John

11 minutes ago, Mark2022 said:

I  refuse to "buy" that until I see the reality of it. I don't dispute it does have an effect but I don't "buy into" that much of an effect. I will be more than happy when I am proven wrong in my thinking. 

It can make a huge difference visually (I am visual only) so I guess it could also make a major difference in imaging.

My best views of Saturn and Jupiter were many years back when they were really high in the sky. I've had some nice views occasionally recently but nothing to rival those views, despite my equipment and experience having moved forward someway in the meantime.

On 30/09/2023 at 11:02, johnturley said:

I am planning to get a Takahashi 100 DZ Refractor after selling my Celestron CPC 9.25 (selling due to back problems), and although I usually buy most of my Astro stuff from FLO, I will probably get the 100 DZ from Rother Valley Optics (who are just 15 miles away from me), so that I can pick it up in person, so as to avoid the risk of any possible damage or misalignment of the optics, due to rough handling by the courier. When I purchased my Esprit 150 (from FLO), this was 'drop-shipped' direct from OVL (the UK Skywatcher distributor) to ES Reid for testing, and I arranged to pick up the scope direct from ES (whom I know personally) after testing.

I will however, probably buy the tube clamps and saddle plate to attach the 100 DZ onto my AZ-EQ5 from FLO, as they offer a better choice which are more competitively priced. FLO also appeared more knowledgeable than RVO in so much as they  pointed me towards an adapter bar to enable the attachment of the Takahashi cradle to the AZ-EQ5 mount, whereas RVO said that it wasn't possible. Utilizing this adapter bar with the Takahashi Cradle, however works out more expensive than the StellaLyra 95mm tube clamps, and I gather is also less stable. 

John 

I can see the sense in that. Taks are packaged better than most other scopes though. My FC100-DL (purchased from Ian King) came triple boxed with expanded polystyrene struts supporting and separating each layer. Very impressive.

I have an Altair 70mm ED travel scope - I think it was the model before the one advertised on here ?

Nice little scope. I use it on a Slik photo tripod and a TS alt-az mount for a very "grab and go" outfit weighing less than 10 lbs all up. A one handed carry outside. It shows a little CA on the brightest targets but the objective is well corrected so it gets very close to the limits for the aperture in performance.

To some extent that scope has helped me over a period of reduced enthusiasm for astronomy as well 🙂

7 minutes ago, bosun21 said:

On the nights of heavy dew I just used a standard dew shield and if really bad I used heated bands on my eyepiece and finder. You can make a dew shield from a yoga mat or the like.

Good advice above to keep dew off the mirrors.

Keep your eyepieces a little warmer than the outside temp and they will stay dew free and not mist up from body heat on colder nights. I keep mine in foam lined cases. The foam seems to retain a little heat for some time.

5 hours ago, Bugdozer said:

I know I am late to the party here, but to answer something in the OP... I believe barrel security recess is a groove around the part that the little grip screws grip on, so if a screw works too loose to grip the barrel, the eyepiece can't drop out as it's still within the groove. My default Celestron eyepiece has one. 

Also known as undercuts.

It ought to be mentioned that are not universally popular 😉

7 hours ago, MalcolmM said:

I see, from another forum, you have done some comparisons with the TLPs. I get the feeling, from all I have read, that they are very good eyepieces but not necessarily a huge step up from any other premium eyepieces. Would you tend to agree? I suspect they would be excellent in the Mewlon, but I can't believe I would find them noticeably better than my Tak Abbes or Masuyamas (but I'd love to be proved wrong 🙂 )

Malcolm 

That is the impression that I have gained regarding the TLP's. I did buy and try a 4mm TOE and compared that with my Pentax XW, Nagler zoom and Astro Hutech HD orthos but, while there were small differences in their characteristics, I didn't find that the TOE was consistently better than the others. 

