dpreview review

dpreview.com posted a review of the 40D! Looks really nice compared to the 400D

Well, i guess a 18-55 IS is all I can afford. I don't know how much the IS is reliable..does it push the anti-shake really far?

Say that a basic 10-55 is blurry at 1/50, can the IS system be free of any blur at 1 sec ?

Cr4zYH3aD wrote in post #4234944
Say that a basic 10-55 is blurry at 1/50, can the IS system be free of any blur at 1 sec ?

No. to take your example, a picture without IS at 1/50 will be equally blurry as a picture taken with IS at shuttertimes of:

1/50 without IS
1/25 at one stop effective IS
1/12 at two --- " ---
1/6 at thee --- " ---
1/3 at four --- " ---

In general multiply your non-IS shutter time by 2^n (2 to the power of n), where n is the effective number of stops of the IS, to get the shutter time you can pull with IS.

I don't know how good the IS of the 18-55 is, but I would be highly surprised if it was above 3 stops (real world stops, not the marketing kind)

/lk

well, IS, worth it ? .. Maybe not

Cr4zYH3aD wrote in post #4235632
well, IS, worth it ? .. Maybe not

Until you miss a really important shot you’ll not know the answer to that question, I’m afraid..

hehe.. im just tired of blurry picture when there's just not enough light. I wanted IS to give me clear shot like when the camera is on a tripod.

Pictures can be blurry for two different reasons: Camera motion blur and Subject moving blur.
Image Stabilization lenses will help you only with the former.
High shutter speed will take care about the later.

I know !

Im trying to lessen the former.

I would say, skip the 18-55IS, save up more and go for the 17-55IS. It's a long way there, but it'll be worth it. In that case, the F2.8 and the IS will help with movement and camera motion blur.

Without the need to whip out your slide rule (calculator, if you are a youngster), a rough rule of thumb for Canon IS systems is an improvement of 2 EV in shutter speed compared to not using image stabilization. If you are shooting hand held indoor exposures, then your results will still not be up to the quality of using a tripod.

In addition to the description of motion blur given above by Hermeto, hand held motion can further be broken down into two components: low amplitude oscillatory motion (shake) and steady state drift motion which changes direction much slower than shake.

Image stabilization handles the first component well, but cannot effectively help steady state or very low frequency drift. Do a self examination of your ability to stay on target by aiming a long lens at a clearly discernible distant object using your normal holding technique. It is easy to determine your shaking motion. But, examine how well you are keeping the camera aimed at a fixed location.

Fire off several shots while trying to keep the camera steady. Examine the results for motion blur due to shake -- the amount of blur with IS active will be roughly 1/4th as much assuming every thing else remains the same. Now compare all of the shots to see if you have a drift problem. If you tend to drift significantly, the results will not be helped by IS.

In my humble opinion i could not be without IS now. All my cameras now have it and it is a god send. I have lost count now on the times it has helped me out and allowed me to get shots i had no right to get. It of course isnt perfect but what in life is (well my wife is just in case she reads this one).

I have just got myself the 40D with 17-85 IS Lens. The lens is great and camera is outstanding.

Cr4zYH3aD wrote in post #4235786
hehe.. im just tired of blurry picture when there's just not enough light. I wanted IS to give me clear shot like when the camera is on a tripod.

OK, so then your initial example might not be helped much by IS - i assume you are familiar with the 1/fl (or 1/fl*1.6) rule. If the shot is blurry at 1/50 and 18mm, the problem is not camera shake but subject motion. At 100mm, then yes IS would definitely help. Honestly, a cheaper and better way to deal with poor lighting at short focal lengths is external flash with diffuser - much better than the popup flash. Flash will freeze motion and allow higher shutter speeds to compensate for shake; properly bouncing or diffusing it can help preserve the "mood" of the setting. Alternatively, adding something like the 50/1.8 can also do the job.

IS has really helped me with focus precision (I'm not very steady). Quite often I find myself trying to focus on one relatively small object (ie: a single leaf in a mass of branches, a childs eye...) Using the center focus point, IS helps me keep the point on the correct subject.

I like IS, but it's not a miracle cure. I've taken some pretty nice shots down to 1/8th of a second using my 24-105 f/4L IS - but that was on a full frame 5D at 24mm. 1 second would be really pushing it, even with that combo.

Mark

With IS you'll find your can hand hold much slower with reasonable results. Like others have said there's no substitute for tripod.

I've held 1/10th on a 24mm setting and got a good shot.

ok I guess 40D would be the perfect camera if it would have been Full frame.

Anyway, Thanks. I dont want a flash, it kills the atmosphere when you take pictures outside. Always carrying a tripod is troublesome. I thought IS was much better !