Lens Cleaning
 

I picked up an old Pentax K1000 for about nothing, hoping to use it's lens.
It looked as if someone tried to clean the lens and camera from sitting
around with no case or lens cap and smeared whatever was on it.

Gathering from the stench of cigarettes on some other things selling with
it, I'm guessing it's nicotine. I see no dust inside and the rear of the
lens looks great.

I tried using my regular lens cleaner with only marginal success.

What can I use on the glass that will not harm the multicoating? Alcohol?

Thanks.

Lens Cleaning
 

rdoc wrote:

I tried using my regular lens cleaner with only marginal success.

What can I use on the glass that will not harm the multicoating? Alcohol?

Modern lens coatings are not likely to come off in alcohol.

I would suggest dipping q-tips in either alcohol or Windex
and work gently, changing q-tips frequently. There should
never be enough liquid at the front of the lens that there
is a risk of some seeping inside, you can alternate wet
and dry q-tips. The real risk is scratching the lens or
coating, a little bit of grit can do quite a bit of harm.

A single big scratch is actually nearly harmless, but lots
of tiny scratches will ruin the definition of a lens. People
sometimes do make lots of tiny scratches, so be sure to change
q-tips very frequently, especially at the start.

Peter.
--

Lens Cleaning
 

"Peter Irwin" wrote in message
...
rdoc wrote:

I tried using my regular lens cleaner with only marginal success.

What can I use on the glass that will not harm the multicoating? Alcohol?

Modern lens coatings are not likely to come off in alcohol.

I would suggest dipping q-tips in either alcohol or Windex
and work gently, changing q-tips frequently. There should
never be enough liquid at the front of the lens that there
is a risk of some seeping inside, you can alternate wet
and dry q-tips. The real risk is scratching the lens or
coating, a little bit of grit can do quite a bit of harm.

A single big scratch is actually nearly harmless, but lots
of tiny scratches will ruin the definition of a lens. People
sometimes do make lots of tiny scratches, so be sure to change
q-tips very frequently, especially at the start.



I was thinking about one thing and typed another originally... it is not on
a K1000... it is an 'A' lens on a Program Plus. As to my original concern...
how modern does multicoating have to be, to be modern enough to tolerate
alcohol or whatever? Shame there are no real camera shops anywhere around
these days.

Lens Cleaning
 

rdoc wrote:


I was thinking about one thing and typed another originally... it is not on
a K1000... it is an 'A' lens on a Program Plus. As to my original concern...
how modern does multicoating have to be, to be modern enough to tolerate
alcohol or whatever? Shame there are no real camera shops anywhere around
these days.

It shouldn't be a problem with any multicoated pentax lens. Some
early coating technologies (1940s) were quite "soft" and delicate,
and while the coatings used in the 1950s and 1960s were supposed
to be quite durable, some of them are easier to damage in practice
than they are supposed to be.

The Magnesium Flouride used in single coatings is NOT actually
soluble in alcohol, but people do sometimes harm some old
coatings by careful cleaning anyway. The materials used for the
outer layer of multicoatings tend to be quite durable. The real
thing to avoid is rubbing dirt into the lens.

Peter.
--

Lens Cleaning
 

On 11/26/2011 7:11 AM, Nervous Nick wrote:
On Nov 25, 9:16 pm, wrote:
I picked up an old Pentax K1000 for about nothing, hoping to use it's lens.
It looked as if someone tried to clean the lens and camera from sitting
around with no case or lens cap and smeared whatever was on it.

Gathering from the stench of cigarettes on some other things selling with
it, I'm guessing it's nicotine. I see no dust inside and the rear of the
lens looks great.

I tried using my regular lens cleaner with only marginal success.

What can I use on the glass that will not harm the multicoating? Alcohol?

Thanks.

Have your mom or dad go to your local home supplies store and pick up
a gallon of hydrochloric acid. Soak the entire lens in the acid for
at least 24 hours, then dry it in a 250 degree oven for another day,
and you will be good to go.
Idiot! You are good to go in my news reader and ZAP! You are gone.

Lens Cleaning
 

On Sat, 26 Nov 2011 10:03:19 +0000 (UTC), Peter Irwin
wrote:

rdoc wrote:

I tried using my regular lens cleaner with only marginal success.

What can I use on the glass that will not harm the multicoating? Alcohol?

Modern lens coatings are not likely to come off in alcohol.

I would suggest dipping q-tips in either alcohol or Windex
and work gently, changing q-tips frequently. There should
never be enough liquid at the front of the lens that there
is a risk of some seeping inside, you can alternate wet
and dry q-tips. The real risk is scratching the lens or
coating, a little bit of grit can do quite a bit of harm.

A single big scratch is actually nearly harmless, but lots
of tiny scratches will ruin the definition of a lens. People
sometimes do make lots of tiny scratches, so be sure to change
q-tips very frequently, especially at the start.

Q-tips are made of cotton, a natural product, which therefore can
contain natural impurities. That can include stuff like sand (quartz),
which can leave scratches on the glass.

Instead of using product made for babies, it's best to use products
intended for cleaning photographic lenses.

Wally

Lens Cleaning
 

Wally wrote:

Q-tips are made of cotton, a natural product, which therefore can
contain natural impurities. That can include stuff like sand (quartz),
which can leave scratches on the glass.

Maybe they could, but do they generally? People use q-tips and surgical
cotton for cleaning front surface mirrors which are much more
delicate than lenses.

Instead of using product made for babies, it's best to use products
intended for cleaning photographic lenses.

What product made specifically for lens cleaning would you suggest
for a very dirty lens? Moistened lens tissue, even if harmless in
itself, will very quickly pick up abrasive dirt from the lens. The
gadgets known as "lens pens" work wonderfully for removing fingerprints,
but I wouldn't dream of using one on a lens that wasn't already pretty
clean.

