Sigma lens compatibility

rootedinvermont

Hi. Shortly after buying my T2i, I bought a Sigma 17-70mm 2.8/4 DC Macro HSM lens. I bought it for the macro capabilities (shooting plants), but I've been disappointed with the results. Don't see it on your recommended lens list. Is it not a good match for the camera? If OK, then I need some coaching, so which cheat sheet set would apply? Thanks!

PBked

Hi,
You don't say why you were disappointed which is a bit like saying "I've got a noise in my car". Your Sigma is a pretty good lens and more than capable of producing good close-ups. Notice, I did not use the word 'macro' because I have very definite ideas about the difference between that and 'close-up'. If you have ever seen photos of the compound eye of a fly, then that is what I call macro.
Also, you give no indication of how you were attempting to shoot your subject.
So, without much information to go on, I venture the following:
1) A good tripod is essential. Switch image stabilization off.
2) Switch into live view mode. Focus is much easier to achieve on the large LCD.
You do not have to switch MF off on the lens unless you want to use manual for everything. Your lens has full-time manual focus, so you can use auto focus in the first instance and then tweak the focus with the focus ring without causing damage to the lens.
3) Set your ISO to 100 and your metering to spot.
4) Use aperture priority set to f/2.8 to soften the background, although you may want to up this by a stop if you want greater depth of field.
5) Position your subject at about 25cm from your lens (it's minimum focus is around 22cm) and use your zoom to frame the subject. By pulling back a little you may avoid cutting light to your subject.
6) If you don't have the remote control, use the timer function set to 2 seconds and then press the shutter button.
I hope this helps and I'm sure others on this site will add anything I may have forgotten.
Regards,
PBked

rootedinvermont

Thank you for this advice. Sounds like user error.
Just not getting the crisp images I get with my Canon G9 or my old film SLR.

I am not photographing insect eyes, mostly garden scenes and individual flowers.
Have not been using the LCD, but will start do that. Also, I have been using MF and will switch to AF.
I have a tripod but rarely use it. I will drag it out and try to love it.
Curious why you suggest switching IS off. What's the downside?
I don't have a remote control so will try using the timer function.
I like the idea of your cheat cards. Would any of the sets apply to my set up?
Thanks again.

bruto

Generally, IS should be off for tripod use or any time it's not needed. Though its effect is positive when it's needed, it can compromise sharpness a tiny bit when it's not. You will of course get some conflicting views on this, with some saying you can leave it on and never notice, but the safest bet is that if you don't need it you should turn it off. That means, off for tripod or for high shutter speeds.

ohyeahar

Why turn off IS when camera is stabilized? Very easy to see for yourself. Try this.

Turn IS off.
Turn on Live View.
Stabilize the camera either on a tripod or just place it down somewhere. It helps to have multiple objects in the frame so you can use them as points of reference.
Notice how the frame is absolutely still, which you would expect since the camera isn’t moving.

Now try it with IS on.
Notice how the frame is actually slightly moving around? You’ll notice the effect more if you look at the edges of the frame.