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C6 or 6SE? New York City dilemma re: TV eyepieces

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#26 FishInPercolator

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Posted 19 May 2013 - 06:46 PM

True but wouldn't the Newt provide more contrast and larger field of view (even though people have advised not to overwhelm myself with it)?

The 6" newt is 2.5 lbs heavier and 10.5 inches longer... the weight variance is nominal and due to its longer length, I would just have to position it vertically as opposed to horizontally in whatever large case I find for it...

#27 FishInPercolator

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Posted 19 May 2013 - 06:47 PM

It also includes a 2" crayford focuser ;)

#28 azure1961p

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Posted 19 May 2013 - 10:03 PM

Fish,

Which one in the avatar is you and whose the other guy?

Pete

#29 FishInPercolator

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Posted 19 May 2013 - 10:08 PM

lol, actually, I was the one who took the photo

#30 WesC

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Posted 19 May 2013 - 10:57 PM

I still think you should go back to the refractor suggestions I made and seriously consider that approach. Its much lighter, and a lot easier to deal with.

Have you made it to a store yet?

#31 FishInPercolator

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Posted 19 May 2013 - 11:07 PM

Hey Wes, yes I am certainly considering a refractor but as a second scope. Right now it's a toss between a C6 and the Omni 150 XLT Newtonian 6"... it's inexpensive and still portable, albeit a bit longer than the C6. I've made it to Adorama and they only had an EdgeHD 800 which I had asked them to ship from the warehouse. It's lovely but heavier/bulkier than the C6. The latter along with the 6" Newt are also significantly less expensive.

#32 Patrick

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Posted 19 May 2013 - 11:40 PM

My first scope was an 8" f/5 on a manual GEM. That scope nearly made me give up on astronomy. It's a pain in the neck using a Newt on a GEM mount, literally. You'll be rotating the tubes in the tube rings and/or have to look at your eyepiece upside down in certain parts of the sky. With the SCT all you rotate is the diagonal...much more convenient.

Contrast? Yeah, there's a bit of a difference...but you also have noticeable diffraction spikes with bright objects llke Jupiter, something you won't see in the SCT. Everything you can see in the Newt you can see in the SCT. There are only a very few objects that the 750mm Newt might get completely in the FOV that the 960mm C6 (operating with a focal reducer) might not be able, but the vast majority of objects will fit in both of the FOV's.. To be fair, at 1525mm native focal length, most deepsky objects look better in the C6 because they'll be bigger with the same eyepiece. It will take much shorter eyepieces to get any decent image scale from the Newt. Shorter eyepieces generally equate to shorter eye relief. I prefer to use longer focal length eyepieces and barlow if I have to.

My 2 cents...others may disagree...

Patrick

#33 FishInPercolator

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Posted 19 May 2013 - 11:44 PM

They are worthwhile points... I just think a faster scope like an f/5 will work best for both visual and imaging. I read about a bunch of problems bringing the C6 f/10 down with reducers for use with a CCD camera or DSLR. Unless I'm mistaken...

#34 Patrick

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Posted 19 May 2013 - 11:51 PM

I read about a bunch of problems bringing the C6 f/10 down with reducers for use with a CCD camera or DSLR. Unless I'm mistaken...



What kind of problems?

Okay, now you're throwing imaging into the mix? Does the imaging setup need to fit in your backpack too? :foreheadslap:

Go with a small 80mm refractor if you're going to image. The SCT will be easier to image with than the Newt, but an 80mm refractor will be better than either. I thought you cared more about visual, but if imaging is your end game, then go with the refractor.

Patrick

#35 Spacetravelerx

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Posted 19 May 2013 - 11:53 PM

I 110% agree with Patrick!

But you knew that fish... ;)

#36 FishInPercolator

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Posted 19 May 2013 - 11:56 PM

I will probably end up getting a 6" Newt, a 6" SCT, and an 80mm refractor by the end of the year anyway... all portable solutions...

