Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

150mm Instrument for Planets, Which Type?

  • Please log in to reply
35 replies to this topic

#26 MalVeauX

MalVeauX

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 5763
  • Joined: 25 Feb 2016
  • Loc: Florida

Posted 24 August 2019 - 04:56 PM

I guess there's also the big question... at what point does it not matter, aperture wise, relative to how low on the horizon the planets are. Here in Florida, the planets tend to be around that 35~38 degree mark, so not high in the sky, but not dreadfully low. Definitely not ideal. At what point does this play in heavily? Also, does an ADC work for visual?

 

Very best,



#27 Jond105

Jond105

    Skylab

  • *****
  • Moderators
  • Posts: 4185
  • Joined: 19 Feb 2018
  • Loc: Detroit

Posted 24 August 2019 - 05:19 PM

I looked at Jupiter & Saturn tonight in my 200mm F6 Quartz newtonian and it was a lovely view. I'm curious if a 150mm F8 ED refractor would truly best it easily in all conditions.

 

48609877387_03c74bc0e3_b.jpg

 

48609877882_124868e03a_b.jpg

 

48609878257_0656009a4d_b.jpg

 

48609784676_8150da54ef_b.jpg

 

We compared some scopes tonight. The 200mm F6 Quartz newtonian through up a great image. The refractors did well, but none were ED/APO. The C8 Edge did well and had the benefit of the tracking mount in the observatory, so it was super pleasant. But on the manual mounts, the 200mm F6 did quite nice with a 25mm eyepiece. Things got tricky and fussy at 8mm with it. 

 

It helped me really realize without tracking, I'm not terribly fond of planets over 100x magnification. By the time you focus it, move things, wait for settle, etc, you have to re-do it all. I think my high-mag viewing will be in the observatory. I still can easily discern rings and cassini division at low power with smaller apertures (120mm & 200mm) no problem with very little magnification.

 

But.... I'm still curious for a 150mm F8 ED.... sigh!

 

Very best,

First off, great pics 

 

I do a ton of observing now with planetary on my undriven, no slow motion controls, alt az mount. It may just be so small of FOV in your eyepieces to why you aren’t to fond of it. I doubt I’d use that mount over my driven EQ if I didn’t have the FOV eyepieces I do at high power. Instead of a new scope for the T-2, maybe you just need a couple eyepieces instead?  Just a thought at least. 


  • MalVeauX likes this

#28 MalVeauX

MalVeauX

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 5763
  • Joined: 25 Feb 2016
  • Loc: Florida

Posted 24 August 2019 - 05:36 PM

First off, great pics 

 

I do a ton of observing now with planetary on my undriven, no slow motion controls, alt az mount. It may just be so small of FOV in your eyepieces to why you aren’t to fond of it. I doubt I’d use that mount over my driven EQ if I didn’t have the FOV eyepieces I do at high power. Instead of a new scope for the T-2, maybe you just need a couple eyepieces instead?  Just a thought at least. 

I have the eyepieces to get me two 240x magnification with the native focal lengths, Paradigms. I've gone as far as barlowing one on Saturn. But I find that at those magnifications, it's not pleasant to chase the subject on a non-tracking mount. On my EdgeHD on my mount in the observatory I'll push magnification and it stays put so we can just stare at it a while, in binos. Very nice. But, I generally like to also just setup a scope and look at it manually. Dunno why. Even with the observatory and mount, I'm still weird and like to do a manual experience at lower power. A more primal experience I guess? Maybe it's truly just laziness? I'm happy to stare at the planets at lower power, if the contrast is high and bright. Last night, at 48x magnification in the 8" F6 I could see bands on Jupiter no problem and 4+ moons, very bright. At 150x magnification on the same instrument, the planet would of course move quickly but I could easily discern details unique to the planet. I would easily stare at it at 150x all day. So I'm happy with the 100~150x area visually on manual setups. This makes me wonder what would put up the better image at this magnification range, such as a 6" aperture instrument like in this topic and what design. I can get larger apertures in my observatory and look at things at higher magnification, but this isn't that, this is just looking for the simplest manual alt-az experience, something I can haul around somewhere if I want to, drag it out with kids, and not worry about them pulling on things and making problems (no kids in the observatory with the mount and stuff). Collimation with respect to refractors is becoming very appealing. So the Skywatcher EVO 150 ED just has a lot of appeal to it. I need to get my butt somewhere with some scopes and get an idea by looking through them. I really just need to compare a 10" F4, 8" F6 reflectors to a 150 F8 ED refractor and maybe even something like 120~130mm F7~F8 ED/APO refractor to get an idea of it.

