johnturley

8 minutes ago, JeremyS said:

Thanks @Rob. I didn't know there was a 26 mm Nagler. It's not on FLO's website.

I think that its been discontinued now, just the 22mm and 31mm in the +20mm range.

I have the ES 82 24mm eyepiece, its quite a nice eyepiece, but quite big and heavy at about 800g, as is also the 22mm Nagler.

Because of the weight issue (my 14in Newtonian, on which my Esprit 150 is piggybacked, is quite balance sensitive), and the convenience of being 1.25in, I now tend to use my 24mm Panoptic more than my ES 82 despite the smaller FOV. 

Although I've not had the chance to compare them, I would imagine the 22mm Nagler will have the edge in performance over 24mm ES 82, as the T6 Naglers do over the 1.25in ES 82 degree eyepieces, but at about twice the price.

John 

18 hours ago, x6gas said:

For single shot images and only 30s exposures these are incredible!  Just shows what a light bucket you have on your hands!  I'd really encourage you to take multiple exposures and start stacking.  Deep Sky Stacker is all you need to get you started and it's free.  PixInsight is excellent and very capable but with capability comes complexity and the greatest bump you'll get right now is taking multiple images and stacking them.

By the way, it's definitely worth capturing your frames as RAW files - it will allow you to get the absolute most out of your data as you progress.  JPEG uses compression and you lose hard won information so best avoided for processing.

Excellent stuff, though.  Well done.

Hi x6gas

Thanks for your comments

I've tried longer exposures (1-2 minutes), but found a big increase in background brightness (probably due to light pollution), and also showed imperfections in the tracking. So I think that 30 seconds (which is incidentally the longest manual exposure setting with my Canon 6D) is just about on limit for an unguided shot with my current set up. The mount is a massage fork equatorial, in appearance not totally dissimilar to the Paramount Taurus (which sells for £25,000 +, and I paid just under£3,000 for the whole set up in 1984), but the drive system is very much based on 1980's technology being a 1/2 rev per minute mains synchronous motor via a 12in diameter 720 brass (not aluminium as on the Taurus) worm wheel. This requires a variable frequency oscillator to change the mains frequency from 50 to 50.14 hz, and the mains frequency varies slightly. I used to have a frequency meter so I could adjust the frequency to exactly 50.14 hz , but this no longer works (I keep meaning to try to get it repaired). In addition I moved the observatory shed and telescope 2 years and may not have realigned the mount exactly since then, and the only way of checking this is manually by trial and error based on drifting of star images (no polar scope or PEC available). I may also have loaded it a quite heavily mounting the Esprit 150 piggyback and with 15kg of counterweights, but its fine for visual (a planet at 200x will stay in the field of view for over an hour). Visual observation of the moon and planets is my main interest, and I only occasionally delve into deep sky imaging.

I will however have a look at Deep Sky Stacker, maybe it will also help with planetary imaging, although to be honest I'm never likely to be into spending hours stacking and processing images. My Canon 6D also has RAW + JPEG modes so that I can check the images and delete poor ones, rather than waste time loading them into Adobe Lightroom before I can view them (I cannot view the unprocessed CR2 files with my PC). 

John 

On 12/03/2020 at 03:49, JeremyS said:

Me too. Especially as new scope ordered for it. But maybe it won't progress. Or maybe it's over by opposition.

Anyway, keep an eye on the BAA Mars Section blog. Richard McKim is an expert in Martian dust storms, so his thoughts will be interesting to follow. 

Me too, the upcoming opposition of Mars was one of the main reasons for getting my Esprit 150

John 

2 hours ago, Littleguy80 said:

Good seeing today. Granulation looking as good as I’ve seen it. The spot has developed since yesterday. One larger spot with a smaller spot next to it and then another pair of smaller spots nearby. Well worth a look!

Didn't see anything when I looked yesterday, now overcast and looking like rain.

John 

Thanks for all the likes regarding the above.

I have also attached a shot of M51, which I took with the same settings.

