[Wheatfield]

Is this you???


https://youtu.be/0Mi_bfEcRaw

Almost as bad. I use canned gas.

[stevebrot]

Fresnel have always been made of plastic. And that’s how they were cleaned.


Hang up and DRIVE!

This is where I might ask for a reference, but given that conventional wisdom and pervasive advice is that isopropanol and focusing screens are a poor mix, I won't.


Steve

[stevebrot]

Wear latex or nitrile gloves.

Thanks for adding that bit. Good idea!

Ether will raise the vapor pressure of the mixture so will evaporate faster at room temperatures What other effects as far as a solvent has I don't know.

Diethyl ether is a rather strong polar solvent, though I would not guess at its effect on screen plastics. One thing is for sure, it is unlikely to be found on the local druggist's shelves...explosive peroxides on exposure to air...


Steve

[MikeMcE]

This is where I might ask for a reference, but given that conventional wisdom and pervasive advice is that isopropanol and focusing screens are a poor mix, I won't.


Steve

The USA importers in the 70’s all used this in their optical rooms, most which had disappeared by the 80s due to local fire codes. It was a nasty area, I watched them cleaning and testing on an optical bench setup.
I don’t know the specific alcohol used, but that was old school way.


Hang up and DRIVE!

[photogem]

Actually a very powerful method was using Freon.
It did work perfectly, cleaned other stuff accidentely as well (necessary parts and unnecessary parts of your brain possibly as well),
was hidden.

So nowadays one has to retreat to other liquids
Particular, if one holds the longer lever in one's hand

[MikeMcE]

Yep Freon came next, nasty also, and wasn’t reclaimed then.


Hang up and DRIVE!

[rogerstg]

I indeed used a soft teeth brush with water and a soft soap as they said, but too late, isopropanol left traces, the FS is still usable but not very nice...

I think that the last thing I would try would be to briefly soak the screen entirely in iso, then, while still wet, rinse it well with distilled water. I usually dry them by holding the screen vertically and touching the bottom edge to a paper towel. I finish with a light application of canned air.

[photogem]

I finish with a light application of canned air.

I finished once the same way.
Canned air specially recommended for cameras, lenses etc.:
Druckluftspray Staubfrei ? Druckluftgas

Afterwards the screen was finished.
Forever!

[rogerstg]

I finished once the same way.
Canned air specially recommended for cameras, lenses etc.:
Druckluftspray Staubfrei ? Druckluftgas

Afterwards the screen was finished.
Forever!

I've dried them with canned air; never a problem. You need to use a light application. Blast away and/or shake the can as you use it and you risk forcing propellant onto the screen. That's why I only mentioned the way I do it. It's up to individuals to learn to use tools correctly.

[bygp]

If you use isopropyl, you need to mix it with ether and use a vented hood. That’s the only way the factories cleaned glass and fresnel


Hang up and DRIVE!

do you mean ether that you can find in drugstore for medical purpose ???
I cannot remove the prints let by isopropyl 99% with just dish liquid + water, even gently use my fingertips, so maybe a bath in isopropyl + 40°C water would remove all prints and than i rinse with water before let it dry in a clean cotton cloth ?

---------- Post added 05-09-21 at 01:10 AM ----------

I think that the last thing I would try would be to briefly soak the screen entirely in iso, then, while still wet, rinse it well with distilled water. I usually dry them by holding the screen vertically and touching the bottom edge to a paper towel. I finish with a light application of canned air.

TY for this advice, I'm pretty sure it will work (I'm not a chemicals expert but still Engineer, your advice makes sense to me ) +++ Nice Sunday and thanks to all that contributed to this thread

P.S. the problem is the water in TOULON is very charged with "calcaire" but a friend told me I could find distilled water in any good supermarker, gonna take a look...

[bygp]

do you mean ether that you can find in drugstore for medical purpose ???
I cannot remove the prints let by isopropyl 99% with just dish liquid + water, even gently use my fingertips, so maybe a bath in isopropyl + 40°C water would remove all prints and than i rinse with water before let it dry in a clean cotton cloth ?

---------- Post added 05-09-21 at 01:10 AM ----------


TY for this advice, I'm pretty sure it will work (I'm not a chemicals expert but still Engineer, your advice makes sense to me ) +++ Nice Sunday and thanks to all that contributed to this thread

P.S. the problem is the water in TOULON is very charged with "calcaire" but a friend told me I could find distilled water in any good supermarker, gonna take a look...

all solutions tried, even with distilled water made it worst, it's just a bull... quality chinese item and they don't answer to my request en ebay to get a new one ! I'll be refund via PayPal I hope.
Luckily I had kept in stock a good FS I used with my K200D, it's a genuine Pentax FS with grid and much better for MF than the ML-60, I just tested with my 50mm prime, it is perfect
(I well have the green hexagon displayed and a small red center square when focus is OK.
It's just a pity no good non-chinese company products this kind of item, there was one years ago (Cats eyes or something like) and they stopped their business...

If I'm looking for this type of MF FS it's jusr because I taked my forst shots in 1979 on a good Minolta reflex with this type of FS but better quality (no lcd screen in the 70ies, no AF either, all manual)

[photogem]

I had several screens from Taiwanese Focusing Screen.com
and never had a problem.
Chinese screens I tried twice, too cheap and difficult to find the correct shim (none provided)
Focusing screen provides shims.

Katzeye was the best but even used these days in Europe really expensive.
Particular the Optiplus version.

You could try to find a Katzeye for the K10D/K20D and clip the nose off but never file/sand it!

[bygp]

I had several screens from Taiwanese Focusing Screen.com
and never had a problem.
Chinese screens I tried twice, too cheap and difficult to find the correct shim (none provided)
Focusing screen provides shims.

Katzeye was the best but even used these days in Europe really expensive.
Particular the Optiplus version.

You could try to find a Katzeye for the K10D/K20D and clip the nose off but never file/sand it!

TY for these precious informations !

[gatorguy]

I really think some of you are making this far more difficult than it is. Keep it mild, and avoid water spots when drying. Focusing screens really don't get that soiled.

[Rob-48]

Is this you???


https://youtu.be/0Mi_bfEcRaw

LUV the vid.