Peter.
--

Lens Cleaning
 

On Sat, 26 Nov 2011 09:47:54 -0600, Allen wrote:


Have your mom or dad go to your local home supplies store and pick up
a gallon of hydrochloric acid. Soak the entire lens in the acid for
at least 24 hours, then dry it in a 250 degree oven for another day,
and you will be good to go.

Idiot! You are good to go in my news reader and ZAP! You are gone.

Yeah, the fool forgot the bit about drying the lens with sandpaper.

Lens Cleaning
 

On Sat, 26 Nov 2011 18:23:14 +0000 (UTC), Peter Irwin
wrote:

Wally wrote:

Q-tips are made of cotton, a natural product, which therefore can
contain natural impurities. That can include stuff like sand (quartz),
which can leave scratches on the glass.

Maybe they could, but do they generally? People use q-tips and surgical
cotton for cleaning front surface mirrors which are much more
delicate than lenses.

Instead of using product made for babies, it's best to use products
intended for cleaning photographic lenses.

What product made specifically for lens cleaning would you suggest
for a very dirty lens? Moistened lens tissue, even if harmless in
itself, will very quickly pick up abrasive dirt from the lens. The
gadgets known as "lens pens" work wonderfully for removing fingerprints,
but I wouldn't dream of using one on a lens that wasn't already pretty
clean.

I pretty well never have to clean very dirty lenses because mine never
get that dirty... but I would consider commercial lens cleaning paper,
folded a couple times and then torn across, which gives a very
absorbent and safe medium -- or microfiber lens cleaning cloth should
work great (but I have no experience with it).

You will most likely need a liquid to help lift the grunge off a very
dirty lens. I'm pretty sure water, isopropyl alcohol, or naphtha
(lighter fluid, varsol, some paint thinners, etc) are all harmless to
glass or lens coatings. But one needs to use a minimum so as to keep
the liquid from penetrating at the edges.

Which liquid to use? Depends on the dirt. I would first try breathing
on it (suck in slightly before the breath so you don't get any
aspirated saliva on it). If the dirt is fatty, water won't help much,
so try IPA, which will lift some fat. Naphtha is better for that, but
some kinds leave a residue. Never use stuff like lacquer thinner,
acetone or turpentine.

There is of course also commercial lens cleaning liquid, but I don't
have recent experience with it.

As you say, rubbing on a lens surface can cause scratches from the
dirt on the lens. That probably happens less with more absorbent
tissue/cloth, but it is still a peril. I also agree with you about
lens pens.

Wally

Lens Cleaning
 

Wally wrote:
On Sat, 26 Nov 2011 18:23:14 +0000 (UTC), Peter Irwin
wrote:

Wally wrote:
Q-tips are made of cotton, a natural product, which therefore can
contain natural impurities. That can include stuff like sand (quartz),
which can leave scratches on the glass.
Maybe they could, but do they generally? People use q-tips and surgical
cotton for cleaning front surface mirrors which are much more
delicate than lenses.

Instead of using product made for babies, it's best to use products
intended for cleaning photographic lenses.
What product made specifically for lens cleaning would you suggest
for a very dirty lens? Moistened lens tissue, even if harmless in
itself, will very quickly pick up abrasive dirt from the lens. The
gadgets known as "lens pens" work wonderfully for removing fingerprints,
but I wouldn't dream of using one on a lens that wasn't already pretty
clean.

I pretty well never have to clean very dirty lenses because mine never
get that dirty... but I would consider commercial lens cleaning paper,
folded a couple times and then torn across, which gives a very
absorbent and safe medium -- or microfiber lens cleaning cloth should
work great (but I have no experience with it).

You will most likely need a liquid to help lift the grunge off a very
dirty lens. I'm pretty sure water, isopropyl alcohol, or naphtha
(lighter fluid, varsol, some paint thinners, etc) are all harmless to
glass or lens coatings. But one needs to use a minimum so as to keep
the liquid from penetrating at the edges.

Which liquid to use? Depends on the dirt. I would first try breathing
on it (suck in slightly before the breath so you don't get any
aspirated saliva on it). If the dirt is fatty, water won't help much,
so try IPA, which will lift some fat. Naphtha is better for that, but
some kinds leave a residue. Never use stuff like lacquer thinner,
acetone or turpentine.

There is of course also commercial lens cleaning liquid, but I don't
have recent experience with it.

As you say, rubbing on a lens surface can cause scratches from the
dirt on the lens. That probably happens less with more absorbent
tissue/cloth, but it is still a peril. I also agree with you about
lens pens.

WallyI

IMO, you have offered some good advice. I would like to offer a
suggestion that I have found to be worthy of note. I shun commercial
lens cleaning paper. My experience with such items has not been good. I
prefer to use a microfiber cloth. I have used a cotton dish drying towel
but much prefer to use a microfiber cloth.

Wash the cleaning/drying cloth in Woolite soap&water solution to remove
any dirt and residue that may be in the cloth. When washed in Woolite,
the cleaning cloth will be free from dirt, oil, and old soap residue.
I've found nothing yet that's as good as Woolite to clean cloths to be
used to wipe optical lens glass or plastic.

The lens is generally the item that is looked at to see if any oily
substance or hard particulate may be on the lens. I've learned that
people just assume the cloth they intend to use is contaminant free.

Save the Woolite cleaned cloth in a plastic Zip-lock bag to be used for
future lens cleaning needs. I keep a 10 in x 6 in microfiber cleaning
cloth (80% Polyester and 20% Polyamid), which I always wash in Woolite,
that my wife bought at the local super-market for about 0.60 cents just
for cleaning optical lenses.

Nick