Is this acceptable sharpness for Zeiss 35mm F2?

[John Ricard]

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My Zeiss 35mm F2 lens is sharper at F2.8 than it is at F2. Is this to be expected? I've read the Leica's are optimized for widest aperture. Should I expect the same from the Zeiss?

 

I'm posting 2 pics that illustrate the difference in sharpness at F2 and F2.8. Before you comment, I beg you to read the statement in bold below.

 

I realize that these two images are not "identical". The model is in 2 different places in the frame, and when shooting at 1/30 motion blur can affect sharpness. Those concerns are irrelevant here because these two images are consistent with the dozens of comparison images I have shot at F2 and F2.8 with this lens.

 

I don't want to post the full size images here, so if you want to see the 2 images, click the link below. It will take you an unlisted page on my blog where you will find small versions of the images. If you click the small versions of files a couple of times, you will eventually be able to view the full size versions of the images.

 

| John Ricard

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[pico]

[...]I don't want to post the full size images here, so if you want to see the 2 images, click the link below. It will take you an unlisted page on my blog where you will find small versions of the images. If you click the small versions of files a couple of times, you will eventually be able to view the full size versions of the images.

 

| John Ricard

 

Too much trouble navigating your site for said pictures. Provide direct URLs.

But no lens other than some priced-on-the-moon aerial lenses are sharpest wide open and none are made for formats less than 5" on the short side.

[John Ricard]

Last time I linked to large images a moderator complained. But since you requested it:

 

F2

http://www.johnricard.com/blog/wp-content/uploads/2011/07/F2.jpg

 

F2.8

http://www.johnricard.com/blog/wp-content/uploads/2011/07/F2.8.jpg

[denoir]

My Zeiss 35mm F2 lens is sharper at F2.8 than it is at F2. Is this to be expected? I've read the Leica's are optimized for widest aperture. Should I expect the same from the Zeiss?

 

"Optimized" means simply that they've made their best to get it as sharp as possible - it does not mean that wide open is sharper than stopped down. Any lens, Leica or Zeiss, is sharper when stopped down - until you hit the diffraction limit (usually in the f/8-f/16 region).

[Guest roey]

All lenses are less sharp when shot wide open. Most lenses reach their peak performance after a couple of stops. With most Leica lenses the difference between wide open and stopped down isn't very big. As far as I recall the Zeiss 35mm f2 shows a noticeable improvement from f2 to f2.8.

 

To what extent your copy is in line with other samples of this lens I can't say -- especially since the images you have posted are high ISO and apparently shot hand held.

[Xmas]

My Zeiss 35mm F2 lens is sharper at F2.8 than it is at F2. Is this to be expected?

yes

I've read the Leica's are optimized for widest aperture. Should I expect the same from the Zeiss?

Zeiss PR might have the same sympathy but it is marketing speil if it does.

Leica have gone bald headed at the design to make a compact lens with good performance wide open, Zeiss allow the design to grow in size, to make it 'simpler'.

Puts indicates the 35mm f/2 Summicron is optimium between /2.8 and /4, and some regard him as a leica groopie...

Note optimium should be in quotes a value judgement at best.

If you are worried you need a heavy tripod and a large brick wall, and a borrowed cron to compare in shoot outs.

There should not be much difference.

 

Noel

[jgeenen]

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Your sample is not optimal and does not allow to judge sharpness of your Biogon. Sharpness is always a result of contribution of many factors, i.e. lens performance, motion blur, focus accuracy, motion between focus and release, sensor performance, light conditions etc.. The 2.8 looks slightly sharper but that can be the result of improved DOF, too. I have produced many similar results with my Biogon, too. Doing people shots indoors under poor light conditions is always kind of a gamble.

 

I did some boring test shots with a resolution target from tripod. Those exhibit that the Biogon is sharper stopped down (as any other lens). It is already very good wide open, but if you do a side by side comparison, you will notice the enhanced contrast of the stopped down image that results in much more "crispiness" but not generally much more details.

 

In fact I believe (I did mention test shots are boring, so don't take this as a scientific analysis) that the Biogon 2/35 is one of the best lenses I ever had, my Summilux 50 pre-asph, which I love, is by far outperformed by the Biogon at comparable apertures (I know I am comparing apples and oranges, but both taste very good).

 

Johannes

[lct]

Portraits at 1/30s and 1600 iso are not the best samples to judge the sharpness of a lens but at full aperture, the Biogon 35/2 looks somewhat like the Summicron 35/2 v4 i.e. fairly sharp in the center but quite soft on the sides and the corners. To get sharper results at f/2 i would choose a Summicron 35/2 asph or any Summilux 35/1.4 asph (or aspherical).

[Double Negative]

The 2/35 Biogon isn't as sharp wide open as some of the other ZMs (e.g. 2/50 Planar for one) but it's not bad at all. And yes, stopping down will sharpen the image.

 

However - both of these images appear a little softer than they should be, IMO. Whether that's due to the shutter speed or not, but I'm thinking it had at least a little to do with it.

[RobertW]

I've got the Biogon 35 mm f/2, the Leica 35 mm f/1.4.

 

The 35 Lux is much sharper in the centre wide-open at 1.4 (when I hit the focus) than the Biogon is at f/2. My copy of the Biogon is simply not a sharp lens in the centre. If you have a read at Reid Reviews that's his conclusion as well.

 

That said the Biogon focuses a lot more easily than my Lux and doesn't suffer from focus shift as I stop down. My copy of the Lux has slight FF at f/1.4, perfect at f/2 and then starts to BF at f2.8, by f/8 everything is fine.

