Do I need to buy a new lens?

Question

Lately, I've been getting more and more into photography, and I've noticed that when I shoot, my camera doesn't want to go below f/5.6. (I have a Canon Rebel XT digital camera with the standard lens that came with it - an 18-55mm f/3.5-5.6, I think.. that is what I can read off the lens).

This is particularly frustrating when I'm shooting in dim light - I can only push the shutter speed so high before it gets blackened out (and too low makes most shots - like at a concert with moving people - blurry). I push my ISO as high as I can....

Looking online, I thought maybe it was my lens, and am looking at a couple, including the Canon EF 85 mm f/1.8. Will this lens give me more range in aperture? Or what do I need to do?

I've noticed this quite a bit, but now it's starting to affect my photos more. (This is also the case with my 35 mm Canon Rebel camera, as well).

I don't mind getting new equipment, but I want to make sure I'm not buying something I won't ever need or use. :-)

Also - I am shooting in Manual mode. Would shooting in a different mode make a difference? (I don't want to shoot in automatic because I don't want a flash) and I would use a tripod, but I come across this problem most when shooting live acts onstage, so my subjects are moving around anyway, so they would still blur.

Answer 1

the 85mm of course gives more "range" - 1.8 vs 3.5-5.6----- see the difference?

if you got the 85mm you would use it alot i would think, awesome for portraits.......if portraits arent your thing then check out a 50mm F1.8

a

Answer 2

It's not easy to tell from your summary whether you believe the kit lens is broke, or whether it just doesn't perform well in the lighting conditions you find yourself in.

As mentioned below, at 55mm/F5.6 it is not good for a low light situation. If you are getting the composition you want at 55, the canon 50mm 1.8 is about the least expensive alternative you will find. It is a decent lens and you will not get a faster lens without spending oodles more money. While prime lens give you speed and usually some quality, you'll have to zoom with your feet. If you are also looking to get closer pictures, the 85 mm is a good lens.

Answer 3

Just adding to whats already been said, your kit lens has a variable aperture, meaning as you zoom out, your maximum aperture is reduced, as marked on the lens. At 18mm, you've got f/3.5 as soon as you come off 18mm, your aperture is reduced, say to f/4 getting progressively smaller as you approch 55mm., thus transmitting less light and driving down your shutter speed. Shutter speed, handheld should be the reciprocal of the focal length of the lens, minimum. IE: handheld w/ a lens focal length of lets say 100mm, your shutter speed should be no slower than 1/100 sec. Even the pulse of your heartbeat can be enough to blur the image slightly, giving it a 'soft' look.
I wanted to point out that the 85mm f 1.8 is a fixed focal length, and might cramp your style if your used to the flexibility offered by a zoom. f 1.8 is respectable but an 85mm lens on your camera will have the perspective of 1.6x X 85mm = approx. 130mm , which will again limit your useable shutter speeds hand held. How about buying annother kit lens, 18mm-55mm f 3.5- 5.6 to replace the existing one your having the problem with, and you'll be able to use your existing filters, lens hood ect.
G'Luck

Answer 4

If you are zoomed out to 55mm then your lens is wide open at f5.6 - and that is very slow for low-light shooting. I'm guessing you have the camera in Shutter Preferred (AV) Mode and at any shutter speed the lens can only open to f5.6.

The 85mm f1.8 should correct this problem. The ultimate would be the 85mm f1.2 but its a real budget buster so settle for the f1.8.

You might find the FotoSharp (fotosharp.com) Day & Night Exposure Guide useful.

Answer 5

First, is your camera set to aperture or shutter priority for automatic exposure? Try switching and see if that helps.
Second, what is the focal length setting? Many zoom lenses have the lowest f/number (greatest effective light gathering power) only at the wide-angle setting.
Third, with the lens removed, see if there is a mechanical pin connection to the diaphragm and _gently_ wiggle it to see if there is "stiction" or if it's broken. Check that it correctly engages with the camera body. If the adjustment is electrical, you could have it tested, but get a quote first: minimum charges might be more than a brand new lens!
The lower the f/number, the more light gathering power but you are trading off depth of field and size and weight for the wider aperture. You might try to use the lens in the store to see if it gives you a useful advantage of faster shutter speed.
BTW, rather than increase ISO, I prefer to use a min-tripod, or even a big one. The photos are sharp, and it gives me the opportunity to look and compose, rather than snap-shoot (is that a word?).