First Light from the All Reflecting Refractor

[dvj (John)]

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...

But did you really expect anything less

[multiweb (Marc)]

+1 terrific shot.

[alpal]

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

[dvj (John)]

Originally Posted by Peter Ward

A superb first light result...

But did you really expect anything less

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 (Bob)]

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

[strongmanmike (Michael)]

Originally Posted by dvj

It did however, take my inner Strongman Mike to lift, snap, and drop the OTA into the rings.
JG

He he: Scope Lifting

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

Mike

[dvj (John)]

Originally Posted by strongmanmike

He he: Scope Lifting

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

Mike

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

j

[dvj (John)]

Originally Posted by 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

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]

Originally Posted by 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.

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 (Jason)]

What more can one say...really...
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

[gregbradley]

Congrats John. Magnificent image.

Greg.

[Satchmo]

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

[Peter Ward]

Originally Posted by Satchmo

.... 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 .

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 to a "roll-over" pair of images to illustrate the point.

[Larryp (Laurie)]

Originally Posted by 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 to a "roll-over" pair of images to illustrate the point.

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

[Peter Ward]

Originally Posted by Larryp

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

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 (Laurie)]

Originally Posted by 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

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

[Peter Ward]

Originally Posted by Larryp

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

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