 

As you have noted the Biogon gets sharper as you stop it down. The Biogon also has more contrast than the Lux as well.

 

I should mention that my CV40mm f/1.4 is also sharper than the Biogon in the center. That said the bokeh wide open on the CV is quite jarring/busy (love it or hate it).

[Double Negative]

I don't know that I'd necessarily call the 2/35 Biogon "soft" in the center or otherwise. Just that the other ZMs have a bit of an edge on it. These were both shot at f/2.8...

 

http://litpixel.com/ee/photo.php?photo=2462&exhibition=61&ee_lang=eng&u=65976,82

http://litpixel.com/ee/photo.php?photo=3958&exhibition=103&ee_lang=eng&u=65976,29

[pico]

[...]

 

F2

http://www.johnricard.com/blog/wp-content/uploads/2011/07/F2.jpg

 

F2.8

http://www.johnricard.com/blog/wp-content/uploads/2011/07/F2.8.jpg

 

Well, F2.8 made her smile! Your shutter speed of 1/30 might be a major factor in sharpness. I'm pleasantly surprised at the low noise level at the higher ISO. Maybe you should try more optimal conditions, say 1/500th at F2 and F2.8.

 

All lenses are sharper stopped down just larger than 6mm (absolute) where diffraction begins to negate sharpness. (It's why us LF photographers almost never worry about diffraction at small stops.)

[John Ricard]

Thanks for the responses. Maybe its just an issue with the Zeiss 35mm F2 as one poster pointed out. In the Overgaard review he was saying we should ONLY be shooting at the widest aperture on the Leica lenses. Seemed like such an odd statement to me. That's what prompted me to write this post. Article is here:

 

http://www.overgaard.dk/leica-M9-digital-rangefinder-camera-page-13.html

 

And I just want to point out again, that I understand you can't judge sharpness at ISO 1600 and you can't judge it at 1/30s. I know. I know. I know. I posted these 2 photos as samples even though they were shot at 1600 and 1/30s because the results are consistent with dozens of other images I have shot under more ideal testing conditions.

 

(Hate to be so obnoxious with the bold type and all, but it seems any time someone posts images as a sample on any photo forum half the responses point out why the sample images prove nothing since there was some flaw in the testing methodology).

[Double Negative]

So, return your lens for a new one or send it in for service...

[earleygallery]

Thanks for the responses. Maybe its just an issue with the Zeiss 35mm F2 as one poster pointed out. In the Overgaard review he was saying we should ONLY be shooting at the widest aperture on the Leica lenses. Seemed like such an odd statement to me. That's what prompted me to write this post. Article is here:

 

leica.overgaard.dk - Thorsten Overgaard's Leica Pages - Leica M9 Digital Rangefinder Camera - Page 13: "Learning the simplicity of the Leica M9"

 

 

That's nonsense! Leica strive to design lenses that perform as well as they can wide open, but all lenses will sharpen up a bit as you stop down towards f5.6/8.

 

On the other hand, every rule has an exception, I've said before, why buy a Noctilux unless you're only going to use it wide open, Leica may as well omit the aperture ring and blades!

 

As for your test images they appear to be 'normal'.

[lct]

Zeiss 35mm f2.8 is a great lens and tack sharp at any aperture.

Agree, it's a bit weak at f/2 though.

[Xmas]

Hi

 

The MTF (ie the IQ) for the Zeiss and Leica lenses is available on their respective manufacturers web sites, to look before you buy. The alternative is a heavy tripod and lens resolution charts/brick wall.

 

The Zeiss f/2 35mm MTF is pretty good, e.g. when compared wth the Leica f/2 35mm..

 

My friends who use them say nothing bad about them, but this last is subjective.

 

Noel

[lct]

For MTF charts of various lenses on the M9, including Zeiss', see Sepulchre (in French).

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Hallo,

Look here: Leica M

[Double Negative]

I wouldn't put all that much stock in MTF charts. Sure, they're a guideline, but... Especially from different manufacturers when comparing; it's not always apples to apples.

 

There isn't a bad ZM in the bunch. They're all sharp, typically from wide open, with minimal vignetting and little if any distortion. If the image is soft - either the camera and/or lens are out of spec - or you did something wrong. Now granted, some are sharper than others wide open... But it's a ridiculously miniscule difference (aside from maybe the Sonnar which is unique on its own).

[denoir]

I wouldn't put all that much stock in MTF charts. Sure, they're a guideline, but... Especially from different manufacturers when comparing; it's not always apples to apples.

 

Leica and Zeiss use both the Ziess K8 MTF machine and they are directly comparable. Furthermore although it won't tell you everything about a lens, it will tell you a lot.

 

 

There isn't a bad ZM in the bunch. They're all sharp, typically from wide open, with minimal vignetting and little if any distortion. If the image is soft - either the camera and/or lens are out of spec - or you did something wrong. Now granted, some are sharper than others wide open... But it's a ridiculously miniscule difference (aside from maybe the Sonnar which is unique on its own).

 

It will obviously depend on your standards. I find the 35/2 Biogon to be mediocre at best wide open, awful at worst. It's significantly worse than the 35/2 ZE/ZF and the 35 Summilux ASPH. Stopped down however, from f/4 and up it's hands down the best 35mm lens I've ever used - and the only one I feel entirely happy with for landscape photography. Incidentally, the MTF charts give a very good explanation as to why - the 35 Lux ASPH as well as the 35/2 Distagon ZE/ZF lack contrast in the fine detail (i.e ~40 lp/mm).