Dual Purpose Viewing Scope

[groberts]

Was wondering if anybody could recommend a dual purpose scope that could be used on a standard Manfrotto camera tripod for some basic astro viewing and double-up for bird watching. I'm thing a spotting scope but which one + what sort of spec do I need to lo out for?

Thanks Graham      

[michael.h.f.wilkinson]

I use my 80mm F/6 triplet as birding scope. I use a 2" Amici prism to get a correct image view through the scope, but equipped with e.g. a 22mm Nagler (or even the humble MaxVision 24mm 68 deg) it produces absolutely stunning views (22x with 3.76 deg true FOV, and 20x with 3.4 deg FOV).

[groberts]

Thanks I can imagine it is good but... I'm looking for something more portable that will easily fit on a conventional camera tripod and can easily go in the back of the car or suitcase.  Also would prefer to leave my astroimiaging WO GT81 scope set-up alone and have something separate for casual viewing.    

[ronin]

MAybe gp the other route and get something like an Opticron spotting scope that you can point at the skies. You might lose the option of swapping eyepieces, but there will need to be a bit of a compromise.

If it were to be a scope then it sounds like one of the 72mm or 66mm ED options.

Actually wasn't someone selling a WO 66 not long back? May have been snapped up.

[avtaram]

I use my 90 Mak with a WO 1.25" erecting prism diagonal with helical focuser on a photo tripod, I find it good for both astro and birding. The helical focuser is not shown in the photo.

[Ricochet]

The Celestron Regal and Pentax spotting scopes use the standard 1.25" astronomical eyepiece fitting which may be useful if you want to be able to mix and match eyepieces. However, angled spotting scopes are fixed at 45° and so for a dual purpose astro/birding scope a small refractor that can be used with a 45° erecting prism during the day and a 90° diagonal at night is probably your best bet if you want to be able to comfortably look at objects near the zenith. Personally, I went with two separate scopes: a small (65mm) spotting scope with stay on case and shoulder strap that can easily be carried for miles and an 8" dob that shows more than any small scope could.

[groberts]

Thanks all will consider the suggestions.  

Really just like looking at birds from time to time i.e. casual viewing + have what I need for the moment for 'serious' astronomy/astroimaging, so thought maybe there was a compromise + easy & quick to use general scope.  I accept this will have shortcomings for astronomy but would just like to take a squint at the odd planet etc whilst imaging is underway - like many I'm usually so consumed with the imaging process that I spend little if any time looking at the night sky!    

[Geoff_L]

Orion do an 80mm short-tube achromat that's available as a 'Terrestrial' model with a fixed dovetail that has three tripod mounting points and a 45°, correct-image diagonal. The supplied finder is correct-image also. It's a 400mm f/5. (here's a link to the product page) I have one of these and it's been a good multi-purpose tube as it's good for grab 'n go astronomy, wildlife watching and it's a good guidescope for AP. HTH, Geoff

[groberts]

Thanks Geoff, that looks interesting.  

• How does it handle on a standard camera tripod?
• What are the optics like?
• Will it take a DSLR for short exposure shots or it that too heavy?

Graham 

Edited June 27, 2017 by groberts

[iPeace]

No, it won't take a camera. But small scopes don't get much better than the TV-60. It goes everywhere and gives great views day and night. So glad I finally got one.

[Geoff_L]

3 hours ago, groberts said:

Thanks Geoff, that looks interesting.  

• How does it handle on a standard camera tripod?
• What are the optics like?
• Will it take a DSLR for short exposure shots or it that too heavy?

Graham 

How it handles depends on the tripod. I have a couple of cheapie tripods on which the 'scope has some shakes. However, it's rock steady up to 80x magnification on a photo ball head when attached to my ES Twilight 1 (see photo).

The optics are pretty good for terrestrial and for DSOs. It's a doublet achromat, so you have to expect some chromatic abberation on brighter objects, but I don't find it objectionable.

