IBIS degrades image quality

[T-Man]

Hello all-

 

I was at the Hasselblad X1D preview yesterday. The product manager stated that, "Hasselblad very consciously decided against IBIS. It degrades overall image quality." Is this also Fuji's position? What do you guys think, is Hasselblad correct? Is it something that pertains more to larger (medium format) sensors?

 

Cheers.

 

T-Man

[Aswald]

Fujifilm stated the same when asked about their xf16-55 F2.8.

 

Generally, any form of IS degrades image quality. It is great when compared without in difficult handheld situations like 1/30s and slower.

 

The absolute acid test would be handheld IS on vs tripod mount IS off in difficult scenarios. You'd see that tripod mount wins most times.

 

At 50mpix, Hassleblad is probably speaking from experience. With some lenses and shooting scenarios however, it's almost impossible without IS. I'm thinking very long zoom lenses but I don't think Hassleblad is going that direction anytime soon.

 

If at all possible, I try to shoot with higher shutter speeds rather than depend on IS.....which brings us to the discussion of having IBIS when it isn't going to be used most times.

Edited July 11, 2016 by Aswald

[JaapD]

In an ideal situation you would have a tripod and no IBIS. For those less ideal situations in life IBIS has most certainly an added value. So Hassleblad (!) is correct but not telling the complete story here.

[jfoxshoots]

It can depend. If IBIS results in the corners of the sensor moving outside of the image circle then you will lose image quality in the corners. If the lenses and mount are designed for IBIS then it shouldn't be as much of a problem.

[aceflibble]

IS in a lens means adding more glass, which inherently degrads image quality. IS on a sensor means either moving the sensor, which can cause a kind of inverse camera shake effect if it's not shifted in 100% the right way (rare, because it's a very expensive way of doing it); reading off the sensor multiple times per exposure, which can effectively blur the image if the shutter speed is actually high enough to not need it (rare, because at that point you may as well just make a video file and take a frame grab); or cropping in and enlarging, which inherently degrades the image quality. (The most common method.)
 

For medium format it's a bigger problem because you're typically talking about very large files which will be scrutinised. Medium format, these days, is where technical perfection really matters, because the only people shooting medium format now are people who are expecting to make very, very large prints, working for big name publications, doing celebrity portraits, etc.
IS is also a little more pointless for medium format, because the sheer size and weight of most medium format cameras and lenses means you're most likely going to be using a tripod anyway or at least a monopod. You're also more used to using high shutter speeds, further reducing the need for IS.

Of course, because of the size, putting IS on the sensor for medium format is also far more expensive than with smaller sensors. There's also battery drain, write speed, and heat to consider.

So, basically, it's all just a bit pointless for medium format. It's a lot of effort and cost for something which isn't going to be used most of the time, and might degrade image quality even when it is useful.

Edited July 12, 2016 by aceflibble

[chris joy]

I shoot with the A7rII and I haven't seen any degradation between IBIS on and off. It may happen with lens based systems, I don't know, but a lot of this discussion falls into the internet myth category, much like the FF look.

[T-Man]

Thank you all. As stated in the above responses, tripod is definitely ideal.

 

Aceflibble- You do have a logical point regarding the larger sensor size in medium format. I was thinking along the same lines.

 

-T-Man

Edited July 12, 2016 by T-Man