GH5 GH5s + Sigma 18-35 f/1.8 which speedboosters work without vignetting?

3

3dit0r

Member
Anyone tried the different speedboosters with the above combination? Reports from the internet seem to vary, and I don't trust random YouTube 'reviewers' much...
 
Rented Metabones ultra started to take a look with the sigma at 18mm no viengette unless i had maybe one case so far i saw vignette but the metabones ultra (.71) shouldn't cause it.
 
3dit0r said:
Anyone tried the different speedboosters with the above combination? Reports from the internet seem to vary, and I don't trust random YouTube 'reviewers' much...
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Trust or not but you should be able to use your own eyes when watching the videos to see if it vignettes or not. Don't trust the guy talking for ten minutes to hear himself talk kind of videos but actual GH5s with a 18-35 tests. As long as you watch videos of the actual camera its kind of hard to get it wrong or fake the results unless somebody really wants to go out of their way to deceive people. For what reason I wouldn't understand.

One thing I can say is stay away from the Speedbooster XL if using APS-C lenses. The XL should only be used with full frame lenses. The Ultra should work for the most part but there could be some lenses that do vignette. One solution as a work around could be to shoot DCI 4k and crop down to UHD in post vs shooting UHD. This will help the vignetting a bit since you are cropping off the area of the multi-aspect sensor more likely to vignette on the GH5s.
 
Dphotog said:
Rented Metabones ultra started to take a look with the sigma at 18mm no viengette unless i had maybe one case so far i saw vignette but the metabones ultra (.71) shouldn't cause it.
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Sorry, to be clear, did you find that the 18-35 vignettes on the SB Ultra or not?
 
Thomas Smet said:
Trust or not but you should be able to use your own eyes when watching the videos to see if it vignettes or not. Don't trust the guy talking for ten minutes to hear himself talk kind of videos but actual GH5s with a 18-35 tests. As long as you watch videos of the actual camera its kind of hard to get it wrong or fake the results unless somebody really wants to go out of their way to deceive people. For what reason I wouldn't understand.

One thing I can say is stay away from the Speedbooster XL if using APS-C lenses. The XL should only be used with full frame lenses. The Ultra should work for the most part but there could be some lenses that do vignette. One solution as a work around could be to shoot DCI 4k and crop down to UHD in post vs shooting UHD. This will help the vignetting a bit since you are cropping off the area of the multi-aspect sensor more likely to vignette on the GH5s.
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I don’t think they go out of their way to deceive anyone, but I’m talking about the type where you don’t actually get to see the image, just some dude talking about it, subjectively.

It’s not as simple as just avoiding the XL, as some APS-C lenses don’t vignette much or only do so at specific FLs. The multi-aspect sensor is why I’m asking for experiences from actual GH5s users with the lens and the speeedboosters; what is known to work in the GH5 might not apply to the 5S.

If you own the combo it would be great to hear your experience with it in this regard.
 
Thomas Smet said:
http://davidmorganjones.net/blog/vignetting-panasonic-gh5s-sigma-18-35mm-f1-8-speedbooster-ultra/

Pretty good test.

Yes I know some of APS-C lenses can vignette. Fortunately there are a ton of people out there using the 18-35 lens. Other lenses like the Sigma 17-50 f2.8 might be harder to find a visual test.
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Ah that’s a great test, thanks, just what I needed!

Hm, so the fact there’s no vignetting on the Ultra (.71) makes me wonder whether the XL is an option; clearly the 18-35 throws quite a big image circle...

On some GH5 tests some people seemed to find some vignetting, but they weren’t specific about which FLs were affected, and then mentioned it was occurring when moving the camera, which suggests IBIS which the 5s doesn’t have. Then others show no vignetting at all, but again don’t mention FL or whether they cropped. The only 5s test with the 18-35 and XL seems to be what’s described at a bokeh test. Again, no specifics provided.

If anyone here has that combo and could comment that would be very helpful.
 
3dit0r said:
Ah that’s a great test, thanks, just what I needed!

Hm, so the fact there’s no vignetting on the Ultra (.71) makes me wonder whether the XL is an option; clearly the 18-35 throws quite a big image circle...

On some GH5 tests some people seemed to find some vignetting, but they weren’t specific about which FLs were affected, and then mentioned it was occurring when moving the camera, which suggests IBIS which the 5s doesn’t have. Then others show no vignetting at all, but again don’t mention FL or whether they cropped. The only 5s test with the 18-35 and XL seems to be what’s described at a bokeh test. Again, no specifics provided.

