topic Re: SteadyShot tech data please. in Alpha & NEX interchangeable lens cameras

SteadyShot tech data please.

mikeyp2000 — Wed, 04 Jul 2012 12:25:05 GMT

I'm sure there are more than a few patents and industrial secrets behind the operation of Super SteadyShot sensor shift stabilisation as found in Alpha SLRs/SLTs but I'm keen to find out more.

There seems to be a theory that at certain high shutterspeeds, SSS can interfere with ultimate image sharpness. Of course, it is visibly useful at slow speeds and very nice indeed. However, is there a chance that at higher shutter speeds, it can cause problems?

It appears that the Nikon (in lens) VR system samples movement at 1000hz and so according to 'information theory' (Nyquist), it can't resolve vibrations at more than half of this. Hence, above 1/500s shutter speed, it is recommended to turn off VR on a nikon lens (ref: Thom Hogan and others) as it can introduce incorrect compensations. Admittedly, this is all 'pixel peeping' stuff but it would be nice to know if there are similar limits to Sony's sensor shift technology.

Q1. What is the sampling frequency for SSS on various camera models?

Q2. Is there some sort of built in software thing that might disable SSS 'behind the scenes' above a certain shutter speed?

Q3. Is this worth worring about? It's so gloomy here, I can't get shutter speeds faster than 1/1000s today but I can't see any problems between 1/500 and 1/1000s on my A77.

Cheers,

Michael

Re: SteadyShot tech data please.

mikeyp2000 — Wed, 04 Jul 2012 13:07:25 GMT

I'm revising my above statement - my test was flawed catastrophically! I was switching of SSS for movie mode by accident. I tried again, comparing Still SSS on or Off (:smileyblush:) at 1/500, 1/800, 1/1000 and 1/1250 and in each case, SSS on caused the image to be a bit softer.

In good light for best sharpness, switch SS off! So, I'm renewing my call for Sony to allow SSS to be assigned to the customisable buttons (and also to allow the ? button to be customisable). Perhaps, with more knowledge of how SS works, it could have 'on' 'off' and 'auto' settings with the 'auto' activating or deactivating SSS, dependent on shutter speed......

Cheers

Re: SteadyShot tech data please.

cmosse — Wed, 04 Jul 2012 15:46:46 GMT

I have tested with A57 at following shutter speeds: 1/500s, 1/800s, 1/1000s and 1/2000s. A far distant subject was photographed handheld with a 200mm fixed focal length lens with focus set manually. For each shutter speed 3 images were taken with steady shot on and off.

Comparing images showed no difference in image sharpness (side effect/influence of active steady shot on resolution)

Test images (1/500s and 1/800s, Steady Shot ON: left; SteadyShot OFF: right)

1. Overview

2. Detail (100% crop)

Re: SteadyShot tech data please.

mikeyp2000 — Thu, 05 Jul 2012 13:30:40 GMT

Cmosse, I'm glad you took this up and tried it out. You made me want to try my equivalent test over again to see what happened on my A77.

It seems my test was flawed again! When I tried again both yesterday evening and this morning, I just can't see SSS having any negative impact on image sharpness, just exactly as you found!

My earlier test where I found a softening effect must have been an anomaly. I can't reproduce that effect at any distance or FL whatsoever. (Perhaps I nudged the focus ring by accident in my anomalous test - that would explain things nicely).

Therefore, I'm am officially impressed with both the A77 and a57 steady shot system. In fact, given that Nikon's in-lens VR system *does* apparently have an impact on IQ at 1/500s or quicker, it seems us Sony user's have an advantage.

I'd still like to hear from Sony with some more info in how SS works (eg in panning or constant camera movement) and how it has been improved over the generations.

Cheers