I have mounted my EOS 450D on my ST80-T both for prime focus AP and for eyepiece projection with some success. With a DSLR attached, it will be camera-end-heavy unless you attach a counterweight at the objective end or use a secondary mounting bar to move the pivot point under the focuser. With that said, I've done this with the tube mounted on the Twilight 1 or an EQ5 pro rather than a photo tripod. In other words, again it depends on the tripod.

HTH, Geoff

[groberts]

Thanks again Geoff, looks like a worthy contender at a competitive price.

[Ricochet]

I would suggest that an st80 is probably unsuitable. For birding I think you really, really need ED glass or you will end up with an image that I can only describe as "blurry". Fast achromats are also not recommended for planetary observations, which was one of the suggested night time uses. 

[Geoff_L]

No one OTA can fit all purposes - and perhaps my expectations are a little lower? I'll agree that 400mm focal length is too short for optimal planetary observation, although I can get a good view of Jupiter and the Gallilean moons through a 5mm EP. For its price, it's excellent for lunar and brighter DSOs. It has a wide enough FOV to take in the whole of the Pleiades with a 25mm EP. The attached photo of the Moon was taken a couple of days before the supermoon last November with my ST80-T and a Bresser HD Mikrokular webcam. This is 30 seconds of video stacked in Registax 6. I didn't completely nail the focus, but it does show the extent of CA with that tube.

That said, having taken a closer look at the Graham's list of equipment, I suspect that he already owns a better instrument that can be pressed into service for both birding and basic astro obs for less than the cost of an ST80. Graham's WO GT81 has a better spec than the ST80-T and has the same order of aperture and focal length. So add a tripod to dovetail adapter (ADM etc. also available) and a 45° correct-image diagonal and you have something that will fit a photo tripod and should outperform the ST80.

[michael.h.f.wilkinson]

My APM 80mm has a standard tripod adapter, and at 2.5 kg is light enough for many photo tripods, especially when you use something like a mini-giro head shown below on a wooden tripod with the APM, and on a carbon photo tripod with my Coronado SolarMax-II 60.

If you want a lightweight scope for planets and birding, this might be worth considering

http://www.teleskop-express.de/shop/product_info.php/language/en/info/p1178_Vixen-VMC-110-L---Flatfield-Maksutov---110-1035mm---optischer-Tubus-mit-Sucher.html

The bigger aperture really helps on planets

[Stu]

I would probably go for one of the 66mm ED scopes. I expect that spotting scopes might be a disappointment on astro targets, but these scopes are lightweight, not so costly and will give great views. They show credible views of planets; I have seen shadow transits and the GRS with a William Optics SD66mm on a photo tripod. Get yourself a 3 to 6 Nag zoom a 24mm Panoptic/ES 24mm and maybe something in between and you are away  

[GavStar]

17 hours ago, iPeace said:

No, it won't take a camera. But small scopes don't get much better than the TV-60. It goes everywhere and gives great views day and night. So glad I finally got one.

Off topic, but I just was wondering what finder bracket you used on the tv60 to attach the finder to the scope?

[iPeace]

15 minutes ago, Gavster said:

Off topic, but I just was wondering what finder bracket you used on the tv60 to attach the finder to the scope?

It's from my TV-85, an original TeleVue job. Mr. Nagler had the tapped holes in the dew shield conveniently drilled at exactly the same distance. Knowing him, that's no coincidence.

I did need to use a pair of rubber washers as spacers between bracket and dew shield to keep the screws from protruding too far through the dew shield, preventing smooth operation. The rubber also protects the finish on the dew shield.

The finder bracket is offered separately by TeleVue.

http://agenaastro.com/televue-quick-release-finder-base-qrb-1002.html

[ollypenrice]

My feeling is that erecting prisms do very little damage to the terrestrial view but are a bit of a disaster in astronomy.  When I was trying to learn my way around the moon (an obsession which has since deserted me!) I tried using an erecting prism in my TeleVue Genesis. The image degredation was awful. I really didn't want it to be so and tried a better prism. It was still awful. But, by day, I could see no difference between prism and star diagonal in terms of image quality.

