johnturley

2 minutes ago, John said:

The TAL Apolar 125 used no exotic glass amongst it's 5 elements as far as I know. While the scope had some other issues, the colour correction achieved was really good.

Interesting that we are seeing some new large aperture refractors using lots of FPL-53 glass. Not so long ago it was rumoured that it was going out of production. Obviously Ohara decided to do some more melts of it

 

I think that TEC stated that one reason why they switched to Fluorite in their APO Refractors, was due to shortage of FPL53 glass.

John 

On 26/11/2019 at 14:51, Davey-T said:

https://www.teleskop-express.de/shop/product_info.php/info/p11814_TS-Optics-140-mm-f-6-5-Super-Triplet-Apo-mit-2-ED-Elementen.html

Or the version in English

https://www.teleskop-express.de/shop/product_info.php/info/p11814_TS-Optics-140-mm-f-6-5-Super-Triplet-Apo-with-2-ED-elements.html

I noticed that they also have the 152mm f8 on special offer at 3,395 EUR 

https://www.teleskop-express.de/shop/product_info.php/info/p10776_TS-Optics-PHOTOLINE-152-mm-f-8-Triplet-APO---3-7--RPA-focuser.html

John 

P.S. They were in English, but appear now to have switched to German for some reason.

P.P.S. You just have to click on the Union Jack icon top right hand, to get it to change back to English.

31 minutes ago, Dinglem said:

@FLO am I missing something to do with taxes but why are the prices in the USA the same in dollars as the pound over here? Or has sterling fallen that much 🤔

Not always, if you look at most Skywatcher prices you will find that they are actually cheaper in the UK, also be aware quoted prices in the USA do not usually include local sales tax, whereas UK prices usually include VAT @ 20%.

John 

52 minutes ago, JOC said:

I've got a reflector, but I am not confident enough of it's construction materials to want to whack concentrated sunlight about inside it.  At least when you cover the end of an OTA with Baader solar film you know you got it all locked out the correct side of your optics

I thought that Hershel Wedges were NEVER recommended for reflectors due to the concentration of heat on the secondary mirror.

John 

I purchased one recently as a quick 'grab and go' mount for my ES 127 Refractor and quite pleased with it, reasonably portable, although a bit fiddly going through all the settings when all you want to do is place it roughly in a north-south direction and switch on the motor drive. For what I wanted the HEQ5 mount would probably have been just as good, but it didn't cost much more than the version of that with a Rowan Belt modification, and worth having the added flexibility of the AZ function, and also being able to mount 2 scopes on it in AZ mode. 

For further details see my posting on 'AZEQ5 First Impressions' dated 31 October under the Equipment-Discussions-Mounts heading

John 

I have a pair of the Vixen ones, but the Omegon ones appear almost identical, maybe made by the same manufacturer, and I'm quite pleased with them, they enable you to view whole constellations, and see stars a couple of magnitudes fainter the can be seen with the naked eye.

John 

22 minutes ago, John said:

I agree that the Nagler T4 22mm would also be a good option to consider.

It might make the Baader Aspheric 31 look a little "ordinary" though

Do be aware that the Nagler T4 22mm is a fairly heavy eyepiece, about twice the weight of 17 mm Morpheus,  quite a bit heavier than the Baader Aspheric 31 mm, and may require rebalancing of your scope.

On 20/11/2019 at 20:09, JamesF said:

And perhaps not by coincidence, an 11m Type 6 has just popped up on AB&S!

James

That is just typical, likewise just after I ordered and paid for my Esprit 150 a second-hand came up, especially as I hadn't seen a second hand one advertised for several months previously.

One reason I bought the11mm Type 6 when I did was that, apart from the Tele Vue sale, it looked as if it might the last new one available with them being discontinued, and second hand ones could become as rare as great auks and pricey.

John 

24 minutes ago, Rob Sellent said:

Re: Solar viewing & Petzval fracs....(@Hallingskies)

I also find it quite confusing.

On the one hand, it's acknowledged from experienced observers on sites like Solar Chat, SGL and Cloudy Nights that using Petzval fracs and a wedge is fine. On the other hand, we get warnings from the wedge manufactures like Baader and Lunt categorically stating that they're not suitable for such scopes.

