John

Does the scope use foil spacers ? If so and one of those has moved a bit, that can make an impact on image quality as I've been finding out with a 90mm F/11 achro that I've been playing around with lately.

Lovely scope Jeremy - congratulations Nice wind-up by Paul as well (I assume)

The "Cloudynights" forum has a classifieds section that is US / Canada based: https://www.cloudynights.com/classifieds/ The forum is free to join.

Mars opposition this year is a very good one - the best that we will get for many years. I think it's natural that the months leading up to the opposition show an increasing interest in the red planet. While we do have many members from around the world I guess the majority are from the UK and the EU where Jupiter and Saturn have been low and difficult to observe well recently. At other times those two planets feature much more here than Mars does. Reports from folks who do have good views of Saturn and Jupiter because of their location are always very welcome of course When you have been a member for a bit longer I think you will see a different pattern to reports in this section as Mars moves away and it's size dwindles rapidly to a small pink disk. You joined us just as Mars was peaking

Thats true. A Skywatcher Esprit refractor is a very different quality of product to, say one of their standard Evostar refractors.

The Ring Nebula can seem washed out when there is a bright moon in the sky although last night the moon was on the other side of the sky to Lyra. Sometimes there is high, thin cloud that you are otherwise unaware of which dims nebulous targets. I find using a bit more magnification helps this target to pop out a bit more. 70x - 120x is good. A UHC filter also enhances the contrast of Messier 57 / The Ring.

Many scopes of the brands you list are made by the same manufacturer now so in many ways it doesn't matter ! Orion (USA) branded scopes can be more expensive in the UK than the Skywatcher or Celestron branded versions. I've owned scopes by all the brands you list and they seemed to be similar in overall quality. Bresser is one brand that I would add to your list. They are popular on this forum. Currently I own scopes branded Skywatcher, Celestron, Vixen, Takahashi, APM / LZOS and Orion Optics (UK) and I'm very happy with them all The challenge at the moment, if buying new, is finding what you want in stock. Stocks are getting very lean with the vendors.

Hi, The numbers on the eyepieces are their focal lengths in mm so it is 10mm rather than 10x. To get the magnification that a certain eyepiece gives you divide the focal length of the telescope (750mm in your case) by the eyepiece focal length so using a 10mm eyepiece gives you 75x in your scope. Using a 2x barlow doubles the effective focal length of the scope so you then get 150x when using the 10mm eyepiece with the 2x barlow lens. If you use a 3x barlow then it's 225x as you have worked out. Maximum useful magnification depends on lots of factors including the size and optical quality of the primary mirror or objective lens in the scope, the seeing conditions on that occasion (the main factor really) the state of cooling and collimation of the optics in the scope scope and the target being observed. In reality much of the observing through telescopes is done at low or medium magnifications so using very high magnifications is not really the be all and end all. On the planets and double stars and often the moon, higher magnifications (say 130x - 250x with your scope) are very useful but for galaxies, clusters and nebulae low to medium magnifications (say 30x - 100x with your scope) are often much more effective. In theory a 150mm aperture scope should have a maximum useful magnification of 300x or so but that assumes that all the many factors involved come together perfectly and that the target object is suitable. This is only very rarely the case which is why the highest useful magnifications are usually quite a bit lower than the theoretical maximum. Hope that helps a bit

It is a good question though, so I have given another "like"

Good points Adam. You are right - the LZOS lens is 105mm. APM (and others) claim that the 107mm triplet is of similar quality to LZOS. They do all look very similar !

Nice clear night again tonight. Mars is looking great even 300x with my 100mm Takahashi refractor. Just for kicks I got it up to 900x using a 2.25x barlow and the main dark areas and tiny pole cap could still be discerned. Rather sharper and more contrast at 300x though ! The pale band that I think is the Eridania plain is showing between the dark Mare Cimmerium and the south polar area. Over the past couple of hours the pale notch adjacent to the Hisperia region has rotated towards the central meridian. The seeing here tonight is better than it was on the 6th when I last observed Mars. Very nice

I'm a visual observer like Geoff. I do often see a satellite whizz across the field of view through a scope but they don't bother me at all. I can see that imagers would not be so relaxed about them though.

