First light GSO10RC and G11 - Page 2

TrevorW · #21 01-02-2010, 02:50 PM

Frank

You've got to put only the tube on the scales mate not yourself

Cheers

leinad (Dan) · #22 01-02-2010, 03:10 PM

Quote:

Originally Posted by telecasterguru

As trevor has pointed out, the G11 has a carrying capacity of 60lbs which works out at 27.21 kilos.

From my intrernet research, the EQ6 has a carrying capacity of 40lbs which works out at 18.14 kilos.

As I said, when I weighed the 10"RC on my bathroom scales they came in at nearly 16 kilos which doesn't leave much room on the EQ6. The OTA sure doesn't feel like 16 kilos to me though.

Frank

Bout right, they are advertised as 34.4lb; roughly ~15.7kgs.

tlgerdes (Trevor) · #23 01-02-2010, 04:19 PM

Quote:

Originally Posted by telecasterguru

As I said, when I weighed the 10"RC on my bathroom scales they came in at nearly 16 kilos which doesn't leave much room on the EQ6. The OTA sure doesn't feel like 16 kilos to me though.

Frank

I think you might have one of those "FAT" scales. You know the ones that always indicate more than what you think. I have a set of those in my bathroom, it always says I weigh more than I feel I am.

Paddy (Patrick) · #24 01-02-2010, 07:42 PM

Congratulations Frank. I very much look forward to some images. Perhaps some Arps?

telecasterguru (Frank) · #25 01-02-2010, 08:50 PM

Paddy,

Thanks and arps are my ultimate goal. All of them but not all at once.

Frank

Paddy (Patrick) · #26 01-02-2010, 10:12 PM

Quote:

Originally Posted by telecasterguru

Paddy,

Thanks and arps are my ultimate goal. All of them but not all at once.

Frank

Fair enough, 'twould be quite a task!

gregbradley · #27 05-02-2010, 11:46 PM

"CCD, don't go for the KAF8300. Your sampling will be way too over sampled."

Is there really such a thing as oversampled? The only consequence as I understand it if your pixels/arc sec is less than about .66 seeing is less sensitivity.

Also limited by your local seeing assuming you will always image at the same location.

The real danger is undersampled and lowered resolution isn't it?

Image scale is really another consideration and one chip doesn't do all jobs especially if you have multiple scopes. This why I have 2 CCD cameras.

On another topic I see at OPT they are advertising a 12 inch Astrotech RC now.

This is getting interesting.

Greg.

AlexN · #28 06-02-2010, 01:04 AM

I'd agree with Greg there.. Oversampling is good... Any negative affects can be controlled during processing of data.. Oversampled data tends to go through deconvolution a hell of a lot better in my experience.

Image scale is a factor that needs to be considered. Although at F/8 the focal length of the GSO 10" RC is not overly long.. 2000mm is longer than your average amateur photographers focal length, but its still a moderate focal length.. the KAF8300 would provide a good field of view.. Very usable, and given you want to chase PNe's and ARP's, the smaller pixels give you a larger image scale (pixel resolution) than a sensor with bigger pixels..

I would worry about the well depth of the 8300 though.. Chasing the real small, dim targets might be difficult with an 8300, as going much over 10 minute subs can cause star saturation... I've done a little testing on this myself, however Greg has done quite a lot of work with his 8300 and assures me that 10mins in the optimal exposure duration for the 8300, a few exposure calculators that I've checked out indicate the same..

If you want a serious CCD for that scope. Look no further than the KAF-3200ME found in the FLI ML3200/PL3200, SBIG ST3200/ST10XME

gregbradley · #29 06-02-2010, 08:51 AM

Yeah a FLI ML3200 could be a hot camera for that setup.
The 8300 does have small wells but there are lots of images now that
show pinpoint stars. On brighter objects shorter exposures than 10 mins are the go and in a scene with lots of bright stars as they spill over from the small wells first and can look a bit bloated. Same with any camera though but more so with this chip due to the small well capacity.

I wouldn't get a Proline for this scope as that camera needs a beefy focuser unit to handle all the weight and I doubt this scope could handle that (only a few can). So get a light camera whatever you get.

Greg.

Paul Haese · #30 06-02-2010, 11:57 AM

Quote:

Originally Posted by gregbradley

"CCD, don't go for the KAF8300. Your sampling will be way too over sampled."

Is there really such a thing as oversampled? The only consequence as I understand it if your pixels/arc sec is less than about .66 seeing is less sensitivity.

Also limited by your local seeing assuming you will always image at the same location.

The real danger is undersampled and lowered resolution isn't it?

Image scale is really another consideration and one chip doesn't do all jobs especially if you have multiple scopes. This why I have 2 CCD cameras.

