My question is really regarding the Samyang 14mm 2.8 lens: this cheap lens seems to be supersharp, but has a whopping and complex distortion (basically a bubble in the middle of the frame). I note that DxO optics, which I haven't used yet, has a reputation of first-rate lens corrections - will it be up to the distortions of that lens? Looking through their manual and their website, I could not find information on this.
DxO's corrections rely on the results of actually testing the lens on various camera bodies, then creating a lens/camera profile for the program to use in apply corrections.
If they haven't tested this lens with your camera yet, then it OpticsPro wont correct the distortion automatically.
They used to have an on-line form for requesting that a lens/camera combo be tested. However, with their recent web site redesign, I can't find it. (Links in their support forum just go to the Optics Pro main page, which is glitzy but virtually useless in providing information.)
>They used to have an on-line form for requesting that a >lens/camera combo be tested. However, with their recent web >site redesign, I can't find it. (Links in their support forum >just go to the Optics Pro main page, which is glitzy but >virtually useless in providing information.)
Well, yes, just what happened to me. I saw on dpreview a link which was supposed to provide a list of all combinations tested, but that also went only to the main page.
But what about correcting manually? Is there a way to correct complex, mustache-style distortions? If not by dxo, is there other software which does this?
I don't think you can make corrections for mustache distortion manually in DxO - just barrel, pincushion and fisheye.
BTW, DxO doesn't currently correct the 14mm Samyang lens. For LR or ACR, you can download a user-created profile that will correct that lens or create your own. The Adobe tool for creating your own profile (if you want to do it yourself) will also correct mustache distortion. PTLens also has a profile for it.
>BTW, DxO doesn't currently correct the 14mm Samyang lens. For >LR or ACR, you can download a user-created profile that will >correct that lens or create your own. The Adobe tool for >creating your own profile (if you want to do it yourself) will >also correct mustache distortion. PTLens also has a profile >for it.
Thank you for the answers, and Rick, from where can I get those tools, that is, eventual user-created ones and the Adobe tool for creating my own profile? (perhaps with some instruction?) I don't think it is in my ACR, there are only sliders for barrel and pincushion (and automatic profiles for most of my lenses, except the 24 pc-e) I am so far very comfortable with PS, and would like to know whether and how this can be done.
Btw, I don't own the 14mm yet, I just want to find out whether it is possible to do something about this whopping distortion.
Thu 06-Jun-13 10:41 AM | edited Thu 06-Jun-13 10:44 AM by walkerr
Both the tool for creating your own profile, as well as one for downloading profiles that others have created, are found in the Resources section of this webpage. Look for the Adobe Lens Profile Creator and the Adobe Lens Profile Downloader. Both are free.
If you go the route of using one that is already out there, use the Downloader tool, select Nikon under Camera Make, then 14mm 2.8 under Lens Model. You'll then see a bunch of entries, many of which are for the DX format (labeled 1.5 crop factor). Look for the D700 profile for the 14mm 2.8 Rokinon (same lens as the Samyang), select it and then hit Download. That's all you have to do and that profile will now be available to you within both LR and ACR. That specific profile should fix distortion for you, but looking at the detailed description of how it was calibrated, won't fix light fall-off. The better user-created profiles (which you could always do yourself in the future if no one else creates a better one) will correct light fall-off that varies with the aperture.
The primary advantage of these profiles vs. PTLens is that PTLens requires that you render a file (TIFF or JPEG) before using it. The Adobe profiles can be used non-destructively with your raw or jpeg files, with no need to create anything new until you export the image. In my experience, most of the user-created profiles are pretty decent, especially if you look for ones with higher star ratings. The lower star ratings are a good indicator that they may correct only distortion.
BTW, if you explore a bit, you'll find profiles that were created by members and staff of Nikonians. Not me, though.
Also, if you want to check what's already officially profiled for LR and ACR, here's a reference:
Thank you, Rick. This is really, really helpful. I will try these links, and if I will be able to make sense out of them, I think I migbht get this lens (lacking currently the resources for the Nikon 14-24).
