Astronomist

Just saw this come up on MSN when i opened my browser, Interesting stuff! Not very useful in practise though, the planet is much too far away to ever go there.

If you do go with a >6" Dobsonian, be aware that to non-astronomers they seem quite enormous. I woud be hesitant to give one as a surprise gift. I would concur with Ricochet that a 5" maksutov is probably the best choice at this price point, as it is easy to transport and takes up very little space to store.

The ar102xs has been on my 'to-buy' list for far too long, it looks like a lovely wide field scope. It has the same hexafoc focuser as the rest of the Bresser messier range, which i can report is very solid and slop free.

It took me a while to get around to it, but I have searched my hard drive and cannot find my data screenshots. I don't remember deleting them so probably they are in some obscure folder with a non-descriptive name. I hope they aren't in my 'lights' folder. I'd never find them among 16000 pictures of the moon.

why are you using a fixed eyepiece? most telescopes have a eyepiece holder (usually 1.25" or 2") so the user can use many different eyepieces for different magnifications. even in the very unlikely scenario that you could get hold of a 8" F2.5 lens (this is the minimum you will need for 500x at 500mm focal length) with acceptable chromatic aberration control, 500x is going to be tricky to aim unless you have a very excellent goto mount.

Probably the best M27 image I've ever seen. 👍

All the scopes you listed are Bird jones designs, with the exception of the Polaris 130. these cheap bird jones scopes have a reputation for mushy views, so probably best to steer clear of them. I agree with previous posters that a small long refractor or table top dobsonian would be sound choices.

Welcome to SGL.

At the moment I don't think imagers have much competition from these 'robo-scopes', but in the not too distant future maybe we will see robotic telescopes that can produce images rivalling 'proper' astrophotography. maybe not for a while though...

I will have a look and see if I still have some screenshots of the data, I am fairly sure it was the hydrogen line as I got a nice hump in the IF average spectrum on several occasions peaking around 1420.5 MHz (this was with the dish pointed into the milky way in the Cygnus region). The PC was not always as close as it is in the picture, I had to use a USB extension cable on the dongle as I did experience issues with noise. I also wrapped a piece of tin foil around the LNAs, not sure it made a lot of difference though. I like the loop feed, if I do build another i will use one of those instead of a biquad. I never thought about using an umbrella as a dish, that sure would have saved me a lot of work.

Strong agree on the Nirvanas, I have those also and they are great! at F8 an ideal set would be in the range between 50mm and 5mm.

What is the focal length or F ratio of your Dob? what might be an ideal set for a F8 might not work well at all in an F5.

Way Back in February I built this Radio telescope for the school science fair. I meant to post it here for a while, but never got around to it until now. The dish was 1.5m diameter (it split in two in order to be car portable), constructed from surplus thin Corex sheet over a frame of scrap 1/8" ply. It was then covered in extra-strong tinfoil. The feed antenna was a biquad design. I did not use a hydrogen line bandpass filter due to the low budget nature of this build, the electronics were as follows: antenna - LNA - LNA - RTLSDR dongle - laptop running SDR sharp The dish was not made to very tight tolerances, and thus probably close to the performance of a satellite dish of half its aperture, but it worked fine for my purposes, i did manage to detect the hydrogen line, which was cool.😀 some of you may notice I wrote this post in the past tense as after the science fair i broke it up because i couldn't store it long term. There may be a mk2 at some point, but with a bandpass filter and proper satellite dish. Heck, i might even build a mount for it!

see this thread over on Cloudy nights for some inspiration. To take long exposures with the scope you will most likely need autoguiding too, which can be achieved using OnStep to control the mount with stepper motors

a eq5 is marginal with a 8" for DSO imaging, you would be better off with a beefier mount elaborate please...

Welcome to SGL!

aliens, without doubt. 😆 seriously though, that's really weird, I've never seen anything like that before

welcome to SGL! M57, M15, the dumbbell nebula, the double cluster, the star fields around Cygnus, and M31 all make for a fine sight around this time of year. You could try a planetarium software like stellarium for target suggestions, but be aware the pictures are nothing like the view in the scope. Clear skies!

possibly an atmospheric dispersion corrector?

C9.25 for £151! congratulations on an absolute bargain. the 3.2mm eyepiece is really to much magnification for long focus scopes like your f13 swift, not surprising that it doesn't give a good view. the 6mm is about the maximum power you can expect to use in reasonably good seeing. those are two great scopes you have there! clear skies

Welcome!

Thanks everyone , that's kind of as i expected with the diffraction effects. Out of interest @Louis D, how effective is your apodising mask for high magnification? Does it really help with poor seeing very much?

spotted this lurking on eBay today, I was wondering if such a stray light blocker could work. the one advertised looks quite shiny inside, so is probably useless, but is the concept workable? I get the idea behind it but i imagine i would have seen one before if they were at all useful? https://www.ebay.co.uk/itm/203868931199?hash=item2f7789047f:g:4h4AAOSwwndiL5NL thanks Astronomist

thanks everyone, I didn't know the messier scopes had a 10 year warranty, mine was sold to me with a 2 year warranty, however inspection of the Bresser website reveals a 10 year warranty is indeed offered, not sure i really want it though, as some of the mods I have in the works at the moment would most likely void it Edit: Bresser got back to me very promptly, but it seems there is no obvious answer. I think I will just live with it as conveniently my only really heavy EP is very low power, so there is no significant worsening of the view. Also, i measured the 5mm with the focuser racked out some distance and the tube horizontal (looking at a distant pylon), so in normal use at night the flex is not as bad.