Sony Zeiss 24mm f1.8 Sonnar available at B and H

[Vivek]

Philber, May I make a suggestion?

Instead of continuing the conversation here (and elsewhere), would you start a new thread with your comparisons. I think from your posts, you have made the effort to do the tests in your own way and there is certainly interest form some to see what you found.

Please keep in mind that no one has to accept your conclusions and neither any contradiction has to be taken as a personal afront.

Thanks!

 

[Show Performance]

Besides, there is a much simpler test for proving that this lens truly does have a deficiency that causes darkness across the frame - shoot it in a controlled studio environment with identical exposure settings. What you claim may be perfectly accurate, I am simply pointing out that you have a highlight in the Leica image that is not apparent in the zeiss one. If the zeiss was darkening the image uniformly then you would still see the highlight in the zeiss shot, just at a lesser intensity.

 

[Show Performance]

Please keep in mind that no one has to accept your conclusions and neither any contradiction has to be taken as a personal afront.

Thanks!

Well said. And I do apologize if my post crossed the line into personal affront territory! None intended. I think everyone here appreciates comparisons like these but disclaimer or not, once posted they are open to evaluation and critique.

 

[philber]

In my disclaimer, I wrote that "But you are entirely welcome to disagreeing in any way you feel appropriate, as I do not, sadly, have any copyright on "the truth", much as I wish I had...".
A couple of matters require clearing up. I never claimed the lens to be deficient, only that I didn't like it. Others have posted that they love theirs, and I am comfortable with that. I also wish it had been a straight deficiency, because then I would have bought a not-deficient one and been happier than having to fork out twice as much for a slower MF Leica. Which is why I own so many Zeiss and only one cheap Leica R.
Also, if it were a simple matter of "darkness", why was I not able to correct for it in PP with exposure compensation? And why across multiple shots? And why across a comparison of 8 lenses (the kit, two Leica, two Contax G, one Contax C/Y, one ZM) ?

My last hope, to be honest, is that the ZA 24 is fine-tuned for the NEX 7. Early reports by a member of another forum indicate that he found an exposure difference between his 5N and his 7. That could explain a lot IMHO, because it seems to me that many buyers of the 7 will want "better" than the kit lens, and then the ZA 24 is a very attractive option for those who can stomach the price. So if there is a difference between the two Sony cams, it stands to reason that the Zeiss people would go for optimizing on the 7. But that is a guess -and a last hope!- based on just one forum opinion...

 

[Show Performance]

Well, if my 5N ever gets back from Sony Laredo (was supposed to be here today but they screwed that up), I will be doing my own comparison with the C/Y Zeiss 25mm and other legacy lenses. Right now I have this nice new 24mm sitting on my desk with nothing to shoot it on!

Some quick test shots on a demo C3 looked very promising. In the end it is up to the individual to decide if the lens is right for them or not but Philber's comparison posits that there is a issue with the lens that could effect all copies and that will need to be further researched.

Rooting out any problems with a new product is a good thing but I've also seen plenty of non-issues being reported at early stages in a product lifecycle. Hopefully this is one of those and if not, kudos to Philber for bringing it to our attention.

 

[iskaII]

Unlike other Zeiss lenses I have, this ZA 24mm Sonnar does not come with usual Zeiss MTF chart and optical structure diagram. It has not been listed on official Zeiss website. From a Chinese website, I finally got the information I have looking for. Hope they will help dicussion about this interesting lens. Sonnar or not, you be the judge.

original link is here
http://xjrumo.com/2011/08/24/e24-za/

 

[philip_pj]

Thanks for the work, philber, it is certainly appreciated by me at least, because it is one thing to do these comparisons oneself and entirely another to publish them, with the extra time commitment, file prep etc.

After your earlier post, I checked out the MTF of the two wide Leicas you mentioned, this 24mm Elmar and the 21mm as well. As you know I believe MTF (where accurate) to be a scientific representation of lens performance. Yes, we know the limits, but in terms of sheer contrast levels and resolution, MTF is it. The MTF charts of these two Leicas are very, very close and both are extremely good, guaranteeing image brilliance and fine resolution levels across the frame. To be sure, the 24mm is this one: 'Elmar-M 24mm f3.8 Asph'? If so, a little slower, f3.8.

To your near-centre crops: what I find interesting is the lack of apparent contrast the 24ZA shows, which co-occurs with high resolution at fine levels (micro-contrast). I tried downloading but the crops come up as php script files, and PS would not open them for me. The density of the two images is almost identical, in a pixels per file size ratio. Not surprising as the 24ZA is a very good performer, and even show some details not apparent in the Leica image. I'll bet the histos tell an interesting story! There is clearly a tone level difference but also contrast differences, and the very obvious colour transmission differences, these last two significantly affected by the first. [Some of this one sees in each company's other offerings, of course.] Shadow detail is very similar..but the midtones are night and day, and would remain even if tone range was 'equalised' in post.

BTW, iskaII, that MTF data is highly misleading, being so optimistic that it belongs in a fairy tale. Zeiss would be first to agree I am sure.

What it does show however is that the lens has consistent contrast from the centre to the edges of the APS-C frame wide open, with the centre at a much higher level. At f8, things are quite different, the midle of the image improves greatly, and we see a significant drop-off in fine detail from mid-frame and edge degradation due to separated lines and the kickup for 40 lpmm sagittal. In a nutshell, optimised for wide open use and centre-based images stopped down, not a landscape lens!

Why don't Zeiss themselves publish ZA series MTF on their website? Their name is on the lens...I have no idea, but we are poorer for the omission.

 

[philber]

Fascinating, Philip! So, if I understand you properly, it is optimized for wide open use and snapshots stopped down at the cost of "proper" performance for landscape? Well that certainly would rule it out for me, as landscape and cityscape are what I do most. Unfortulately, at that price point, I think that customers rightly expect a Zeiss lens to perform for all types of shooting. After all, if it were a lens for FF, its price would be right up there with the big boys, so there is no reason for this lack of all-round performance.

 

[Vivek]

Though it is speculation at this point due to lack of proper (authentic) data and/or tests (LL had some outrageous $%#^ on the comparison with the Leica Summilux.), wide open (or therabouts) better performance and stopping down leading to image degradation is not new to me. Some of the sharpest lenses I have exhibit this behaviour.

I would not shoot with the E-Sonnar stopped below f/4 at anytime.

 

[philber]

I tested at f:5.6, which is my most used aperture. So I was unknowingly comparing thislens well outside its sweet spot to others exactly at theirs. This could explain my findings.