Second Time Around

I have the Skywatcher observing chair that looks to be the same as the Omegon. This design is very quick and easy to adjust in height. What I particularly like about it is that the seat goes down as low as 11 inches compared with about 24 inches for the Mey chair for instance. This makes observing at low altitude with a Dobsonian or at high altitude with a cat/refractor very much easier. Having neck and back problems, for me that's essential rather than just being more comfortable as it would be for most people. However, although I haven't seen one in the flesh, the mechanism of the Mey chair appears to be better. The problem with the Skywatcher/Omegon is that the seat can suddenly slip down if you don't sit on it the right way. The solution is simply not to put your weight solely on the back of the seat as you first sit down - it's this that causes the slippage. If there's some weight on the front as well or instead of then it doesn't slip. One thing that I don't like about the Skywatcher is that it's black, that makes it hard to see in the dark. I get round this by slipping a white carrier bag over the seat. I notice that the Mey chair comes in various colour schemes, and for this reason I'd choose the two-tone black and white.

My brother and I had a secondhand 6" f/8 AE on an undriven German equatorial with a metal tripod, both in that same blue colour. Both the optics and mount we're excellent. Our scope had a closed tube, but most AE Newtonians were an early truss design. That would have been about 1975. I well remember the excitement of seeing the Ring Nebula for the first time!

Sorry to hear that, Louis. Best wishes for a speedy recovery from a fellow neck sufferer.

Thanks so much for the memories! I remember the 1965 catalogue very well! I never did visit the premises, but my brother Chris did some years later to have the first mirror he made tested. Dudley Fuller told him it was so good that they offered him a job, but Chris turned it down. Mind you, it might have been they were desperate (sorry, Chris!).

I've got one of the "posh Russian ones" in black. I hope to do some solar observing before long. I had the idea of putting a foil cover over the top (as in the frost protectors for windscreens). Anyone tried this? If so, did it work?

Here in the UK the following is added: 1) VAT @ 20% 2) Import duty (5%?) 3) Handling charge from the parcels company or Royal Mail. The latter is £8.

One important thing to point out is that you shouldn't wear a headlamp when other people are around as it can ruin their dark adaption. You won't be very popular if you do so at a star party! For this reason many people use a handheld torch instead. However, unless you use a special headband you can't use a torch as a headlamp. But you can easily do it the other way round and use a headlamp as a torch simply by holding it in your hand. A headtorch also allows both your hands to be free, plus it points wherever you're looking.

I'd strongly advise you go for a headlamp that has separate switches for white and red light, plus the ability to dim the light right down. The former is important as sooner or later you'll turn the white light on and ruin your dark adaption. The latter is important because nearly all headlamps are way too bright. By far the best I've found are some of the 2019 Black Diamonds. Confusingly, although the model name (but not the number) remains the same, many have been totally redesigned for 2019 with two buttons instead of just one. One of the great things about them is that only the larger button turns the headlamp on; the smaller button just changes from red to white, but nothing happens when you press it if the headlamp is off. Additionally, they remember the last setting you used before turning off. For instance, if you finished with the red light at its dimmest setting, that's what you get when you turn it back on. Set up like this it means that it's impossible to turn anything on at the start but the dimmest red light - whatever button you push. Not all the 2019 Black Diamond two button range are suitable for us though. Some of them have battery check LEDs that light up when you first switch on. The problem is they're bright blue! Also note that the poorly-named Astro model doesn't have a red light. I started by buying two models, the Cosmo 225 and the Spot Lite 160, that use 3AAA and 2AAA batteries respectively. The numbers represent the max. brightness in lumens. Surprisingly, the red light on the Cosmo 225 goes dimmer than that on the Spot Lite 160, although this may just be a sample variation. The former is also on special offer at the moment because a new model, the Cosmo 250 has just been launched, that seems to be identical but has a higher output. I've just tested this, and comparing all 3 with fresh disposable batteries the 250 is indeed slightly brighter on full power white light than the 225, but there isn't much in it. On the dimmest red light the 225 and 250 are exactly the same. So any of the 3 models are fine for astronomy. There were complaints about older versions of these products having a weak closure on the battery compartments. This appears to be rectified nicely in the new models that have a firm, precise click action. I'd add that, here in Europe at least, these Black Diamonds have a 3 year guarantee. That doesn't of course prove anything, but they're expected to last at least that long. These headlamps should also be suitable for my fishing and camping as they have a waterproof rating of IPX8. This means that they can work for at least 30 minutes submerged to a depth of 1.1 metres (3 1/2 feet). However do note the battery compartment itself isn't waterproof and will need drying out. So for the first time I'm satisfied with a headlamp for astronomy and can thoroughly recommend these 3 Black Diamond headtorches. They're also very reasonably priced. Do check though that you're buying the latest 2 button models. Many outlets are still selling the similar 1 button type that's not good for us. For instance Amazon UK even has a picture of a 2 button Cosmo but the description suggests it's the old 1 button model. For the special offer Cosmo 225 go to https://www.trailblazeroutdoors.co.uk/outdoor-equipment/lighting/black-diamond-cosmo-225-headlamp-dark-olive

The 24mm APM UFF has had excellent reviews and has plenty of eye relief. Cost is only about £150. In fact I'll probably get one for my f/4.8 DOB.

