Camera or lens problem? My Sigma 105 macro lens and my A77 seem to have a "failure to communicate" from time to time. Sometimes everything works great for several pics and sometimes...

planepics Loc: St. Louis burbs, but originally Chicago burbs

My Sigma 105 macro lens and my A77 seem to have a "failure to communicate" from time to time. Sometimes everything works great for several pics and sometimes, it seems to lose f/stop information and I can't use the lens (display reads "f-.-"). I end up having to turn the camera on and off again a time or two or remove and replace the lens to get it working again.

Helge Loc: Sarnia, ON, Canada

planepics wrote:

My Sigma 105 macro lens and my A77 seem to have a "failure to communicate" from time to time. Sometimes everything works great for several pics and sometimes, it seems to lose f/stop information and I can't use the lens (display reads "f-.-"). I end up having to turn the camera on and off again a time or two or remove and replace the lens to get it working again.

Try cleaning the contacts on the lens and camera. Use a pencil or better ink eraser just make sure no eraser particles stay on camera or lens, use some canned air carefully. Do your other lenses work OK? Computerized electronics so much fun!! If this continues you may need to send the lens and or camera in for servicing. Trying another lens will determine if the problem is in the lens or camera body.

planepics Loc: St. Louis burbs, but originally Chicago burbs

I don't recall either of my other lenses having that problem, but I will check them out and erase the contacts. What about cleaning them with isopropyl alcohol on a swab? I don't have any canned air.

Helge Loc: Sarnia, ON, Canada

planepics wrote:

I don't recall either of my other lenses having that problem, but I will check them out and erase the contacts. What about cleaning them with isopropyl alcohol on a swab? I don't have any canned air.

Alcohol will work but cotton swabs do not work well for the cleaning of contacts because the will leave fine strands of cotton fibres caught in the contacts, so if you can get a lint-less cloth apply some 99% Alcohol to the cloth sparingly that may work. For cleaning your camera canned air is a must, but one has to be careful.

Sheila Loc: Arizona or New York

You may use a small amount of alcohol on a Qtip to clean the contact. Then use the dry end of the Qtip to dry the contacts. Make sure everything is completely dry before you try using lens and camera. You may need to do this twice to clean thoroughly.

Helge Loc: Sarnia, ON, Canada

Sheila wrote:

You may use a small amount of alcohol on a Qtip to clean the contact. Then use the dry end of the Qtip to dry the contacts. Make sure everything is completely dry before you try using lens and camera. You may need to do this twice to clean thoroughly.

Q tips are great for cleaning many other parts of cameras but definitely not the contacts!

tsilva Loc: Arizona

Yeah, cotton swabs aren't the best to use for cleaning on cameras.

As to your problem, it does sound like a contact problem. I am not sure if just cleaning the contacts will cure it. Is there any play between the lens and body?

planepics Loc: St. Louis burbs, but originally Chicago burbs

tsilva wrote:

Yeah, cotton swabs aren't the best to use for cleaning on cameras.

As to your problem, it does sound like a contact problem. I am not sure if just cleaning the contacts will cure it. Is there any play between the lens and body?

Never thought of that. Just checked. If I grab hold of the lens while holding the body and I give the lens a twist, there is a TINY bit of movement back and forth.

dmeyer Loc: Marion, NC

planepics wrote:

My Sigma 105 macro lens and my A77 seem to have a "failure to communicate" from time to time. Sometimes everything works great for several pics and sometimes, it seems to lose f/stop information and I can't use the lens (display reads "f-.-"). I end up having to turn the camera on and off again a time or two or remove and replace the lens to get it working again.

I had the same symptoms with a new Tokina 12-28mm and sent it back to the factory. The technicians found that the aperture blades were sticking. It works fine now.

lamiaceae Loc: San Luis Obispo County, CA

tsilva wrote:

Yeah, cotton swabs aren't the best to use for cleaning on cameras.

As to your problem, it does sound like a contact problem. I am not sure if just cleaning the contacts will cure it. Is there any play between the lens and body?

Yup, I found that out the hard way. :-(

Donkas1946 Loc: Southern NH

I would never use canned air on my camera body as it can drive small particals of dirt deeper into the body..

Helge wrote:

Alcohol will work but cotton swabs do not work well for the cleaning of contacts because the will leave fine strands of cotton fibres caught in the contacts, so if you can get a lint-less cloth apply some 99% Alcohol to the cloth sparingly that may work. For cleaning your camera canned air is a must, but one has to be careful.

Mgpfonner

In the cosmetics section of any drug store you can buy swabs tipped with foam for applying eye makeup. They don't leave any residue.

47greyfox Loc: on the edge of the Colorado front range

Easiest troubleshooting is using the lens and bodies with other equipment. Follow the problem. Camera stores may help you, but not always, for obvious reasons. When you isolate the issue, it becomes decision time on whether you want to attempt repair. Everyone has a different comfort level. Some don't advise it, but I use 90% isopropyl to dab clean contacts with a fine woven micro cloth and carefully aimed air. Make sure the air is just that - air. No sense making the problem worse. I always start with a squeeze duster. Best of luck!

peterg Loc: Santa Rosa, CA

Helge wrote:

Try cleaning the contacts on the lens and camera. Use a pencil or better ink eraser

I suggest NOT using abrasives, since many contacts have very thin non-corrosive layers (e.g. gold). Removing these layers would probably be only a temporary fix.

planepics Loc: St. Louis burbs, but originally Chicago burbs

I wrote an e-mail to Sigma last night about the problem. Hopefully they will respond today or tomorrow with a suggestion. It should still be under warranty. What is it? Six years? I bought it, I believe in Feb. '14.