 

Very best,


  • Jond105 likes this

#29 MalVeauX

MalVeauX

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 5763
  • Joined: 25 Feb 2016
  • Loc: Florida

Posted 26 August 2019 - 02:31 PM

8" F6 Quartz vs 6" F8 Achromat.

 

Size wise, they're equivalent and similar weight, the newt is a little heavier. Eyepiece location is perhaps more convenient, for planets, on the newtonian if I wanted to stand. On the refractor, at max height, it puts the eyepiece a little low so I'd have to stoop or stand side-ways to it and angle the eyepiece horizontally (making it similar to the reflector's placement, but still lower). So really, a wash in terms of comfort of viewing. But at least I could have two viewers at the same time on the same target.

 

Just testing this, I don't see adding a 6" F5 newt to the line up. While it's cheap and 6", it's not going to do better than this 8" F6 Quartz and I consider this portable enough that I would take this somewhere with me if I were going to a star party and it lives in my observatory so getting it out takes 2 minutes tops to get it and set it up. Super simple. I likely wouldn't spend much time, visually, with a 6" F5 newtonian since it would be short and lower contrast with the lower aperture and shorter focal length, on planets. So that leaves the longer newtonian with larger aperture, or exploring an ED/APO with similar aperture but better correction.

 

My 6" F8 Achromat is bad on planets, the color is wild, great for sweeping at low power, but not a planetary scope for sure. I would like to explore replacing it with a 5" or 6" ED/APO. But then again, I have to consider, why bother with a 6" ED/APO when the 8" F6 Quartz does the same thing? Maybe does it a little better or a little worse? Not sure there. I can mount them both either way. The Twilight II bosses these scopes around on problem.

 

So I suppose it's.... what will beat the 8" F6 Quartz.... a 6" ED/APO? Or, call it good with the 8" reflector. I can't help but want to try a 5" or 6" ED/APO for this...

 

48625551868_fc0d829f07_c.jpg

 

48625901071_9ed97e48a3_c.jpg

 

48625553858_7f36c179e4_c.jpg

 

Very best,



#30 Special Ed

Special Ed

    Voyager 1

  • *****
  • Posts: 10372
  • Joined: 18 May 2003
  • Loc: Greenbrier County, WV 38N, 80W

Posted 26 August 2019 - 03:35 PM

Marty,

 

I have had good results using an ADC visually on Mars, Jupiter, and Saturn.


  • MalVeauX likes this

#31 MalVeauX

MalVeauX

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 5763
  • Joined: 25 Feb 2016
  • Loc: Florida

Posted 26 August 2019 - 03:47 PM

Marty,

 

I have had good results using an ADC visually on Mars, Jupiter, and Saturn.

Thanks, that's helpful to know that its not just an imaging device.

 

Was this on a refractor or mirror? Shouldn't matter though I suppose!

 

Very best,



#32 Special Ed

Special Ed

    Voyager 1

  • *****
  • Posts: 10372
  • Joined: 18 May 2003
  • Loc: Greenbrier County, WV 38N, 80W

Posted 26 August 2019 - 08:32 PM

It was with my C14.


  • MalVeauX likes this

#33 RadioAstronomer

RadioAstronomer

    Mariner 2

  • *****
  • Posts: 226
  • Joined: 13 Jun 2018
  • Loc: Tucson, AZ

Posted 28 August 2019 - 11:36 AM

Thanks so far,

 

The argument goes.... does it make sense, or am I nuts, to think a 10" F4 reflector for DSO next to a 6" F8 ED refractor for planets makes sense on a dual-mount for visual? Shouldn't the 10" mop the floor? I just hear so many accounts of the 6" ED refractor being the better visual experience than a bigger reflector, without ideal conditions, high in the sky, thermal acclimation, etc. For casual quick setups, it just seems to make sense than the refractor might truly be superior? Mean while, for a DSO, nothing tops the light gathering of a big mirror. Am I nuts thinking a 10" F4 newt next to a 6" F8 ED frac is a good combo?

 

Very best,

Not sure if this will help, but my 4" ED f/9 refractor outperforms my 6" Maksutov-Newtonian on luna and planets every time. Even when I take a lot of care on getting a good collimation on the reflector, the refractor bests it on lunar detail, planetary detail, planetary contrast and general sharpness of the image. 


