Smudge on the INSIDE of corrector on my C8

[kaomoo]

During one of the recent night observation, I was struck by dew formation.

I return the OTA to dry box for drying. When I took out for last night's observation, I notice smudge/spotting on the inside of the corrector...



Initially I thought my eyes were playing tricks but upon removing the corrector plate, I was definitely on the inside.

Any one has idea how this happened? its it just from dew formation and spotting subsequently? The primary and secondary were all alright though.

Also, can I clean the corrector as per camera lens method?

[orly_andico]

Yes you can! I think denatured alcohol is best (100%).

Corrector plates are pretty tough, so no need to be gentle. :-)

I've done worse to mine..

[kaomoo]

Yes you can! I think denatured alcohol is best (100%).

Corrector plates are pretty tough, so no need to be gentle. :-)

I've done worse to mine..

Orly LOL... do share...

anyway, i cleaned it with lens solution, which is basically methyl alcohol i reckon?

[orly_andico]

Yes you can! I think denatured alcohol is best (100%).

Corrector plates are pretty tough, so no need to be gentle. :-)

I've done worse to mine..

Orly LOL... do share...

anyway, i cleaned it with lens solution, which is basically methyl alcohol i reckon?

You know I've always been of the "fungus?!! it's an overrated risk!" school.

Well I found several spots of fungus under my C9.25 corrector plate (oops.. there goes the resale value)

Anyway I used my time-honored technique to get rid of it.. my pinkie finger and dishwashing soap. All gone.

I read somewhere that since the corrector plate is.. a simple glass plate, even with no coating whatsoever you'd only lose ~5% of the light, which is negligible. So even an aggressive cleaning which eliminates the coating won't really hurt functionality (it would definitely hurt resale value though).

Another thing I read is, don't use those Zeiss lens cleaning pads as they are abrasive.

Also 100% denatured alcohol is best because it dries without sleeks. Anything with water in it will dry with sleeks that you then have to clean off. Of course with dishwashing liquid you need water to rinse it. Hence, more elbow grease to eliminate the sleeks.

[kaomoo]

I am old fashion, mama lemon's the best :p

Yes you can! I think denatured alcohol is best (100%).

Corrector plates are pretty tough, so no need to be gentle. :-)

I've done worse to mine..

Orly LOL... do share...

anyway, i cleaned it with lens solution, which is basically methyl alcohol i reckon?

You know I've always been of the "fungus?!! it's an overrated risk!" school.

Well I found several spots of fungus under my C9.25 corrector plate (oops.. there goes the resale value)

Anyway I used my time-honored technique to get rid of it.. my pinkie finger and dishwashing soap. All gone.

I read somewhere that since the corrector plate is.. a simple glass plate, even with no coating whatsoever you'd only lose ~5% of the light, which is negligible. So even an aggressive cleaning which eliminates the coating won't really hurt functionality (it would definitely hurt resale value though).

Another thing I read is, don't use those Zeiss lens cleaning pads as they are abrasive.

Also 100% denatured alcohol is best because it dries without sleeks. Anything with water in it will dry with sleeks that you then have to clean off. Of course with dishwashing liquid you need water to rinse it. Hence, more elbow grease to eliminate the sleeks.

[shirox]

kaomoo, use distilled water instead of water from the tap if you wanna be on the safe side also to protect your "investments" lol

[kaomoo]

kaomoo, use distilled water instead of water from the tap if you wanna be on the safe side also to protect your "investments" lol

sounds like a good idea.

i read about 50:50 with alcohol:distilled water with 1 drop of mama lemon