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Thread: The FE 35mm F2.8 ZA...

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    Subscriber Member tashley's Avatar
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    The FE 35mm F2.8 ZA...

    Hmmm. Not as good as the RX-1 lens but it doesn't have the midfield weakness of that lens.

    Possibly a little better at the edges than the Sigma 35mm ART on the D800, in terms of resolution, but even with shading corrections turned on in camera, there is still quite some colour shading going on, especially at F2.8

    The lens is nowhere near as good at the edges as the 35 Lux FLE - you might argue that at a fraction of the price this is not surprising but then as an F2.8 lens, designed specifically for this camera, there might have been less of a difference.

    Some inconsistent behaviours that might imply a mild focus shift and a mild field curvature working together to confuse me. Edges sharper at F2.8 and F4 than at F5.6.

    Diffraction is from F5.6 onwards but appears to stay pretty constant from F5.6 thru F11.

    F4 is the 'best' overall aperture from my limited tests so far.

    Here's an F2.8 file shot using Shading Compensation, followed by the same file corrected in LR with flat field plugin from a calibration file shot at the same time:





    In other words, the shading compensation is, as with the RX-1, partial only.

    This is a very key lens for the A7R - as the first one available in FE mount, and at a relatively rich price, it is the single lens that most lays down Sony's intentions for the range and therefore for the entire A7 system. It is probably going to disappoint a fair number of people and might therefore raise questions over the entire system. But it is worth noting that it is tiny, light, has a great hood (more a shade really) and as I say above, seems to have better edges than the lens that many people think is best in this focal length for the Nikon D800E.

    Oh, and 35mm? My a$$. You get maybe up to 5mm worse than that for your money - it seems closer to a 40mm...
    Last edited by tashley; 29th November 2013 at 06:41.
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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    The series of these shots, including Lens Cast Calibration frames, is here...
    Last edited by tashley; 29th November 2013 at 08:54.

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    Senior Member Joe Colson's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by tashley View Post
    The series of these shots, including Lens Cast Calibration frames, is here.
    I'm having trouble with the link. I get this message:

    "Sorry, the page you were looking for cannot be found."

    Joe
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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    I made another link Joe, and edited the one in the post above so it should now work...

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    Senior Member Joe Colson's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by tashley View Post
    I made another link Joe, and edited the one in the post above so it should now work...
    Thanks Tim. The link works and I do appreciate your doing these tests and posting the images. You continue to be an excellent source of objective information regarding lens (and camera) performance.

    Joe
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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by Joe Colson View Post
    Thanks Tim. The link works and I do appreciate your doing these tests and posting the images. You continue to be an excellent source of objective information regarding lens (and camera) performance.

    Joe
    Awww shucks! Blush. Thanks Joe...

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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by Joe Colson View Post
    Thanks Tim. The link works and I do appreciate your doing these tests and posting the images. You continue to be an excellent source of objective information regarding lens (and camera) performance.

    Joe
    +1.

    Thanks, Tim.

    I am not being a sadist in reading something that reaffirms what I suspected with this lens. Honest!

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    Re: The FE 35mm F2.8 ZA...

    Tim, thank you again for the testing. The Sony FE 35mm looks pretty decent. It would be nice if the edges were a little better, but probably pretty close to what I expected (not quiet as good as the 35mm on the RX1).

    Maybe I will be luckier than you and get a better performing copy of the lens.

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    Re: The FE 35mm F2.8 ZA...

    Diffraction is from F5.6 onwards but appears to stay pretty constant from F5.6 thru F11.
    Hi Tim,

    This seems a bit of a disappointment to me as its 'safe' range is 2.8-4.0
    Why is it that diffraction kicks in so early ? Is it the high MP count of the A7r ?

    Kind regards.
    Bart ...

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    Subscriber Member kit laughlin's Avatar
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    Re: The FE 35mm F2.8 ZA...