I know that it does not compare with most of the images of this that have been posted on SGL, but as I stated before it was not taken with a specialised astrophotography camera, and did not involve multiple imaging, stacking, and hours of processing, just a few minutes enhancing the image and darkening the background in Adobe Lightroom. Don't know whether I would to better with more specialised astrophotography software such as Pixinsight, in addition I have taken images in both JPEG and RAW format, but the latter did not appear to offer any particular advantage, and took up a lot more megabytes on the SD card and computer hard drive. 

Interestingly I got out an old astrophotography book from the 1980's, the Cambridge Deep-Sky Album by Jack Newton and Philip Teece, and my images do appear better than what could be achieved at the time using cooled emulsion film cameras, and amateur telescopes. 

John 

My first attempt at the above through my f5 14in Newtonian, just a 30sec exposure with my Canon 6D at ISO 1600, and just a few minutes processing in Adobe Lightroom.

Fairly basic, but did not involve multiple imaging, stacking, and hours of processing.

In addition (although I do have one), I did not use a coma corrector, and the stars at the edge of the field do not appear to show a massive amount of coma.

John 

17 hours ago, John said:

The only one that I know of is Steve Collingwood:

https://sctelescopes.com/sc-telescopes-broadhurst-clarkson-and-fuller-fullerscopes/

 

I don't think that Steve offers this service any more. 

You could try Rother Valley Optics, I know that they offer a collimation service, not sure about cleaning.

John 

1 hour ago, Star101 said:

https://www.rothervalleyoptics.co.uk/celestron-edgehd-1100-optical-tube-assembly.html

https://www.rothervalleyoptics.co.uk/takahashi-toa-150b-f73-triplet-ortho-apochromat-refractor-ota-package.html

I did agree with the images but then, on checking the scopes, the prices don't compare.

I am looking at something of value between the two. 

According to Es Reid the performance of the Esprit 150 comes very close to or even equals that of the TOA 150, but costs about one third of the price, and is only slightly more than the C11 Edge HD OTA.

Es had the chance to compare my Esprit with a second hand TAK FS 152 at the same time, and thought that there was very little difference between them. 

If you wanted to stick with a high end refractor you could go for either the TAK TOA 130, or the TEC 140, both around £7k

John 

18 hours ago, kirkster501 said:

Quality refractors on a Mesu mount.  I'm not sure there is anything to beat that combination. 

I have observed The Moon through my TEC140 many times. Sure it may "only" be a 5.25 inch aperture.  But it is spectacular.  The Starfire will be even better.  It will be fabulous on imaging as well.

Why would you assume that the Starfire 130 would be superior to the TEC 140

John 

I get the same problem with the focuser on my Esprit 150, and on the later models like mine they replaced the variable tension knob with a simple locking leaver. 

John 

Attached is the best of several shots I took of Venus that evening.

1/40th second at ISO800 with my Cannon 6D, using eyepiece projection with a Meade 12.4 mm Plossl through my 14in Newtonian, and processed using Adobe Lightroom.  

John

It looks like your mount has stainless steel shafts, the original Mark III (which I once had), and I'm pretty sure the original Mark IV also, had mild steel shafts making them prone to rusting.

John 

I always find the term 'Back  Focus' a bit confusing, and is frequently used when what people actually men 'In Travel' on the focuser.

At first glance some people (like me) might think that it means the amount you can rack out the focuser by, i.e.  distance of travel on the focusing mount, but I think it means something completely different. What I actually think it means is the amount the focuser can be racked in from the focal position. For example most Explore Scientific Refractors state in their specification 150mm Back Focus, and yet only have a miserly 45mm of travel on their focusing mounts, and come with two 40mm extension tubes, yet to reach focus with most eyepieces without a star diagonal you still need a further extension tube of about 50mm, as a simple eyepiece (not one with a built in barlow lens) will come to focus at a distance further out from the focal point equal to the focal length of the eyepiece. Incidentally back in the 1980's most refractors had focusing mounts with travel distances of  around 125-150mm, but now the average is around just 80mm, or even less in the case of ES Refractors. 

