How do you know when it affects image quality before that happens?If you work in an optical shop, you use canned air, warm soap and water, Kimwipes, Ethanol (or Isopropyl, ACS grade), Acetone, or Windex. Oh and single-sided 6" cotton swaps from Edmund Optics.
Anybody tells you to use something different doesn't know how to clean optics properly. Unless I find something that works better.
Don't clean optics unless it affects image quality or you are shipping out newly made lenses to a well-paying customer.
How do you know when it affects image quality before that happens?
If you work in an optical shop, you use canned air, warm soap and water, Kimwipes, Ethanol (or Isopropyl, ACS grade), Acetone, or Windex. Oh and single-sided 6" cotton swaps from Edmund Optics.
Anybody tells you to use something different doesn't know how to clean optics properly. Unless I find something that works better.
Don't clean optics unless it affects image quality or you are shipping out newly made lenses to a well-paying customer.
My point is I don't want to wait until the image is affected. Then it's too late. So how do you determine before the image is affected that it's time to clean the lens?By looking at the image or measuring MTF.
My point is I don't want to wait until the image is affected. Then it's too late. So how do you determine before the image is affected that it's time to clean the lens?
Is there an alternative to Kimwipes? I don't live in North Korea...
Don't clean optics unless it affects image quality or you are shipping out newly made lenses to a well-paying customer.
*my* point is that you don’t clean them unless you absolutely need to, as cleaning optics is the most damaging purposeful thing you can do.
The analysis will tell you that 13% clear aperture area obscuration begins to impact the MTF. That’s a lot of dust. Scatter impacting contrast is the other mode, and I haven’t seen it yet on my telescope where its use in viewing dim objects in space is very sensitive to contrast change.
Can I use this Kimwipe instead of microfiber cloth on my lens or plastic eyeglasses with Zeiss lens cleaner?
Can I use this Kimwipe instead of microfiber cloth on my lens or plastic eyeglasses with Zeiss lens cleaner?
Also, I've noticed that with the pollution in the air, glass will take on a slight coating that brightens up with the Zeiss cleaning or even a breathe cleaned with the lens cleaning microfiber cloth. Does this "haze" lower contrast or have other effects?
In fairness, the aluminum reflective coating on a telescope mirror is *much* more fragile than modern lens coatings, unless it's overcoated (silicon monoxide still isn't anything like as hard as glass, but it's a good bit better than pure aluminum). That said, the coatings on a lens aren't as hard as the glass, either, and optical glasses are generally some of the softest glasses you'll find.
BTW, if you are considering cleaning your telescope mirror, I'd suggest looking into collodion cleaning. Yes, that's the same collodion (without the halide salts) that you'd use for wet plate photography; it's poured coated onto the mirror surface (ideally, with no run-over onto the edges, to minimize the possibility of it sticking too well), and allowed to dry completely, then carefully peeled off (scotch tape makes a good way to start it, then it'll usually come off in a sheet). It'll take the dirt with it, and won't damage the aluminum.
I've done this using SIG Nitrate Dope (for model airplanes) on the mirror of a cheap Christmas reflector, and it worked (including no detectable damage to the coating); I'm sure it would be better with higher nitrogen content collodion.
The mirror will clean up fine with a mild soap and warm water bath.. By “fine”, I mean “incur the least amount of surface damage with the least risk of incurring scratches”.
It doesn’t matter how hard or soft the coating or glass is... every time you wipe or touch the surface you’re removing material. Harder glasses simply take longer to wear through (coating materials and optical glasses are slightly soluble, btw..more or less so depending on acidity/alkalinity of your solutions). Nanometers of thickness count..especially for coatings and that’s not a lot of material. This aside from the risk of scratches.
Error #143245.78
Error #143245.78
RESPONSE TOO LITERAL.
Worth noting that bare aluminum coating (without overcoat) is also susceptible to attack by any alkali, including soaps and most detergents, or any chloride in solution -- and though not a nanometer level of thinness, typical mirror coatings are a couple micro-inches thick (well, okay, that's a few tens of nanometers). Then again, there's an expectation in the amateur astronomy community that you'll need to recoat a mirror periodically -- used to be, with silver, every 3-5 years, but aluminum lasts a bit better than that (downside is, it can't be applied by most amateurs; silver can, by anyone competent to mix developers or emulsions).
Right. This particular mirror is a special sixth-order aluminized coating with protective overcoat (google VC200L). In any case, as mentioned I haven't chosen to clean it in 15 years because of the risk. Screw up that coating and there's only one place in the world that can re-coat it.
I shoot better when my lens is clean.Then don't show the last photo.
Remember the number one rule of cleaning optics: Don't.
If you really can't stand how dirty your lens is, Don't.
If it's causing flare or unsharpness, maybe...
Seems easier to just clean the smudge off. In any case, what good is waiting until you see it affecting your images. It's too late then.By looking at the image or measuring MTF.
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