First Light from the All Reflecting Refractor

[dvj]

First light from this remarkable instrument:

http://img818.imageshack.us/img818/4620/1oiw.jpg

Data:

Date: 11/25/13
Exposure: 6 x 1800s
Camera: SBIG STL11000M
Filter: AstroDon 3nm Ha bandpass
Mount: 1200
Telescope: RHA 305 f/3.8

Notes:
Gentle curves and levels adjustments, with a minor bit of noise reduction around the outer edges. No sharpening. Needs a few more sub exposures.

Sky flats

Used the onboard guider chip in the STL. 6 second exposure integrations.

The uploaded image is full resolution, but an 8 bit jpg. The dynamic range found in the original image is compressed.

The journey has just begun.

John Gleason

[Peter Ward]

A superb first light result...:thumbsup::thumbsup:

But did you really expect anything less :D

[multiweb]

+1 terrific shot. :thumbsup:

[alpal]

Wow - a dream telescope & a perfect first light.
Can't wait to see more pics with this.

[dvj]

Just think. Personally tested by Roland. No collimation, no tip-tilt adjustments needed. Yeah Baby! It just worked out of the box. It did however, take my inner Strongman Mike to lift, snap, and drop the OTA into the rings.

And on top of all that..... clear sky!

Waiting on the motor drive for the focuser. Hard to do f/3.8 with cold fingers. ;-)

JG

[alistairsam]

Wow, look at the size of those stars.
Did you just add them in for some seasoning? They're next to non-existent.
Amazing.

Any pics of the setup?

Cheers
Alistair

[astronobob]

Faaarr Oouutt, I remember seeing images of this with the animals listed from the dark shapes, now I see fleas on them :eyepop:

[strongmanmike]

He he: Scope Lifting (http://www.pbase.com/strongmanmike2002/image/134140809/original)

Yeah baby is right...very nice John, where do you point it now :eyepop::driving:..bet your mind is swimming, so many choices :thumbsup:

Mike

[dvj]

Yah! Looking for something completely off the beaten path in Orion maybe. Funny photo Mike.

j

[dvj]

Hi Alistair. I'll have to shoot some equipment photos. It's of the usually high AP standards. Fit and finish is excellent.

j

[Satchmo]

Theres been another long thread about ray trace spot sizes of various designs which evolved ( again ) to whether optical quality in Deep Sky imaging is obvious in the final image . An instrument such as this ( assuming perfect optics ) with a 50% central obstruction will put about 50% of its available light into the Airy Disc and the rest spread out into surrounding rings .

Matched with the right pixel size in the camera , we can assume then that this kind of result ( equivalent to 1/2 wave RMS of spherical aberration in an an unobstructed telescope ) , is some kind of bench mark for quality in deep sky imaging equipment .

[jase]

What more can one say...really... :thumbsup:
For a tire kicker image, purchasing the car is gonna be spectacular. Looking forward to it. Who knows, we may see some colour too folks... :)

[LewisM]

HOLY...well, just HOLY!

I can only dream of such a rig. But then I'd have to be on the AP waiting list for 10 years anyway.... hmmmm... might place the order now :D

[gregbradley]

Congrats John. Magnificent image.

Greg.

[Satchmo]

How much does one of these scopes cost to the front door ?

[Peter Ward]

Yes it is.

BTW .....a half wave of spherical error spreads light in a totally different manner to a scope that is obstructed, but perfectly corrected.

..i.e actually reaches focus over it's entire field....as opposed to some clunker you can't actually focus anywhere in particular.

With obstructed systems, sure some MTF spatial frequencies may suffer, some may actually improve, but if well made, everything is *in focus*
(I frankly couldn't give a rats it the light is spilling into the first or even second diffraction ring...so long as that is the only place it's going)

Here is a link (http://www.atscope.com.au/BRO/roll/RefractorVSRha.html) to a "roll-over" pair of images to illustrate the point. :P

[Larryp]

Certainly a major difference, Peter. What refractor was used for the comparison?

[Peter Ward]

Rather not say..and it doesn't really matter.

Suffice to say, the data is not mine...I'm invoking "fair use of copyright" for comparative purposes ;)

[Larryp]

Ok-just wondering if it was a run-of-the-mill refractor, or a top shelf one.

[Peter Ward]

Run-of-the-mill.... But, to the point, still nicely made and way-better than 1/2 wave.

[RobF]

Gosh that's beautiful. It just "feels" right - and no sharpening. What an OTA.

[strongmanmike]

Pleeeease don't resign this beautiful beast to the ho hum been there done that over and over again corridors of more boring B&W Halpha :zzz:...spread it's wings and fly it through the colours of the universe John, let this be thy awakening...for us ALL :prey: :thumbsup:

Mike
You have produced amazing Ha work...just sayin :whistle:

[Peter.M]

What a magnificent first light.


I don't really agree with your comparison as all things are not equal, seeing guiding mount ect. What I don't really understand is people arguing about the telescopes design not being optimal when the real world results are staring them in the face and then pointing to the cost of the scope as a fall back.

eg "50% obstruction, diffraction rings blah blah blah"

"But look at the image its amazing"

"Yea but that's because it costs a fortune!"

[Peter Ward]

Absolutely! :) ...it was hardly an apples vs apples.

