Hi all another lens quest, Has any one have any experience with this lens on a C100/300 or any other video camera? I can't find a solid answer on whether this lens is parfocal or not. I did find a thread over on Reduser about this one and one person said it shifted focus as you zoomed out, while in another review they said it appeared to be parfocal. If anyone has any experience or knows someone who has, any info would be great! Please note I am chasing info on the OS version of this lens, I have already read that the previous model is a stella lens but I shoot haandheld heaps, so would like the OS. Cheers again everyone. Phil sorry for the lack of line spacing........My computer is doing some weird stuff!
C100: Is the Sigma 50-150 2.8 HSM OS Parfocal?
- Thread starter MPM
- Start date
Tim Nitsch
Well-known member
I know its this thread is kinda old but I wanted give you a definitive answer, I too wanted to know but couldn't find anyone who had tried it. Well I finally just said f#&k it and ordered it.
It came in today I can tell you from first hand experience that yes, it holds focus perfectly though out the focal range. The image also does not darken when you zoom in like my 24-105 does which is going to be a nice change.
If you have any other questions about it let me know and I'll answer it as best as I can.
It came in today I can tell you from first hand experience that yes, it holds focus perfectly though out the focal range. The image also does not darken when you zoom in like my 24-105 does which is going to be a nice change.
If you have any other questions about it let me know and I'll answer it as best as I can.
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cpreston
Veteran
I can tell you that the older non OS version is not parfocal.
I realized this weekend that the tolerances required to make a lens parfocal are extremely tight. I decided to make my 70-200 2.8 II parfocal by adding some spacers behind the mount. It ended up requiring about 0.2 mm of space and now it moderately holds focus. Basically you could ruin the parfocal quality of the lens by tightening or loosening the screws slightly on the mount. I think it's a crap shoot when purchasing a lens, especially a fast lens.
I realized this weekend that the tolerances required to make a lens parfocal are extremely tight. I decided to make my 70-200 2.8 II parfocal by adding some spacers behind the mount. It ended up requiring about 0.2 mm of space and now it moderately holds focus. Basically you could ruin the parfocal quality of the lens by tightening or loosening the screws slightly on the mount. I think it's a crap shoot when purchasing a lens, especially a fast lens.
Tim Nitsch
Well-known member
The focus ring has about a 100° throw. It's a little stiff right now but I would imagine it would loosen up a bit over time but it's fairly smooth and I like it. The "end points" on the focus ring are "harder" than my 24-105. You can still run past them if your not careful but it's a little easier to feel them. The zoom ring is like butter, very smooth. Both OS settings work and they seem to work really well. I tried to hand hold it at 150mm and it was surprisingly stable for 150mm. On my 24-105 sometimes I can hear the OS working especially when I'm hand held, the 50-150 is pretty much dead silent.
Tim Nitsch
Well-known member
Crop sensors only. I haven't shot with the Canon 70-200 2.8 II so I can't compare them. But from all the reviews I've read they say the 50-150 a sharp lens, even wide open. I heard RED used it's glass to build their 50-150 RPZ. Personally I got it for its focal length. I've used the 70-200 2.8 non-is and for what I was doing it just seemed like 70mm was just a little too long so I went with the Sigma and my first impressions are very positive.
indiawilds
Veteran
What is the lens support used in this image?
LeavingTheCandy
Well-known member
Looks like a Redrock support. If not, theirs is just about the same.
Tim Nitsch
Well-known member
Here's the link for it:
http://www.coollcd.com/long-lens-su...7.html?zenid=a8b749cb5195fb2b1838eb0233926a5a
Although I think they updated it from when I bought mine, because the version I have doesn't have those loops or the jewel thing on the knobs.
The quality is surprisingly good for how cheap it is, very well machined.
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SantaCruzMichael
Well-known member
Is this lens internal focus/zoom like the 18-35?
In other words, does it extend and retract when zooming or focusing?
In other words, does it extend and retract when zooming or focusing?
Tim Nitsch
Well-known member
Yes, Internal focus and zoom.
Sorry for bumping the thread, but I think this is a pretty important question for future Googlers:
Tim (or anyone else), has the focus ring on your 50-150 gotten any smoother? I picked one up and found mine appallingly bad - very jerky start-stop making it nigh unusable without a follow focus. Got a replacement and that was just as bad.
Tim (or anyone else), has the focus ring on your 50-150 gotten any smoother? I picked one up and found mine appallingly bad - very jerky start-stop making it nigh unusable without a follow focus. Got a replacement and that was just as bad.
Tim Nitsch
Well-known member
Mine was always pretty smooth, not cine-lens smooth obviously, but smooth enough to easily pull focus with out needing a follow focus, definitely not what your experencing.
In terms of stiffness, It was pretty stiff when I first got it, but has since loosened up and while it's still a little stiffer than my 24-105, I'm having no issues with it at all.
anatusa
Veteran
just got 1 for my self - yes seems like its parfocal , Yes, Internal focus and zoom! focus ring smooth, but mine if u hold focus ring to hard makes sound.... the only thing i find the focus throw kind of short...
got one from ebay very cheap , AF was not working..... and with c300 i dont need AF not with that lens...., - seems like constant f2.8
got one from ebay very cheap , AF was not working..... and with c300 i dont need AF not with that lens...., - seems like constant f2.8
IndyFilmPhreak2013
Carbonite Member
I guess you've never used an Angenieux then.
A back focus ring is only needed when the other elements of the system are not robust enough to hold their positions exactly. Plastic construction, sloppy tolerances, or just plain cheap build can make such a workaround necessary - but know that it is a workaround for a problem that doesn't exist on better systems.
Build a camera/lens combo properly in the first place, and no such workarounds are needed - all that will be needed is a method of setting it up once (shims are commonly used by Arri, Angenieux and others) and you'll never have to touch it again.
As far as stills lenses go, variations in parfocality will exist between different examples of the same lens model - so reading that one person's lens is parfocal is no guarantee that another will be too. This happens when parfocality was never a design goal but merely a happy accident - meaning that the aforementioned sloppy construction can and will easily change that for the worse in any particular lens.
Until you put that lens on a different camera. We used to swap ENG lenses at will and after a short back focus procedure, they were totally parfocal.