    40 is my favourite FL, so that's a big plus for me! Thanks Tim.
    Kit Laughlin, www.StretchTherapy.net/, www.KitLaughlin.com/bodypress/
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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by Knorp View Post
    Hi Tim,

    This seems a bit of a disappointment to me as its 'safe' range is 2.8-4.0
    Why is it that diffraction kicks in so early ? Is it the high MP count of the A7r ?

    Kind regards.
    Tough call. It surprises me that some of the Leica glass I tested seems quite happy to f11 - diffraction has started at f5.6 or so but it doesn't really matter until past f11. My brain for optics isn't large enough to understand why the 35 f2.8 seems to take a bigger and maybe earlier hit especially at the edges, which start to slacken from f5.6 on some subjects.

    I am going to shoot the lens on a lot more 'real world' subjects this weekend but initially it strikes me as having been designed with fixed and not 'healthy' aims in mind, and consequently to have all sorts of odd and slightly unnatural feeling behaviours going on just under the surface. One correspondent has emailed me to say that it has worse shading at f8 than at 5.6 for example. I'll do my best to test but we may have to wait for the big guns to review it if we're to know what the science is behind all this...
    Last edited by tashley; 30th November 2013 at 07:11.

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    Senior Member W.Utsch's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Yes made the tests myself, the Sonnar 2.0 in the RX1 is a little better than the ZE and the FOV of the RX1 is a little larger. Color shading is for me a non issue with the ZE, which is still a very good lens - better than my Leica Cron 35/2 asph. 1.Gen.
    It is strange though, that a 35 is not a 35 ???

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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Here's a nerdacious image that come might find interesting


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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by tashley View Post
    Here's a nerdacious image that some might find interesting
    I find it interesting. Are they jpgs?

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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Shot RAW and then composited as Adobe RGB pegs.

    In-camera shading compensation applies to RAW files as well as jpegs, but distortion corrections are applied only to jpegs, just like in the RX-1.

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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Here is a series of focus shift tests

    From F2.8 to F8 at about a 3 metre distance using a proper target. The DOF of the lens at this distance is great enough to hide any effect there might be so none is visible, but I am wondering whether the tendency of the edges to get softer as you stop from F4 downwards might have a focus shift and curved field of focus component that is only visible at greater distance. More testing needed!

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    Senior Member W.Utsch's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Thanks for the tests, Tim!

    I did similar tests, years ago, with the Leica M8 and M (coded) lenses.
    With my mostly older to very old M lenses it does, even on the not FF M8, not look any better.

    I do not see color shift problems, that would make problems in real live photography. The vignetting fully open with no corrections in camera looks a little heavy but nothing i would really complain about. On the RX1 it is better, but i alway have the corrections in camera on.

    The question is: Is there a FF WA lens, that does not vignette wide open?? Maybe only a tilt/shift lens with very large image circle.

    Regarding focus shift: I found FS with the M8 to be a real problem with some lenses (Noctilux!).
    But with correct focusing on the A7r it should be no problem, as long as focus is measured with the F-stop in use. Or is the A7 AF always working fully open, i am not sure about this.

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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    The A7R won't have problems with focus shift if you MF at the shooting aperture but it might (if it has any shift) if you focus wide open for less ambiguity and then stop down to shoot, or shoot an aperture bracketed series from the initial MF. In AF, it seems to focus at the shooting aperture (different IFRC from the RX1 which has variable behaviour I think).

    As for the vignetting, I like a bit of it and it is entirely normal and natural especially at wider apertures. My concern is more for the colour shading not being fully corrected. I agree that it generally won't matter but I do dislike seeing odd colour shifts in the sky or on white backgrounds, if they are too noticeable!
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    Senior Member W.Utsch's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Thanks Tim for the info about focussing.
    I agree about your concern with color casts/shading. But i could not see this in real life so far (oc my experience with that lens and cam is still pretty basic)

    Here a quick and dirty test out a window on a typical shi.. grey german winter day:


    DSC04396.jpg by W.Utsch, on Flickr

    A7R, Ef 35/2.8 @ F4.


