Can the CP photogs please give me some insight into the IS vs non IS lens debate.
Is it really worth it to spend 2X the amount for an IS lens for a Canon Rebel T2i?
I am looking at either the Canon 55-250 mm (is and non is) and the 70-300 mm IS and non IS
Depends on a few factors. How often will you be hand-holding the camera instead of using a tripod? Is there an instance where you'll be shooting in lower light more often than not?
For somebody using it to take pictures while they go hiking it may not be as useful as somebody who's buying it to take pictures (edit: poor example) without a tripod in low light.
Personally I went with it just because I wanted the lens to be as versatile as possible. I stand by my decision. It doesn't make a night and day difference in my pictures, but it certainly has saved a couple pictures from being throw-aways.
IS WILL NOT help you to shoot your kids playing hockey in an arena since IS does not allow more light into the sensor. It allows for you to shoot with a slower shutter speed and compensate your movement, it does not freeze the movement like a faster shutter speed would. If you are going to shoot low light and sports like basketball and hockey.. a f2.8 would be the ideal lens.
IS WILL help you when you are using a telephoto lens and don't use a tripod or monopod for your stability. The ideal shutter speed is 1/mm so if you are shooting at 300mm, then the ideal shutter speed is 1/300s. which sometime you won't be able to get without either opening up the aperture ( i believe the far end of these are F5.6) or bumping up your ISO. So with IS, you will be able to shoot at say 1/200 or 1/150 without needing to shoot at ISO 100000000....
I waited forever for Canon to come out with the 70-200 F4 IS... best decision ever.
For my aviation shots having the IS is great, and the ability change it to 'mode 2' where only one axis stabilizes is great as I'm tracking a landing aircraft.
I have a Nikon 70-200 2.8 IS. Like mentioned above, I don't turn it on when I shoot hockey or other sports. But it's great for shooting concerts (like a HS Band etc) where the light it pretty low and you've got to drop the shutter.
Always buy the best lens you can afford.....in the long run it's much more important than any body, and if it's a good lens, you might have it for 20+ years.