Cheap sensor swabs

Some sensor cleaning liquids are sensor specific

Is that right? Eclipse used to do a separate fluid for tin oxide sensors, but seemingly discontinued it after coming to realise that the original fluid did such sensors no harm.

John,
When I first bought a DSLR I was aware of the whole sensor cleaning business and the cost - that's partly why I bought an Olympus E-410 at the time. However by the very fact that you change lenses in open space you'll end up with something on your sensor at sometime. I felt that I could do as good a job as any other technician in this field - particularly when I read a quote purportedly from a technician who said they used compressed air at the initial cleaning stage. I think you reference to plastics might not be correct - Rubbing Alcohol (70% IPA) should not be used on vinyl records - but IPA and methanol are standard cleaning agents in the electronics industry. Canon seemingly recommend IPA if a wet clean of your sensor is required.

I can assure you alcohols will damage plastics - keep them well away from cameras would be my advice. The finish can be ruined very easily.

I would be wary about any unnamed report, why not just follow the instructions? The manufacturer is the best source as they know exactly how their products will respond.

It's possible to abuse things of course and even get away with it, I knew someone once who took great pleasure in driving his van and never using the clutch. I wonder if one day the gearbox fell apart.

IPA is a rather different solvent to EtOH or MeOH. I used to service video recorders, I'm also manufacturer trained in a number of brands of microscope (brands which shall not be mentioned on this site...);don't get me started on cleaning solutions ...

I'd be rather interested to hear your views on cleaning solutions

Can't beat a bit of spit and polish!

--

Truly interesting conversation on cleaning fluids, but as far as anyone having experimented with the cheaper swabs, there seems to be two instances mentioned: one which worked out well and another a clear disaster.

Aye, with the right cloth, breathe on and wipe off. Not so easy for a sensor tho.

There's a lot of personal preference here Ken. Each optical surface may have different contaminants and therefore different needs. I'm sure I don't need to tell you how to suck eggs, and I wonder what advice you've had from your side of the trade over the years?

It's my experience that coatings are resilient and that I'd worry more about seepage into a built-up element with the attendant risk of delaminating a cemented joint.

Clean and dry solvents are important. "Wet" alcohols- esp 70% or less- don't flash off nicely. They instead leave watery spots full of the removed contaminants. Likewise impure solvents leave their own residue.
Less is better here, obviously.

Sadly, some of the more interesting solvents are offlimits now- tricloroethane was super stuff, for example, and not just for video heads. Likewise straight Diethyl Ether was listed by at least one manufacturer.
My own brew of preference is HPLC-grade EtOH with a splash of ether. Flashes off very quickly and leaves little-to-nothing behind.

And then there's wiping media. Worst thing to bring near a dirty lens in s lens tissue IMO. The Whatman stuff in particular might be grand for particulates but will smear wet and greasy stuff like nothing else. Facial tissue is abrasive (talc filler) but a good unbleached white tissue roll (yes even kitchen roll at a pinch but it's not strong enough...)

I dread to consider just how many microscope objectives I've cleaned over the years.

I think we'll need to agree to disagree on this John. From my experience pure IPA - ie 100% isopropyl alcohol - does not damage plastics. Here's a quote from the Ask a Scientist website for the US Department of Energy..

The main difference between n-amyl and isopropyl alcohols (in this context) is the length of the hydrocarbon "backbone". N-amyl alcohol's carbon chain is 5 carbon atoms long, whereas isopropyl alcohol's carbon chain is only 3 carbons atoms long. The result is that isopropyl alcohol is more volatile and therefore evaporates faster after it is used for cleaning.

Neither of these alcohols "dries out" plastic, since there is no water (or any other substance) in plastic to "dry out" in the first place. Both of these alcohols act as both polar and non-aggressive non-polar solvents, which is very advantageous for cleaning. Acting as polar solvents, they are able to dissolve polar contaminants such as salts, and other water soluble contaminants.

Both of these alcohols are also able to dissolve non-polar contaminants such as oils and greases, with isopropyl alcohol acting as a somewhat more aggressive non-polar solvent because of its shorter carbon "backbone" and therefore lower molecular weight. Unlike many hydrocarbon solvents, neither of the two alcohols are damaging to any common plastics.

To summarize, when comparing the two, isopropyl alcohol is the cleaning solvent of choice for most plastics. Unlike normal-amyl alcohol, which is not easily available, 99% isopropyl alcohol is available at any drugstore. Isopropyl is better at removing oily deposits, and dries faster after use.

I may have not made myself clear in my original response but I believe that if you have a good knowledge and understanding of what you are doing then there is no difference in what I am doing and what Pentax Service personnel would do.