Second Time Around

I have both 8 inch and 10 inch Dobsonians, and there are pros and cons to both. I ought to start by saying that I have somewhat of a disability. As a result, my strategy was to buy the best scope of the biggest aperture I could easily transport. Both weight and physical size are considerations here. I went upmarket and bought secondhand Orion Optics UK (OOUK) dobs, but had to wait a long time for the 10 inch I really wanted to come up. In the meantime I bought a secondhand 8 inch. However if I were buying new I'd certainly consider a Bresser Messier, partly because it's also easy to transport, and partly because it's better engineered with a higher spec than many competitors. The focal lengths and tube lengths of the 8 inch and 10 inch are within about 2 ins of each other, and both should fit on the back seat of a car for trips away. When comparing scopes in various shops, with the OOUK and Bresser Messiers I found it much easier than competitors to lift the tube assembly as you can use the altitude rings. I can carry both my OOUK 8 inch and 10 inch tube assemblies in one hand like this. Granted the 10 inch is heavier, but even with my disability I can manage it. On the other hand, I struggled with makes other than OOUK and Bresser as it wasn't so easy to grasp them. The OOUK is particularly light as the tube is made from aluminium rather than the usual steel, and I seem to remember that the Bresser is as well. The OOUK mount is also made from aluminium, and I can carry the 8 inch in one hand and the tube assembly in the other. For the 10 inch OOUK mount I need 2 hands but it's not overly heavy. As I said, it's not just the weight to consider though, but also the physical size. The OOUK mount is smaller than the usual wooden ones, including the Bresser, and so can be held close to one's body, making it less of an effort to carry. So as far as weight and size are concerned, and bearing in mind that I can manage a 10 inch OOUK or Bresser even with my disability, there's no reason not to go for the 10 inch Bresser. With other makes I'd be limited to an 8 inch. As for what each size scope will show, there's not a huge difference on say, the moon. However comparing side by side, my 10 inch is a big step up from my 8 inch for many deep sky objects, and hugely so for globular clusters. This would be even more so if you're in city or suburban skies. So, once again, I'd choose a 10 inch here. Turning to the price, you're likely in time to spend a lot more on accessories than on the scope itself. So the extra £120 for the 10 inch compared with the 8 inch will soon be forgotten. However you need to factor it that the 10 inch is an f/5 so you may or may not have to spend a little more on eyepieces. I haven't as my choice of eyepieces are the same with both anyway. Additionally, at f/5 you're on the borderline of needing a coma corrector. All this begs the question why stop at 10 inches, why not buy a 12 inch? The jump in size and weight is such that a 12 inch is much more difficult to transport. For this reason many 12 inch scopes have a collapsible truss tube that has pros and cons, and is also quite a bit more expensive. For me, a 10 inch is the best compromise, and I suspect it would be for a lot of others.

If you do a search on "setting circles" you should find a lot of information. There are 2 general types, digital and non-digital. The latter are inexpensive, whereas digital setting circles, whilst superior, are much more costly, Like Dr Strange, I too have the Astro Devices electronic digital setting circles. I chose the Nexus II model that with the encoders came to about £500 after import duty, VAT and carriage. Whether manual or electronic you'll need a star map app to work in conjunction with them. I use Sky Safari Plus, although have just upgraded to the Pro. These apps aren't just for setting circles though - they're a wonderful and inexpensive resource and a lot of posters here recommend Sky Safari or something similar.

Wow! Brilliant!

I agree that you should perhaps forget astrophotography for the moment. For AP the accepted wisdom is that you should spend the greatest percentage on a mount, and with your budget that would be very limiting. You mentioned getting a Dob and later converting it to an equatorial mount. That's the way that I'd go. I'd especially recommend the Bresser Messier 8 or 10 inch Dobs (Explore Scientific in the US) These are well within your budget, and although a little more expensive than others they're are a cut above in specification. One of the many advantages is the tube rings make it easier and less expensive to upgrade to an equatorial later on. Granted there's no push to, but you add that yourself without spending too much money.

Both my 8 inch and 10 inch OOUKs have semi-closed mirror cells and small fans. I've always turned the fan on about an hour before observing so have no idea what if any difference it makes. I also keep the fan on throughout the session - it doesn't seem to cause undue vibration.

Pinched this from Cloudy Nights. CALLER: Is this Starshine Telescopes? GOOGLE: No sir, it's Google Telescopes. CALLER: I must have dialled a wrong number. Sorry. GOOGLE: No sir, Google bought Starshine Telescopes last month. CALLER: OK, I would like to purchase an Astrograph. GOOGLE: Do you want your usual type, sir? CALLER: My usual? You know me? GOOGLE: According to our caller ID data sheet, the last 3 times you called, you purchased a 6 inch Newtonian Reflector, an 8 inch Newtonian Reflector, and a Coma Corrector for a fast Newtonian. CALLER: OK! I'd like to purchase a 10 inch Skywatcher Newtonian Astrograph. GOOGLE: May I suggest that this time you order the much lighter 80mm short tube Refractor. CALLER: What? I don't like Refractors. GOOGLE: Your cholesterol is not good, sir, and the 10 inch Astrograph is way too heavy for you. CALLER: How the hell do you know? GOOGLE: Well, we cross-referenced your home phone number with your medical records. We have the result of your blood tests for the last 7 years. CALLER: Okay, but I do not want your terrible small aperture Refractor. I want a 10 inch Astrograph! GOOGLE: Excuse me sir, but you have not taken your medication regularly. The 10 inch Astrograph is way too heavy for your condition. According to our database, you only purchased a box of 30 cholesterol tablets once, at FamilyCare Pharmacy, 4 months ago. CALLER: I'll be OK! I bought more from another chemist. GOOGLE: That doesn’t show on your credit card statement. CALLER: I paid in cash. GOOGLE: But you did not withdraw enough cash according to your bank statement. CALLER: I have other sources of cash. GOOGLE: That doesn’t show on your last tax return unless you bought them using an undeclared income source, which is against the law. CALLER: WHAT THE HELL? GOOGLE: I'm sorry, sir, we use such information only with the sole intention of helping you. CALLER: Enough already! I'm sick to death of Google, Facebook, Twitter, WhatsApp and all the others. I'm going to an island without internet, no cable TV, where there is no cell phone service and no one to watch me or spy on me. GOOGLE: I understand sir, but you need to renew your passport first. It expired 6 weeks ago…..

