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Archive 2005 · Fast Wide Prime + IS
  
 
nutek
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p.2 #1 · p.2 #1 · Fast Wide Prime + IS


phidong wrote:
I think the biggest assumption in this thread is that IS for wide angle works and that it is as effective as IS in other lenses.

First off, to understand if it is even possible to put IS into a wide angle lens, we really have to understand how IS works. When you shake your camera like a polaroid pictah, what is happening is that you're shifting the image plane around either up and down, forward to backward or right to left. But how does IS compensate for this? Easy. Theres an element or a group of elements that shifts the
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While I generally agree with your points regarding the business parts of the debate, from an engineering standpoint, your analysis may be inaccurate.

If the said accelerometers can already "notice a shake and compensate for it" for a telephoto lens, then the same said accelerometers will also be able to notice the shake for a wide-angle lens (keeping of course, the "shake" as well as the size and weight of both lenses constant). The resultant image or FOV has nothing to do with the equation.



May 01, 2005 at 08:49 AM
phidong
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p.2 #2 · p.2 #2 · Fast Wide Prime + IS


nutek wrote:
While I generally agree with your points regarding the business parts of the debate, from an engineering standpoint, your analysis may be inaccurate.

If the said accelerometers can already "notice a shake and compensate for it" for a telephoto lens, then the same said accelerometers will also be able to notice the shake for a wide-angle lens (keeping of course, the "shake" as well as the size and weight of both lenses constant). The resultant image or FOV has nothing to do with the equation.

Theres obviously more compensation for a smaller field of view than a larger one (wide angle). And while it will still relize there is movement, whos to say that the degree of accuracy of the mechanism is great enough? Think about why it doesn't work when you're on a tripod.



May 01, 2005 at 08:53 AM
nutek
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p.2 #3 · p.2 #3 · Fast Wide Prime + IS


phidong wrote:
Theres obviously more compensation for a smaller field of view than a larger one (wide angle). And while it will still relize there is movement, whos to say that the degree of accuracy of the mechanism is great enough? Think about why it doesn't work when you're on a tripod.


Yes, definitely there will be more compensation for a smaller FOV. I don't know enough about the *precision* (not accuracy) of the IS mechanism, so I won't comment on it.

The new IS mechanisms do detect that the lens is mounted on a tripod. A simple enough algorithm: if shake < threshold, disable IS. If shake > threshold, enable it.

If you're hand-holding it still enough for 2 seconds such that the IS cannot detect the movement, then great, you're as sturdy as a tripod But not everyone can do that...

In any case, this is all for the jest of pedantic debating. It may be surprising to see new forms of photography that may appear, if wide, fast IS lenses become available on the market.


Edited by nutek on May 01, 2005 at 02:07 PM GMT



May 01, 2005 at 08:58 AM
phidong
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p.2 #4 · p.2 #4 · Fast Wide Prime + IS


nutek wrote:
If you're hand-holding it still enough for 2 seconds such that the IS cannot detect the movement, then great, you're as sturdy as a tripod


Yes, I commented on the older IS to illustrate the fact that when there is little movement, the IS shuts off.

Even if you can only hand hold for 1/30s how much would IS be able to help? The amount of "help" you would get is dependant on how *precise* (sorry for my misuse of termonology) the mechanism is.



May 01, 2005 at 09:03 AM
nutek
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p.2 #5 · p.2 #5 · Fast Wide Prime + IS


phidong wrote:
Yes, I commented on the older IS to illustrate the fact that when there is little movement, the IS shuts off.

Even if you can only hand hold for 1/30s how much would IS be able to help? The amount of "help" you would get is dependant on how *precise* (sorry for my misuse of termonology) the mechanism is.


Yes, that is true. But since the 17-85 IS already exists and is working well, there is evidence to say that the IS mechanism is precise enough for a 17mm (~28mm)-wide lens.



May 01, 2005 at 09:24 AM
phidong
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p.2 #6 · p.2 #6 · Fast Wide Prime + IS


nutek wrote:
Yes, that is true. But since the 17-85 IS already exists and is working well, there is evidence to say that the IS mechanism is precise enough for a 17mm (~28mm)-wide lens.


Again, that's fine. We're talking about a 600 dollar consumer lens meant for cropped sensors. A full frame version would be over the 4 digit mark for a consumer grade lens. The 1-2 stop differential puts you around f/1.8 and theres already a 20mm f/1.8 prime available from Sigma for less than a third of that price which will produce sharper pictures.

