FS7: Third-party e-mount lenses and lens distortion compensation

V

vilrockerdefer

Member
Hello,

The title says it all pretty much.

Specifically, before buying it, I was wondering if using the Tamron 28-75mm F2.8 Di III RXD on the FS7 would allow me to use the in-camera lens distortion compensation.

Thanks...
 
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Proabably not. But I'll bet it isn't needed anyway. Have you heard that this lens suffers from distortion? If so, don't buy it at all whether it can be corrected or not.
 
Well, as all the zoom lenses in this price range (below 1K$), it does suffer from distortion. Automatic correction makes a huge difference for some of the lenses I tried...
 
Hmm, I don't recall needing distortion control for my Canon EF 24-105mm f/4 on the couple of times I tried it on my FS7. I think I bought it for $800 as a gray market model through Amazon.

Edit: Okay I see you are looking specifically for native e-mount lenses so maybe the Canon is not what you are looking for. But my advice is still not to invest in any lens that requires distortion control. Get a speedbooster for the Canon and it's not a bad lens if you want to use SLR lenses.
 
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Thanks. My experience with the sony 18 200 and distortion control is not bad. Besides, I need autofocus and to use the lens on both the Fs7 and my A7. According to reviews, the tamron beats them all. But at max focal range it's well possible that lens disto comp would be helpful. So if anyone knows the answer...
 
I use the Sony 18-105 and in 4K the distortion correction doesn't work. But it is no problem at all to do that in post.
 
vilrockerdefer said:
...to use the lens on both the Fs7 and my A7...
Click to expand...

You might end up disappearing down a rabbit hole with this. Assuming you wish to shoot FF on the A7:

1) 28 good for FF wide. Useless for S35.
2) If you go for an effective S35 wide-angled long range zoom (ie minimum 18), you’re in S35 zoom territory - no good for your FF A7.
3)If you’re not shooting any FF, go back to point 1. Rinse and Repeat.

There’s some great crossover between E Mount glass between FF and S35, but not with long range zooms for video.
 
Oh, and Publimix’s suggestion of the 18-105 is a goodun. I think that’s a great budget option for HD S35 on the FS7. Distortion correction definitely works, but only in HD and there’s some other silly gotcha on the monitor LUT that I’ve blissfully forgotten.
 
Well since I've already gotten the 18-200 I will not buy the 18-105. I need to keep the 18-200 for certain kind of films I do.

I would buy the Tamron mostly for my A7, taking pictures. But would benefit from its 2.8 aperture and nice optics when filming interviews.
 
My 2 cents of experience with most of the decent FF photo lenses is not so much distortion as most of them appear to be pretty rectilinear. I find if there is a weakness with most of the non native lenses is that there is no compensation for chroma aberration. Nasty CA issues are much harder to fix in video than they are in stills. On the FS7 with a speed booster ultra I find the range and one stop speed increase, to f2.8 of the Sigma ART 24-105mm f4.0 lens comes in as a good combo. Works very well for interviews. Of course it's back to f4.0 on a FF body.

In most situations I find the added reach, nearly 4.4 x of the 24-105 more useful that the extra stop and the 3 x range on the 24/28-70/75mm lenses. On FF with the 24-105 I can set up further back in an interview and shooting wide open at f4.0 and can generate a very similar look look to a 24-70 at f2.8 that's if you are after subject separation from background. Find I'm using the 24-105 much more than the 24-70. Why the Sigma 24-105? I find it is the one 24-105 that maintains constant aperture over the range as opposed to the Canon 24-105 I used previously as that lost nearly a stop at 105.

Chris Young
 
vilrockerdefer said:
Hello,

The title says it all pretty much.

Specifically, before buying it, I was wondering if using the Tamron 28-75mm F2.8 Di III RXD on the FS7 would allow me to use the in-camera lens distortion compensation.

Thanks...
Click to expand...

In direct answer to your original question I would say 99% no.

In the 2/3" B4 broadcast and S35 world Fujinon and Canon worked with the likes of Panasonic and Sony and developed CAC and ALAC circuits to work with their lenses on cameras that supported CAC and ALEC. CAC and ALEC were lens compensation circuits that worked to correct lens peripheral illumination in the corners throughout the zoom and aperture ranges and it also to corrected the CA aberrations that dynamically altered at different apertures and zoom lengths. Sony internally with their own products have done a similar thing developing corrective circuits with their own native camera bodies and lenses. Coming back to my 99% comment I have never heard any comment to the effect that Sony's proprietary lens correction technology has been licensed or released to any other lens manufacturer other than Zeiss on the Zeiss/Sony lenses that Sony have collaborated on. If I put a Canon 17-120 onto the FS7 I'm relying on the pure integrity of Canon's lens design to deliver the most pristine image possible to the FS7 sensor. On the other hand if I put the Canon 17-120 onto an F55 then I do get the certain correction parameters through an intelligent PL mount. I would be very surprised to see this sort of lens compensation capacity ever appearing in third party lenses. Especially on what are ostensibly still camera photo lenses.

Chris Young
 
I couldn't resist when I found a pristine second-hand model this morning and bought it. Was well inspired, it seems very very good from the first photographic tests, and it definitely does apply lens distortion compensation while mounted on the FS7. It also seems to correct chromatic aberration when the option is activated. For the curious here is a basic test I just did : https://youtu.be/tfidDEqj2m4

Maybe it is due to the fact that Sony owns part of Tamron so I've heard. Just a guess.
 
Interesting. I guess you are stating that the second half of the clip, at around 9 seconds shows the corrected clip. I see there is a slight crop into the frame. Was this a result of the lens behaving that way once the correction was turned on?

Chris Young
 
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