If anyone here has that combo and could comment that would be very helpful.
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I think the XL is going to be pushing it. That video does show vignetting is starting to happen. It isn't significant yet and minor but if you go any wider that minor vignetting will suddenly turn into much darker corners. Since I don't have that combo I can't speak for certain but if the Ultra is giving minor vignetting then the XL will be more severe. Thats a given. How severe and if that is acceptable to you is up to you but personally I wouldn't use the XL with any APS-C lens. The XL was designed strictly for the GH4 and its extra crop factor when shooting 4k and UHD video. It was never really designed for full m43 sensor use. Even Metabones mentions on their website to use the XL with full frame lenses and the Ultra with APS-C lenses. That isn't to say the XL may not work to a certain degree with APS-C lenses on the GH5 or GH5s but that it is a risky move and not optimal.

DCI cinema 4k on the GH5s with the XL has a crop factor of like 1.2x which is much closer to full frame than it is APS-C. Even if the 18-35 has a fairly large image circle that is asking a lot for an APS-C lens to cover that close to full frame safely.
 
neilmac said:
The sigma 18-35 does vignette on a XL speed booster at 18 to around 24mm
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Brilliant, thanks! My widest FF lens is 28mm f/2 (so 35mm f1.4 equiv. with the XL). Since the 18-35 vignettes after 24mm it’s not worth the extra few mm it would give me with either adapter.
 
Your FOV is still identical if you zoom till the vignette disappears, as the XL has a wider FO than the Ultra, but perhaps most importantly a 1/3 stop faster than the Ultra...it's up to you what's important, and do your own tests....it's then a simple question of zooming on the XL thill it dissapears....I sold my Ultra and bought an XL and would do the same again given the choice.
 
fboonzaier said:
Your FOV is still identical if you zoom till the vignette disappears, as the XL has a wider FO than the Ultra, but perhaps most importantly a 1/3 stop faster than the Ultra...it's up to you what's important, and do your own tests....it's then a simple question of zooming on the XL thill it dissapears....I sold my Ultra and bought an XL and would do the same again given the choice.
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Yes but you then have a limited zoom range to work with which really limits the point of having a zoom lens in the first place. Having a zoom lens limited to 24-35mm is not much of a zoom lens anymore. Honestly 1/3 of a stop is not a ton of extra light. If one can't get the shot with an Ultra then the 1/3 extra stop of the XL isn't going to suddenly save the day.
 
I bought the XL mainly to use with my other FF lens. As for the sigma, 24-35 is OK for my needs as I have other Panny lens to cover the broader range. A lot of my work involves Interviews so the XL's benefits are gold to me.
 
Thomas Smet said:
Yes but you then have a limited zoom range to work with which really limits the point of having a zoom lens in the first place. Having a zoom lens limited to 24-35mm is not much of a zoom lens anymore. Honestly 1/3 of a stop is not a ton of extra light. If one can't get the shot with an Ultra then the 1/3 extra stop of the XL isn't going to suddenly save the day.
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Can't disagree with that...except for my purposes the Sigma is such a limited zoom...what it is though, is a very fast lens with some range...I also own the 11-16 Tokina and the f2.6 28-70...APS-C, but admittedly most of my lenses are FF...Nikon mount...with ETC on the GH5 though (that's what I use the XL with, I find I have plenty of range. I also use the XL with IBIS though I don't move the camera too much...in 16x9 aspect it's just not been much of an issue for me, as it's easy to crop slightly if vignetting starts....of course if you just have to hand the footage you've shot off, no question about the Ultra....lastly the 1/3 stop does become more relevant as you get to the higher ISO like 1600...of course how we use our gear is as subjective as the image or edit we find acceptable and your advice to the OP is sound.
 
fboonzaier said:
Can't disagree with that...except for my purposes the Sigma is such a limited zoom...what it is though, is a very fast lens with some range...I also own the 11-16 Tokina and the f2.6 28-70...APS-C, but admittedly most of my lenses are FF...Nikon mount...with ETC on the GH5 though (that's what I use the XL with, I find I have plenty of range. I also use the XL with IBIS though I don't move the camera too much...in 16x9 aspect it's just not been much of an issue for me, as it's easy to crop slightly if vignetting starts....of course if you just have to hand the footage you've shot off, no question about the Ultra....lastly the 1/3 stop does become more relevant as you get to the higher ISO like 1600...of course how we use our gear is as subjective as the image or edit we find acceptable and your advice to the OP is sound.
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And does the 11-16 Tokina work with the XL?

-DES
 
It does in 16x9 aspect ratio, but I just shot a test scene of a white wall for a brief glance at the camera LCD screen, so there may well have been some slight vignetting shadow not seen on the LCD....the GH5 was locked off and I never checked it in post...It's at 7.4 mm wide with the XL, which is wder than I'd ever have use for, and the individual's workflow would dictate what you do there...I would simply crop slightly in post if need be...as Thomas previously stated, the Ultra is the safe bet...for me it's the XL, as I use it with FF Nikons, but it would not preclude me from using it with the 11-16 if I needed ultrawide or the Sigma 18-35 if I needed ultrafast.
 
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