Someone please explain IBIS to me ... ?

Started 8 months ago | Discussions thread
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blue_skies
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Someone please explain IBIS to me ... ?
8 months ago

Ok, I am reading the same things about IBIS over and over again.

IBIS, OIS, OSS, IS, which ever you want to call it works very well for:

  • reducing video shake
  • stabilizing long lenses

and, drumroll please,

  • low light landscapes ....

And this is where I get confused. Ok, IS lets you shoot at a slower shutter than handheld would allow. But, since I am going to shoot at such slow shutter speeds, would I not do better ... with a tripod?

I find that if people are the subject, even 1/60th already shows motion blur. I try to keep it at 1/100th whenever possible, raising ISO or widening the aperture. The resulting images are more pleasing.

Using the 1/(2*FL) formula (I think 1/FL is for FF), I just put out a simple table for sharp images (if no subject movement:

  • 16mm: 1/32
  • 20mm: 1/40
  • 24mm: 1/50
  • 30mm: 1/60
  • 35mm: 1/70
  • 50mm: 1/100
  • 100mm: 1/200
  • 200mm: 1/400

But, and this is perhaps a personal one: I can shoot comfortably at 1/FL without getting camera shake. Yes, 1/16th at 16mm and 1/300th at 300mm are very doable for me, handheld. But I seldom have to go there, I find acceptable aperture and ISO combinations for 1/(2*FL), so why push the edge?

In this pattern, I see that long lenses (50mm and above) will benefit from IS. I can keep shooting at 1/100th, even 1/50th, and get the sharp image.

But at 35mm and below, does IS buy me anything? I mean, if people are in the picture, I may as well bump the ISO or revert to HHT or AMB methods. And if not, a tripod lets me shoot at 10s or longer at ISO 100.

The majority of my shots are between 20 and 35mm. This to me is non-IS territory.

IS works, don't get me wrong. With the kit lens, I tried at 50mm, and I can get a sharp image all the way down to 1/12th of a second - or 3 stops below my 1/100th target. Great, but everything that moves is blurry.

And then, there is this conundrum: IBIS is so important to so many, so that they can shoot any lens (=their favorite lens). But I have the 35mm and 50mm with OSS, and the 16-50/18-55 and 18-200 with OSS. Why would I want OSS on other lenses, other than perhaps an E85 and a faster telephoto lens. I need two more lenses, not IBIS.

Birdwatchers shoot at 1/1000th or faster - IBIS is wasted at them.

Wildlife (long tele) photographers tend to use a tripod or monopod - IBIS is nice-to-have, not must-have.

I have lots of legacy (non IS) lenses, as well as lenses such as the E24Z and E20, and some A mount lenses. Guess what? Using my 1/(2*FL) formula I never have a problem with IS.

Ok, there are situations where I want IS (I use kit zoom, 18200, or the 35 or 55 -- or a tripod/monopod). But these are rare and uncommon.

I mean, so what if IS lets me shoot at 1/12th under low light? Cars become streaks, people become blurs, leaves and branches disappear. I can get a very sharp .... background, lol. Whereas, if I shoot at 1/60th, higher ISO, I can often still stop down, and I get a sharp image .... without IS.

If you were given a choice between a fast tele (let's say 70-250/f4 with IS) versus IBIS in a bigger camera body - which would you choose? Upgrade your camera or purchase the specialty lens? And after you have acquired such a lens, how valuable does IBIS really remain to you?

Oh, and anything that requires longer exposures than 1/60th, f/2.0 and ISO 1000 is, well, rather dark. IBIS would let me shoot at f/4.0 or ISO 250 (either one is two stops slower), but it would have to be at 1/15th.... I mean, should I not bring a tripod for such shots?

Oh yeah, and IBIS requires lens registration. It must know the FL that you are working with, otherwise it will not properly behave. Kind of tedious with legacy lenses, imho. And if you do use a tripod, you must turn it off. Or if you prefer to use a lens with OSS, you also have to turn off the IBIS.

Show me some pictures that I could not have taken without IBIS, and that would not be benefiting from a tripod, monopod, or just a rice-bag.

I'll start with some below: I used a tiny 3" tripod to stabilize the camera on the window sill, but guess what? Yes, the building vibrates....

I would have done better using HHT or an OSS lens - or indeed IBIS.... or I could have brought a tripod. But then again, I used a tripod - I did not expect the window sill to be shaky...

Anyway, back to my question: is IBIS really that big of a deal? And I mean, in other than the three areas that I outlined in my post at the beginning (video, long tele and low light landscape)?

To me, an E85/OSS and a 70-250/OSS would suffice - I don't need IBIS.

Ok, about the FF Nex - I am with you - I probably will use my legacy lenses, rather than purchase these wonderful new non-IS FF lenses. But, for long tele, I probably will still use a crop APS-C lens like the 70-250/OSS and this will cover my tele need. Hence, IBIS would be wasted on me.

And given some time, there will be other long tele FF lenses with OSS, I am sure....

But even for FF, using this 1/FL (rather than 1/(2*FL) for crop), I am ok up to 100mm FL. And, interestingly enough, this covers most of my legacy lenses, especially the fast ones. And for low light, I'd be more inclined to use a fast lens than a slow stabilized one.

So, sorry for the long rant, but I feel that IBIS is overrated. It is great if it can be added to a future (FF or APS-C) Nex camera - I agree with you all, and it is a must add on for a A/E hybrid camera, but with E mount, I have OSS in all the lenses that matter: E1018, E1650, E1855, E18200, E35, E50, and the coming E85 and perhaps a fast tele such as E70250/4. Meaning, I am covered from an OS perspective, and I would not need IBIS.

So, is IBIS overrated?

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Cheers,
Henry

 blue_skies's gear list:blue_skies's gear list
Canon PowerShot S95 Sony Alpha NEX-7 Sony Alpha NEX-6 Sony Alpha 7 Sony E 18-55mm F3.5-5.6 OSS +27 more
Olympus E-3 Pentax Optio E20 Pentax Optio E50 Pentax Optio E70 Pentax Optio E85
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