So I'd be looking at a prism-free astro scope with star diagonal for the night and an erecting prism to use it for birding. I suspect, but don't know, that the classy birding scopes have a considerable part of their budget devoted to the prism. Stars are terribly uncompromising testers of optics. Look at great terrestrial camera lenses which fall on their faces when asked to image stars...

Olly

Edited June 28, 2017 by ollypenrice

[michael.h.f.wilkinson]

37 minutes ago, ollypenrice said:

My feeling is that erecting prisms do very little damage to the terrestrial view but are a bit of a disaster in astronomy.  When I was trying to learn my way around the moon (an obsession which has since deserted me!) I tried using an erecting prism in my TeleVue Genesis. The image degredation was awful. I really didn't want it to be so and tried a better prism. It was still awful. But, by day, I could see no difference between prism and star diagonal in terms of image quality.

So I'd be looking at a prism-free astro scope with star diagonal for the night and an erecting prism to use it for birding. I suspect, but don't know, that the classy birding scopes have a considerable part of their budget devoted to the prism. Stars are terribly uncompromising testers of optics. Look at great terrestrial camera lenses which fall on their faces when asked to image stars...

Olly

Much depends on magnificantion. I actually use my 2" erecting prism on the night sky at low magnification and it is fine. Only at higher (planetary and lunar) magnifications does it fall apart (but slightly). The out of focus image looks seriously WEIRD, but I never spend much time admiring that . I actually find the correct image view using the Nagler 31T5 "Panzerfaust" and the 22T4 really great in the 80mm. Scanning the Milky Way using the mini-giro mount on either the wooden or the carbon tripod is a real joy. For planets, I would not recommend using an erecting prism

 

[ollypenrice]

1 minute ago, michael.h.f.wilkinson said:

Much depends on magnificantion. I actually use my 2" erecting prism on the night sky at low magnification and it is fine. Only at higher (planetary and lunar) magnifications does it fall apart (but slightly). The out of focus image looks seriously WEIRD, but I never spend much time admiring that . I actually find the correct image view using the Nagler 31T5 "Panzerfaust" and the 22T4 really great in the 80mm. Scanning the Milky Way using the mini-giro mount on either the wooden or the carbon tripod is a real joy. For planets, I would not recommend using an erecting prism

 

It was on the moon that I tried and rejected the prism, so I guess we are in agreement. Do you find the Naglers OK by day? I find that the 13 Ethos gives a very significant yellow fringe around the outside of the field by day, the 26 Nagler also, but less so. I wouldn't use either by day, personally. I'm trying to think which scopes I've tried them in but I think it's in several. By day you're not really chasing a wide FOV anyway so I don't think this matters much.

Olly

[Alien 13]

I have realy tried to get on with astro scopes for viewing but the OCD part of me has to have the image the correct way round, I know correct image prisms can be made to work but at a price but would rather have inferior performance than have my brain scrambled with a star diagonal. The Celestron 90 mak I have does however do a good job on both types of subjects with the correct image diagonal and a reasonable 32 mm plossi as standard.

Alan

[michael.h.f.wilkinson]

3 minutes ago, ollypenrice said:

It was on the moon that I tried and rejected the prism, so I guess we are in agreement. Do you find the Naglers OK by day? I find that the 13 Ethos gives a very significant yellow fringe around the outside of the field by day, the 26 Nagler also, but less so. I wouldn't use either by day, personally. I'm trying to think which scopes I've tried them in but I think it's in several. By day you're not really chasing a wide FOV anyway so I don't think this matters much.

Olly

The 31T5 shows the "ring of fire" , but the 22T4 is absolutely superb. The huge FOV is a nice bonus

[ollypenrice]

10 hours ago, michael.h.f.wilkinson said:

The 31T5 shows the "ring of fire" , but the 22T4 is absolutely superb. The huge FOV is a nice bonus

I hadn't come across the 'ring of fire' epithet but I presume it's been discussed since it has this name?

Olly

[michael.h.f.wilkinson]

31 minutes ago, ollypenrice said:

I hadn't come across the 'ring of fire' epithet but I presume it's been discussed since it has this name?

Olly

That's what they call it on CN. Seems appropriate