It's 12 volts. I recently bought just this small battery (that I velcrod to my rocker box) from Amazon: Yuasa NP1.2 – 12 UPS Batteries https://www.amazon.co.uk/gp/product/B000V3S86Y/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 To connect the battery to the fan I then bought this from Amazon: JENOR Dual Red & Black Test Leads with Crocodile Clips Alligator Jumper Cable Wire 105cm https://www.amazon.co.uk/gp/product/B07MZ1JC1F/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1 Hope that helps.

50 years ago! I feel old!

I'm using it on my Dob so no diagonal. However I can put 2 inch filters on my coma corrector, although it won't fit in the focusser of the 8 inch f/6 at the moment as the drawtube is flocked. My 10 inch f/4.8 is being rebuilt, including fitting a Baader Diamond Steeltrack focusser. Once I've finished this I'll probably put the same Baader focusser on the 8 inch. I'm looking forward to testing the Celestron against my Baader zoom. It'll be tomorrow night at the earliest now though, as this evening we've doing an online pub quiz with the family.

The eyepiece has arrived and I've just taken it out of quarantine. It's forecast to be clear tomorrow night so I plan to try it out then. If I like it I'll be getting an adaptor made as I mentioned earlier. One disadvantage though is that it doesn't have a filter thread. Not having the eye lens turning when zooming will be handy with a Dioptrx, especially as I plan to get a binoviewer before long.

Thanks, Craig.

Craig, was your Steeltrack the original or the Diamond model? I ask as I recently bought the Diamond but have some other jobs to do before it gets fitted.

Drat, according to Cloudy Nights it looks as though Comet Atlas has disintergrated.

Sorry Stu, I disagree as well. The Skywatchers are certainly very good value for money. However, amongst other advantages, the Bressers are easier to transport. For me this would mean I would rather have the Bresser. I'd also point out that this thread is about a Bresser. There are a lot fewer of these threads than ones on Skywatchers.

Well done Bresser for acting so quickly! I assume that consumer law is the same all over the EU but, certainly in the UK, it's the retailer that's responsible for delivery of a package not the parcels company. If it doesn't turn up within a reasonable time it's up to the retailer to replace or refund. Quite a few companies try to get round this in their terms and conditions, but they wouldn't be able to enforce it. It would make for a lot of hassle though. I will deal with such companies only if I couldn't buy the product elsewhere. This is one of the reasons I use FLO as my first port of call for astro purchases.

We have this sign on our door:

First time around all my eyepieces were 1 1/4 inch RAS threaded. On my recent return there appear to be no threaded eyepieces for astronomy. What happened, when and why? Thanks.

M35 is a lovely sight in my 8 inch f/6. It's even better in my 10 inch f/4.8. My 10 inch also shows the close by NGC2169 and resolves it into a mass of faint stars. The other night when transparency was poor I couldn't even see it in the 8 inch.

What a spectacular photo!

I've found several step down rings of the right size but all will reduce the eye relief, that's already been reduced by the Dioptrx. The eyepiece hasn't arrived yet, but if I decide to keep it I'll have an adaptor made that's simply a narrow ring with a 37mm inside diameter and a 43mm outside diameter. However, that will probably have to wait until after the pandemic is over.

Do you have astigmatism in your observing eye? If you wear glasses do you use them to observe? Doing so would correct the astigmatism and may solve the problem. I'd add that astigmatism shows up more with lower powers.

Perhaps we need to bear in mind that someone who's lost their income may need to raise funds to feed their kids. Anything that comes into our house gets quarantined for several days and then disinfected.

Having done some business consultancy for a branch of a parcels company I can tell you that quality of service varies not only from company to company but also branch to branch. It also varies from driver to driver. We had a problem with our local Hermes driver at first but now he's brilliant. The biggest problem for us is that, being stuck out in East Kent with the sea on two sides and also being very rural, we're a long way from any depot. It means that we're at the end of each company's route. The result is that on busy days we get missed out for both pickups and deliveries. On the other hand, our Royal Mail postal service is excellent. I agree with others that, of the courier companies, DPD has been the most reliable for us. Given a choice of retailer we always give preference to those who use DPD. I twice emailed DPD a couple of years ago suggesting that publishing a list of companies using them would both help recipients and also help them get more business, but didn't get a reply.

The Orion Optics Dobs have a focal plane 100mm from the outside of the tube. As Joe said you may be able to move the mirror further down to the bottom of the tube. On my OOUK Dob there are 2 sets of holes, and my mirror cell uses the upper holes. If you're just a little off you may be able to move the mirror enough by loosening all the mirror cell screws.

Brilliant, Louis! Many thanks.