As for the cost....hey, if you are seriously looking at the latest, say, Ferrari 458 speciale (http://458speciale.ferrari.com/en/)....price is irrelevant :)

[dvj]

You're killing me Mike! :rofl:

If you want to see what this scope can do in color, here is a tri-color shot that Roland did with this instrument as part of his pre-shipment testing.

http://www.qsimaging.com/gallery/NGC7000-Christen-QSI683.jpg

He shared the original with me at the AIC which blew me out of my chair. Too bad the 8300 array has such shallow well depth and poor QE. I'm actually thinking a 6303 camera to match the instruments light gathering capabilities on very obscure narrowband targets.

jg

[strongmanmike]

Sniff sniff...I smell B&W Ha agaaain :scared3:

Hmmm?...O-K, I guess I'll allow that :confuse3:... but only if they are in tricolour NB or RGB :shrug: hey just about anyone can get sharp wide field images with a 3nm Ha filter :rolleyes: :zzz2:

:thumbsup:

[Satchmo]

My post was actually in response to exclamation at how sharp the images were.

I wasn't arguing . I'm pointing out that a good telescope with an EER of 50% does very nicely for imaging and this is some kind of benchmark - something we couldn't seam to establish in the other thread. It is not about the optics beeing 1/20 wave rather than 1/4 wave although I'm sure every bit helps..

Still wondering how much one of these costs to the front door .

[Peter Ward]

About $23.5K ....and probably headed north of that, with the $A headed south at present.

[Shiraz]

that's a lovely image John - top shelf.

[Poita]

24 grand? (Choke). I would hope it would outperform a run-of-the-mill 'ED Refractor' then, seeing as it costs 24x as much :)

I would love to see a compare image between it and a quality refractor.

It is a beautiful image.

[dvj]

$24K? Maybe in Australia dollars it costs that much, but not in the US. Not even close. No argument from me that there are better value instruments out there.

I've seen the comparison images from this scope and Roland's amazing 175 F/8 refractor. Nearly identical, although I would probably give the F/8 refractor a slight edge in star sharpness. The 175mm refractor is actually several thousand US dollars more expensive.

[bratislav]

Re tiny stars.
It is the fast f-ratio (as well as superb field correction, AND an uber narrow H-alpha filter) that makes stars so small. At f/3.8, even including several rings of Airy disc pattern ('cause of 50% obstruction), they will still fit into STL11K's single pixel, more or less.

Spectacular first light BTW. Those tiny Bok globules are so well resolved it beggars belief the shot was taken at only 1160mm focal length!

Bratislav

[Larryp]

Sigh! A 175mm f8 Starfire-one can only dream!

[dvj]

2nd light from the RHA 305

This is a crop from the full res STL 11000M format.


IC 1805
9 x 1800s
RHA 305 f/3.8
STL 11000M
3nm AstroDon Ha filter
1200 mount.


Because I am currently manually focusing, I was off a tad during the last 4 exposures. But happy with the result. Even at 9um pixels, the resolution is fine enough to perform a crop on this interesting portion of the nebula complex, representing about 30% of the original STL11000 image.


http://img837.imageshack.us/img837/5350/cyp4.jpg (http://img837.imageshack.us/img837/5350/cyp4.jpg)


Cheers,


jg

[LightningNZ]

Jesus, it's beautiful.
-Cam

[strongmanmike]

:zzz2:

Neb looks good but the stars are flat and hard edged so booo lift your game Gleason...or pass that scope on to someone to do real imaging with it :mad2:

:lol:

Nice work ;)

Mike

[dvj]

No worries Mike. I've already taken the scope down and packed away into the vault. Back to the FSQ for me.

[gregbradley]

Such an impressive instrument. Are the hard stars a characteristic of the scope or too much deconvolution?

Greg.

[iceman]

Stunning image, John.

It's now IOTW (http://www.iceinspace.com.au).

[strongmanmike]

Yeh, funny how some people actually do that with AP scopes, buy them and then store them, they aren't really scopes but rather collector items to some :shrug:

Oh well, fair'nuff completely understand :lol: at least you will be able to move that around more easily :P

Ok how about an M42 next, that's pretty obscure :question: haaaaave to do that in colour though :shrug:

:thumbsup:

[Paul Haese]

Both images are really nice John. Great detail.

[whzzz28]

Every time i look at such amazing images some part in the back of my mind immediately starts saying: "No. No you can't afford it."
Then i get all sad :(

Awesome images, looks to be an amazing scope.
Hard stars could be processing - mine look like that sometimes when over-sharpened.

[Rex]

WOW! I can only dream of producing something like this. Congratulations on a great first light John.

[Peter Ward]

Maaate.... even McDonalds costs 25% more here. Go figure. :shrug:

[dvj]

Holly Smokes, Thank you Iceman!

[dvj]

I don't understand the hard stars comments when it comes to narrowband imaging. There is no sharpening or deconvolution to these images. Processing consists of curves and levels only with a little bit of noise reduction because they are a short set of subs. These first images represent what the RHA is capable of producing without massive post processing and software trickery.

[Peter.M]

Who cares how hard the terrible magenta stars are when you mask them away anyway. I would prefer slightly hard edged stars than a blurry blob any day!

[marco]

Wowowow :) Now let's the dance starts, can't wait to see what a such instrument will produce in your hands under the pristine sky of Coona!

Superb first light John :thumbsup:

Regards
Marco

[Leonardo70]

Congrats....on first light and on IOTW.

All the best,
Leo

[SkyViking]

Those are some awesome looking images John, you must be very happy :) Looking forward to more!

[White Rabbit]

Stunning image, congrats on IOTW.