The APM 107mm referred to by @Coco is one with the LZOS (Russia) triplet objective lens in it. These are quite different level of quality from some of the other APM branded refractors. LZOS objectives are world class - right up there with Takahashi and Astro Physics. And so they should be for what they cost. I have an APM branded scope with a LZOS 130mm F/9.2 triplet objective and it is probably the finest instrument that I've ever observed with.

The Skywatcher 150p has a primary mirror 150mm in diameter. With that scope I think I would be using the 10mm eyepiece with the 2x barlow to get 150x magnification. Allow the scope to cool down to outside temperature, focus carefully and give your eye time to adjust to the brightness of Mars and you will start to see darker markings and maybe the tiny south polar cap. South is at the top with the newtonian scope view. I don't image so I can't help you there.

To see the Veil Nebula you really need to use an eyepiece that gives a true field of view of around 1.3 to 1.5 degrees as a mimimum. That is just about wide enough to view most of one of the brighter sections of the nebula, ie: the east or west segment. With a C5 SCT that means using 32mm plossl with a 52 degree apparent field of view which gives you a 1.33 true field. Unless you move to using 2 inch eyepieces. A 24mm 68 degree apparent field eyepiece shows a similar true field to the aforementioned 32mm plossl. A good UHC or O-III filter will also be pretty much essential to see anything of this target with a 5 inch scope.

I'm not surprised though Stu. I've known significant variations in seeing and / or transparency between my garden and my society observing site which is only 5 miles away. Quite often I've found my garden better when I get home from a society session though it's sometimes the other way around. Very local factors can make quite a difference as well as more distant ones.

No, I don't use a filter.

Interesting comments on the seeing conditions for observing Mars last night. I found the contrast of features quite strong for the first hour of observing and then things gradually went downhill from there until Mars was showing that "viewing through a running stream" look Checking out some close double stars proved that the seeing had taken a plunge so I packed the scopes away. It was good to see Mars at it's closest this opposition but I'm hoping for better seeing for a longer period in sessions to come when Mars will still be a pretty decent angular diameter. I still intend to try and catch Phobos and / or Diemos with my 12 inch dob when they are furthest from Mars. They do move around the planet quite quickly though so I need to be on my toes to catch them at max elongation from their host planet.

Actually quite useful. What many will see when they initially view Mars I reckon. But observe for longer and more detail will gradually be teased out

Which in itself is interesting because the first time I heard of this eyepiece was when the Astro Tech Paradigm range were reviewed 11 years ago on CN by Tom Trusock: https://www.cloudynights.com/articles/cat/cn-reports/eyepiece-reports/first-look-astro-tech-paradigm-eyepieces-r1845 At that time, $80 apiece.

Interesting comparing these prices: https://www.firstlightoptics.com/bst-starguider-eyepieces/bst-starguider-60-12mm-ed-eyepiece.html and https://www.teleskop-express.de/shop/product_info.php/language/en/info/p4931_TS-Optics-1-25--ED-Okular-12mm---60--ebenes-Bildfeld---hoher-Kontrast.html Exactly the same or subtle differences ? £47 vs £85

The seeing here went downhill after midnight and clouds have put the finishing touch on the session for me. Hope others still have it good though

If the test is done under excellent seeing conditions, at appropriate magnifications that might be the case. Do you really want to star the OP worrying about SA just now though, given the circumstances described in this thread ?

Still nice and clear here - very nice martian details showing. Even my Mrs came out see them ! I've had both the Tak 100 and the LZOS 130 out tonight. Just the latter now. Also had some decent views of Jupiter, Saturn and Neptune. Nice night so far despite some suspicious looking lumps of cloud here and there.

I agree with Geoff - the diffraction rings are not always well defined by any means. Sometimes they are better defined on one side of focus and mushy on the other. Seeing conditions play quite a role in this and it's all to easy to think you have an optical issue when it's really the seeing playing around with you !