Similar kind of thing happens with Quark's solar eyepieces. Quark makes no mention but again, experienced observers argue that either a) it makes no difference, b) it only becomes a concern if you're tracking for a long time, c) they canot be used in oil-spaced Petzval's d) but can be used in air spaced Petzval's.

Icing for proverbial cake comes in the form of using Fluorite fracs for white light. Again, experienced observers argue that either a) it makes no difference, b) the risk of cracking a €2.5 - 6k scope is just not worth even contemplating, and c) thermal expansion, fracturing and shock of the lens is augmented in Fluorite.

In my own case solar viewing is important. I'm not out everyday but I reckon we get an average of around 300 clear days a year. For white light I finally settled on a portable TV-76 + Wedge. A Lunt 60mm for H-alpha (ease of use, no cables, no faff) and a fluorite strictly for those delicate and tender photons of the night .   

I think that's a very sensible approach, I recently purchased an Es Reid tested Esprit 150, and I asked Es (who incidentally does quite a bit of solar observing, but with a dedicated solar scope) about using A Quark solar eyepiece with the scope, and his opinion was that he wouldn't risk it.

As Rob suggested, a Hershell Wedge probably ok with refractors up to 80-100 mm, for larger sizes  a full aperture solar filter such as the Baader or Seymour is a safer option, or best of all a dedicated solar scope. 

John 

Would you be able to use H alpha filter such as the one below in conjunction with the Hershel Wedge to view further details of the chromosphere, and possibly also prominences

https://www.firstlightoptics.com/narrowband/baader-ultra-narrowband-35nm-h-alpha-filter.html

John 

The 11mm NT6 Eyepiece arrived today, so I must have got one of the last ones available.

The box was very plain and basic compared to those supplied with ES eyepieces, but obviously its what's in the box that counts, also surprisingly a little more compact and lighter than the ES equivalent. 

John 

Have ordered an 11mm Type 6 Nagler from Telescope House while Tele Vue eyepieces are on special offer and the 11mm is still available. I was advised by another retailer that Tele Vue had discontinued production of this eyepiece, and was initially a bit surprised by this, but subsequently found that its no longer listed on Tele Vue's website, hence wondered whether this has anything to do with the production of their limited edition 11mm Apollo eyepiece. 

I will find it interesting comparing this eyepiece with my existing 11m ES 82 degree eyepiece, and establishing whether the Nagler is significantly superior, if I find a major difference I may gradually replace my ES 82's by Type 6 Naglers.

John 

16 hours ago, Mr Spock said:

Yes, lot's of lovely refractors  Quite a few stunning 150mm apos I'd like to take home, and, an interesting ES 165mm apo... 

The ES 165 never seems to get mentioned anywhere, not seen a review.

At the normal price of £8,900 (Telescope House currently have it on special offer) it is more than twice that of the Esprit 150 and some other 6in APO's, that's a lot to pay for an extra 13-15mm of aperture, although it does now appear to include a Feathertouch focuser as standard, and quite a bit cheaper than a TEC or CFF 160. 

John

54 minutes ago, Ouroboros said:

Well, I can only report what I've found. If the scope is loose enough to rotate then it's loose enough to slip in the rings. 

That's the whole point about the slip band, it prevents the tube slipping down in the rings when you rotate the tube.

John 

4 hours ago, Ouroboros said:

@woodblock It's one reason that I enjoy using my refractor. The eyepeice is always accessible and can b rotated to a more comfortable position if necessary. 

I've never done this but I know that some people buy and modify another ring which sits tightly around the scope tube but isn't connected to the mount. This third ring then rests back on one the 'proper' scope rings. The scope can then be rotated within the lossened scope rings without sliding out of the rings. I hope that makes sense. 

Someone might have a photo of such an arrangement. 

In the 1970's Fullerscopes used to sell dedicated slip bands for their Newtonian Reflectors at a relatively modest extra cost, so that the telescope tube could be rotated without having to loosen the tube clamps and affecting the balance, and I purchased one to go with the 10 in Newtonian I had at the time, and found that it worked quite well. Few (if any) suppliers appear to offer them nowadays.

