Paz

I agree with comments above that good eyesight matters when getting the most out of a small high end refractor at high magnifications, and so does experience, technique, and the conditions. The laws of diminishing returns apply but although the gains are marginal and despite me being very happy with my altair 102mm f7, a 100mm Tak remains on my hit list, not right now but eventually. The reason why is the same as why I have T/&×@*e eyepieces (name redacted to avoid further controversy!). I know other lower cost items are very close (and in the real world of the wobbly stack they are just as good really) and unless you A-B them side by side or are very experienced, it can be tough to spot the difference but I enjoy my observing more because I believe I can't get anything better and so it is all down to me and my ability to get the best out of them. This means I'm totally focused on enjoying observing and I'm not thinking about what other kit I might use.

I have thought about this in the past when observing with an eq5 with the RA motor going but I couldn't detect this effect myself.

I've only been observing for 8 or so years and the weather has always been rubbish so long spells of unrelenting cloud is normal to me. I'm in the Midlands and we have a microclimate where I live where very often it is blue skies in the morning, cloudy by late morning, clear early evening and cloudy soon after dark. So usually solar is best done in the morning and night time observing is best done early evening.

Signed, when you sign consider if you can also flag it to your friends on things like facebook/twitter.

Thanks for this, all this time and I just assumed it couldn't be changed!

I really like my 102mm f7 (the altair version) but I really dont like twist locks. I replaced the 1.25" collar with other types with screws/compression rings or I just use T2 connections. The real problem is the 2" twist lock that I assume can't be replaced. If that could be replaced I would use my 2" set ups more often. ...but all of the above is really about not liking twist locks rather than the scope, my 102mm f7 is my most used scope by far, the relationship between the quality of the views, cost, ease of use, and flexibility is the best Ive come across so far.

The field guide is really designed to compliment the atlas. If you were to look up a dso in the index it then only refers you to the page of the atlas that that dso appears in and it says what type if dso it is. Then in the field guide you turn to the pages covering the relevant page of the atlas, then go to the section for the right type if dso and there is your list of, say, open clusters on that page with details like magnitude, ra, Dec, etc. Having said that theres nothing to stop anyone from using it as a stand alone reference.

I think big jumps across the longer focal lengths and small jumps at the shorter focal lengths is a useful principle and is reflected in some of the sets up mentioned already. I have use NPLs/SLVs for light set ups and Naglers/Delos for heavier set ups and use both with my 102mm f7. But if I am taking a reduced number of eyepieces out here's how those full sets will typically get trimmed down if it is useful to illustrate.,.,. NPL/SLV collection is 40, 30, 25, 20, 15, 10, 6, 5, 4, 2.5, these would typically get thinned down to: 25, 10, 6, 4. Nagler/Delos collection is 31, 22, 17.3, 12, 10, 8, 6, 4.5, 3.5, these would typically be thinned down to 17.3, 8, 4.5, 3.5

That tripod in the link looks a bit like mine, and as I mention mine is great for light weight and small pack down size but it's not as sturdy as I would like. Here's my set up...

I use heat holders socks and over sized sorel boots.The socks wear out quickly if you walk in them but not if you are standing around, and they are super warm. The boots are crazy hot, your feet and lower legs become radiators passing heat back to your body because it can't get out through the boots. The link below is the closest I can find to my boots which it looks like they don't make any more. https://heatholders.co.uk/products/mens-original-heat-holders-socks-6-11-uk-39-45-eur?variant=29960345321581 https://www.sorelfootwear.co.uk/p/mens-1964-pac-nylon-boot-1855191.html?dwvar_1855191_color=011

I have a 72mm and 102mm scopes that cover slightly different roles. My 72mm scope is mostly for travel where size is a limiting factor, and it is used sometimes at home where I want a set up I can have ready indoors and lift straight outside in one hand i.e. super fast. My 102mm if for home use but takes 2 trips to set up rather than one one to take out a mount and one to take out the scope. It's not as fast as the above, but it is still fast and therefore I rarely use the 72mm at home as the 102 beats it overall when considering the relationship between set up time and quality of the views. Whether you go for FPL53 or something less expensive is a judgement call but I would say in my set up the limiting factor for enjoyment is not the scope but the tripod. I use a light Neewer carbon fibre tripod with an AZT6. The AZT6 is fine but the tripod could be better, it is brilliant for lightness and small pack down size but the vibes are more than I would prefer. Overall though I am happy with the compromise. So if thinking about how much to spend and what makes for good value, if I was starting again in my case there could be something to be said for thinking through having a lesser quality (or lighter) scope on a higher quality mount for a better overall experience (by the way the ST80 is great in this respect - it is not such high end optics but it is very light for its aperture and it is flattered by lesser mounts/tripods).

I've used a 31mm T5 on a 72mm apo and 102mm apo and it was ok. I've used it on a ST120 with an upgraded dual speed crayford focuser and it was fine there also. I have not tried it with the standard focuser on the ST120. I think the 80mm and 102mm EDs with a 31mm T5 would be ok on an AZ4, but an ST120 would be a tougher ask (it might be ok, but I would not want to guess). As well as the scope and mount there is the question of the diagonal being reasonably sturdy.

