binbeto said:
Good info so far, even though temperature has raised a bit.
Clockunder, you have raised a few good point in your post that I find beneficial.. Please continue to contribute as I can see you have spend time to write all these.. At 3am+?!!
Wai, you have pointed out some grey/discrepancy in other info. Very useful for people like me who know nuts. To have someone in the know to correct some misinfo is good.
Still wanna emphasize that this is just a discussion and all info shared is good.
Hope this kind of discussion will go on..
After having some thoughts over it, I think no one can please everybody. As long as my conscience is clear and that, from the expressions I use, most people know where I'm coming from (whether stating facts, guesses, deductions or opinions), I shouldn't behave just to please the dissenting ones to the detriment of the discussion.
By the way, back to the subject of this thread.
A lot more info have surfaced and this thread is now not only ISO vs Image Stabiliser but also the technical implementation of Image Stabilisers and whether they work in certain situations.
Just in case someone misunderstand, I have to state clearly that when I use the term "Image Stabiliser", I refer to the term in general and not specifically to Canon IS.
After reading most (if not all) the info above and also doing a little more research on Image Stabilisers, this is my understanding (may or may not be correct) :
1) May or may not work with panning, depending on the camera model and brand and how it's implemented. Some work with only panning horizontally but not vertically; some work regardless of panning directions. In general, they do work with panning.
2) May or may not work with tripod, depending on the Lens (how it's implemented. Old vs new), the stability of the tripod and the shake experienced (vibration on roads/bridge or wind). In some forums which I came across, opinions differed mainly because of the differences cited above. For some lenses (new?), the image stabiliser works even when mounted on tripod because the manufacturers have improved the implementation. Actually, the issue is NOT the tripod but the magnitude of the shake the camera experiences, be it handheld or on a tripod. If the camera is rock steady (by rock steady hands (if that is possible), or mounted on a tripod which is a very firm one and there is little vibration from the floor or wind), then the Image Stabiliser (in older lenses or (some brands still haven't improved?) tends to over-compensate the shake and caused the image to be blur. So the issue is "shake/vibration" instead of "tripod". For some (newer?) lenses, over-compensation of the Image stabiliser in " too steady "conditions have been reduced (not sure if it has been eliminated) and therefore there is no problem even when mounted on a sold tripod without any wind/virbation when the Image Stabiliser is turned on.
3) Image stabiliser is helpful not only in low light conditions but also when long zoom is used and there is a presence of some kind of shake (e.g. vibration from car, on helicopter, on a bridge with fast moving vehicles, strong winds etc.) even in strong light conditions (as long as it's within 2 stops or so. The FZ7 compensates up to 3 stops if I didn't read wrongly ). As long as the shutter speed used is lower than the focal length and it's within 2 (to 3) stops, Image Stabiliser has a role to play. Moreover, this is regardless of the light conditions. For e.g. shooting on a windy morning and focal length used is 400mm while the shutter speed used is 1/200. So Image stabilisers are not restricted to use only in low light conditions and slow shutter speed.
And now back to the main issue of high ISO vs Image Stabilisers.
ISO is about light while Image Stabilisers are about image blur due to camera shake.
In one of my previous posts, I categorised into 2 situations in which Image Stabilisers might be useful.
In the first situation, high ISO with noise levels as low as low ISO would solve the problem and Image Stabilisers would be redundant.
In the 2nd situations where shutter speed is the priority, high ISO doesn't help and Image Stabilisers has a role to play and the use of Image Stabilisers in this shutter priority shooting is not limited to only low light conditions. E.g. if you want to propeller of planes or blades of the helicopter to give a "rotating" effect in your picture, your shutter speed used may have to be slower than 1/focal length when you're using very long lenses (e.g 300mm, 400mm or 500mm). From what I read in one website, someone said that the shutter speed to have this effect is 1/200 or slower. If shot at 1/400, the propellers and blades may be freezed still and the plane/helicopter appears "dead" (i.e. stationery) in the picture. So this is where Image stabiliser comes in : shutter speed 1/200 at focal length 400mm in bright day light condition. Low noise high ISO is not useful in this situation. Of course, the actual shutter speed to be used depends on the rotating speeds of the propellers and blades and the preference of the photographer (just in case someone mistakes that I'm saying that die die must use 1/200 shutter speed and 400mm lens.) I think there are many other situations both in low light as well as day light that we encounter situations where we want to shoot with shutter priority but it happens to be within 2 stops slower than 1/focal length. Therefore Image Stabilisers may be useful in panning in which the shutter used is slower than the focal length (racing circuits, F1 powerboat, Wakeboard etc.) even though this is not a low light condition. I have previously tried 1/125 and 1/500 for panning on F1 powerboat and found that 1/125 gives a much better result as the background is blurred. I could't go any slower shutter speed with my camera because I had already used lowest ISO and smallest aperture in my camera and over-exposure would occur if I set it to 1/60. I've seen some very nice panning pictures of the F1 powerboat taken at 1/60 or 1/80 with very long zoom (200mm or more) and I suppose Image Stabiliser would help.
The key here is "shutter priority" where higher ISO would be of no use.
So in my opinion, low noise high ISO and Image stabilisers have a place to co-exist.
After doing a bit more reading, I discover that most of the postings here are not 100% correct (because they're only part of the whole story) and could also be misleading if they not viewed in the right frame of mind, especially when it's not expressly qualifed.
Anyway, thanks for starting the thread. Your question about Image Stabilisers vs low noise high ISO has triggered some thinking about the difference between them.
The above may not be 100% or even 50% correct and is just my own understanding.