  • Tyson M and MalVeauX like this

#34 aa6ww

aa6ww

    Vanguard

  • *****
  • Posts: 2065
  • Joined: 23 Oct 2011
  • Loc: Sacramento, Calif.

Posted 28 August 2019 - 03:09 PM

This is usually the case when seeing conditions aren't that great to support larger aperture or scopes aren't fully acclimated.
Level the playing field where seeing conditions are better, at least 4/5 and smaller scopes struggle when larger SCT's are just getting started.

People who live in mediocre skies generally do better just owning a small refractor or small SCT.
Few people who in Arizona or dark sky country's boast about how spectacular their 4" refractors are when they have a larger SCT or dob set up beside them.

The older we get, the more valuable our small refractors become to us. I'm starting to feel that lately.

...Ralph



Jon - normally I'm with you 99.9%.  But I have seen numerous times FIRST HAND where a quality 4" refractor beat out much larger apertures on the planets.  And I don't think the guys with these scopes didn't have them properly collimated, etc.  These guys with scopes (like the Meade 10" SCT) were my observing buddies and they concurred.   They were active seasoned observers like myself.
 
Mike


  • MalVeauX likes this

#35 Joe Eiers

Joe Eiers

    Viking 1

  • *****
  • Posts: 660
  • Joined: 08 Sep 2011
  • Loc: Arcata, Ca.

Posted 29 August 2019 - 05:45 AM

Two years ago I did an extensive shootout with my C102F (AMAZING optics!), an ETX125, my C6 SCT, a 1974 C8 with superb optics, and a Questar 3.5.

 I used the same eyepieces, and spent a LOT of time comparing Mars, Jupiter, and Saturn.

 My background:  been observing since early 1970's and have used/had many many scopes.   I didn't just buy and flip em.  I really USED them.

 My biggest interest was between the C102F flourite and my C6.

 I could go on and on and and on about my experiences, but I'll just throw my results out there.  Let me start by saying that during excellent seeing the C8 won handily.  The issue was that those moments were few and far between.  The Questar ALWAYS lost and NEVER got close to any of the larger scopes.  Nothing magic there - except whole thing was cool to use and just look at!  

 In the end, my C6 was the clear winner.  Yes, the C102F had great contrast, but the C6 was still pretty good.  My goal was to see and draw details. I could see more details for me to draw and keep track of night after night.  The ETX125 came very close to the C102F and there were times that it was better.  The problem was that the ETX had issues with focusing and needed something electric.  It also needed to be deforked as the mount was complete junk.  I was always amazed how excellent the OTA was and how terrible the mount was - from the same company!

  I ended up selling off the C102F, the ETX, Questar, and the C8 to buy a C11 GPS. I'm thrilled with the 11, it's great for deep sky (as well as planets too!!!)

  So now I use my lowly C6 SCT for planetary work, and the 11 when the seeing is excellent (not very often with the planets so low).  The portability of the one-armed mount is great and works perfectly with my portable lithium battery.   Really is a killer planetary setup for me.

   I mean no dis-respect to you refractor lovers out there!!  Perfect round stars and black backgrounds RULE!

   Joe


  • aa6ww and Tyson M like this

#36 MalVeauX

MalVeauX

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 5763
  • Joined: 25 Feb 2016
  • Loc: Florida

Posted 07 September 2019 - 10:44 PM

Update,

 

While not 150mm, I did compare a few things...

 

I let both scopes acclimate. I didn't push them hard or anything. Just casual viewing tonight. Seeing was decent for visual.

 

ED80mm F7.5 (FPL53) vs 200mm F6 Quartz mirror.

 

With the ED80 I could barely make out the great red spot. It was bright, not a lot of contrast, but sharply focused and wasn't boiling in the eyepiece.

With the 200 F6 Quartz, I could see the bands and the great red spot clearly. It was bright but contrast was much higher and seeing was decent so no boiling at the eyepiece.

 

This leads me to wonder... 150mm F8 ED refractor vs the 200mm F6 quartz. I don't think it's going to be that much better, or even equal to it. So I think that solves everything for me. I guess 6" just isn't for me. I'll probably just stick with the 200mm F6 Quartz in general for visual. I am thinking of getting a 130mm triplet APO eventually which will be interesting to compare. But for now, the 200mm just does the job. I can't see a 150mm F8 ED doublet beating it. And that's not even serious visuals, that's casual spontaneous visuals.

 

The view tonight at merely 150x magnification was fantastic in the the quartz mirror.

 

48696767587_8fd88bdd4c_b.jpg

 

Very best,


  • Jond105 likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics