September 23, 2014, 12:53:07 AM

Author Topic: do image stabilisers decrease image quality?  (Read 12466 times)

Mt Spokane Photography

  • Canon EF 600mm f/4L IS II
  • ********
  • Posts: 8689
    • View Profile
Re: do image stabilisers decrease image quality?
« Reply #15 on: November 07, 2012, 09:37:27 PM »
Hi,
    IMHO, every element added will decrease IQ by a bit, so a lens without IS will have slightly better IQ than lens with IS (when both lens are from the same generation and same grade) under perfect shooting condition.
So you believe a lens with one element is sharpest?  Maybe one with no elements is the ultimate?

That would be so. Looking through a hollow tube will always give you the clearest sharpest image. You can not improve the light when it is in it's near perfect unrestricted form.
If you believe that, then why buy a lens?  You can get a sharp image without one?  Why don'y you start selling them, you can sell sharper lenses for just the cost of a roll of toilet paper.
Multiple lens elements do, in fact correct the various abberations that come from just one element.  Thats why the lenses that are sharpest have multiple elements.
Your theory seems pretty badly flawed when compared with the real world.

canon rumors FORUM

Re: do image stabilisers decrease image quality?
« Reply #15 on: November 07, 2012, 09:37:27 PM »

PackLight

  • Guest
Re: do image stabilisers decrease image quality?
« Reply #16 on: November 07, 2012, 09:45:45 PM »
Hi,
    IMHO, every element added will decrease IQ by a bit, so a lens without IS will have slightly better IQ than lens with IS (when both lens are from the same generation and same grade) under perfect shooting condition.
So you believe a lens with one element is sharpest?  Maybe one with no elements is the ultimate?

That would be so. Looking through a hollow tube will always give you the clearest sharpest image. You can not improve the light when it is in it's near perfect unrestricted form.
If you believe that, then why buy a lens?  You can get a sharp image without one?  Why don'y you start selling them, you can sell sharper lenses for just the cost of a roll of toilet paper.
Multiple lens elements do, in fact correct the various abberations that come from just one element.  Thats why the lenses that are sharpest have multiple elements.
Your theory seems pretty badly flawed when compared with the real world.

Exactly what do you think lenses do?
They take the pure raw light and the bend it, skew it, rearrange it then focus it.
Multiple elements correct the aberrations that the first few elements create. Multiple elements are used to put the light back in the arrangement it started with. It doesn't improve what is natural.
Without one element the light isn't flawed, it isn't until light hits the glass that it changes and bends and compresses.

Weixing is partially right, in that when it touches the first element something is lost. Every element it touches after it looses something, but the following elements are putting it back in the right order for focus. Put enough elements in a lens the light will never make it through.

bycostello

  • 1D Mark IV
  • ******
  • Posts: 910
    • View Profile
    • London Weddings
Re: do image stabilisers decrease image quality?
« Reply #17 on: November 07, 2012, 10:09:50 PM »
if weight and size were not issues they all would have it

neuroanatomist

  • CR GEEK
  • ********
  • Posts: 14465
    • View Profile
Re: do image stabilisers decrease image quality?
« Reply #18 on: November 07, 2012, 10:13:59 PM »
Put enough elements in a lens the light will never make it through.

How many would that take? Let's try 65:



Nope, not enough - light still makes it through.
EOS 1D X, EOS M, and lots of lenses
______________________________
Flickr | TDP Profile/Gear List

PackLight

  • Guest
Re: do image stabilisers decrease image quality?
« Reply #19 on: November 07, 2012, 10:22:15 PM »
Put enough elements in a lens the light will never make it through.

How many would that take? Let's try 65:



Nope, not enough - light still makes it through.

Keep adding, but it was this article that came to mind when I was typing that.

But, I do have two single element lenses in the house that have near perfect focus with no aberrations. If Canon RD would get their act together they could perform the same miracle these two lenses perform daily...or maybe Canon RD will never get there.

sanj

  • 1D X
  • *******
  • Posts: 1502
    • View Profile
Re: do image stabilisers decrease image quality?
« Reply #20 on: November 07, 2012, 10:31:07 PM »
But how does IS reduce quality?
I am really trying to understand this for a while now.
Pls educate! THx

PackLight

  • Guest
Re: do image stabilisers decrease image quality?
« Reply #21 on: November 07, 2012, 10:32:39 PM »
But how does IS reduce quality?
I am really trying to understand this for a while now.
Pls educate! THx

I don't think it does. Not to any amount that is significant. Canon's sharpest lenses all have IS.

canon rumors FORUM

Re: do image stabilisers decrease image quality?
« Reply #21 on: November 07, 2012, 10:32:39 PM »

sanj

  • 1D X
  • *******
  • Posts: 1502
    • View Profile
Re: do image stabilisers decrease image quality?
« Reply #22 on: November 07, 2012, 10:34:31 PM »
Hi,
    IMHO, every element added will decrease IQ by a bit, so a lens without IS will have slightly better IQ than lens with IS (when both lens are from the same generation and same grade) under perfect shooting condition.
So you believe a lens with one element is sharpest?  Maybe one with no elements is the ultimate?

That would be so. Looking through a hollow tube will always give you the clearest sharpest image. You can not improve the light when it is in it's near perfect unrestricted form.
If you believe that, then why buy a lens?  You can get a sharp image without one?  Why don'y you start selling them, you can sell sharper lenses for just the cost of a roll of toilet paper.
Multiple lens elements do, in fact correct the various abberations that come from just one element.  Thats why the lenses that are sharpest have multiple elements.
Your theory seems pretty badly flawed when compared with the real world.

Well one does need a lens to take a picture!!

It seems correct that one cannot improve on light/optics 'when it is in it's near perfect unrestricted form.'

No flaw here.
« Last Edit: November 07, 2012, 11:15:19 PM by sanj »

unfocused

  • Canon EF 300mm f/2.8L IS II
  • *******
  • Posts: 2109
    • View Profile
    • Unfocused: A photo website
Re: do image stabilisers decrease image quality?
« Reply #23 on: November 07, 2012, 10:44:41 PM »
This is all very amusing, but it doesn't seem as though anyone is answering the OP's question. As I understand it, he/she is asking if the addition of optical image stabilization negatively impacts the sharpness of a lens.

I'm like the least technical person on this whole forum, so I'm certainly not qualified to answer this. But it does seem like a good question. I might expand on it a bit.

First, the idea that adding lens elements would degrade an image seems irrelevant because, as I understand it, stabilized lenses don't have any more or less elements. (That doesn't mean there aren't a different number of lens elements in a stabilized lens vs. an stabilized lens, just that the two are not related to one another.)

I think a more relevant question might be whether or not the construction of a stabilized lens sacrifices sharpness under certain conditions. From what I have read, the difference between stabilized and non-stabilized lenses is in how a group of lens elements are mounted within the lens – not the actual design of the lens elements. In a stabilized lens, a group of elements are mounted in a housing that uses gyroscopes to keep the elements stable when the housing shifts or moves. So, I guess the question really would be: since the lens elements effectively "float" within the IS housing, is there a reason why they might not be as sharp as elements that are solidly mounted within a lens tube?

One reason this seems like a logical question is that Canon recommends turning off stabilization when a lens is mounted on a tripod. If you get a sharper image without stabilization on, when the camera is firmly mounted, it does at least raise the possibility that a non-stabilized lens would be sharper than a stabilized lens.

Okay, all you tech geeks, have at it.
pictures sharp. life not so much. www.unfocusedmg.com

Daniel Flather

  • 1D Mark IV
  • ******
  • Posts: 860
    • View Profile
Re: do image stabilisers decrease image quality?
« Reply #24 on: November 07, 2012, 10:46:43 PM »

away from the center

That's a variance.  Like a half-truth, just sayin'.


they're all damn sharp!

Agreed.
| 5D3 | 8-15L | 24L II | 35L | 50L | 85L II | 100/2.8 | 200/2L | EOS M | 22 STM |

agierke

  • 7D
  • *****
  • Posts: 354
    • View Profile
Re: do image stabilisers decrease image quality?
« Reply #25 on: November 07, 2012, 10:51:47 PM »
you actually dont need a lens to take a picture. you do however need an aperture to direct light towards a medium that will record the picture. unless you consider photograms using non silver chemistry and then you dont even need an aperture.

i dont know the engineering or physics involved with IS as it pertains to image quality but i do know that a person who doesn't understand how IS is intended to be used can quickly find their image quality degrade from user error. i work with a guy who repeatedly insists on shooting in daylight with IS turned on with shutterspeeds slower than 1/60th of a sec on a 70-200mm and is shocked that he continues to get camera shake in his images....

*edit*

 a gyro will create some level of vibration so at a certain point image stabilization becomes moot due to increasingly slow shutterspeeds being much more sensitive to the vibration. i imagine that is why canon recommends turning IS off when on a tripod because the assumption is that your shutterspeeds will decrease with the use of a tripod.
« Last Edit: November 07, 2012, 10:56:56 PM by agierke »
5D3, 5D2, 5DC, s15mm Fish, 24mm TSE, 35mm F1.4L, 50mm F1.2L, 85mm F1.8, 100mm F2.8L, 24-70mm F2.8L, 70-200mm F2.8L, 580EX, 580EX2, 600EXRT

Radiating

  • 7D
  • *****
  • Posts: 336
    • View Profile
Re: do image stabilisers decrease image quality?
« Reply #26 on: November 07, 2012, 10:56:23 PM »
The inclusion of an image stabilization system in a lens DOES often lead to reduced image quality, BUT not all lenses that are poor quality have image stabilization and not all lenses that are of good quality lack image stabilization. For proof look at any lens that comes in IS and NON-IS format released in the SAME technological cycle. Tamron, Canon, Nikon, Sigma etc al have had lenses that meet that criteria and the IS version has worse IQ.

Adding image stabilization is like making a rocket that can land on the moon then deciding to make it go to mars afterwards, it's going to be harder than just making a rocket that goes to the moon, but that doesn't mean you can't achieve IQ perfection with IS, you certainly can, it's just harder.

PackLight

  • Guest
Re: do image stabilisers decrease image quality?
« Reply #27 on: November 07, 2012, 10:59:44 PM »
This is all very amusing, but it doesn't seem as though anyone is answering the OP's question. As I understand it, he/she is asking if the addition of optical image stabilization negatively impacts the sharpness of a lens.

I'm like the least technical person on this whole forum, so I'm certainly not qualified to answer this. But it does seem like a good question. I might expand on it a bit.

First, the idea that adding lens elements would degrade an image seems irrelevant because, as I understand it, stabilized lenses don't have any more or less elements. (That doesn't mean there aren't a different number of lens elements in a stabilized lens vs. an stabilized lens, just that the two are not related to one another.)

I think a more relevant question might be whether or not the construction of a stabilized lens sacrifices sharpness under certain conditions. From what I have read, the difference between stabilized and non-stabilized lenses is in how a group of lens elements are mounted within the lens – not the actual design of the lens elements. In a stabilized lens, a group of elements are mounted in a housing that uses gyroscopes to keep the elements stable when the housing shifts or moves. So, I guess the question really would be: since the lens elements effectively "float" within the IS housing, is there a reason why they might not be as sharp as elements that are solidly mounted within a lens tube?

One reason this seems like a logical question is that Canon recommends turning off stabilization when a lens is mounted on a tripod. If you get a sharper image without stabilization on, when the camera is firmly mounted, it does at least raise the possibility that a non-stabilized lens would be sharper than a stabilized lens.

Okay, all you tech geeks, have at it.

I think you described it right from all I have read and seen. The IS doesn't add another element so if it is turned off it wouldn't have any affect.

If you have the IS on while on the tripod and it kicks on it could cause motion blur, and then would affect IQ. That is one reason to turn it off. The other is battery life.

The OP's question might have been better said can they design a sharper lens by leaving the IS out. Chuck Westfall mentioned this at the release of the 24-70mm II, if memory serves. The comment was that the IS was left out to get the very best image quality out of the 24-70mm II. What this really meant who knows, but it could have meant just as easily that other versions that could have been in the target price range wouldn't have had the same quality lens grouping. It could be that IS could have been put in the new 24-70mm II for a substantial price above the $2300 the lens is going for now. Imagine how a $3000 24-70mm f/2.8 II version would have been received by the public. I don't think Westfall's comments shed any light on the question the OP posed.

I am of the opinion that IS has no affect, other than if it is miss used or malfunctions.

canon rumors FORUM

Re: do image stabilisers decrease image quality?
« Reply #27 on: November 07, 2012, 10:59:44 PM »

sanj

  • 1D X
  • *******
  • Posts: 1502
    • View Profile
Re: do image stabilisers decrease image quality?
« Reply #28 on: November 07, 2012, 11:19:17 PM »
Yeah, the question: "How does IS reduce quality." needs to be addressed. NOT how IS can reduce quality.
All lenses have IS on/off switch.

I really want to know.

Thx!

PackLight

  • Guest
Re: do image stabilisers decrease image quality?
« Reply #29 on: November 07, 2012, 11:27:24 PM »
Sanj, how could it do anything to IQ? It is a mechanical device outside of the row of elements in the lens, it is not optical.

The only way it would affect optics is if it doesn't work properly.

But really this thread is about a non issue. There is no IS vs non IS lens that Canon makes that would be equal, those that are close the IS version is superior to the Non IS version.

canon rumors FORUM

Re: do image stabilisers decrease image quality?
« Reply #29 on: November 07, 2012, 11:27:24 PM »