I'm looking at Sigma lenses and notice they have OS. Is that the same as VR? I want a lens that is going to be sharp when shooting hand held.
VR = vibration reduction
OS = optical stabilisation
they are exactly the same thing, it is just that a company trademarks their name for it, so other companies cannot call it the same thing. Stupid really! But be assured it is the same thing
"It is one thing to make a picture of what a person looks like, it is another thing to make a portrait of who they are" - Paul Caponigro
Constructive Critique of my photographs is always appreciated
Different wording, possibly for commercial reasons: Vibration Reduction, and Optical Stabilisation.
CC, Image editing OK.
The VR / OS terminology is explained above but more importantly for obtaining "sharp" shots will be your understanding of focal length to shutter speed relationship and your technique of holding the camera and releasing the shutter. VR / OS has some fantastic capabilities to help with getting the shot but all the technology in the world cannot counteract sloppy technique.
Ah, yes. And while you're delving into this stuff, LS, have you come across the "unit" for VR or OS?
That is, the effective "motion dampening"?. It's given in exposure "stops", and means how much longer
exposure times you can use. With zoom lenses this varies with focal length selected. So, for example,
a lens rated at 4 stops of VR or OS (or IS) would allow you to use a 4x longer exposure time than a lens without
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Oh, and a PS: (Not to be confused with the preceding terms). Another way of getting a stable image is by
"sensor shift technology". You can Google that. I think, though, that lens stabilisation is supposed to be
"the better" way.
Most companies have some image stablisation system in some of their products.
Sony calls it OSS, Tamron call it VC, Canon call it IS.
They all do the same thing, in that the system moves a small lens element(usually towards the back or at the rear of the lens) but most of them differ in some way.
I'm not exactly sure in what way, but lets say that the most obvious differences will be in actual mechanisms that drive the moving elements.
Some time back, Nikon too Sigma to court claiming that a lot of their OS stabilisation system was based heavily on Nikon's VR system.
I think only a few months ago Nikon finally won the battle, and Sigma had to pay them something like $10M or so in penalites.
So in this instance they may literally be the exact same system
I haven't tried Sigma's OS yet, but I have two Nikon and one Tamron lenses(and tried another Tammy).
In overall operation of the lenses I have or have tried, the Tammy version feels a little nicer.
It's not a clear cut win, as the Tammy lens I have seems to have a delay(or it seems like it), in that you don't really notice it come on or off as you do on some Nikon lenses.
The Nikon lenses I have are 18-105VR and 105VR, and have tried the Nikon 70-200VR and 80-400VR.
They all seem to come in and out in a very similar manner. They seem to 'kick in' when they start .. so you notice it more, and hear the sound of the lens element(or magnets operating the element clacking a little)
With the Tammy 24-70 you don't hear it (unless I've totally lost my hearing!), and you don't really notice the image going stable in any way .. it just is. So it feels like the start/finish routine in the electronics is smoothed out in some way.
The 70-200VR Tammy I once played with(for too long, I think) felt more like the 24-70 lens. I can't remember it coming on or off like the Nikon's do.
I have actually used a Sigma lens that I remember, but don't remember how good/bad it works relative to Nikon's VR lenses.
This lens was a 150-500OS lens, and I have a few images remaining in my archive that point to a very good OS efficiency level.
One image at 500mm and 1/40s and the other at 400mm and 1/30s both sharp enough that if the images were of anything good, you'd not only consider them to be keepers but would also be happy with any large prints.
The effective exposure stop difference that Am is referring too is by way of comparison to the 1/focal length rule.
That is, at 500mm you would reasonably expect that 1/500s shutter speed will result in a sharp image capture.
So if the OS/VR/IS system is good for 4 stops advantage, then you should be able to shoot at 1/30s at 500mm and get the same or similar sharpness results in your images.
But this needs to be offset by a hit ratio. I'm not 100% sure on what hit ratio manufacturers use, but I think(really don't know!) that it's supposed to be something like greater than 50% hit ratio.
So more than 5 shots in 10 need to be acceptably sharp to be considered an exposure stop advantage.
So, all of our inadvertent camera shake is countered by some built in Good Vibrations from the lens makers!
(Were the Beach Boys into lens making?? Maybe this is how they do it?)
Last edited by ameerat42; 13-07-2015 at 8:57pm.
I used to think that I was just hopeless at photography once I started using the Tamron 28-75/2.8 on the D800.
I know the lens can be sharp as I have quite a few shots with this combo to prove that it can be.
The problem was tho, that many shots with that combo weren't and it was obvious that my technique isn't as good as the beach boys' sound was in it's day.
So I took the punt, and got myself another lens of similar range(and aperture) the Tammy 24-70/2.8 VC.
That VC(as Kev accurately and concisely summed up) is a bloody brilliant!
I couldn't even hazard a guess as to a keeper ratio, or even if it's higher than it used to be with the 28-75 lens.
But the 24-70 weighs in at about 3x as much(about 1000g vs 300g!!) but I know I'm more impressed, overall) with some of the images that I get with such a lens now.
The only downside with the 'better' 24-70 lens, compared to the 28-75 tho is bokeh. I don't notice it in all images but the 28-75 definitely has better bokeh.
I've been meaning to do some comparisons between the two .. just for a new way to kill some (valuable)time.