John

16 minutes ago, Philip R said:

At least I can honestly say, to date, I have visually viewed two Transits of Mercury and one of Venus.

Me too

John

Glimpsed Mercury on the solar disc briefly at 12.45 during a break in the clouds and the rain showers, was clouded out at the time of the ingress at 12.35, and by 13.00 it had clouded over again and started to rain.

John 

I think you will find that the Explore Scientific 40mm 62 degree eyepiece has a 2in barrel, it is not possible to get a 62 degree field with a 40 mm eyepiece and a 1.25 in barrel.

John 

54 minutes ago, alacant said:

Thanks. We're planning for the Mercury transit on Monday...

Alicante is 1 hour ahead of London, so Alicante is UT? IOW the times I see as UT on the transit diagrams e.g. this one, are Alicante local time?

Sorry, plain English to the rescue. I'm being yelled at in several different languages!

London is currently on GMT (or UT), Summer Time or Daylight Saving Time having finished on 27 October, so Alicante is 1 hour ahead of UT, when on Daylight Saving Time, Alicante would be 2 hours ahead of UT. 

17 minutes ago, Mark at Beaufort said:

Here you are Dave - https://en.wikipedia.org/wiki/Black_drop_effect

I saw no sign of the Black Drop effect at the 2004 Transit of Venus, originally it was thought to be caused by the atmosphere of Venus, but I thought that it had now been put down to an optical illusion.

John

On 03/11/2019 at 23:50, rml63 said:

I have been struggling with what mount to get.  I have to say the AZ EQ5 has been on my list, I read a great deal about “slop” in the dec axis both here and other boards.  I have also looked at the AZ EQ6 which looks like a good mount but as was mentioned it is not as portable as the 5.

I have looked at the Vixen SXD2 and the SXP2 , the SB 10 controller looks great, but it is strictly and EQ mount.  I have heard great things about Vixen’s quality and ease of use right out of the box.  My question is would I be missing out on alot of quick viewing sessions with strictly an eq mount?

 

I am assuming that the advantage of AZ mode is quick setup when you just want a quick view or do some EAA?

 

Mike

Hi Mike

I haven't noticed any slop in the dec axis, the dec motor appears to operate quite smoothly, but then I haven't used it at high magnification. I would imagine the Vixen mounts you refer to are a cut above the Skywatcher ones,  as looking at the specs they utilise brass worm gear with 180 tooth RA and Dec wheels, but then cost considerably more (note: for comparison my 14in Astro Systems Newtonian has a 720 tooth brass RA wheel, and a 360 tooth Dec wheel, but predates any GOTO system)

Regarding the weight issue, the AQ-EQ5 mount head weighs 7.7kg, I have 2 x 3.5kg of counterweights, and the tripod 5.6kg, making a total weight of around 20kg, which I'm reasonably comfortable about moving around, but with the scope on the mount this brings the total weight to nearly 30kg, which I find difficult to move and anyway best avoided in case of accidents, so I move them separately. In the case of the EQ6-R and the AZ-EQ6 the mount heads weigh around 16kg, and the heavier tripod 7.5kg, so the total weight with counterweights would be over 30kg. So with this set up I would probably have had to remove (and subsequently replace) the counterweights from the mount to move it, adding to the set up time. Of course someone younger and fitter than me would probably have no problem in carrying this, I remember in the 1970's, when I was in my 20's, I used to have a Fullerscopes 10in Newtonian with fiberglass tube (wonder why this material is no longer used, I suppose that it has been replaced by carbon fibre) on their Mk 3 equatorial mount with pillar stand. I used to carry the mount and OTA out separately, I guess that even with the fiberglass tube the OTA must have weighed at least 15kg, and the mount and pillar stand with counterweights at least 30 kg. 

I was looking at the sun again yesterday, and after possibly improving the north-south alignment, the sun at medium power was staying in the field of view for 10-15 minutes (which I as good as my Celestron CPC achieves using solar system align), and will probably be better still if I can set the angle of dec axis more accurately using a polarscope. So I am thinking along the lines that for quick grab and go, I did not really need the dual equatorial/altazimuth facility, although I've not yet tried the daytime quick alignment method in altazimuth mode to see how it compares, and anyway as mentioned there was only a £40 difference in price between the AZ-EQ5 and the HEQ5 with the Rowan Belt modification. 

