Sigma APO AF ZOOM 70-210mm 1:2.8

Hey all

 

OK so I have inherited a Sigma APO AF ZOOM 70-210mm 1:2.8 len which looks amazing but it has on really weird issue, its super sticky where the rubber is! Where you select MF or AF the band is made of rubber or plastic and its so sticky, the black sticks to my hands, its probably the case on other rubber parts also, any idea what is going on or what I can do about this. Is this a common thing or totally weird and I'm just lucky.

The term is Rubber Reversion. It is common.

 

I have had good results using Isopropyl Alcohol sparingly rubbed on the surface, which typically re-bonds the molecular chains and has an effect similar to, but not the same as Rubber Vulcanization. (i.e. in simple terms - "back to normal").

I am not versed in the chemistry of it, that's just an outline and also to state, what has worked for me.

 

WW

OK thanks William, I shall try that.

The same happened to my old Eos 300D. Wiping it with isopropyl alcohol (or surgical spirit, depending on where you are - but I once had to tell a hospital what surgical spirit was, so maybe the term is out of use) made the goop come off, but also removed the soft touch surface and left hard plastic. Not ideal, but at least not sticky. Don't panic if this happens...

The grip on my rarely used Nikon D50 became sticky. All it really needed was a little fresh air.

The grip on my rarely used Nikon D50 became sticky. All it really needed was a little fresh air.

 

Interesting. I admit that's not something I tried. (Either for my kit or, often, for myself.) Not that my 300D was in a sealed box - it was just on a shelf - but unsurprisingly it's not been heavily used. Why would air help? (Is it actually ventilation, or daylight, or handling rubbing off the stickiness?)

Just carry it around outside, if you are allowed outside.

The same happens to the Nikon N (D) 90's. I used Isopropyl alcohol and a soft cloth to reconstitute the covering, though in some places it did thin the coating.

 

My son has a Sigma 60mm f/2.8 with the same issue.

 

I also own a 70-200 f/2.8 AF APO. It's a winner!

alternatively, if you can find it, you can cover it with Lenscoat or comparible covering

wow ok thanks everyone! Going to air it for a bit and then scrub it with alcohol. Intrigued by lenscoat, haven't heard of that before. I will look into what that is.

I briefly had a Sigma Super-Wide 24mm f/2.8 whose Zen coating (that is what they branded it) was very sticky. I used isopropanol to remove it entirely. I liked the bare anodized aluminum much better.

wow ok thanks everyone! Going to air it for a bit and then scrub it with alcohol. Intrigued by lenscoat, haven't heard of that before. I will look into what that is.

Lenscoat is mostly camo-covering meterial a bit like a neoprene jacket for camouflaging your equipment...

 

LensCoat

I may have tried hydrogen peroxide.

. . . or surgical spirit, depending on where you are - but I once had to tell a hospital what surgical spirit was, so maybe the term is out of use

 

I believe another term is 'rubbing alcohol'. This was a common term used when typical practice was to keep patients in bed for long periods of time; this alcohol was used to rub on patients to help prevent them getting bed sores.

 

WW

I may have tried hydrogen peroxide.

Lol, and and is it now bleached? ;)

Lol, and and is it now bleached?

The 3% mouth wash strength.

The 3% mouth wash strength.

Enough to bleach hair...

Enough to bleach hair...

or a rabbit.

 

Follow the white rabbit..

 

Knock, knock, Neo...

 

I had an early AF Sigma UWA, with very gooey Zen, both the body and the outer hood surface. Took it all off with IPA. Looked OK.

OK so I have inherited a Sigma APO AF ZOOM 70-210mm 1:2.8 lens

I think I had the same lens a few years ago. Very nice.... when it was new!

 

However, it appears that in order to get the 'APO' performance on the cheap, Sigma used some type of glass/resin/plastic element that deteriorates over time. My copy of this lens gradually misted up internally over a number of years. The misting is irreversible, and cannot be cleaned away. It's due to micro-crazing of the surface of one or more of the elements.

 

Mine wasn't an isolated case; I've seen this in another example of the Sigma 70-210 f/2.8 Apo zoom. And in their 400mm f/5.6 Apo AF prime tele lens. Also in a cheap consumer-level Canon tele zoom.

 

So my advice would be to worry more about deterioration on the inside, rather than the outside. Have a good look through the lens with a flashlight at the other end. Even a slight 'misting' will severely affect contrast, and will only get worse over time. In short, it may not be worth spending a lot of time on this lens at all.

Edited May 5, 2020 by rodeo_joe|1

In short, it may not be worth spending a lot of time on this lens at all.

 

Yeah but: if s/he's going to touch it, then surely it would be nice is it wasn't sticky.

 

WW

Yeah but: if s/he's going to touch it, then surely it would be nice is it wasn't sticky.

 

WW

 

Having eventually worked out where to buy the stuff, surgical spirit isn't expensive. Also, when you use scissors to open the amazon pack containing whatever you replace it with, it's very good at removing packing tape goo. On a related note, I think I've worked out where to buy swarfega... (Something I've discovered about modern soaps and hand washes is that they're designed to be kind to the hands and avoid removing the skin's natural oil. Which is fine, unless you actually wanted to wash oil off your hands, because they won't dissolve it. I put oil on my beard and ended up using kitchen paper to stop my hands being gloopy afterwards.)

Hey all

 

If it was a little sticky I'd just deal with it but it actually leaveas a surprisingly think amount of sticky black gloop on my hands which I have to scrub off hahaha, its wild! But I must look inside the camera also so will be doing that, thanks for the heads up on that rodeo_joe.

hey thanks everyone

 

OK I scrubbed and I scrubbed and this sticky stuff is all off. I see a few tiny specks of white on the glass near the mount I can't clean off. Is this the beginning of mould or haze i hear about? Without shooting to test, how noticeable will it be in photos out of interest

I see a few tiny specks of white on the glass near the mount I can't clean off. Is this the beginning of mould or haze i hear about?

That sounds more like fungus or just dust spots or some other 'muck' inside the lens. Fungus is also bad, but can usually be removed if caught early enough.

 

The misty micro-crazing in my 70-210 Sigma occurred in the middle of the lens near to the iris mechanism, or apparently so. It was near-invisible to a casual inspection at first, and only showed up under the glare of a bright light shining through the lens. Not in small patches, but evenly across the whole of one or two of the glass surfaces.

 

Its effect is to take the edge off contrast when the subject is backlit, or has a bright light in, or just out of, frame. In some lighting conditions it has a very minimal effect.

 

However, once started it will get worse. How quickly? I don't know. It probably depends on the heat and humidity that the lens is used or stored in, but I can't testify to that for certain.