The Tak 102mm I need to save up for so that will take a bit more time... ;)

#37 Starhawk

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Posted 20 May 2013 - 01:29 AM

So, after posting on this a few times, I went out and did an experiment with a mobile rig to see what happened. The participants were a NexStar SLT mount (with the 4" OTA it came with removed), an 80 mm C80ED telescope (f/7.5 600 mm FL refractor with the same optics as the Orion ED80), and a C5 OTA.

I started out witht the 80mm on the mount, and at a total of about 17 lbs, it's pretty even to move, even though it isn't obvious how to pack a scope that long in a backpack. The mount has some bounce since even this relatively small scope has a bit of a moment of inertia, which small mounts have trouble with. The views were quite nice, and the moon was bright enough to look a bit like the last big city sky glow I got to endure. The view of the moon had great contrast, though the seeing didn't seem to want me to go over 100X. Likewise, Saturn didn't want to give up the Cassini division, although I have seen it in this telescope in the past. DSOs were quite difficult with the setting double cluster only seeming to be a few of the bright stars.

I then went on to the C5, which has sadly been wanting wear since the AP 130 EDFGT showed up in 2011. The C5 threw down a fantastic image on the moon which held up at twice the magnification I was able to use on the C80ED. We've been having a lot of wind, so there is a lot of dust in the air, but the C5's image still came through to make fuzzy details like some of the older rays on the moon fairly obvious. At over twice the magnification I had reached in the C80ED, Saturn showed the Cassini division, cloud stripes, and subtle color variations as well as three moons. Double Cluster was improved, but still, you really needed to have seen the object before to know what you were looking at since only the brighter stars came through. What was interesting was the mount was much more stable with the C5, even with the longer focal length effects, thanks to the small moment of inertia of such a stubby telescope. I finished the evening quite sure I could never part with that telescope.

With AA batteries and a basic assortment of eyepieces, this or something like the NexStar 5 SE would be around 25 lbs, and ideal for visual work.

Packing it up isn't trivial, but at least it is possible on a frame backpack, and with a bit of a stretch, I can probably see getting the NexStar 6 SE across the city as well (again, the issue isn't just weight- it is bulk, clumsiness, and fragility all tied together).

With that said, this evening reminded me of starting out thinking I could get really light mounts to cooperate for imaging with enough elbow grease and smarts. The sad truth is: They just don't. Whoever put the 5 SE together even had enough of a sense of humor to add a wedge into the tripod. In reality, it isn't going to be easy.

The only thing I have done for photographing DSOs which has ever approached being "Easy" has been moving a C11 to the boonies, setting it up with land-line power, hyperstar, a computer monitor, and about 200 lbs of gear total. What was easy about this, you ask? The images were shot at f/2 so a 30 second exposure could get to 22nd magnitude. That solves some heavy duty issues. Sure, refractors are really easy to get set up for photography. And if you have 70+ lbs. of mount on your side, they can even be guided through an image. Astrophotography is unforgiving, but when you have the right rig in the right place at the right time, those amazing images can come. But if anything isn't just so, the only comment back is, "Your stars aren't round."

If you can set photography on the back burner for a while, I anticipate you can make this work. If you want to do photography, there is an adapter for iphones to make getting a parfocal image easier to start out (you can actually do a lot with this).

-Rich

#38 FishInPercolator

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Posted 20 May 2013 - 01:42 AM

Thanks for the post, Rich. I've decided on two portable tubes - C6 f/10 or the 6" Omni XLT 150 reflector f/5. And with the ZEQ25 it'll be about 40ish pounds which I feel I'll comfortably lug around when not transporting via car. My concern is to successfully focal reduce the C6 f/10 as I have heard there are issues with that. I will most likely start off with a scope and then work my way toward an imaging system, but I figured it wouldn't hurt to do some preliminary research now so I can get a general idea of total costs and payload requirements.

#39 Starhawk

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Posted 20 May 2013 - 01:53 AM

I don't know that I would say reducing a C6 i especially problematic; its more that there are limits to what you can get in return. If you want to reduce a C6, you can get all the way down to f/1.9, since it has its own mini version of hyperstar (yes, it is cute). The real problem is no matter what you do, the best photography means a trip to the boonies. The broad spectrum lights people have started using have made filtering far less effective than it was 10 years ago. If you're in the city, get images of stuff in the solar system; there's still a lot to learn, but it's a lot more fun.

