Second "first light" of Quattro 8" CF

[MikeWilson]

Dear all,

This is my second attempt with the Quattro 8" CF using a selection of cable ties and carefully balanced objects to weight it. Guiding was absolutely shocking and had to be restarted every 60 seconds or so.

8 x 5 mins + 1 x 10 mins.

I thought this time I would try to image something fainter without any bright stars (they appear oblong) to see how the faster focal ratio performs.

And here it is after a quick and dirty process.

The original stacked data: http://dl.dropbox.com/u/3717210/Heart%20Nebula%20-%20Quattro%208CF%20-%2002-09-2011.TIF

Just for those interested...

[blinky]

Looks pretty good to me! The stars look nice and round - How do you find collimation?

[MikeWilson]

Comparing collimation from my previous Explorer 150P (6" f/5) to the Quattro (8" f/4) seems similar to comparing cycling a pushbike compared to a penny farthing. In principle the mechanics are the same although f/5 is very much more forgiving to collimate than f/4.

It might also be scope dependent but I noticed that the Quattro did not hold primary mirror collimation very well (testing with a laser) compared to the f/5 newt. For instance the return path of the laser drifted approximately 50% across the surface of the laser collimator over the course of this imaging session. This was after leaving the scope outside for two hours to acclimatise. I saw this behaviour with the f/5 too, but no were near as severely. The secondary mirror remained spot on or very close to the center spot.

In actual practice it's probably not a problem and it's probably too early to say for sure but I suspect that many 8" Quattro owners will want to be performing the 'silicon' modification to the primary mirror cell.

As for the stars being round; they were processed to look rounder than the raw stacked data does, although I couldn't get the scope balanced.

All the best,

Mike

[blinky]

Very interesting, you gotta tell me how to get round stars in processing though.....

[MikeWilson]

Very interesting, you gotta tell me how to get round stars in processing though.....

Noel's Actions for Photoshop - "Make Stars Smaller" (although you can do a similar thing using deconvolution; I read a tutorial on it once).

Resize/resample smaller.

All the best,

Mike

[johnrt]

Looking good Mike and a long time coming from what I gather?

[shaunster]

Also a last light mike? Selling it and moving over to what?

[evanapp]

Hi, Mike,

Is the Quattro at all suitable for visual, or is it strictly an astrograph? Thanks.

Evan

[MikeWilson]

Hi Evan,

Yup, it's suitable for visual. I used it with the Baader Click-zoom eyepiece and thoroughly enjoyed panning the skies with it.

All the best,

Mike

[TheDaveWalker]

I'm gonna get me one of these, but it's 'vital statistics' seem hard to get hold of

- for example, how long is it?

...and how much does it weigh?

Pretty please?

Taa

[MikeWilson]

Hi Dave,

I don't have the Quattro anymore, so can't advise although I did post all the vital stats in the Quattro thread on the Dealer forum. Gotta be one for the forum search tool, I think

Search for posts by MikeWilson in the Sponsored Dealer forum. It's a big thread.

All the best,

Mike