7 replies to this topic

[Nate1701]

Last night I used my (new to me) AZ GTi, and boy-o-boy was it a lot of fun.

I was out from 10pm to midnight in -25C ( -13F) trying to get a shot of the comet.

It was so cold everything was more difficult - but still had a great time mostly due to ease of setup for AZ GTi.

I have the WO high latitude wedge / counter weight bar etc. but i couldn't bear the thought of tinkering with EQ alignment - thus I just had the AZ GTi mounted and ready in Alt-Az.

 

I wanted light weight to make the job easier; and mounted an ST80 ( SW version). I have a GT81 ( far far better color but much heavier) but did not want to Balance it - one less thing to do!

I knew the penalty for convenience is CA but i was willing to accept that. And Below is the result....  Canon 60D @ISO 1600  10Sec subs X 15 shots ( that was all i could get out of my camera batteries)

Processed in Siril and GIMP

 

Afterward i hopped around all kinds of clusters and aterisms and the internal battery pack of the AZ-GTi was doing just fine. So i got some nice visual in too.

 

So here's the thing - I LOVED the light weight of the ST80. AZ-GTi seemed to handle it like a piece of cake. And i LOVED the convenience of shooting in Alt-Az mode without balancing.

So now I'm shopping for a perfect refractor that will get me enough aperture for short exposures but still light enough to not worry about balancing, or not as much worry anyway.

 

Any thoughts? Or experiences?

Obviously a Redcat is plenty under the weight limit but.... meh, I'm not really keen on 50mm.

There is a AT65EDQ for sale on astrobuysell.... might be more in the zone I'm looking for.

Ya, thinking in the 60mm to 70mm class since anything 80mm will probably be too heavy. Or 80mm might work... but not that great.

 

Edited by Nate1701, 04 February 2023 - 07:58 PM.

[Nate1701]

Because of above i started weighing some of my refractors.

The "Spec" is the specified weight online.

My ST80-Custom is the blue Meade  outfitted with TS_Optics 2" Crayford, rings, longer dovetail, and homemade handle.

 

Here are my notes and some pics for splash of color:

 

ST80 1.36 kg ( 3 lbs) measured

ST80-Custom 2.33 kg ( 5lb 2oz) measured

GT81 3.85 kg (8.5 lbs) measured

GT81 outfitted w/Camera 5.3 kg ( 11.5 lbs) measured

 

GT81 3.9 kg  Spec.

SV503 70ed 2.2kg  Spec.

zenithstar 73  2.83kg Spec.

zenithstar 61  2.2 kg  Spec.

AT72EDII  2.2 Kg Spec.

 

Starting with the Rig i used last night and then some pictures of weighing scopes:

Edited by Nate1701, 04 February 2023 - 06:05 PM.

[Nate1701]

More thoughts from Last nights experience and my weight measurements:

 

Last night the light blue ST80 ( Skywatcher) had focus shift when i tightened the thumb screw - normal for those focusers. THUS, if i had to repeat i think I would grab my ST80-Custom for better focus. If the extra 2lbs of the OTA was OK then that means really a 5lb scope should be the target for what I want, which puts me in the SV503 70ED Zone.

So the subject line could really be titled "Which 5lb APO/ED scope should i get?"

 

The results from last night were not bad considering it was a true grab and go.

But I know the focus was off because of the thumb screw, and the cold was pinching the lens real bad also. ( IF YOU CLICK on the comet picture you can see the triangle shape)

Then factor in CA and really I can't complain about my result - but a better quality scope would help all those issues.

Edited by Nate1701, 04 February 2023 - 06:44 PM.

[Nate1701]

Also my future plans are to mount the GT81 on the AZ-GTi in EQ mode. Yes, it's overloaded, but I'm curious to see how it will do.

So I'm thinking.... use the GT81 in EQ mode and have something smaller and lighter for Alt-AZ mode. Maybe in that case a 70mm is too close to an 80?

 

I did a test with the GT81 on a friends new Star Adventurer GTi, and we had GOOD tracking despite being almost a pound over the 11lb limit.

We only took a few shots on Andromeda. 4 shots @ ISO 200 for 150Sec.

The results were encouraging that I could get the same with the GT81 + AZ-GTi in EQ mode.

 

 

I processed the Four shots in Siril and Gimp. I used Starnet++ and it really helped reduce star bloat.

I only dream how this would turn out with more data....

Edited by Nate1701, 04 February 2023 - 06:27 PM.

[Jethro7]

Hello Nate1701,

Here is my candidate for the perfect G&G scope. The Takahashi FOA 60Q, they are "IN STOCK" The FOA 60Q is the best corrected scope in Takahashi's line up with a Strehl ratio of 99 %.(Untested by me but the views are Razor sharp) It  is really two scopes in one. You can run this scope without the Focal extender (Q Modual) giving you a F/8.8 Or with the Focal Extender giving you an F/15. FOA 60Q is small, light and because of the removable Q Modual, it will pack up into a small case for travel. 

 

HAPPY SKIES AND KEEP LOOKING UP Jethro

 

 

https://takahashiame...matic-refractor

 

[Nate1701]

Hello Nate1701,

Here is my candidate for the perfect G&G scope. The Takahashi FOA 60Q, they are "IN STOCK" The FOA 60Q is the best corrected scope in Takahashi's line up with a Strehl ratio of 99 %.(Untested by me but the views are Razor sharp) It  is really two scopes in one. You can run this scope without the Focal extender (Q Modual) giving you a F/8.8 Or with the Focal Extender giving you an F/15. FOA 60Q is small, light and because of the removable Q Modual, it will pack up into a small case for travel. 

 

HAPPY SKIES AND KEEP LOOKING UP Jethro

 

 

https://takahashiame...matic-refractor

 

Nice suggestion!

I forgot that 99% of perfection comes at a cost... 

[Jethro7]

Nice suggestion!

I forgot that 99% of perfection comes at a cost...

Hello Nate1701,

I have been with the Astro Hobby for awhile and I am a refractor junkie. And own a number of refractors from 60mm to 152mm and Have a 155 triplet APO in bound.I decided a few years ago to start acquiring premium refractors. The Takahashi's have one huge advantage over AP, TEC, and the APM LZOS APO's, they are actually available. What you get buying a premium refractor is the ability to focus tighter and better color correction because of the finer precision in manufacturing of the lenses. This is really noticable when you run the magnification up. This is the reason why buying premium is well worth the cost, at least from my point of view anyway. Being honest about it, those super high Strehl ratios only really count if you are imaging. I really don't think anyone can visually tell the difference between a Strehl ratio of a scope with 95% and one with 99% The Tak FOA 60Q has become one of my all time favorite scopes, even though the Tak 60Q has too small of an Aperture to actually watch one of Jupiter's Galilean Moons Transit across the face of Jupiter instead of just the Moons shadow like I can with my Tak TSA 120. Aperture does have its virtues but not always. The Views of the Moon and Planets as well as showcase DSO's are still wonderful through my baby Tak.

 

HAPPY SKIES AND KEEP LOOKING UP Jethro

Edited by Jethro7, 04 February 2023 - 07:55 PM.

[sevenofnine]

The AT72EDll is getting great reviews on the forum. It's worth considering 

 

https://www.astronom...fpl-53-f-6.html.