The more I've compared high power eyepieces, the more I find myself agreeing with Roger Vine's conclusions on them:

Eyepieces for Planets (scopeviews.co.uk)

Find some that you like and stick with them. Observe as much as possible to develop your skills and catch the good seeing nights. Enjoy 🙂

8 minutes ago, Mandy D said:

It matters very little how the word was derived. The discussion came about because @Mr Spock gave me advice on collimating my telescope earlier in this thread and used the spelling concentre, which most of us assumed to be correct, because it is only logical that we Brits would spell such a word this way. Unfortunately, this caused significant confusion until someone else posted a link and the problem became apparent. It is not about what you or the manufacturer think is the correct spelling, it is about potential customers finding the desired product.

Yes, the manufacturer has the right to spell product names however they wish, but that does not automatically make it good practice or wise. You suggest that you would not change the spelling of your name when in a foreign country, but if your name were (let's say) Richard, the French would almost certainly spell it Ricard and, to your ears, mispronounce it. An even more extreme example is a certain diminutive of Amanda, rather than Mandy, which is Manda, but if that were your given name you might not want to use it in Russia! 🤣

I'm sure this will help the original poster no end with their issues 😁

50 minutes ago, Greymouser said:

If you don't mind @John could you expand on this please? I have been considering getting a triplet, from FLO of course, but Exeter is a bit far from me. Is it so much more risky than getting a doublet delivered? Might have to reconsider things...

I might make an exception with FLO because of their service record 🙂

More generally though, I know what I am doing with doublets but triplets are, to me, somewhat more challenging and, if the collimation gets a knock, diagnosing the issue and then sorting things out can be a much more complex affair. 

With the best will in the world, one can't know how a package is treated when it gets into the hands of a courier. It seems to me a risk to have a triplet checked and tested at before the start of it's journey, then subject it to the uncertainties of a courier. 

I'm probably over cautious on this though. I have only owned one triplet and I was able to collect that and bring it home myself from a seller whom I knew and trusted.

1 hour ago, Spile said:

Cleaning the primary mirror of the 200P is very straightforward.

The original poster has one of these:

The principles are the same as with a smaller scope but it's getting the mirrors safely in and out of the cells, especially the primary, is likely to be more challenging with the 16 inch Explore Scientific than with the 200P dob I think. When I had a 12 inch Meade the primary was held in place with a number of sticky pads on the rear as well as the mirror clips. Each pad had to be loosened and then cut away. A tricky task.

The reason that I'm wary of being able to help, apart from lacking the time, is that I don't know the ES design so my advice based on Skywatcher, Meade and more lately Orion Optics dobs might mislead rather than help.

I think the original posters best bet is to ask around forums (especially CN because there are more of these in the USA I think) to find someone who has actually removed and cleaned mirrors from an ES dob, preferably the 16 inch version, and find out from them about the process and any little quirks / issues that might be encountered and any tips to make the task easier.

I did the same with the Meade 12 inch and so at least I knew that there would be sticky pads (16 of them !) to deal with and had some tips for how to handle them before starting the task.

I agree with @Franklin - it is an EQ1 class mount.

10 minutes ago, JBadger said:

I don't understand why you felt the need to explain this to me? I didn't say 2" is inherently better than 1.25" nor did I ask to be told what eyepieces I do or don't need, thanks.

I misunderstood the 2nd paragraph of your previous post so tried to post some helpful information. 

Sorry about that.

16 minutes ago, lawsio said:

Thanks for that, makes sense! Still not a million miles out, will do me for now anyway whilst I decide what others to get!

 

If you have the 32mm plossl, that will show you the same amount of sky as the 40mm but with a more pleasing, and wider, apparent field. The exit pupil will be smaller as well so you should see a slightly darker background sky which helps pick out deep sky objects.

6 minutes ago, lawsio said:

Fair enough - that's what the AFOV is listed as online. What's a more accurate number to us?

42-43 degrees at best. As has been said, some are less.

I think the original poster here has more in mind than just the collimation of the scope. 

