Take two with the little AT65EDQ

atalas · #1 03-02-2011, 01:44 PM

Hi again guys

This shot of the Southern Pleiades is take two of the testing of the AT65EDQ.

Exposures on this on were: 10 minutes x 15 guided.

http://www.atalas.net/components/com...ate=&location=

h0ughy (David) · #2 03-02-2011, 02:07 PM

nice looking shot Louie - did you software add the spikes?

Peter Ward · #3 03-02-2011, 02:58 PM

I would have expected the star sizes to be much much smaller at that focal length.

....didn't need the fake diffraction spikes either.

Sorry, just calling it as it see it

atalas · #4 03-02-2011, 03:26 PM

Quote:

Originally Posted by h0ughy

nice looking shot Louie - did you software add the spikes?

Hey Houghy!

Thanks mate....spiking,fake...guilty as charged !

atalas · #5 03-02-2011, 03:33 PM

Quote:

Originally Posted by Peter Ward

I would have expected the star sizes to be much much smaller at that focal length.

....didn't need the fake diffraction spikes either.

Sorry, just calling it as it see it

Hi Peter

Hey,I've long respected your opinion and don't see which other way you should call It ! but(the"but"you'll hate)as far as star sizes go mate I fail to see why you would think that a 1.6mag cluster with 10 minute subs would transpose to smaller star sizes

....still,I haven't star tested these optics yet to see how well corrected the figure is an that would degrade things I'm certain of that mate...will take on board your comments I promise you that!

Peter Ward · #6 03-02-2011, 04:51 PM

Quote:

Originally Posted by atalas

1.6mag cluster with 10 minute subs would transpose to smaller star sizes

....

No worries Louie, but it's not the bright stars to which I'm refering...

The background suckers look indistinct and fuzzy to me...given the exposure time I would have expected to a mryiad of tiny needles there.

The forground stars are actually very good, if there is a spherical error it's trivial at best.

atalas · #7 03-02-2011, 05:39 PM

Quote:

Originally Posted by Peter Ward

No worries Louie, but it's not the bright stars to which I'm refering...

The background suckers look indistinct and fuzzy to me...given the exposure time I would have expected to a mryiad of tiny needles there.

The forground stars are actually very good, if there is a spherical error it's trivial at best.

Oh I see Peter! well,could be the fact that my mount and guiding don't cut the mustard(highly likely) could be the fact that I soften the background to get a better sense for depth of field,could be the fact that I smash the image with Highpass,unsharp mask,and a touch of gama radiation, or the seeing was bad or just the simple fact that this scope just ain't an FSQ!

I think I just about covered everything.....on a more serious note though,any thoughts Peter?

Oh,actually Peter,the stars don't look much tighter in this shot of M93 I took with the FSQ and the AP mount....so,could be the way I process the background? oh yeah,then It could be the fact that It is only 65mm? or maybe the faintest are with resolution?

http://www.atalas.net/components/com...ate=&location=

bert (Brett) · #8 03-02-2011, 06:04 PM

A poor mans FSQ perhaps?
Is that image a crop? How does it compare with the fs60?

I think the image works quite well. I'd be happy with it.

Brett

atalas · #9 03-02-2011, 06:19 PM

Brett,when I can get the FS60's chip to reducer space accurately, so It performs at It's best, I let you know mate...have had two adapter made up already and both are incorrect....very frustrating! but honestly,I don't believe a doublet can cut It for color correction on bright stars anyway.

richardo (Rich) · #10 03-02-2011, 11:34 PM

Hi Louie,
ahh, good to see you've sorted your issue with elongation to the edges... what was it??
I know how hard it is to track down these issues..

Image looks good... well processed.
But I'm not really an artificial spike fan though, although it does direct ones attention straight to the cluster. jimo

Look forward to more from this great priced little quadruplet scope.

All the best
Rich

atalas · #11 04-02-2011, 01:48 PM

Hi Rich

Spikes.....sorry mate,I tried hard to resist but resistance was futile!

Ah,like I mentioned in the first light post,I had to use an extension tube to get to focus and It was one of those cheap one thumb screw bintel ones...cause It was going to create issues,I new that but didn't think I had anything else with me on the first night.

The next night I ended up finding some screw on T-thread extensions that I could use,so hence the improvement.

gregbradley · #12 04-02-2011, 02:41 PM

Interesting image Louie. Is this scope a Petsval like the FSQ? I wonder if they plan larger apertures. I am surprised Tak does not bring out an FSQ125. I know they have their TOA series but the FSQ is their best seller surely.

As far as star sizes go that is tricky. I find myself the best star sizes usually come from larger apertures and bigger chips. Small apertures often get larger stars?? Even the FSQ106ED with its reducer gets larger stars than I would have hoped. I think you get better star sizes with the FSQ at its native focal length.

Of course seeing and focus play a big part here. Did you use an electronic focuser? It is hard to get exact focus with Petsval scopes without one and the faster the scope the smaller the critical focus zone.
A small bit off and the FSQ with reducer star sizes can be nearly 50% bloated.

Greg.

Peter Ward · #13 04-02-2011, 02:58 PM

Quote:

Originally Posted by atalas

.....on a more serious note though,any thoughts Peter?

I think Greg may be on to something: Focus, focus...and did I mention focus?

atalas · #14 04-02-2011, 03:28 PM

Greg,no not a petzval,here's a link to the specs:

http://www.optcorp.com/product.aspx?...w=AT65EDQ&st=2

No motor focuser was used but does have a very nice 10-1 micro.

atalas · #15 04-02-2011, 03:37 PM

Quote:

Originally Posted by Peter Ward

I think Greg may be on to something: Focus, focus...and did I mention focus?

Focus!!! no you didn't mention It! easy to see what you were leading to though!

Well,on this night I used a Bahtinov mask and checked the focus every few subs and can promise you It was as tight as It was going to get on the night.....cause,unless there's some issue with these masks that I don't know about.

At the moment I'm still leaning towards the optics....a star test will reveal all,when I get around to doing one.

gregbradley · #16 04-02-2011, 03:52 PM

An interesting scope design. Basically a triplet with a single lens flattener. Sounds on paper like a winner.

Greg.

atalas · #17 04-02-2011, 05:11 PM

Yeah they always do on paper mate, but I didn't have high expectations from this cheap scope anyway and having owned two FSQ,the ED and the N myself I know what sharp optics is.

My next scope will be the BabyQ and reducer and no doubt after that I'll get itchy feet again and try something else....you know how It is.

gregbradley · #18 05-02-2011, 10:02 AM

That's a nice offering though at modest cost.

Arh yes I do indeed know the scope/camera/mount itchy feet feeling!

Greg.

Paul Haese · #19 06-02-2011, 11:39 AM

Nice image Louise. I really like the colours and the field of view makes the cluster look great.

atalas · #20 06-02-2011, 06:34 PM

Paul,thank you very much....It's nice to hear from you. Now,being a fellow ceiling fixer I take It you didn't mean to call me Louise!