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Forums > Back > Any Otus users around? How do you focus?
#1
Last week I asked a dealer who also has lenses to rent, if I could rent an Otus 55 mm to compare it with the Sigma Art. I was curious about how big the differences are. Reply was "no, we don't have them on our list yet, but you could ask for a free 2…3 days tryout". I did, after I explained what I'm up to do and that I don't expect myself giving up my Sigma.

 

I've not the time nor the equipment to test anything properly. I was just wondering how those two would behave wide open. I know of some tests, I know also of a very nicely done comparison for Nikon by Flowtography Berlin but what I didn't know was how it feels to me and if I could get used to a manual focus lens because a lot of people said (until now me included) that's simply the best lens.

 

Is there any Otus owner or renter who is able to focus this lens on a Nikon properly wide open without LiveView? I'm asking because for me it's impossible to perform. The focus indicator changes from arrow to dot and remains that way until I turn the focus ring 2…3 mm more, then it changes to arrow again. Without tripod, having an eye on the indicator and at the same time at the small focus frame, well, I just run one eye short… I didn't get a single shot focused on spot by using the indicator or the screen with the Otus when I tried slowly swimming birds - I did get nearly 100 % sharp pictures with the Sigma and D810's excellent AF even with flying birds, although I was shooting wide open.

 

I consider the lenses as hard to compare. Just the 10% more focal length makes it very difficult to see what is normal enlargement and therefore more information of structure / texture and what is just the sheer resolving power. In the beginning I sized the Otus pictures down to 90…92 % (interestingly, this has to be different for different distances), but then I lost details as I did only work with the previews given by Aperture. I'd expect better result by using 100% Tiff - but only as output quality, I expect no difference in what can be seen. Also, the Otus comes up with about ⅔ … 1 full f-stop brighter results which are to be corrected as well. I could have used Manual mode, but changing lens and focusing properly with LiveView and LCD-loupe takes time, the light was changing as well since I wanted real life samples instead of chart pictures. I could not tell the difference from checking the pictures afterwards on camera LCD

 

LenScore  finds a difference between them of 1532 resolution points (Otus) to 1160 (Sigma). I was hoping to see some of that massive 32%, but then the sensor of a D810 is only rated to 1051 points. Does this mean, we have to wait to a 50MP Fullframe sensor to get full advantage of an Otus? Conclusion too easy?

 

I'm curious how Otus owners do regular pictures - or do you always use a tripod and LiveView?
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#2
50mp is only 100 / √36 * √50 = 117.85% more resolution. So of those numbers of that website are in any way meaningful (i doubt it..), that would mean a D820 with 50mp would be rated 1238 points, not a meaningful difference to that Sigma lens.

 

Now back to the real world. When one measures the lenses, one can see a difference already on a 24mp sensor (the Zeiss being a bit sharper in the center). The difference on 36mp might be a tad more pronounced, but whether one actually sees the difference, without measuring it, is another thing.

 

Shooting wide open, the difference in character should be more important than any difference in resolution, in my opinion.

As to manual focus, it is a bit difficult to judge focus with a standard focus screen (some people are much better at that than others). I changed my focus screen especially for that purpose (big aperture, manual focus).

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#3
JoJu, If you already use AF, don't even bother with MF. It requires skill and good eyes, and for better results you will need focusing screen. It can be really frustrating some times and at F1.4 it is even harder. The focusing dot in the OVF is not 100% correct, but it helps. You mentioned moving birds... this is hard with MF lens. I believe this lens should be used in controlled environment where the subject can remain static during focusing or you can always re-take the shot.

Don't tell me you will buy the Zeiss if it is noticeably sharper than Sigma?

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#4
Quote: 

I'm curious how Otus owners do regular pictures - or do you always use a tripod and LiveView?
 

I'm not an Otii owner, but Ming Thein's reviews have the answers:

 

http://blog.mingthein.com/2013/12/17/zei...55-part-i/

http://blog.mingthein.com/2013/12/18/zei...5-part-ii/

http://blog.mingthein.com/2014/09/09/len...po-planar/

 

In short, he concludes:

 

On the 55:

 

"If you have the means and opportunity to own one, do it. Learning the shot discipline to extract its full potential can come later. [...] No other brand has anything that comes close, especially on the 36MP+ cameras; that said, you really do need to have outstanding shot discipline, good eyesight and a D800E or better to appreciate the full difference."