6 minutes ago, Ricochet said:

I think there must be something wrong with the online tool you have used. You can't get a wider true field of view from a 1.25" eyepiece than with a 32mm/50° Plossl. As a result the 40mm Plossls have a more restricted apparent field of view, about 40°. The online tool probably had the 40mm listed at 50° like the rest of the line. 

Congratulations on the new scope purchase. 

Agreed. A 40mm plossl in the 1.25 inch fitting has a max apparent field of around 43 degrees. Some are less than that.

1 minute ago, johnturley said:

I don't find the Aspheric 36 too bad in my f7 Esprit 150, but the edge quality is rather poor in my f5 Newtonian, hopefully (assuming that it arrives) the Vixen 42mm LVW will be better in both, besides giving a slightly wider field of view.

John 

That is a big exit pupil in the F/5 !

1 hour ago, Mr Spock said:

According to this http://astro-talks.ru/forum/viewtopic.php?f=32&t=1483#p41976 the aspheric has very bad image quality. The 42mm LVW does ok and the other LVWs rate as excellent image quality.

I did not think too highly of the Aspheric 36 that I had and that was in an F/12 refractor. I could still see some astigmatism towards the field edges.

2 hours ago, JBadger said:

I have the full set apart from the 2.3mm. I find them to be great considering the ~£90 price tag. I tend to use mine with my 4" mak, because focussing that instrument is pretty fiddly, and these eyepieces are pretty much parfocal so I don't have to faff with much refocussing when switching eyepieces.

Edited to add: also, for me at least, the ability to get a set of decent 1.25" eyepieces across a useful range of focal lengths for relatively little cost means I save my budget for the nicer 2" eyepieces I'm trying to assemble for my better 'scopes that accept 2" eyepieces. 

You only really need 2 inch format eyepieces for longer focal lengths and wide angles of view. 2 inch eyepieces are not inherently any better in performance than 1.25 inch ones, other than being able to offer a wider view because the wider barrel can accommodate a larger field stop diameter.

I am usually the only member of our society that brings a refractor along to outreach events (apart from the solar ones of course). I find that folks are often rather surprised at the quality and contrast of the views that my ED120 puts up even when deep sky objects are the target.

I don't envy anyone trying to show folks galaxies at an outreach event though. Apart from M31 and perhaps the M81/82 pairing, even with the larger scopes the reaction is often "well I think I can see something there ????" when showing a galaxy to someone new to scope use.

Often with these small lunar features the illumination needs to be "just right" to catch them clearly. Sometimes these windows of effective illumination only last a couple of hours.

The rille (some sections especially) that runs down the Vallis Alpes and the smaller Plato craterlets are other examples of such features.

Some Tele Vue refractors use a form of sandpaper painted matt black to line the inside the scope tubes. It seems to work pretty well.

59 minutes ago, Stu said:

 

It’s a 77mm f12 Hilkin in lovely condition, and complete with all its accessories.

Much better pics here in the ad.

I guess I’ll have to do a side by side with the FC-76DCU now 🤪🤣

Very fine looking example of a classic 3 inch refractor @Stu 😄

I'm sorry that I was not able to follow though with my offer to help with your issues but, as I explained in our PM exchange on the other forum, having reviewed the issues that concern you, I realised that my lack of knowledge of the approach that Explore Scientific have used in the design of their dobsonians was likely to prove un-helpful to you and possibly even confusing. 

You may already have seen this thread on this forum from 2014 but it is quite extensive, relates to the same scope that you have and was started by one of our experienced members. It contains a number of tips and modifications that the owner discovered were helpful as he got to know the scope and these might be of use to you as well. Good luck with the scope !

Here is a link to the thread I mention above:

If I was purchasing a triplet refractor then I would probably arrange to pick it up myself rather than trusting it to a courier, even if it had been checked prior to sending. 

7 minutes ago, RobertI said:

Interesting that transparency is not included - I would have thought poor transparency would reduce contrast in diffuse objects such as galaxies and nebulae? We could probably have a whole thread devoted to discussing that list! 

Transparency is more relevant to this thread I agree.