I have never used a 13mm T6 but I am sure that is an excellent eyepiece , that's my helpful input and of course it has nothing to do with the fact that if you want to offload the 12mm Delos I would be happy to help with that, I've been looking for one for ages to make up a binoviewing pair I started out with ES82 eyepieces and they are great but eye relief issues plus realising I was not that bothered about having very wide AFOVs led me to Delos which I have been very happy with.

I was wondering about the same thing, I'm not sure it's safe to sell this without a nd3 filter.

The band of light you describe across the sky I think would be our galaxy, I don't think any trail of stars relating to those collisions would be visible naked eye. I assume they identy the trail from huge scientific scopes and/or estimating then position and motion of many stars and using computers to find patterns that indicate such associations. The dwarf galaxy is I think PGC4689212 and in terms of easily visible things associated with it M54 is a globular cluster that is thought to be associated with it and is right in the middle from our perspective.

I have just got a second Baader 2.6x glass path corrector for a Maxbright 2 binoviewer so that I don't have to constantly swap it across from my solar set up to my lunar/planetary set up and there is a plastic/rubber retaining ring that is used to seat it centrally in a T2 optical train. There is a problem in that the outer diameter of the ring is slightly too small so it does not sit snugly against the T2 extensions that it sits within (enough that the ring will fall out), and the inner diameter is slightly too large so the glass path corrector does not quite sit snugly in the ring. All this amounts to meaning the glass path corrector rattles around a bit and therefore isn't sitting centrally. I could return it but what are the chances of the next one being the same, as long as the optics are good when I get an opportunity to test them I was wondering about if it is possible to get via 3d printing copies of the retainer ring but with a range of slightly amended inner and outer diameters such that one of them would hopefully be a good fit. In the picture below on the left is a gpc with the retainer ring on it, and on the right is one with the retainer ring off and sitting below the gpc, that's the thing I am wondering about. Does anyone know what is possible with 3d printing and if I could commission such a thing relatively inexpensively if I provide accurate measurements?

Interstellarium gives you more information on a plate and I think is more simple to use than Uranometria, also the field guide for interstellarium gives images giving you an idea of what targets look like, whereas the Uranometria field guide gives you empirical metrics only. You can tell from the metrics how doable a target is but Interstallarium makes it easier to assess. The spiral binding is not a pro or con for me as I don't use paper maps in the field any more, I only use them indoors for planning targets and for reviewing what I've seen afterwards. If I was using them in the field then the spiral binding is certainly an advantage to Interstellarium (and I think the paper used for interstallarium would hold up better in the field than the paper in Uranometria). In the field I use Sky Safari like I would use a paper map and find things manually.

I have both and I would also recommend interstellarium, its easy to use and the field guide is also good.

Congratulations on capturing a full-house (or should it be called a flush?) of cloud on clear outside. I've been looking out for this on clear outside for years and whilst it is mostly cloudy most of the time I've never seen it 100% red.

This has been interesting to follow. I've been vaguely aware of people who churn a lot of gear but I never really stopped to think about it. In the end though, I'm not too concerned if people want to try and make a profit, because bear in mind that they have to invest the time and go through the hassle and take the risk. As has been said above, what is not so good is if someone presents as being something they are not, but that can happen in any endeavour.

I had a read of the Q&A on ABS and it mentions that Kit Testers are individuals (not businesses) who buy and sell for profit, and unlike those just buying and selling for personal use and not for profit, Kit Testers pay a fee for each ad.

I agree binoviewers would help with planetary. I have been binoviewing with a 102mm f7 reflector and various other scopes for a couple of years or so now and I prefer binoviewing when it is possible. It can be a bit of a rabbit hole as there are many options but with a bit of research like this plus perhaps a bit of trial and error you should end up with a set up that you are glad you have.

This is really useful thanks for posting. I mostly get inspiration from the cambridge double star atlas for easy doubles. There are 12 doubles in Canis minor in that atlas which one would think is plenty, and I have never had a problem finding nice targets to that level, but this post illustrates how as you go a bit deeper the number of targets grows exponentially.

That's a very nice collection!

One thing I notice is that as you allude to they are best when they are complimentary to each other. I looked at length at 120-130mm refractors as I was aiming for downsizing to just 3 scopes, a 72mm refractor for travel so that had to be small, a 14" reflector for epic sessions, so that had to be epic(!) and being big/heavy didn't matter, and a third scope in between. I looked at some 120-130mm refractors in the flesh and was worried about their size/weight and that I might need a more serious mount and that setting one up would be in the same league of challenge as the vx14 in which case the vx14 would probably get used and the big refractor would probably not. So I thought longer about the point of a 3rd scope. In the end I decided it had to be a general purpose great grab and go scope, I e. did not have to be small but did have to be fast and flexible and l easy to set up so it filled a gap that didn't compete with the 72mm or 14" and I ended up with a smaller 3rd scope than I initially wanted. The above is just my own story and everyone would have different choicesabput a good mix of scopes that would work best, but the thing that helped me was considering scope purpose again in detail and seeing if that helped to solidify a choice. Regarding your starting point a challenge you have is that a 10" dobsoinian is a great visual scope and so anything else is going to have to have a specific advantage over that to make you motivated to use it once the novelty has worn off.