You want a f/2.8L? How much would you charge for it? Again, how many people will buy this?

Would you pay 1,500-2,000 for a 17-40mm f/2.8L IS?



May 01, 2005 at 09:32 AM
Kevin Yong
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p.2 #7 · p.2 #7 · Fast Wide Prime + IS



Imagine you are on vacation in Europe and want to get a wide shot of a dimly lit church interior. You don't have a tripod or other support but want to stop down for enough DOF (say f/8). The only lens which can do this is the 17-85IS. Yes - IS is useful on a wide angle.

Say you then wanted to take a portrait of the priest in the same church. IS would be no help because the subject cannot stay still enough to prevent motion blur. Thus opening up to f/1.8 or f/2.8 would be the solution. This would mean changing to a faster lens - none of which have IS.

This is where a fast wide lens with IS would be fantastic. It gives the best of both worlds and saves having to switch lenses.

Putting IS on the Sigma 18-50/2.8 or any of the wide primes would be fantastic in this and many other situations.





May 01, 2005 at 09:49 AM
 

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phidong
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p.2 #8 · p.2 #8 · Fast Wide Prime + IS


Kevin Yong wrote:
Imagine you are on vacation in Europe and want to get a wide shot of a dimly lit church interior. You don't have a tripod or other support but want to stop down for enough DOF (say f/8). The only lens which can do this is the 17-85IS. Yes - IS is useful on a wide angle


What shutter speeds are you getting in a dimly lit church at f/8?



May 01, 2005 at 09:52 AM
phidong
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p.2 #9 · p.2 #9 · Fast Wide Prime + IS


If you want fast wide angle lenses with image stabilization, switch to Minolta.


May 01, 2005 at 09:59 AM
normski
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p.2 #10 · p.2 #10 · Fast Wide Prime + IS


sounds to me like people are wanting to shoot practically in the dark with no flash. the only solution to that little conundrum is to go infrared. in the meantime the "fastest" lens canon makes for hand holdable operation is the 24mm f1.4L. it has the same hand holdability as the now defunct 50mm f1 and nobody talked about needing IS with that. think about it - a 50mm lens needs 1/50 sec. the 24mm needs 1/24th sec. ie 1 stop difference in shutter speed and there's one stop betwwen f1 and f1.4, so in terms of handholdabilty they equal out. it's also therefore faster in handholdability than the 85mm f1.2L and even the 35mm f1.4 and obviously the 50mm f1.4. so if you want the "fastest" lens get the 24mm f1.4L. it's a real whizz.


May 01, 2005 at 09:42 PM
bwaterme
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p.2 #11 · p.2 #11 · Fast Wide Prime + IS


If I remember correctly, an article I read in Popular Photography about IS lenses stated that IS was less effective on the wider end on the lenses tested. Basically, on the zooms the IS might help for up to 3 stops at the long end, but only 1 stop on the wide end.
I guess there are a few scenarios where IS on a fast prime could help improve the image, but probably not enough to justify the cost...IMHO.



May 01, 2005 at 10:23 PM
charlesk
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p.2 #12 · p.2 #12 · Fast Wide Prime + IS



sounds to me like people are wanting to shoot practically in the dark with no flash. the only solution to that little conundrum is to go infrared.

Nah, you just have to be creative and not worry if people look at you like you are insane.

Here's a shot from the Royal Tyrrell museum in Alberta. It's a renowned dinosaur museum -- and very dark, with no pods allowed. 17-40 f/4L, 29 mm, f/8 @ 0.3s, taken with the camera smooshed against a sweater held under pressure against the handlebar of my son's stroller.

I took others that involved me holding the camera sideways on walls, or sprawling on my belly across the floor. But many of them came out... --c

http://www.pcguide.com/pers/steg.jpg



May 01, 2005 at 10:31 PM
nutek
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p.2 #13 · p.2 #13 · Fast Wide Prime + IS


Good call. I withdraw my argument

Kevin Yong wrote:
Imagine you are on vacation in Europe and want to get a wide shot of a dimly lit church interior. You don't have a tripod or other support but want to stop down for enough DOF (say f/8). The only lens which can do this is the 17-85IS. Yes - IS is useful on a wide angle.

Say you then wanted to take a portrait of the priest in the same church. IS would be no help because the subject cannot stay still enough to prevent motion blur. Thus opening up to f/1.8 or f/2.8 would be the solution. This
...Show more



May 01, 2005 at 10:40 PM
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