17-55 Aperture Advantage 2.8 New to DSLR

SeanGrey wrote:

Hi there

I am a beginner by every means, had my 650D for around a year now. Know about settings and aperture and iso and everything.

When it comes to deciding between a fast lens (2.8 or 1.8 and so on) and another lens say 3.5 or f4 and higher. The latter being better in low light photography. Is that just low light hand held? I see many incredible photos taken with the 17-55 and many say due to its 2.8 aperture its better than say a slower 15-85 in some instances. All the great pictures I see during low light are sitting at f9-f11. So the low advantage over another lens goes out the window?

I have other threads deciding between lenses, do not wish to double post questions but the aperture part over more reach must then apply to hand held getting higher ISO and shutter speeds?

If so I could get a lens with more reach thats slower and use a tripod in the later evenings or indoors. Do not need it for sport or video just still photography.

As Lemming51 alluded to, there's no right answer. What I can say for myself is that I wouldn't be without a fast medium range lens. Having had both (or having both) and more, I would stick with less focal range to have a faster lens. But, I shoot a lot of low light environments, so this is the way I'm biased. Before this I was perfectly happy with the precursor to the 15-85 (EF-S 17-85)

Don't discount the third party lenses, which can be had for a lot less than the 17-55 and are every bit as sharp. The Tamron 17-50 (non-VC) is very sharp.

This is the EF 24-70/2.8 II on my 70D. It's at or above 1900 resolution on this chart (Reikan FoCal), with a dropoff at 2.8. Otherwise, the only other lens I have that beats it is my 100/2.8L IS Macro

However, the lowly Sigma 17-50/2.8 OS bests it at 2.8 and 3.5, and is awfully close elsewhere. This is amazing performance for a $500ish lens.

You already know the pros and cons of a 2.8 or faster lens. The difference between this and F4-5.6 is quite apparent when you're up against having to dial up your ISO or not. Of course at a distance, the DOF is less apparent and less of an issue.

IS is really helpful, and makes a huge difference when shooting. I usually find it to make up for at least 1 if not 2 stops in real life shooting, which is a lot. But, it won't stop your subjects if they're moving. That's the limitation of stabilization. F2.8 will allow you to use a faster shutter speed, and this is even noticeable if you've got a flash (which I highly suggest at some point).

Once I got my 6D I found that F4 would really suffice for many situations, but I'm sure glad I have this faster glass for my crop cameras still.