Have you tried manually correcting mustache distortion and creating a preset? I recommend you do that. As for the rest of the note, if I ran DxO, I'd be embarrassed to have something like that show up on a public forum.
Fri 07-Jun-13 01:27 AM | edited Fri 07-Jun-13 09:33 AM by mpage
>Have you tried manually correcting mustache distortion and >creating a preset? I recommend you do that.
Actually I have and it worked perfectly. The preset worked well for other images taken at the same time and under the same conditions. But the original comment was not about presets; rather it was about whether or not DxO Optics Pro could manually correct for Mustache distortion, which it can.
Fri 07-Jun-13 02:01 AM | edited Fri 07-Jun-13 03:13 AM by walkerr
Perhaps I'm missing a hidden feature of DxO that allows you to combine manual barrel and pincushion distortion corrections into one preset. Can you provide the step by step process for doing that? I could easily be missing a hidden capability. I mean this seriously.
Regarding his post, companies lose their professionalism when they insult their competitors and potential customers in notes like this. There are far better methods of communicating. I'll leave it at that.
Fri 07-Jun-13 09:31 AM | edited Fri 07-Jun-13 10:02 AM by mpage
>Perhaps I'm missing a hidden feature of DxO that allows you to >combine manual barrel and pincushion distortion corrections into one >preset.
I looked closer at my test moustache preset and discovered that when I selected Barrel Correction the value was eliminated for the Pincushion Correction and vice versa. The Pincushion adjustment was so minor that I did not notice it was eliminated when testing it. I will try to find a workaround.
>Regarding his post, companies lose their professionalism
I understand your point. It was not his post, but mine. I now realize that it was not my place to post his comments in a public forum. I deleted the quotation from the original post. I apologize to all parties concerned.
Sun 09-Jun-13 08:12 AM | edited Sun 09-Jun-13 08:57 AM by mpage
>I would still be interested in how you create a >single preset that works for mustache distortion.
When I created the test preset to test the functionality, I did not notice that a change to the barrel correction cancelled out the pincushion correction, and vice versa. Upon reflection this make sense, since barrel distortion and pincushion distortion are the inverse of each other. I was paying more attention to the program and not enough attention to the image itself.
One would need to process the image with a barrel correction and then apply a pincushion correction.
Is this idiosyncrasy going to prove to be a problem for me in the future? There are DxO profiles for all my lenses (and all likely lenses I want to get), except my old Nikon 300mm f/4 ED.
I think you're talking about double-processing the image, so a single preset won't work. That was my hunch because of how DxO works. I actually tried doing it with a sample image from a 14mm Samyang and could find no combination of barrel and pincushion distortion that could correct its complex distortion pattern. At best, I got a different form of fairly visible mustache distortion. That was one of my issues with the note you got from DxO - it glossed over the issue without providing details.
Despite all that, I don't think this is a big issue in general. In the past, DxO's lens coverage was a lot more spotty and that made using it more awkward. You were constantly having to change your workflow to account for lenses that were profiled and ones that weren't and have fairly complex presets (especially if you wanted to correct distortion, light fall-off and apply sharpening on zooms). It's better now and since your lenses have profiles other than the 300mm, you should be good. For the 300mm, distortion isn't really an issue, so I wouldn't worry about that aspect. You could create a single preset that applies sharpening appropriate for the camera and dial-in any vignetting correction manually or have a couple of presets - one for f/4 with more vignetting correction and one stopped down. The latter could be a generic preset for every situation where you have no lens profile and don't need to correct distortion or vignetting.
Something to watch for is new lenses: DxO is not the quickest when it comes to providing new modules, but they've improved over what they did in the past. They also don't support older cameras well - there are very few profiles for my older D100 and D2H images. That was pretty irritating when I first used it back in 2006 or so, but it's not as big of deal now.