One thing to look out for is the style of the handle. It's much easier to carry a battery with a single handle that runs the whole way along the long axis of the battery. Avoid like the plague any that have 2 small handles that run at 90 degrees. With these you have to carry the battery in front of you - much slower and a strain on one's back. You may also like to consider 2 smaller batteries. These are easier to carry one in each hand rather than a larger heavier one in just one hand. Although it works out more expensive, it also means that if 1 fails you've got a reserve. I learnt this the hard way long ago on my boat where safety is paramount!

Many thanks indeed, Bill. This was on my to buy list and your field test has just confirmed this.

Wow!

You're going to get a lot of different answers to this question, Mike! It's often a matter of personal taste. My own preference is for a Barlow or Barlows because of the increased flexibility. It can also mean reduced cost as one Barlow can be used with many eyepieces and so much increase the range of focal lengths. Others will point to the loss of transmission in adding a Barlow because of the extra elements. Years ago, before the advent of multi-coating, this was a very valid point, and it may be that this maxim has simply continued to this day. The loss of transmission still makes a small difference, but these days is relatively minor -although it can still be seen on careful examination of very low contrast objects. Having said that, many of the most highly regarded ranges of eyepieces actually contain a Barlow (known as a Smythe lens in this case), and this means more elements in the eyepiece anyway! You can usually tell these by all the eyepieces in the range having a constant eye relief. Eye relief (how close you need to get to the eyelens) is an important consideration, especially if you have astigmatism and wear glasses at the scope or add a Dioptrx to correct the astigmatism. Either way you need extra eye relief to be able to see the whole field of view and to avoid being uncomfortably close to the eyelens. Generally, the shorter the focal length the less the eye relief. A Barlow, either a separate one or incorporated in the eyepiece, mitigates this problem as the eye relief increases slightly. An additional consideration if using a Dioptrx is that they can be fitted only to a limited range of eyepieces, so one doesn't have so much choice. It's also possible to have too much eye relief resulting in blackouts. This means that a Barlow with a long eye relief eyepiece may not be as suitable. The answer to my mind is to choose an eyepiece with suitable eye relief in the first place. This will differ from person to person, depending on the shape of one's face/eye sockets plus the style of glasses if used. For instance, those who don't need glasses may prefer 12 to 15 mm eye relief, whilst with glasses or a Dioptrx that same person might need 20 to 23 mm. It's also important to treat the quoted eye reliefs with caution as the useable eye relief can be reduced by a number of factors, including in particular how deep the eyelens is recessed.

Excellent! Just a heads up that the "about this product" section still says it comes with a red dot finder rather than a 6x30.

I'd second what John Inderby posted. The Bresser is easier to carry around thanks to the altitude rings. In fact I found that a 10 inch Bresser is as easy to carry around as an 8 inch from most other makes. This design also results in a lovely smooth movement in altitude. You also get other features as well that more then justify the extra initial cost. In the future you're likely to spend a lot more on accessories, and so the small extra cost will soon be forgotten. On the other hand, for those on a really tight initial budget the Skywatcher might be the right answer. I'd also echo what the other John said about a RACI finder. I find them hugely more comfortable to use than a straight through finder, although some do prefer the latter. However, you'll still find the red dot finder useful to get in the rough area before switching to the RACI. Many experienced observers end up with both for this reason. A very popular alternative to the red dot finder is to use a Telrad or Rigel Quikfinder 1x finder. For more information on finders there are 2 excellent articles on the website of US supplier Agenda Astro. Dinner is being served but I'll post links afterwards. Here are the links: https://agenaastro.com/articles/guides/finders-and-guidescopes/choosing-a-magnifying-finder-for-your-telescope.html https://agenaastro.com/articles/guides/finders-and-guidescopes/choosing-non-magnifying-finder-for-your-telescope.html

Thanks for drawing attention to this excellent topic that I hadn't seen before, and a warm welcome to Stargazer's Lounge!

Much as I like "Turn Left at Orion" I like "The Universe from your Backyard" by David J. Richer even more. That's probably because I've got 8 inch and 10 inch Dobsonians and the drawings and descriptions are more relevant to these apertures.

No worries, Louis. It was well worth a try for the cost of postage. Thanks again.

Yes, you can screw the eyecap off with the Baader, Louis, although I use it with a Dioptrx. I've now tried the Celestron and, although it was wasn't far behind the Baader, it had 2 disadvantages besides the FOV being smaller. Firstly, as already mentioned, it didn't have a filter thread. I realised that without that I couldn't use my 2.25x Baader Barlow as this screws into the filter thread. Secondly, it's nowhere near as parfocal as the Baader, which would make it not so good with a binoviewer (that I wanted to use it for in the future), as both eyepieces would need refocusing. For these reasons I've had to return it. The seller, Northern Optics, was very fast at refunding me and I can thoroughly recommend them. That said, I was very pleasantly surprised at the quality for the price. P.S. Thanks again to John and Louis.

What a gorgeous garden!

Many thanks, Miguel!

Do you have a link to these by any chance? I find sketches much more useful than photos.

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!