    DSC05107.jpg by W.Utsch, on Flickr

    RX1, @ F4.0

    Taken just seconds apart. On both, in camera corrections on, RAW to LR5 to Flickr with no further PP (everything on default in LR). You can see full-size on Flickr.
    Sorry for the banal subject - was just curious about the grey sky!
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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    I think that with in-camera corrections turned on and at F4 you can generally rely, as in your shots here, for natural variations in the sky to hide colour shading well enough for it not to be bothersome.

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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    OK, I just got back from an hour of shooting in reasonable daylight at all sorts of apertures, inside and outside, near and far, and I am liking the lens a lot more now. In general, though sometimes it doesn't quite work, edges are sharp enough by F4. I still have to bottom out some subtleties but in general the lens is giving good results, nice and sharp and contrasty, nice but not amazing micro-contrast, pleasant bokeh, quite close focus, pretty good at most subject distances, a good all-purpose lens.

    In fact, for most situations, I'd rather shoot this lens on the A7R than the Sigma Art 35 on a D800E, regardless of the size and weight differences. It's not stellar, you can't rely on it to alway have sharp edges like you can with the lens on the RX1, but given the task it is set in dealing with the sensor, it seems like a reasonable set of compromises and is fun to use. Maybe they could have made it a little cheaper, or a little better at the as-is price, but a cursory first walk indication is that it does the job…

    I am currently uploading a LOT of full size files to this gallery and though non is an artistic tour de force, there are shots that show a range of the lenses uses and results that might be useful to some.

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    Re: The FE 35mm F2.8 ZA...

    Regarding corners, here is a pic of my hangar door. Left 35 FE at f3.5. Right and just for gross comparison Summicron-R 50mm at - well, I forget. Something in the sub f4 range. LR raw import with nothing at all done.

    On my calibrated monitor there is a definite magenta tinge to the snow in the corners of the FE image. I would not say the 50mm corners are much sharper but the color is even.

    I love the form factor, lightness, ease of use of the 35 FE. Very sharp except at corners, and flare is well controlled so contrast is great. Sadly, the problems will probably outweigh the benefits and I will return it. No idea what an alternative would be.
    Last edited by cunim; 7th January 2014 at 08:56.

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    Re: The FE 35mm F2.8 ZA...

    Doesn't the camera with native lens also perform some diffraction correction?
    What effect does that have? Can that be switched off?
    Thanks.
    With best regards, K-H.

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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    K-H,

    There's no option to turn it on or off and it isn't clear to me whether it is working with RAW files or not. The menu options are for colour, chromatic aberration and distortion, all with either Off or Auto.
    Last edited by tashley; 30th November 2013 at 09:12.

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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by cunim View Post
    Regarding corners, here is a pic of my hangar door. Left 35 FE at f3.5. Right and just for gross comparison Summicron-R 50mm at - well, I forget. Something in the sub f4 range. LR raw import with nothing at all done.

    On my calibrated monitor there is a definite magenta tinge to the snow in the corners of the FE image. I would not say the 50mm corners are much sharper but the color is even.

    I love the form factor, lightness, ease of use of the 35 FE. Very sharp except at corners, and flare is well controlled so contrast is great. Sadly, the problems will probably outweigh the benefits and I will return it. No idea what an alternative would be.
    Cunim, I see that too but I have to say that it wouldn't stop me from using the lens because I would just keep a library of calibration shots for use if as and when required using the Lightroom Flat Field plugin. I wasn't getting good results from Cornerfix and I found it a hassle, but doing it all in LR and with such good results has changed my mind.

    If you have time, look through the images I uploaded today and let me know if you see it as a problem in more real-world use?

    I am, more than anything, snow landscape guy, it is my favourite genre: but armed with the correct library of correction profiles I think I'll end up happily using this lens for that sort of work. Last winter I did a lot with the RX1 and rarely encountered a problem, and could fix it when I did...

