VR According to Thom Hogan

[Lance Peters]

Interesting Read

http://www.bythom.com/nikon-vr.htm

[Desmond Chan]

Here for download is a D3 technical guide from Nikon in case anyone is interested:

http://support.nikontech.com/app/answers/detail/a_id/16247/~/nikon-dslr-autofocus-guide (http://support.nikontech.com/app/answers/detail/a_id/16247/%7E/nikon-dslr-autofocus-guide)

It has something similar to Thom's. But Thom's more detailed for sure.

So, for BIF, VR on :)

[Ed Erkes]

Thanks for sharing. A very interesting read.

[Dave Leroy]

An interesting article about a confusing issue and thanks for posting.
As a Canon user, I am curious about what other Canon users have to say.
The article is very clear for Nikon users.

[Desmond Chan]

As a Canon user, I am curious about what other Canon users have to say.
The article is very clear for Nikon users.

I have questions:

1. Even if leaving VR or IS on in some situations could have a negative impact to your photograph, will your naked eyes be able to see it without enlarging your photograph to 100% to scrutinize it?

2. If you post-process, will some post-processing steps be able to somehow pretty much negate the impact, be it intentional or by accident?

[John Chardine]

Thanks for this Lance. I posted to BPN a while back asking at what shutter speed and focal length does IS/VR become redundant. This more or less answers at least for VR. I suspect that the parameters for IS and VR are different so I am not going to assume that what Hogan says applies to Canon's IS- anyone have thoughts on this.

Desmond- I am sure I'm not alone in always looking to squeeze the most IQ out of images I make so if I can see it at 100% then I'm interested in it, and it probably means it's visible in a full resolution print at a normal viewing distance.

[Dave Leroy]

Hi Desmond,
I think John has given an answer to your first question.
I also think the author of the article helped answer your first question. He mentioned that for web viewing it would make no difference. I think he also mentioned that leaving VR on does not affect every photo.

I think the assumption is if a photographer is prepared to invest several thousand dollars in equipment then they want to get the absolute best quality they can.

[Desmond Chan]

Hi Desmond,
I think John has given an answer to your first question.
I also think the author of the article helped answer your first question. He mentioned that for web viewing it would make no difference. I think he also mentioned that leaving VR on does not affect every photo.

I think the assumption is if a photographer is prepared to invest several thousand dollars in equipment then they want to get the absolute best quality they can.

Probably re the assumption. I also think a lot of the time it's making a mountain out of a molehill, not by the the audience in general but by the photographers themselves.

[Alfred Forns]

Hi Dave On the Canon side can say that since the IS was introduced on the Super Tele lenses we can make sharper images at a lower shutter speed. Mine is on even on the tripod and about the only time it is off is when I'm doing flight at a high shutter speed !! Nothing scientific just personal observations and I go with what works.

[Dave Leroy]

Thanks Alfred.
I am curious as to what mode do you leave the IS at, or do you change it?
I have been leaving mine at Mode 1 all the time and I am always on a tripod.

Dave

[John Chardine]

I don't understand this part of Hogan's essay. Anyone care to take a stab at what sampling frequency has to do with the price of fish (I'm not sure Hogan knows based on the fact that he didn't answer his own question)? And then Nyquist is brought in.

"Most people using VR don't question the mechanics of the system. They simply believe it's some special form of magic. It's not. Physics are involved, not magic. And one of the physics issues is the sampling frequency. The sampling frequency of the motion detection mechanism determines what kind and how much movement can be removed. Care to guess what the sampling frequency might be? 1000Hz according to Nikon. That sounds pretty good, doesn't it? Nope. 1000Hz is 1/1000 of a second. If your shutter speed is 1/2000 of a second and the VR mechanism is sampling at 1/1000 of a second, what do you think happens? Moreover, Nyquist tells us that we can only really resolve data accurately below half the sampling frequency, thus the 1/500 boundary for Nikon VR."

[Dave Leroy]

John,

Wouldn't it mean that the lens, or camera/lens takes a reading at 1/1000 of a sec. to see where everything is at and then another at another 1/1000 and if things have moved, then the lens makes an adjustment so on so forth?

Dave

[John Chardine]

Dave- That's what I thought sampling frequency means but then how does this have any relevance to shutter speed beyond which IS/VR has no effect? I guess that's the part I don't get.

[Lance Peters]

I don't understand this part of Hogan's essay. Anyone care to take a stab at what sampling frequency has to do with the price of fish (I'm not sure Hogan knows based on the fact that he didn't answer his own question)? And then Nyquist is brought in.

"Most people using VR don't question the mechanics of the system. They simply believe it's some special form of magic. It's not. Physics are involved, not magic. And one of the physics issues is the sampling frequency. The sampling frequency of the motion detection mechanism determines what kind and how much movement can be removed. Care to guess what the sampling frequency might be? 1000Hz according to Nikon. That sounds pretty good, doesn't it? Nope. 1000Hz is 1/1000 of a second. If your shutter speed is 1/2000 of a second and the VR mechanism is sampling at 1/1000 of a second, what do you think happens? Moreover, Nyquist tells us that we can only really resolve data accurately below half the sampling frequency, thus the 1/500 boundary for Nikon VR."

Hi John - Thom is usually quite approachable - I m sure if you sent him a email through his website - you would get a response.
:)

[Alfred Forns]

Hi Dave Sorry I'm late in answering Mode two all the time !!!

[Arthur Morris]

I never heard of sampling frequency nor do I care to learn about it. I leave IS Mode 2 on all the time on all of my lenses whether handheld or on a tripod and have taught others including Alfred :) to do the same. I know that this is "wrong" for the handholdable lenses like the 1-4 and the 300 f/4 IS but don't care about that either. Perhaps I could see a difference with a good electron microscope but I would rather spend my money on some great trips and my time on going out and continuing to make great images. Last time that I checked none of my images suffered from my IS policy :).

Just for the record books, my understanding for the Canon super-telephotos is that IS mode 2 performs exactly as IS mode 1 except when you are photographing a static subject from a moving vehicle....

For me, this thread is just another example of folks caring way too much about technical minutiae and way to little about learning the art and craft of nature photography. Just my usual 2 cents. :)

[John Chardine]

Hi John - Thom is usually quite approachable - I m sure if you sent him a email through his website - you would get a response.
:)

Thanks Lance. Good suggestion. I'll do that.

[John Chardine]

Thom Hogan pointed me to a new version (as of 4 May) of the article here:

http://www.bythom.com/nikon-vr.htm

I think it's more clearly written and answers some of the questions we had.

[Alfred Forns]

Thanks for the new link John Good read and does answer some of the questions !