 

On the 85:

 

"However, note that it’s not a lens for everybody: dedication to technique and vision are required to extract the most from it. [...] If you cannot see the difference (and no web image is going to do it justice; full resolution on a high grade monitor as a minimum, a print ideally), then don’t bother – buy a cheaper AF alternative and not have to deal with manual focus. Extremely shallow depth of field wide open plus that beautifully crisp transition between in and out of focus areas makes achieving critical focus both necessary (missed focus is obvious) and challenging; beyond that, if you don’t have a camera that can make full use of the resolving power and color rendition of the lens, or the skill to deploy all of that potential, it’s somewhat wasted. I honestly feel that the lens still has more to give – but we don’t have the sensors for it yet. I suppose that’s future-proofing. [...]

 

Coda: I’ve solved the focusing issue with a Zacuto pro finder and live view – stability, magnification, real DOF – just makes the whole thing a bit bulkier, unfortunately."
/Dave

http://dave9t5.zenfolio.com
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#5
Quote:JoJu, If you already use AF, don't even bother with MF. It requires skill and good eyes, and for better results you will need focusing screen. It can be really frustrating some times and at F1.4 it is even harder. The focusing dot in the OVF is not 100% correct, but it helps. You mentioned moving birds... this is hard with MF lens. I believe this lens should be used in controlled environment where the subject can remain static during focusing or you can always re-take the shot.

Don't tell me you will buy the Zeiss if it is noticeably sharper than Sigma?
No, the Otus only wins in terms of colors and the absence of chromatic aberrations. I could not get sharper pictures out if it than with the Sigma, at least not constantly. In the extreme corners I got maybe 2 shots out of 150 where it was the Otus winning. In the majority of my examples the Sigma is better. And was easier to focus, too.

I once had a focusing screen and found it not very useful: focusing aid is always centerred and the adjustment of the screen is very close to "impossible" because of the distance frames. I'd Say if I can't adjust the focusing screen within a tolerance of +/- 0,05 mm I'd see it in wide open pictures. Less at the 55, but massively at the 85.
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#6
Davet95, I finished my test series with a comparison of D810 and the two great lenses and the Sigma DP 3 Merill with 50/2.8. In terms of resolution the Otus might have the reserves to beat the old Merill once we ever get 50 MP Bayer sensors. If I want a "landscape only" system, I'm convinced of going Foveon. And live with a lot of downsides, being high weight certainly not one of them?
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#7
As I know there are already tons of comparison shot galleries around I thought I keep it simple and stupid and put just some screenshots out of Aperture, showing mostly f/1.4 pictures and 100% crops: http://sojujo.smugmug.com/Testshots/Otus...ma-Art-50/

forgive me the downloading time, those are PNGs from the previews, so no real fine art stuff but at least same conditions for both of them.


I don't think I'll harm any sales numbers. People convinced of the Otus by it's real performance or the myth created around Zeiss (I once was also a believer of that myth) won't stop buying the superdupermegahyper lens and some use it in front of a 16...24 MP camera. Which is fine, it just doesn't give one all it has to give.
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#8
Quote:Davet95, I finished my test series with a comparison of D810 and the two great lenses and the Sigma DP 3 Merill with 50/2.8. In terms of resolution the Otus might have the reserves to beat the old Merill once we ever get 50 MP Bayer sensors. If I want a "landscape only" system, I'm convinced of going Foveon. And live with a lot of downsides, being high weight certainly not one of them?
 

Lots of good choices these days!
/Dave

http://dave9t5.zenfolio.com
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#9
Quote:As I know there are already tons of comparison shot galleries around I thought I keep it simple and stupid and put just some screenshots out of Aperture, showing mostly f/1.4 pictures and 100% crops: http://sojujo.smugmug.com/Testshots/Otus...ma-Art-50/

forgive me the downloading time, those are PNGs from the previews, so no real fine art stuff but at least same conditions for both of them.


I don't think I'll harm any sales numbers. People convinced of the Otus by it's real performance or the myth created around Zeiss (I once was also a believer of that myth) won't stop buying the superdupermegahyper lens and some use it in front of a 16...24 MP camera. Which is fine, it just doesn't give one all it has to give.
 

Very interesting real life images and your comments with them.  

 

Just from the first 2 frames it's obvious (to me) that you're getting better results with the Otus and later images show less (none) LoCA.   That said, the differences are small at 100% indeed.   The Sigma wins on price:performance (and AF) no doubt.  

 

The Merrill images are very convincing indeed!
/Dave

http://dave9t5.zenfolio.com
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#10
Thanks, dave9t5, the salesman mumbled something about in camera sharpening when I returned the Otus and mentioned the Sigma Merill. However, he never compared the Sigma and Otus lens and he also had no experience with the Merills which I find the most underestimated cameras around - clearly for some good reasons, but my back loves them anyway. Smile


The Otus might be the most sophisticated high performing lens you can buy. For a Fullframe with a very sophisticated sensor around. However, I would never fully use it's potential as I found it hard to focus, especially at night.
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