Personally I would find it less confusing if the words 'In Travel' and 'Out Travel' were used instead, I think Back Focus is used to determine whether accessories such as binoviewers, can be successfully fitted.

John 

Hi Owen

Thanks for your reply,

Es Reid also contacted me this morning with much the same infoirmation, very sad news, I assume that it must have been a one man business.

John

On 26/02/2020 at 17:44, CraigT82 said:

Hi John,  I dont really know what the bubble level is for... it's pretty useless!

 

I notice looking at the photos, neither of the vastly more expensive Gutekunst versions have a spirit level, so maybe its just for show.

www.gutekunst-optiksysteme.com/

John 

On 16/02/2020 at 11:44, John said:

I'm interested in one of these (the £124 type rather than the £3K type !) for use with my 130mm triplet refractor. Does it eat up any focuser travel ?

Thanks

 

John

I can now give you more precise figures for the above.

I found that using a Tele Vue In Travel adaptor in my 2in focuser an extra 45mm of in travel was required, it would be similar if you added a T thread to 2in nosepiece to the ADC (a slightly cheaper option).

If used with the included 1.25 in nosepiece, it would depend on the light path of your 2in to 1.25in adaptor, the figure would be about 53mm in the case of a typical 8mm light path adaptor.

John 

20 minutes ago, CraigT82 said:

You may have already seen this page... but it has some good info on how to position your ADC in the focuser

http://skyinspector.co.uk/atm-dispersion-corrector--adc

Basically, the null point (levers together) needs to be parallel with the horizon. 

With your aperture and the low altitudes of the giants this year, I think that maximum correction would be a good place to start (levers 180 degrees opposed).

Remember that the image shifts when tuning the levers, so small adjustments are best 

Hi Craig

Thanks for the information

I had been assuming that with the telescope in a horizontal position, then the ZWO ADC should be rotated in the focuser such that spirit level is at the bottom, and indicating level, but according to this article it appears not to be the case, I can actually get to the horizon when due south.

Cheers

John 

Took the plunge and ordered a ZWO ADC from FLO Monday afternoon, and to my surprise arrived Tuesday lunchtime (well done FLO). Originally I did not plan to order one until early summer, in time for the oppositions of Jupiter and Saturn in July when they are low down again, and therefore when the ADC might help most, but was worried that the Coronavirus outbreak might disrupt supplies of goods from China, so decided to order one while FLO still had it in stock.

I haven't really had the chance to try it out properly yet, although used it briefly on Venus this afternoon between the showers. Like John I was worried as to whether there would be sufficient in travel on the focuser with my 14in Newtonian, as according to FLO it requires an extra 56mm of in travel, however by fitting a Tele Vue 'In Travel' adaptor (which in effects converts the barrel to 2in, and avoids the light patch of the 2in to 1.25 adaptor (typically 8mm), I found it required just 45mm of in travel, which I now have since moving my focus mount about 10mm towards the main mirror.

No instructions came with it, although I had previously downloaded a manual from the ZWO website, these however describe setting it up by attaching a camera to the ADC and running the camera through Firecapture or Sharpcap (which I haven't got). Furthermore to attach a camera would require fitting a female to male 'T' thread adaptor to the ADC before attaching the camera, and substantially increasing the light path further, such that I wouldn't be able to reach focus.

I think that I'll just use a bit of trial and error when using it on planets, I only intend to use it visually and not for imaging.

Further to my original post, a new thread has now been set up on Cloudy Nights, extolling the virtues of the Gutekunst version which costs more than 50 times as much as the ZWO. 

John 

1 minute ago, astro mick said:

Hi I had a mirror recoated by this company last year.

Try them.

Mick.

https://www.galvoptics.co.uk/optical-services/

Hi Mick

Thanks for your reply, however I'm pretty certain that they just do aluminising not refiguring, unlike Oldham and Nichol Optical they don't make telescope mirrors.

John 

Does anyone know what has happened to the above company based in Scarborough, I was recommended to them for honest testing, and if recommended refiguring the mirror of my 14in Newtonian.

