Sigma 100-300 f4 , autofocus woes

riyerca

Hi ,

I just bought a Sigma 100-300 f4 lens, after reading a lot of good
reviews. Yesterday, I hooked it on to my D70 (with new firmware upgrade)
and was quite disappointed with the autofocus speed.

The lens get pretty close to the focus range, and then did this
continuous hunt and went oscillating between two ends of the
focus point. This continues for about 6-7 sec. until either I give up
or the focus resets. This is particularly bad at the 300 mm range.
Does not happen always, but is frequent enough. Also, I had sufficient
lighting, and tried it both indoors and outside.

Anybody, seen this before. I am wondering if I got a defective lens,
or is this common.

Thanks Very Much,
Ram.

Harryb

Hi Ram,

I have never used the lens but almost all the iuser reviews here are very positive. http://photographyreview.com/cat/lenses/35mm-zoom/Sigma/PRD_85165_3128crx.aspx#reviews

Also all the user reviews at Fred Miranda are positive http://www.fredmiranda.com/reviews/showproduct.php?product=103&sort=7&cat=37&page=1

riyerca

Thanks for your post Harry.

Yes, I did read those reviews before the purchase, and am still
very positive about the lens. Just wanted to make sure that the
particular one that I received does not suffer from this problem.

Will be calling Sigma's customer service dept. too to see what
they say about it.

Harryb

riyerca wrote:

Thanks for your post Harry.

Yes, I did read those reviews before the purchase, and am still
very positive about the lens. Just wanted to make sure that the
particular one that I received does not suffer from this problem.

Will be calling Sigma's customer service dept. too to see what
they say about it.

That would be the best approach. What were the shooting conditions when you tried it out? My Nikon 500mm f4 is usually a fast focuser but there have been a few times in bad light when it really hunted before I could get it focused.

riyerca

I tried shooting in the best lighting conditions, at all apertures.

These include the well lit parts in the house, and outdoors.

This might also be a problem with the D70 autofocus, but it has
not given me any problem with the other lenses that I have used.

pepper44

I recently bought a Sigma (well it's actually Quantaray) 70-300mm lens and it does the same thing on my Digital Rebel XT with the auto focus. It drives me crazy because it will zoom past what I want to focus on. It goes on both ends of the spectrum and passes what I'm focusing on in the middle. It seems to be worse in low light, and it runs down the battery. I wondered if anyone else had this problem, I guess so. I've been trying to use it with the manuel focus. Minus that auto focus issue it's a great lens.

--Amy

riyerca

Hi Amy,

Thanks for the post. Did you have any luck with Sigma's customer service.
It is quite disappointing to know that we have to use a lens with HSM in
Manual mode all the time.

-Best wishes,
Ram.

pepper44

riyerca wrote:

Hi Amy,

Thanks for the post. Did you have any luck with Sigma's customer service.
It is quite disappointing to know that we have to use a lens with HSM in
Manual mode all the time.

-Best wishes,
Ram.

Ya know, I actually never thought to call them and ask/complain. I should do that. Did you not have any luck with them?
--Amy

riyerca

I will be calling them tomorrow. Will be posting the details soon.

-Ram.

riyerca

riyerca wrote:

I will be calling them tomorrow. Will be posting the details soon.

-Ram.

Returned my lens to the (internet) store for a replacement.
Now have to wait till the new lens arrives. This is when you realize that you should have paid a couple of bucks more and got it from the local store.

I am sooo happy, I did not get it thru ebay.

-Cheers,
Ram.