Boron

So its been about two weeks since posting this and the shine of my then new purchase has dulled somewhat, to the extent that this evening I've been wondering if I wouldnt actually be (financially, at least) better off with buying a cheap Svbony Mak or 100mm Bresser maksutov since it might turn out cheaper doing that than it is to correct some issues with the scope. Norways import tax puts a significant damper on things. @PeterC65 I'm encouraged by your reply here addressing the coma issue - but do you have any images from them to set my paranoia at ease? I had settled on the Neptune CII but after some light persuasion on another forum another user pointed out that the Neptune 664 has a response curve that is finely attuned to IR so have decided to pick that up instead. EAA is definitely the goal, temperatures drop precipitously in my part of Norway in the winter (also providing most of the clear skies we will get) and standing outside doing visuals in -10 to -30 degree nights in meter deep snow just doesnt appeal. At some point down the line I will need to pay some attention to "winterizing" the scope to allow it to function in such temperatures and I'm not entirely sure if adding a fan to draw freezing air into the tube is going to be beneficial or whether adding heater elements is going to be correct. Dew is obviously not so big of a consideration when prime observation time coincides with sustained significantly below freezing temperatures. Fine focus adjustment is at least something I believe I have sewn up on the solution front, there is an EAF winging its way to me and I am deciding on a new focuser with a 10:1 element. Determining the focus point - by which I mean the focal point distance away from the OTA tube and thus the required focuser extension height - has proved difficult and I'm wary of needing such an array of adapters and extensions that it looks like my newt has taken up smoking.

I suppose out of neccessity I am then coming around to the idea of drilling big new holes in my telescope - although I remain petrified of fouling or scratching the mirrors while being simultaneously petrified of losing alignment if I remove them for safekeeping. AS it happens that Svbony isnt too far removed from what I have already thats giving me grief. I will mark this Svbony out, though, as being only one of two focusers with technical-ish drawings available showing dimensions.

I recently came into the possession of a 2005 8" Bresser Newtonian. It has seen better days and one of the sticking points is the focuser - a simple stock rack and pinion unit. that also has a fair amount of side wobble which is not ideal. I've been trying to find a low cost replacement for it but drawing a blank at finding one to fit the current hole pattern, which is a Ø55mm central tube hole with bolts in a 58x46mm rectangular pattern. Since I've never bought a new focuser before I dont know what to expect - is what I've got going to need modification and drilling new holes to fit?

A nice project! Whats the expected all up costs for a single motor unit?

Hi, I've been wanting a telescope for what must be the last twenty years but never had the time/budget for one. I got lucky recently with a market find that I picked up today, a 2005 Bresser Messier 203/900 (F4.4) Newtonian. Its in pretty good, but not perfect, shape, and I need some help both in identifying what needs to be fixed and holes in my plans for what I plan on doing with it - I'd appreciate any comments here since I am reasonably well read but havent really entered the hobby before. Photos Needs fixing: 1 - Sticker on the OTA is great and identifies it exactly, but I need some help with the mount. I think its like the OTA, and is a 2005 era EXOS2 but it is in need of a bit of love. A few hand knobs and the polar guide scope port cover are missing and the previous owner mentioned that there should be an accessory tray that fits between the legs and gives the tripod more rigidity that he tried to get back with the attached steel cable - but from what I can see the top of the legs make solid contact with the body so this doesnt appear to be the case. Bresser have some replacement parts available but the tray they have only sits there between the tripod legs and acts like a spacer rather than a truly structural element. 1b - If it is an EXOS2 then my plan is to slap a Onstep kit onto it and use largely as-is. 2 - I dont know if the focuser is any good by "modern" (not 20 years ago) standards. It appears to be fairly standard rack and pinion single speed. 3 - Guide scope is 50x8 and surprisingly solid with a nice etched (?) glass reticle in it. The eyepiece rubber has perished and there is some grit on the inside but it appears it diassembles readily. Am I ok to use IPA here to clean it up? 3b - Not sure if I'm going to swap out the bracket for a more standard dovetail and keep the scope in a new set of mounting rings. The Plan: So where I am in Norway we have a lot of cloud cover that should lessen a bit now that the temperature is dropping as we move towards autumn and winter. Winter can be bitterly cold (-30 not unusual here), but it does mean the skies are clear. With this in mind I wanted a scope that will suck as much light as possible in as short a time as possible to maximise any windows where observing is possible - and this 8" fast newt is better than I had any reasonable expectation. I also wanted this to be GOTO'd with an Onstep kit and run both a power extension and looooong USB cable to the scope in my back yard and treat it as a somewhat remote observatory, staying nice and warm inside. I planned to hunt DSOs - nebula and galaxies. For an imaging setup I had provisionally identified a Player One Neptune as being desirable. I found a thread on Cloudy Nights about Etendue that has an equation for comparative signal strength ratios between setups and using this in a spreadsheet the Neptunes came out pretty well. That said its a pretty simplified equation and I suspect the relative pixel size terms are doing some very heavy lifting and leaving out a whole bunch of detail about the physics. Not sure about the tradeoff in shooting with a colour/mono camera since that would then need a bunch of filters and maybe automatic filter wheel with additional cost and complexity. I know as newtonian a coma corrector is high on the priority list, as is a collimating eyepiece. Is there anything else I have missed here or made an obvious mistake with?