Any tips would be welcom: I have an old SCT which is beginning to show the telltale signs of those little spider-webs - I call it crazing for want of a better name - that are appearing on the surface of the corrector (on the inside unfortunately) and was wondering about arresting or removing it. Any tips gladly received.
Peter
Is it a breakdown of the coatings? Any chance of a picture or two?
Hi Peter,
that's what I thought. So I removed the corrector yesterday and gave it a good bath in isopropanol followed by a warm water bath with a drop of detergent and then a careful dry before reinstalling. It seems to have removed the marks I had seen so I suppose either they were a fungicidal growth courtesy of the extended wet period we had or something else OTHER than breakdown in the coatings.
Some DIYers of camera forums recommend removal of fungi on glass surfaces by coating the offended area with cold cream (ask your mum/wife/gf/sister), leaving for 30 mins or so and then thoroughly cleaning the cream off the lens. Some follow up by leaving the lens in direct sunlight for several days before reassembly. I have never tried it but I do have a 60mm refractor and an eyepiece I may try it out on. It seems the cold cream "dissolves" the fungus and prevents it's return.
Just a thought.
Fungi will destroy coatings if left untreated. Same happens with DSLR lenses. It grows and digs into the coating leaving scars after cleaning. Best to keep the back of the scope open when in storage or remove the corrector and stick a couple of dessicant pads in the tube.
I make cold cream with my yr10 science class..fairly easy but I don't see why you'd hit a corrector vwith it, I'd hit the surface with acetone if it's still iffy, but the alcohol should do the job
Hi Peter,
that's what I thought. So I removed the corrector yesterday and gave it a good bath in isopropanol followed by a warm water bath with a drop of detergent and then a careful dry before reinstalling. It seems to have removed the marks I had seen so I suppose either they were a fungicidal growth courtesy of the extended wet period we had or something else OTHER than breakdown in the coatings.
Peter
That is a relief.
That is pretty much the procedure I follow for cleaning my corrector plates, I use distilled water for the final rinse, but not sure if that is necessary or not, and dust it off with a bit of air before re-fitting it.
, I'd hit the surface with acetone if it's still iffy, but the alcohol should do the job
