tab in the menu, the Auto option for Lens Distortion is selected and greyed out and can't be turned to OFF whereas when you use the 35mm F2.8, that option is selectable as liked? The other options remain selectable with both lenses.

Yep, same with mine. Probably not selectable because Sony decided the 55mm didn't need distortion correction. Just a guess.

Joe