-Rich

#40 FishInPercolator

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Posted 20 May 2013 - 02:21 AM

Mini hyperstar? Do tell... :)

I think Jack at Mallincam said the problem I would have with the C6 is if I used it with the Universe, which has a larger chip and made for scopes w/2" focusers. So my thought was I could get a 2" focuser on the 6" Newt... It's not EdgeHD optics though so I not sure exactly how that plays out...

I plan to get images of solar system too... I cannot fathom neglecting our own moon.

#41 coutleef

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Posted 20 May 2013 - 08:27 AM

wow, CN members are doing a lot to help you i am impressed.

if that helps i was in your position several years ago. i needed a portable scope because of back probems. first had a 5 inch newt on a gem. i almost abandonned astronomy because of it (as mentionned by Patrick above) not comfortable positions for observing, difficulty to collimate ( i was unaware of CN then) but mainly, not that easy to transport.

sold it and got a 6 se and it was days and night. after two weeks, i traded it for a 8se and will keep that scope for life. if you are an experienced amateur you will notice the difference in contrast between a newt and a SCT. if not, you probably will not. for wider views on a 6se i would suggest a 9x50raci but i would not stress using a focal redicer but just use 68-72 degrees EPs. for a non motorized set up i use a ES twilight mount and it works well. Thermal equilibrium is fast with a 6 inch SCT.

having had both types of scopes i would go for the sct.

just a word of caution. difficult to rely on internal batteries for the se scopes as they oftwn result in power prolems rapidly. there are lightweigth solutions as could be discussed on the nexstar forum

just my experience and as always ymmv. and this comes from someone who has a SCT, newt (dob)and a refractor

#42 Patrick

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Posted 20 May 2013 - 08:36 AM

Hyperstar for C6 . 290mm fl/ at f/1.9.

Since the camera sits over the front corrector plate, a round style ccd camera is almost essential. A DSLR will severely block the front aperture opening.


So my thought was I could get a 2" focuser on the 6" Newt... It's not EdgeHD optics though so I not sure exactly how that plays out...



There's not a lot of gain going to a 2" focuser on a standard 6" Newt. The 6" f/5 Newt is optimized for a 1.25" focuser and the diagonal is sized accordingly. If you want to use a 6" Newt, you should be look specifically at Imaging Newts, like the AstroTech 6" f/4 Imaging Newt . It's already optimized with a 2" sized diagonal and focuser. You will need to add a Coma Corrector/Field Flattener with this scope because of the field curvature on the f/4 primary (as with any Newtonian below f/6.)

I've never used one of the Imaging Newts, but I've seen one up close and they're cute. At f/4, they're more portable than their longer brothers.

Patrick

#43 Starhawk

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Posted 20 May 2013 - 09:33 AM

Here is a link. You get an adapter with it, and they have one for a Mallincam:

http://starizona.com...-P3032C773.aspx

You'll have to ask about provisions for narrowband filters. Of course, with or without one, you're assured of being able to shoot whatever the sky will allow.

I know earlier C6s always had to have their secondary adapted to a Fastar removable housing. Does anyone know if current ones come from the factory with them? If not, Starizona would know, and might have one with a removable secondary in stock. Alternatively, they'd be the best ones to install the secondary. The removable secondary housing lets the scope work as a regular C6, but the secondary has a bezel which unscrews to allow it to switch over to the camera staring at the primary mirror.

-Rich

#44 FishInPercolator

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Posted 20 May 2013 - 11:51 AM

Thanks guys...

How quick and simple is it to replace the corrector with this? I suppose I won't be doing much observation while in the midst of imaging with the hyperstar setups.

#45 mclewis1

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Posted 20 May 2013 - 02:01 PM

Hyperstar is a replacement for the secondary mirror in the middle of the corrector ... not the corrector itself. You don't go swapping it around all the time during an observing session. You set the scope up for Hyperstar imaging and use it like that for a while. In that mode the scope can no longer be used visually (you've removed the secondary mirror). With a C6 small diameter cameras are a must (Mallincam video, QHY8Pro, Starlight Xpress M25C or similarly sized cameras) ... DSLRs are not recommended at all with the C6 setup (but are ok with larger scope Hyperstar setups). Follow the link that Rich posted, there's a ton of Hyperstar info there.