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    Senior Member Joe Colson's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by tashley View Post
    If you have time, look through the images I uploaded today and let me know if you see it as a problem in more real-world use?

    I am, more than anything, snow landscape guy, it is my favourite genre: but armed with the correct library of correction profiles I think I'll end up happily using this lens for that sort of work. Last winter I did a lot with the RX1 and rarely encountered a problem, and could fix it when I did...
    Tim,

    After seeing these latest images, downloading the JPEGs and viewing them at 100% in LR, I'm convinced that the A7R-FE 35mm f2.8 combo will be well matched to my shooting interests. The DSC6419-22 series in particular convinced me on sharpness, and DSC6442 and DSC6455 had a medium format "feel" to them. I won't give up the RX1, but it may be a lonely elf on the shelf. Thanks again.

    Joe
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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by tashley View Post
    Cunim, I see that too but I have to say that it wouldn't stop me from using the lens because I would just keep a library of calibration shots for use if as and when required using the Lightroom Flat Field plugin. I wasn't getting good results from Cornerfix and I found it a hassle, but doing it all in LR and with such good results has changed my mind.

    If you have time, look through the images I uploaded today and let me know if you see it as a problem in more real-world use?

    I am, more than anything, snow landscape guy, it is my favourite genre: but armed with the correct library of correction profiles I think I'll end up happily using this lens for that sort of work. Last winter I did a lot with the RX1 and rarely encountered a problem, and could fix it when I did...
    Tim, I see no problem in your real world examples. By the way, thank you for providing them and for an interesting blog. My issue is that, with winter coming, I will simply stay in the studio and hibernate - so need for a wide lens is minimal. I can give this back now, get the 55 in a few weeks, and decide on wides once the great and good have pronounced.

    Very interesting circular color patterns in your flat fields. They look like a broad moire between the beam angles and the microlens angles. Don't believe I have seen that before.

    The corner-corner shading is about 20% of dynamic range, actually a bit more than that. Can't tell if your images show the marked corner softness mine demonstrate. Perhaps my copy of the lens is worse. No matter. I can always pick the 35 up again later and I will be interested to see how you feel once the smell of new plastic is gone.

    Peter
    Last edited by cunim; 7th January 2014 at 08:56.

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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Very interesting: I have a sense that 'under the hood' there is something unusual going on with this lens. Like avery good artificial sweetener, the dish is tasty but you almost subliminally know there's something not 100% right in it….

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    Re: The FE 35mm F2.8 ZA...

    Indeed, thanks Tim for all of your sample shots and observations. They're really useful for those of us trying to get a handle on this odd little lens!

    Any chance you could be persuaded to post/provide your "library" of flat field correction photos for the FE + A7R combo? Or at the very least, to walk us through your workflow and gear used to create such high-quality correction photos?

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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by frozenbb View Post
    Indeed, thanks Tim for all of your sample shots and observations. They're really useful for those of us trying to get a handle on this odd little lens!

    Any chance you could be persuaded to post/provide your "library" of flat field correction photos for the FE + A7R combo? Or at the very least, to walk us through your workflow and gear used to create such high-quality correction photos?
    Sharing would be difficult (you need the full size DNG file and uploading several of them will take forever!) and also not optimal for you - each camera and lens combination is best served by bespoke profiles made thereon. But nonetheless next time I am near egregious bandwidth, I will upload some key apertures.

    To make the calibration frames you need something like this.

