Sigma 17-70mm F2.8-4.5 DC MACRO

Image Stabilising Noise?

nobody@flickr.com (Brendan Joziasse) — Mon, 08 Apr 2013 04:49:19 -0700

Just got this lens and was playing around with it from my desk and noticed a wirring noise, I'm quite sure it's the image stabilising working. Is it normal for it to be audible? On my canon 18-55 kit lens I never noticed the stabilising working, it was always silent.

Reply to Galleries: Post your macro shots?

nobody@flickr.com (Jgarcialopez80) — Sun, 03 Mar 2013 09:20:24 -0800

Jgarcialopez80 posted a reply:

www.flickr.com/photos/jgarcialopez/8523950915/in/photostream

Reply to How to manual focus 17-70 2.8-4.5 dc macro

nobody@flickr.com (Digital JC1) — Fri, 01 Mar 2013 07:36:10 -0800

Digital JC1 posted a reply:

Thanks for the reply After testing/your help it looks like my switch is at fault on the lens.
Many thanks for the help

Reply to How to manual focus 17-70 2.8-4.5 dc macro

nobody@flickr.com (leon_all_shots) — Fri, 01 Mar 2013 06:38:22 -0800

leon_all_shots posted a reply:

The MF / AF switch should click into each position.

When it's set to MF you should be able to freely move the focus ring (closest to the front / hood). If you can't, then something is up.

By the way the ring only rotates about 45° from minimum to maximum.

Reply to How to manual focus 17-70 2.8-4.5 dc macro

nobody@flickr.com (Digital JC1) — Fri, 01 Mar 2013 04:17:36 -0800

Digital JC1 posted a reply:

thanks for your reply the switch is all the way down still doesn't move but if i hold the switch down and move the focus ring around it moves. Is this a lock so the focus ring doesn't move by mistake? Having to hold the manual focus switch down while hand holding the camera and trying to manual focus doesn't seem right to me

Reply to How to manual focus 17-70 2.8-4.5 dc macro

nobody@flickr.com (HibernoManchego (Oretani Wildlife)) — Fri, 01 Mar 2013 03:02:21 -0800

HibernoManchego (Oretani Wildlife) posted a reply:

Make sure you move the switch all the way. You are using the right ring.

How to manual focus 17-70 2.8-4.5 dc macro

nobody@flickr.com (Digital JC1) — Thu, 28 Feb 2013 12:11:54 -0800

Digital JC1 posted a new topic:

Hi guys,
just got this lens today AF works fine but i cant get manual focus to work i pull the button down to (M) on the lens and try to turn the focus ring at end of the lens ( The ring with numbers on and infinity logo. I think this is the Manual focus ring ? ) but it wont work
Im using a canon 550d

Can anyone help me figure this out?
Many thanks

Reply to Insanely frustrated with 17-70 focusing

nobody@flickr.com (P^2 - Paul) — Mon, 25 Feb 2013 07:37:58 -0800

P^2 - Paul posted a reply:

The comments above seem to say that this lens focuses well in manual mode, but people have problems with autofocus.

Since the focus adjustment and the determination of whether something is in focus is entirely under control of the camera body (and the operator holding it), then it seems grossly unfair to blame the lens when it's the body at fault for something being out of focus (and that specifically includes that notion of "backfocus").

FWIW: I use center-weighted autofocus almost exclusively. Here's an example at 17mm, f/2.8:

Reply to Insanely frustrated with 17-70 focusing

nobody@flickr.com (leon_all_shots) — Mon, 25 Feb 2013 06:24:02 -0800

leon_all_shots posted a reply:

I documented my focussing issues with my copy of the f/2.8-4.5 (for Canon mount).

The lens has been relegated to a manual focus unit for me, because the AF is too unreliable. The reason for f/8 looking sharp is because there is more depth of field. My copy of the lens is acceptably sharp wide open f/2.8 @ 17mm, but only if I start the focus ring at infinity and bring it back until my camera confirms focus the first time. If I overshoot I will get another AF confimation, which is actually erroneous.

So the trick for me is use manual focus only (unless at 30mm or above):

1: swing focus to infinity
2. half press shutter
3. bring focus ring back until AF confirm
4. check 2-3 a second time
5. snap and zoom image to full maximum on camera screen (the 350d screen is a bit crap-ola!)

But as I say, with f/8 the amount of focus depth at 17mm is quite staggering, so for landscape stuff I have no issues with that.

The lens performs better for me zoom in and on closer subjects <3ft

Reply to Insanely frustrated with 17-70 focusing

nobody@flickr.com (Mika Kumpulainen) — Sat, 09 Feb 2013 18:03:15 -0800

Mika Kumpulainen posted a reply:

I use this lens on a sony a580, at first the lens was quite noisy and had an issue with back focusing which made it hard to use because it would only focus properly under good light. I had no choice but to send it back for repairs, since I got it back the lens has performed perfectly and focused quietly and accurately in all light conditions, I think your lens could have a similar problem it might be an idea to have it looked at.