A Hyperstar C6 is as Patrick indicated above a very wide field instrument. Traditional DSOs like most galaxies, planetary nebulae, and globular cluster are TINY at 290mm fl. Yes it's very very fast but that short focal length really restricts it's use. It's very good a large extended objects and these are generally not the objects you want to be imaging from a heavily light polluted urban area. Highly selective narrow band filters do help (for example an Ha filter for huge objects like the North American nebula).

While it's not particularly delicate you do need to be extra careful with a Hyperstar setup, it's not something you want kids or curious but clumsy adults poking around.

-----

I mentioned this before in one of the many other threads but I'll say it again, this time with more details and a bit more emphatically.

- Get the C6 ota and the small IOptron gem.
- Flexible dew shield for the C6.
- Anti vibration pads for the mount.
- Mallincam Xtreme camera and an MFR-5 focal reducer and the two spacers.
- Use a Windows or Mac OS laptop with good battery life and a USB frame grabber and a USB-serial rs232 adapter.
- A Jumpstart style 12v battery (10-20amp/hr capacity, from automotive or big box stores), and a 3:1 cigarette lighter style adapter (so you can power both the camera and the mount together off of the one battery ... this won't be needed if you have a battery with at least two cigarette lighter style outlets).
- A 6-10' S-Video cable.
- 2.1mm - cigarette lighter style DC power cable (RadioShack) ... to power the Mallincam off of the battery.
- Astronomic UHC, and Ha 12nm 1.25" filters.

- A plastic storage container for the ota, another for the mount head, and a third for all the accessories. You'll also need something to bundle up the tripod legs (there are zip up bags like this). A small folding chair would be very useful as well. You can setup the computer on top of the 3 storage boxes. Bring a blanket for under the scope, this makes it much easier to find anything you drop in the dark and prevents some things from breaking if you are setting up on asphalt/concrete.

Don't mess with iPAD controls, wireless gear, or the like, at least not initially. Get a simple, proven, bullet proof setup working before you consider anything else. You need ultra reliable gear if you're going to be running remotely. Use this setup for a while, get some experience (the most valuable accessory ever) and only then consider other options.

#46 FishInPercolator

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Posted 20 May 2013 - 02:09 PM

Thanks! All understood and points well-taken. Now I await for a new credit card to be issued after my astoundingly unfortunate experience with Herb York over at Astromart.

#47 A. Viegas

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Posted 20 May 2013 - 03:58 PM

I concur with Mark's comments above 110%. Forget the Universe, it will do you no good with a C6 and under NYC's light dome. The MCX smaller chip will work great with the C6. The ZEQ25 mount seems like a real winner and will provide you important future OTA upgrade capability. A jumpstart type battery is a good idea, but they are heavy. Think about how you will be transporting this on the subway. By itself it will weigh more than the OTA... I have heard good things about Starizona's little lithium battery product, not sure if it can be adapted to power more than just the scope, but worth taking a look... Starizona Battery

Good luck

Al

#48 Patrick

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Posted 20 May 2013 - 06:14 PM

Mark,

Great job of explanation there...excellent recommendation for the gear as well. I'm going to give a serious look at your camera recommendations. Nice detail! :) Do you have a Malincam?

IT Guy:

Listen to the man~ :grin: ;)

The C6 is the most versatile scope of the three or four you've looked at.

Patrick

#49 FishInPercolator

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Posted 20 May 2013 - 06:18 PM

Yep, there have been quite a few of you I've been listening to who have been nothing less than helpful and generous with your time. I thank you all.

Looking forward to it.

#50 Patrick

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Posted 20 May 2013 - 06:20 PM

Now I await for a new credit card to be issued after my astoundingly unfortunate experience with Herb York over at Astromart.



Good old Herb...what a character... I've never purchased a single thing at Anecortes, well, just because...

Patrick






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