Lens cleaning

[Russ]

"Adding a little ammonia to the mix improves it further, but ammonia is regarded as a hazardous chemical, so you should take all the appropriate disclaimers into account."
When I got my new coated specs a year or two ago the intructions that came with them advised against using ammonia because it could damage the coating - dont know if it would appply to a lens coating but I am not willing to try. Also it may seem dumb but DO NOT USE HANDY ANDY or any other abrasive kitchen type cleaner. I know of someone who tried to remove sunsreen from a filter with handy andy and ended up with a softfocus filter

[BrerFox]

"Adding a little ammonia to the mix improves it further, but ammonia is regarded as a hazardous chemical, so you should take all the appropriate disclaimers into account."
When I got my new coated specs a year or two ago the intructions that came with them advised against using ammonia because it could damage the coating - dont know if it would appply to a lens coating but I am not willing to try. Also it may seem dumb but DO NOT USE HANDY ANDY or any other abrasive kitchen type cleaner. I know of someone who tried to remove sunsreen from a filter with handy andy and ended up with a softfocus filter

Handy Andy is indeed abrasive and it also contains ammonia (or used to, I am not sure if it does any more). Ammonia itself is not abrasive. It was the abrasive substrate that destroyed your friend's filter, not the ammonia. Ammonia is a very good glass cleaner, but it has drawbacks. It is toxic, but more appropriate to our discussion here, it can corrode anodised surfaces if abused, and it affects some plastics. If you have photochromatic glasses, or polarised ones with an organic film in them, immersing them in ammonia is not a good idea. But, camera lenses never have organic coatings because for one, they are unstable over time. The ammonia will not adversely affect your lens glass, but do not breathe it in excessively, and do not apply it in huge concentrations to plastics, or anodised surfaces.
You could, of course, be ultra-cautious and not use any suspect chemicals to clean your lens, but what would you use? Water is pretty much all that remains, and the flourite elements used in ultra-low-dispersion (read ultra-expensive lenses) elements are badly affected by water. That leaves only one alternative - do not get your lens dirty!

[DaveK]

Some interesting stuff here. Just a little anecdote. Panasonic video cam, belongs to my son. That funny little mechanical lens cover. He gets a little piece of grit somehow (I am making some assumptions here) between the cover and the lens surface - this results in two linear scratches, less than a mm wide, around 5 -6 mm long and 2-3 mm long respectively, very shallow but clearly into the surface of the lens. In the direction of the lens cover closing mechanism.
This camera I have just thrown away: utterly useless for photographic purposes. A TINY part of the lens surface is scratched, but this is in the optical axis. All seems well until any stray light source shines into the lens. Immediately the image is completely destroyed by flare/glare/haze, whatever you may wish to call it. All I know is it is very ugly, very depressing, and renders the lens utterly useless for its intended purpose. Of course more visible in specific conditions, specific focal length, light direction etc. But the cam is utterly destroyed by these two little scratches.

This was an expensive object lesson for my teenager: look after your kit buddy!!
You guys who wish to can keep your scratched lenses. I know from personal experience they will be useless to me. YMMV. Have you seen how just a poor quality filter can degrade IQ?
Hence my interest in garnering any tips I can wrt keeping my lenses clear and scratch free! Thanks for the inputs, some will change my practice!!
Dave

[Leo Theron]

I have read that if there a scratch on a lens, you should cover the scratch with - wait for it - black paint!

And yes - A few years ago I saw a big lens with many miles on the clock in JHB for sale, and a chip on the front element was covered with a blob of black paint.

[walterpike]

@brerfox you sound knowledgable about this and what you say makes sense. Thank you

[Roberto]

Lens cleaning the easy way

[BrerFox]

Nice one, Roberto - this is the new black guy who works as a lens technician at Cameratek, isn't it?
Having established that scratches are not good for your lens, not because they degrade image quality
as much as they have nasty side effects, mostly flare, what can you do when they do occur?
You have two choices - "fix" them, or render the nasty spots inoperable. Fixing involves using a clear
substance to fill in the crack - varnish, nail polish or even vaseline work quite well. You will never get the
surface perfect again, of course, and neither will you match the refractive index of the glass, but the idea
is that the RI of ANY clear substance is much much closer to that of the lens glass than the air that is in the
sctratch, thereby GREATLY reducing the flare. The trick here is to limit your fixing fluid to the scratch only -
as soon as it overlaps to the lens, you start to degrade more of the lens.
Choice two is to keep light off the impediment. Black paint, or black permanent marker, suitably cleaned
up afterwards or even sticky pieces of paper work well.
Dave, a poor filter does degrade IQ, but for a different reason than a scratch. A poor filter is not optically
flat - it has a wavy, uneven surface which causes magnification to be uneven across the lens.

[DaveK]

Thanks for that. I think you have inspired me to have a go at that lens. Must think of a way of masking the undamaged surface, then filling....MMmmm, will perhaps report back in due course.

Dave.

[walterpike]

Choice two is to keep light off the impediment. Black paint, or black permanent marker, suitably cleaned
up afterwards or even sticky pieces of paper work well.
Dave, a poor filter does degrade IQ, but for a different reason than a scratch. A poor filter is not optically
flat - it has a wavy, uneven surface which causes magnification to be uneven across the lens.

Thats interesting - so the black paint idea is sound. It actually makes sense as well. so you coat the scratch - The uneven surface to prevent it taking part in light being refracted by the lens

As regards filters I bought grad ND filters online recently - I didn't realise that they would be, but they are made out of Resin? Plastic? is the material a legitimate material to use or should I just realise I messed up buying them?

[Henk Coetzee]

As regards filters I bought grad ND filters online recently - I didn't realise that they would be, but they are made out of Resin? Plastic? is the material a legitimate material to use or should I just realise I messed up buying them?

No problem, a lot of them will be made of plastic. Some aren't entirely neutral in terms of colour. Try them, work with them and, if they're not good enough for you (or if you discover this over time), you'll know.

[Graybeard]

I use the inside of the T shirt I am wearing...works like a charm especially during all day shooting at the beach, if it is a windy day I have to clean about every 5 minutes or so....and my glass looks like the day it came out the box!

[Richard Sloman]

I want to add, according to this doc, 24-70 F2.8 Nikon, this is the way to clean elements.

http://lens-club.ru/public/files/pdf...07c715f2c2.pdf

Now if someone can send me a PDF with the instructions on what to do with all these left over screws I now have...