Manual focus 'smoothness' question on a macro lens...

**Just1MoreDave** · 01-13-2010, 02:50 PM

Originally posted by boriscleto

I just acquired one of these from fleabay and have a question about the automatic aperture. When set to A the camera does not recognize f2.8. The lowest it will go is f4. Is this normal for this lens or should I send it back?

Clean the contacts with a soft cloth to make sure they all work.

**boriscleto** · 01-13-2010, 03:23 PM

I mounted it again and this time it worked. I think the lens was not used for some time and it does need to be cleaned.

**nater** · 01-13-2010, 05:57 PM

Originally posted by glasbak

Today arrived ths very same sigma macro lens to diagnose/repair for someone.
It suffers from exactly the same problem.
It was easy to repair (if you are a bit technical and have the right equipment)

George, thank you so much! That looks like it describes my problem exactly, because I have the same marks on the barrel as you show in that picture. I will try this fix soon.

Regarding the tape - did you re-use the tape, or did you use new tape? And if you used new tape, what tape did you use?

With the felt, I'll try to re-use that as well, fixing where it's bunched up, but out of curiosity is there a good source for replacement felt for camera lenses like this?

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01-13-2010, 02:50 PM	#16
Just1MoreDave Site Supporter Join Date: Feb 2007 Location: Aurora, CO Photos: Gallery \| Albums Posts: 6,340	Originally posted by boriscleto I just acquired one of these from fleabay and have a question about the automatic aperture. When set to A the camera does not recognize f2.8. The lowest it will go is f4. Is this normal for this lens or should I send it back? Clean the contacts with a soft cloth to make sure they all work.

01-13-2010, 03:23 PM	#17
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	I mounted it again and this time it worked. I think the lens was not used for some time and it does need to be cleaned.

01-13-2010, 05:57 PM	#18
nater Loyal Site Supporter Join Date: Aug 2009 Location: New England Photos: Albums Posts: 706 Original Poster	Originally posted by glasbak Today arrived ths very same sigma macro lens to diagnose/repair for someone. It suffers from exactly the same problem. It was easy to repair (if you are a bit technical and have the right equipment) George, thank you so much! That looks like it describes my problem exactly, because I have the same marks on the barrel as you show in that picture. I will try this fix soon. Regarding the tape - did you re-use the tape, or did you use new tape? And if you used new tape, what tape did you use? With the felt, I'll try to re-use that as well, fixing where it's bunched up, but out of curiosity is there a good source for replacement felt for camera lenses like this?