On another topic I see at OPT they are advertising a 12 inch Astrotech RC now.

This is getting interesting.

Greg.

Point taken, I should have worded this differently. I think one can over sample at some point and you gain nothing by doing so. That said, I should have wrote that well depth when short can create bloat at certain exposure levels, and while it can be dealt with in processing, it is probably best to match the CCD with the scope from the beginning.

Alex, I remember you suggesting to me that I should go further than 10 minutes on my subs several months ago. Have you since changed your tune? This was what I was saying all along. The well depth on the 8300 is just too short to go for really long subs on a larger aperture scope. Saturation just kills the stars. So objects like Thors helmet really require a greater well depth than what I have.

Greg, yep sometime in the next year I will be getting one of the 12 inch scopes at near half price, due to the "effort" I have put in for GSO advertising. Looking forward to a nice large scope like that.

AlexN · #31 06-02-2010, 01:58 PM

Paul - With regard to LRGB imaging yes, I have changed my tune, 10mins is the go. When we're talking about Ha imaging, which we were at the time, i still think 20 or even 30 mins is the go.. I ran a some 20min subs in ha at F/4.8 that were fine. with broad band filters there is just too much light for that..

Good to hear you're getting a 12" on the cheap for your work..

Exfso (Peter) · #32 07-02-2010, 02:14 AM

Hey Paul, does this mean I am going to have to make you a 12" lightbox for this scope...

Paul Haese · #33 07-02-2010, 06:49 PM

Alex, yeah that makes sense for Ha imaging.

Peter, maybe, but it will not be for a while yet.

telecasterguru (Frank) · #34 07-02-2010, 07:12 PM

Gawd,

I've only seen through my scope once and already its redundant.

Bring on the 12" I say. Suppose I will need an AP1200 to carry it.

Next year looks like a new scope and mount again. Where will it end?

Frank

AlexN · #35 07-02-2010, 08:07 PM

Frank, Thats a very "Me" comment to make!

If you're looking to move up in 12 months I'll take this shiny rig off your hands

I dont see it ending to be honest.. I think if GSO find they can reliably create 12" F/8 RC optics, they will go for 14" or 16". The same thing happened with Newtonians. Once the 8/10/12" Dobsonians were at a point where the optics were reliably very good, the 16" was put into production...

I reckon you'd get away with a 12" RC on a G11 depending on the rest of the setup. Going purely by weight, a Planewave 12.5" CDK + STL11002M/remote guide head/AOL and MMOAG setup falls within the weight capacity of the G11... I don't know how accurate the mount would be with that weight on it, however thats why I added AO into the equation..

I reckon you'd get the 12" on a G11, pure speculation on my part considering there is no expected weight specifications for the 12" just yet. I do not see the 12" being much over 25kgs considering the 10" is approximately 16kgs...

MuntiNZ (Daz) · #36 08-02-2010, 07:04 PM

Quote:

Originally Posted by AlexN

I think if GSO find they can reliably create 12" F/8 RC optics, they will go for 14" or 16".

Mate I heard by Astronomics in the USA all ready that Astrotec are making a truss 16" version.
Sposed to be round 8000 American.
Are the Astrotec versions the same as GSO but different stickers or what?

AlexN · #37 08-02-2010, 08:00 PM

GSO are Astrotech's OEM supplier for a lot of items, although Astrotech make certain modifications to the products as they see fit which USUALLY are worth while... Take the GSO 8" F/4 Newt.. Good imaging scope, The Astrotech 8" F/4 Imaging newt - Great imaging scope.. The difference is that the AT model has a tube that is 9.4" longer, giving the scope a built in dew shield, and the extra contrast that goes with that.. And also, 15 knife edge baffles running down the inside of the OTA to stop off axis reflections...

If Astrotech are advertising a 16" truss RC, it is highly likely that GSO are making the optics..

Paul Haese · #38 08-02-2010, 10:49 PM

Only up to the 10" is being advertised on the Astro tech site.

Click Here

The 12" will be demonstrated at NEAF this year and put into production next year.

MuntiNZ (Daz) · #39 09-02-2010, 07:45 PM

Jeebus it took me a while to find the posting it was on Cloudynights about the 16" but here it is .....

AT16RC

AlexN · #40 09-02-2010, 10:40 PM

Yes Astronomics have confirmed that the 16" truss is in the works...

They are hoping to have it released by the end of this year, at or under $8000 USD, weighing in at 70~90lbs..

For 8K US you could do a HELL of a lot worse!

For someone like Paul with his EM400 or anyone currently using a PME/AP900/AP1200 etc, that could be a SERIOUS imaging scope at a very nice price..