    Basically you set the lens to infinity manual focus and then at each major aperture, shoot a frame with the sheet pressed hard against the front of the lens and positive exposure comp of about 1.5 stops, but make sure none of the channels blow. [Note: to get perfect corrections, you need to make them at exactly the same focus distance as well as the same aperture but in practice it won't make that much difference, though very close range shots won't work as well if corrected with calibration files shot at infinity]

    You then have several options:

    1)Shoot a set for (each major aperture) and either import them into LR as DNG, or import as RAW and convert to DNG. Export all these DNGs to a folder somewhere on your drive, and name them so as to be easily identified (e.g.. 35mmF2.8_atF8.dng). Then in Lightroom, select the image you want to correct, convert it to DNG if it isn't already and re-import it then select it again and go:

    File>Plugin extras>DNG Flat field>Apply External Correction
    you will then be required to locate and select the relevant calibration file from the folder you made already. Then select Color Only or Color and Falloff and… a new, corrected DNG file will be made with FF added to the filename.

    or

    2) Shoot a calibration file for every shot you take, as you take it: Shoot Granny on the beach, shoot calibration frame with same aperture, shoot baby in sea, shoot calibration frame. Import to LR with Convert to DNG option at Import and then select the frame you want to correct then and then option select the calibration frame then
    File>Plugin extras>DNG Flat field>Apply Interleaved Correction
    Then select Color Only or Color and Falloff and… a new, corrected DNG file will be made with FF added to the filename.

    In practice it could me more complex than this: you can shoot your original frames with in-camera corrections on or off. Different and matching calibration shots would be needed for each. In-camera correction will usually be enough so I will be shooting that way and then adding a further correction from my library when needed BUT this adds one step to the imaging chain and is not the best, just the most practical, way of dealing with the issue. For important shot, turn in-camera shading corrections OFF and shoot the frame, then shoot your calibration frame and apply it in LR.

    Phew.
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    Senior Member frozenbb's Avatar
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    Re: The FE 35mm F2.8 ZA...

    Tim, that's excellent. Many thanks for the extremely detailed reply! It will definitely add some time to my normal workflow, but I can't argue with the results. I do wonder why Sony failed to add complete correction for the lens from the beginning, and chose instead to offer such partial solutions. Here's hoping they'll see the wisdom in including more complete FE 35 corrections into a future firmware update.

    Also, I had been wondering if it was necessary to shoot a calibration frame for each shot, as opposed to having a set of generic correction profiles on hand. Unfortunately, it seems that for good results for critical work the former is required.

    Anyone know of any decent alternatives to the Universal Lens Calibrator that Tim linked to? £49.00 seems rather steep for a small piece of plastic. =) I wonder if a medium white version of this would serve the same function:

    Cast Acrylic Sheet - .125" Thick, Medium White, 12" x 12" - Pick: Color, Thickness, Size: Amazon.com: Industrial & Scientific

    I suppose it's possible that product has ugly casts of its own.

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    Subscriber Member tashley's Avatar
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    Re: The FE 35mm F2.8 ZA...

    New focus shift series, this time shot at the much closer range of 26 inches in order to root out any shift: I can't find any…
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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by tashley View Post
    Very interesting: I have a sense that 'under the hood' there is something unusual going on with this lens. Like avery good artificial sweetener, the dish is tasty but you almost subliminally know there's something not 100% right in it….
    My own theory, the ff correction is bothering you. I know that even with an LCC made for each MF image in C1, the less correction there is the better I like the output image - just speaking technically of course.

    The real issue with vignetting on the 35 is the steepness of the falloff. If the 20% of dynamic range falloff center to edge is a fairly smooth transition, it is what we expect from a lens and no big deal. This falloff curve, however, gets rather steep as you hit the corners. The steeper the curve, the more bothersome the effect. I stopped using the SpeedBooster with my NEX because it did that (and the MTF thing I mention below).

    As to other effects of flat fielding, sorry if I review basics but it helps me think. In the context of an image that contains a goodly portion of dynamic range at the corners, a proportional lift is fine. However, if the image only contains a small part of the range at the corners (e.g. sky or snow) bumping those pixels by 1.2 can increase noise and artifacts by a very large amount relative to the local information. That is why falloff-corrected skies tend to have what I call "tense" corners. This bothers my eyes. When using LCCs with skies I tend to just correct color casts and do only minimal vignette correction. The color casts are usually a small proportion of the color space so that works fine. Perhaps that is all you do as well?

