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Hotech laser 1.25 or 2"


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Hi theninjagecko.

The only difference is that the 2" version comes with an adapter that allows the 1.25" laser to fit a two inch focuser drawtube. It makes no difference to the collimation you'll achieve, just means the kit is more flexible and can be used with a larger variety of 'scopes.

When I bought my Hotech, the scope I owned only had a 1.25" focuser - so I briefly toyed with the idea of saving a couple of quid and getting the 1.25" only version. Glad I didn't, 'cos my recently purchased 200p has a 2" focuser..

If you plan on sticking with reflectors, and maybe purchasing one or two more - buy the 2" kit. Well made stuff like this is like a good EP - It's the sort of thing that'll stand you in good stead for years, and be with you through many OTAs.

IMO, anyway.. :headbang:

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Yes, I have the baby brother 200p. I think they both have 2" draw tube with a 1.25 adapter. The Hotech will fit either, so long as you get the Hotech dual fitting. If you only want it to fit 1.25" eye piece holders then just get the 1.25" version and save about £20. I fit mine directly into the 2" draw tube though.

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my 300p is 1.25 with a 2" adaptor. Would it work straight in the 1.25 focuser?
Hmm, interesting question. Deceptively simple, but I had to go and test it before I could answer definitively.. :headbang:

The question is, does collimation result differ if you use the Hotech in the 2"->1.25" EP holder that comes with the 'scope - when compared to using the Hotech in it's own 2" adaptor in the 'scopes 2" EP holder?

Answer: Having tested it, yes you do get very slightly different results. I imagine ninjagecko's focuser in his 300p is the same Crayford unit as in my 200p, and as they're both Skywatchers, there's every chance the 2"->1.25" and 2" EP holders are the same too.

I find that if I collimate using the Hotech in it's own 2" adapter - in the Skywatcher 2" EP holder, then switch the SW 2" EP holder for the 1.25" one & reinsert the laser in it's 1.25" guise - the beam misses the centre spot of the primary by ~2mm.

As a result, I'd say "collimate for the EP holder you're going to use".

It suggests that the Hotech SCA mechanism centres slightly differently in the focuser than the SW 2"-1.25" adaptor does. Given there's only 2 setscrews on the collar, I'm not surprised..

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Thanks mike. I don't have any 2 inch eyepieces as of yet. I may just get the 2 inch version to be on the safe side.

Another question, if im going to do any lunar planetary imaging using a dmk21 i should collimate using the 1.25 right? as that's the nose piece with the dmk21.

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