One slightly annoying thing in set up is that although the mount memorises my latitude, longitude, and time zone, it does not memorise the time, and you have to enter it every time you switch it on, presumably because it has no built in clock, and unlike the system on the Celestron CPC, does not obtain the time from a GPS signal, I gather GPS module is an optional extra on this mount. 

John 

1 hour ago, Miguel1983 said:

Don’t know exactly wat the extension tube is for, I probably won’t need it.
It has a male M48 tread so i guess its for getting a DSLR into focus wen you don’t use the field flattener.

This was also included with my Esprit 150, but no mention in the manual as to what it was for, I guess you are right, or to use the scope visually without a star diagonal.

John 

1 hour ago, Miguel1983 said:

Also got a Baader Click Lock for in case of visual use

Is that the Baader 2in ClickLock M74i, available from FLO, which should also fit my Esprit 150

John

Picked up the mount from Rother Valley Optics on Saturday, and had it up and running on the sun (with a Seymour Solar Filter) for the first time today. The mount was purchased to provide a portable mount for my Explore Scientific 127 Refractor, which used to be mounted piggyback on my 14in fork mounted Newtonian (but has recently been replaced by a Skywatcher Esprit 150), and enables me to move the scope to view parts of the sky which are blocked off by trees from my observatory shed, and will be invaluable for upcoming transit of Mercury.

I was initially a bit torn between the HEQ5 and the AZ-EQ5, but a couple of contributors on another thread suggested that for quick grab and go, the latter would be the better choice, plus it cost only £40 more than the HEQ5 with the Rowan Belt modification. Price however was not the deciding factor, I could have afforded the larger EQ6-R or AZ-EQ6, but thought that these would have been much less portable, and my experience with the AZ-EQ5 suggests that this is indeed the case.

Although some have suggested that for quick grab and go it would be better to set up the scope in AZ mode, I have for now set it up in EQ mode, but after setting the angle of the RA axis to 53 degrees (my latitude), I have so far skipped the alignment procedures, and gone straight into ‘Easy Tracking’ (Solar Rate). After pointing the scope and mount in a rough north-south direction, I found that using a medium power eyepieces the sun would remain in the field of view for some 5-10 minutes, similar to what I used to get with my 1970’s Fullerscopes Mk3 equatorial on which I mounted a 10in Newtonian, and for which there was no means of accurate alignment. The rough alignment I have done so far could be substantially improved by setting the angle of the RA axis more accurately by purchasing the optional Polarscope (someone suggested that the angle scale on the mount may be 5 degrees out), and marking out the north- south direction more accurately utilising the shadow of a pole at local midday. The drives appear smooth and quiet in operation, unlike I gather the unmodified versions of the HEQ5. 

As can be seen from the attached photo, I needed to utilise the counterweight bar extension tube to balance the scope with the included 2 x 3.5 kg weights, I could probably dispense with using this if I was to purchase a single 5 kg weight, to replace one of the 3.5 kg weights, but would make the mount that bit heavier to carry, and it is currently no lightweight to carry with the 2 x 3.5 kg weights. The stated capacity of the AZ-EQ5 mount is 15 kg for visual, but I consider that using it with the ES 127, which weighs around 8.5 kg with accessories, including star diagonal and finder, it is near its comfortable capacity, and an additional 8 kg of balance weights would make it heavy for me to carry even after removing the scope.

As can also be seen from the photo, when used with a refractor the eyepiece can end up quite low down, so ideally I may need to consider the optional 16in extension tube to lift the mount higher up, however this would make it somewhat heavier and less portable. Incidentally this was the first time in over 30 years that I have used a telescope on a German rather than a fork equatorial mount, and I forgot how awkward a position the eyepiece can end up in with the former, so the rotatable focuser on the ES scope is invaluable, when mounted piggyback on my fork mounted reflector this was largely redundant.  

What mount are you using with the scope.

John