    Getting back to why the 35 may seem strange - and I stress that this is just for me - it is not only the sudden vignetting. It is also the similarly sudden transition of MTF as you hit the corners. The transition from reasonable MTF to crud is almost cliff-like at wider apertures. Once I was sensitized to this, I found my eyes checking for sudden MTF transitions in every image I see. Don't know why it bothers me so much but, aaargh, it's like one of those jingles that just won't go away. This effect seems to be the Achilles heel of the FF e-mount and we will just have to see how Sony/Zeiss do with subsequent lenses.
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    Re: The FE 35mm F2.8 ZA...

    Tim, thank you for all if your efforts .Very enlightening!
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    Re: The FE 35mm F2.8 ZA...

    Great stuff Tim - thank you once again - . . . . . . I'm assuming there's no sign of smearing at the corners?
    The vignetting looks entirely manageable - the colour shading less so - but not dreadful.

    all the best

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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by cunim View Post
    My own theory, the ff correction is bothering you. I know that even with an LCC made for each MF image in C1, the less correction there is the better I like the output image - just speaking technically of course.

    The real issue with vignetting on the 35 is the steepness of the falloff. If the 20% of dynamic range falloff center to edge is a fairly smooth transition, it is what we expect from a lens and no big deal. This falloff curve, however, gets rather steep as you hit the corners. The steeper the curve, the more bothersome the effect. I stopped using the SpeedBooster with my NEX because it did that (and the MTF thing I mention below).

    As to other effects of flat fielding, sorry if I review basics but it helps me think. In the context of an image that contains a goodly portion of dynamic range at the corners, a proportional lift is fine. However, if the image only contains a small part of the range at the corners (e.g. sky or snow) bumping those pixels by 1.2 can increase noise and artifacts by a very large amount relative to the local information. That is why falloff-corrected skies tend to have what I call "tense" corners. This bothers my eyes. When using LCCs with skies I tend to just correct color casts and do only minimal vignette correction. The color casts are usually a small proportion of the color space so that works fine. Perhaps that is all you do as well?

    Getting back to why the 35 may seem strange - and I stress that this is just for me - it is not only the sudden vignetting. It is also the similarly sudden transition of MTF as you hit the corners. The transition from reasonable MTF to crud is almost cliff-like at wider apertures. Once I was sensitized to this, I found my eyes checking for sudden MTF transitions in every image I see. Don't know why it bothers me so much but, aaargh, it's like one of those jingles that just won't go away. This effect seems to be the Achilles heel of the FF e-mount and we will just have to see how Sony/Zeiss do with subsequent lenses.
    I'm not so bothered by the colour falloff, my colour vision isn't the very most accurate out there and I have reasonable tolerance for some colour shading depending on subject. I, like you, prefer to leave some vignetting and though the examples I have posted here are 'the full Monty' corrections to show how they work, I will mostly be using colour falloff only corrections. So I think what I am detecting is the MTF which, as you say, has some dramatic falloff. It also has quite a bit of wave and a heavy whack of astigmatism. I think you are right that all this contributes to the effect.

    But I also notice that the edges of the frame stretch and contract at different apertures. I need to bottom this out more. I also think there's some focus shift at longer distances that works with the field curvature and astigmatism to make the lens behave a little oddly as you stop down. I think we need a big team think on this one!
    Last edited by tashley; 1st December 2013 at 10:32.
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    Re: The FE 35mm F2.8 ZA...

    Quote Originally Posted by jonoslack View Post
    Great stuff Tim - thank you once again - . . . . . . I'm assuming there's no sign of smearing at the corners?
    The vignetting looks entirely manageable - the colour shading less so - but not dreadful.

    all the best
    A bit of smearing but not much, and it seems to come and go with distance, subject shape and aperture, quite hard to pin down. Grrr! I posted lots of examples in the gallery and some I didn't post, of the harbour side scene but shot with the camera on the diagonal, I will post because they are interesting for corner fiends!
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