Well, that was informative, thank you for sharing it. I tried to get this sort of information from their website, but I couldn't because the links did not seem to work. However, I will hold my horses and seriously think about my strategies before spending any money. Around 350€ is money after all, and I was not aware of the necessity to refocus at different f-stops. DxO appears ever more attractive to me - but what about my Zeiss lenses? The gentleman from dxo-support didn't express that (Still, he gave valuable and detailed information, and as far as I understand, this volume-anamorphosis feature woud work in any case - though I don't know about the selective deconvolution sharpening).
The issue is: I find it difficult to dismiss this lens just out of hand, and the reviews write nothing of focus shift, either. I know, this is a question for another forum, but let me frame it with respect to software: if the distortion can be corrected, are there not reasons for getting this lens?
If you consider how many camera/lens combinations are possible, the probability for a module of the Samyang 14/2.8 and a particular camera is very small. One has to realize that for a single lens/camera module several hundred precision exposures are needed - this is for a prime lens, for as zoom lens several thousand shots are needed.
The DxO corrections are excellent - I was only able to get decent pictures with the 18-200 and my D70 and D200 after using the DxO corrections. Similarly, the 24-70/2.8 improves dramatically with their D700 and D800 modules.
If you have the DxO software, there is a tab where you can request a specific module. I have tried this for my Zeiss lenses for the D800, but they wrote back that they have no plans for these modules - they only have them for Canon cameras...
>If you have the DxO software, there is a tab where you can >request a specific module. I have tried this for my Zeiss >lenses for the D800, but they wrote back that they have no >plans for these modules - they only have them for Canon >cameras...
Pity. That is pretty much a show-stopper for me, having 2 Zeiss lenses which I use all the time. But thank you for this information.
> >>Pity. That is pretty much a show-stopper for me, having 2 >>Zeiss lenses which I use all the time. But thank you for >this >>information. >> >You mean Zeiss lenses need correction?!?!?!?!?
There exists no perfect lens. The Zeiss zf 100/2 is about as perfect as a lens can be; it requires only very minor correction for vignetting. The Zeiss zf 35/2 has fairly strong vignetting and some CA. The Zeiss zf 25/2 has some corner softness. Vignetting and CA are obviously easily corrected. However, what is most important to me is the excellent DxO sharpening algorithm, called "lens softness" which in my opinion is much superior to the common USM sharpening.
I suppose this was a tongue-in-cheek question. But the honest answer for me is, yes and no. I get their distortion profiles in PS also, and often enough I don't use them, like when I actually prefer the vignetting. One of my Zeiss lenses is the 18mm which fares only rather mediocre in many tests, but I like it a lot, it does very much what I want, and I get many keepers from it. Still, if dxo is as good as people say, this softness feature, for instance, might quite improve some frames.
But speaking of dxo and my 18mm, what about this viewpoint program of them which is supposed to correct wide-angle distortions? Is that worth its money?
I just had a look at PTLens' homepage, and it indeed seems useful to me. It also fits my purse. With regard to dxo viewpoint, I was thinking of these distortions you get at the edge of wideangle frames, particularly of persons and faces/heads. That's a different issue, I know but one that has bothered me just yesterday, so I am thinking about that program. I work a lot with wideangle lenses.
I believe one has to be quite clear about the difference between geomtric distortions and lens distortions/imperfections. Geometric distortions become more pronounced with shorter focal lengths, regardless of lens quality. DxO has no "automatic" adjustment for geometric distortions, though their manual geometric adjustment in DxO Pro are quite excellent. The new LR5 test version has an automatic adjustment which I think is quite good.
Regarding lens distortions, not all Zeiss lenses are free of problems. As an example, the highly acclaimed Zeiss zf 21/2.8 has apparently significant "mustache" distortions and some of the Zeiss f/1.4 are not very good wide open. An example is the Zeiss zf 50/1.4.
I asked DXO in the Forum section why, as DXO Mark rates the Samyang lenses so highly, they aren't all supported in DXO. Another member also asked specifically about the Samyang 14mm f/2.8. The response was something to the effect that some of these lenses did not "communicate" well and could not be used to create a module. Bottom line is no module for the 14mm f/2.8 is forthcoming in DXO.