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Removal of Corrector a Simple Matter?

Started by jrbarnett, 08/12/2006 10:01AM
Posted 08/12/2006 10:01AM | Edited 08/12/2006 10:04AM Opening Post
I have an Orion (Synta) 150mm MCT, and am really happy with its performance (especially) for the modest $599 price. Sure there's a tiny amount of mirror "wiggle" when focusing, it takes quite awhile to equlibriate, and it wouldn't win any beauty contests, but for a compact high-mag easy-mounter it's brilliant.

That said, there are a couple of flecks of something (pretty sure that it's flecks of blackening material used on the baffle) on the surface of the aluminized secondary spot. I would like to remove the debris, but before doing so wanted feedback from knowledgable MCT owners. This is my fourth CAT and only second MCT, and the first MCT was a 3.1" el-cheapo. It appears that removing the meniscus assembly is simply a matter of (1) marking the tube and one of the three screw holes attaching the meniscus assembly to the tube (for later orientation during replacement), (2) unscrewing the three screws, and (3) sliding off the meniscus assembly.

Is it really that simple?

If so, I plan on using a camera air bulb ONLY to see if I can dislodge the debris. If I cannot, I'll probably just leave it be.

Thanks,

Jim
Posted 09/08/2006 08:57PM #1
I cleaned the inside of my LOMO Astele 150 Mak-Cass. No big deal if you go slow and work carefully. I used Zeiss lens cloths and Zeiss lens cleaning fluid. First blow off dust with syringe, wipe lightly with first cloth, extra cleaning fluid and another clean cloth for deep cleaning, a final clean cloth for removing any resudues and polishing it all up.

Be sure and do a star test and recollimate the mirror if necessary. It shouldn't be necessary if you mark the position of the corrector and mount it back in the same position. You can also buy a high quality laser collimator and rotate the corrector for best alignment if it has been tampered with by the previous owner, as my LOMO had been. I also installed much higher quality push and pull screws in the mirror cell, hex drive so I could spin the screws in the dark without applying forward pressure like necessary with slotted or Phillips screws, and thus allow use of a ball head Allen key.

Only remove the corrector to clean up any residues on the corrector. Heavy dust and residue reduce contrast, but a few paint flecks do absolutely no harm to the image. Those flecks you mentioned do not warrant any cleaning unless they become very numerous. Don't be afraid to clean the corrector when it really needs it, however.