I spoke to the owner Norman Oldham only last autumn, when I provisionally arranged with him to bring my mirror over for testing this spring, if refiguring was recommended I wanted it carried out in time for the favourable opposition of Mars this autumn. However when I rang their number yesterday (01723 375271) I got number unobtainable, and in addition their website appeared to have been taken down. I also sent an email, to which I have not received a reply.

If they are no longer in business does anyone know of someone else they can recommend, I far as I am aware, the only other company that carries out this type of work is Orion Optics UK, based in Newcastle under Lyne, but I have received mixed reports about them.

John Turley 

52 minutes ago, Cosmic Geoff said:

You should not worry about it too much as the setting circles are essentially ornamental. Even if you could use them expertly, they are only adequate for aiming a very low powered widefield telescope. In the days before GoTo, workable setting circles were at least six inches in diameter, and I have seen circles of two feet diameter in Victorian observatories.

My 14in Newtonian, which was made by Astro Systems (Luton) in the 1980's, has a driven RA circle 12in in diameter, and which is marked out every 4 minutes, but I can estimate to the nearest minute (0.25 degree). When the RA motor is turned on the setting circle moves with the pointer, so the pointer points to the same mark unless the telescope is moved manually. A lot of mounts from that era with synchronous motor drives however, did  not have driven RA circles, so that the circle did not move with the pointer.

I still rely on a sidereal clock (now available as a mobile phone app), coupled with the meridian point on the setting circle (which is set to sidereal time), for finding objects not visible to the naked eye, and probably remains the best method for finding Mercury and Venus in daylight.

John 

1 hour ago, vlaiv said:

 

I've read once that someone found that lead that connects RA and DEC axis to be awkward. This one:

 

 

I'm currently awaiting a replacement lead from Skywatcher via Rother Valley Optics, the original one was slightly frayed, and I now suspect that was the reason as to why to low voltage flashing light was coming on after less than one hour of use. 

I have used the mount for visual use several times since without the above lead attached, and it will now run for several hours before the light comes on, only snag with this is that you have no dec slow motion.

John

56 minutes ago, R.frankish said:

Just wondering why my new eyepiece doesn't have a clear view it's like the telescope doesn't zoom out enough or is it because I am looking at something to close I was trying it out looking at a bird in a tree 

The ES 82'2 do focus a bit further out than some other eyepieces, such as the Baader Morpheus range, but the Tele Vue Nagler T6's are even worse in that respect , focusing some 3-4mm further out still, you may find that you need an extension tube (probably just 35mm), the Revelation range are quite good and modestly priced

John 

31 minutes ago, John said:

I'm interested in one of these (the £124 type rather than the £3K type !) for use with my 130mm triplet refractor. Does it eat up any focuser travel ?

Thanks

 

I've put this question to FLO as I only have a limited amount on in travel on my 14in Newtonian, which was one reason I had to sell my 2in Filter Wheel, although I've now increased the amount of available in travel by moving the focusing mount slightly closer to the main mirror, and utilising a Baader 37mm Click Lock extension for normal viewing with an eyepiece.

John 

Does anybody use one of these for visual observation of planets, if so how useful and effective are they, ZWO do a reasonably priced version which I had some thoughts of getting, and which is available from First Light Optics:-

https://www.firstlightoptics.com/zwo-accessories/zwo-125-atmospheric-dispersion-corrector-adc.html

However there have been a number of posts on Cloudy Nights connected with the thread on the TEC 200 Refractor, extolling the virtues of two products manufactured by Gutekunst 

http://www.gutekunst-optiksysteme.com/

and suggesting that the much more modestly priced ZWO version was of limited benefit in comparison, however I have no intention of paying 7,250 Euros + VAT for the ADC Professional, or 3,500 Euros + VAT for the ADC Compact, the former in particular costing far more than the main scope of the vast majority of SGL members.

Maybe if one can afford £31,000 for a TEC200 then one can afford one of these. 

John