Orion Nebula version deux

[olyinaz]

Started over from scratch and I'm quite a bit more pleased with this version.

Exposures from 8-25 seconds stacked/blended/masked and all that.

Cheers,
Oly

 

[monza]

Very nice. Being able to use the shorter exposures is a big advantage. What is the effective aperture?

 

[olyinaz]

Not sure what the effective aperture is but the actual aperture is 280mm with a central obstruction of about 30%. The Hyperstar makes it act like an f/2 optic so about 560mm of focal length.

Cheers,
Oly

 

[monza]

OK, f/2 that's only a few stops faster than my f/10. That's a big advantage...much shorter exposures.

 

[olyinaz]

LOL! Oh yes, that's what you were getting at!

Indeed that's what one is paying for with the Hyperstar - a fully corrected, flat field (no coma and pinpoint stars all the way to the edge of frame) f/2 astrograph. It's the f/2 that makes it because most of us simply can't afford mounts that will track straight and true for tens of minutes.

Cheers,
Oly

 

[monza]

Oly, can you take photos like this with an alt-azimuth mount since the exposures are so short?

 

[olyinaz]

Yep, the Hyperstar was designed with alt/az mounts in mind. Many folks are having great success with their Celestron Nexstar mounts. I'm told that about 30 seconds and less works best with alt/az mounts due to field rotation.

Cheers,
Oly

 

[monza]

That's good to know. I do have a wedge for my scope, and if it's polar aligned, that could stretch the exposure time somewhat...I'm thinking maybe it would be best to invest in Hyperstar first, and then a better mount later.

 

[Jack]

A stupid question as I know zero about astral imaging technique...

Can you take one exposure and then create multiple layers of it, or do you have to blend physically separate exposures, and why?

Thanks,

 

[olyinaz]

That's good to know. I do have a wedge for my scope, and if it's polar aligned, that could stretch the exposure time somewhat...I'm thinking maybe it would be best to invest in Hyperstar first, and then a better mount later.

I don't disagree at all. Even your older mount should be able to do quite well on the wedge if you get it polar aligned.

The only thing that comes to mind is to give the folks at Starizona a call about converting your C8 for the Hyperstar. They replace the unit that holds the secondary with a part that allows the secondary/Hyperstar to be swapped in/out without losing collimation of either - it's really slick but it requires that the unit holding the secondary be disassembled and replaced (just the central part that holds the secondary mirror - the corrector plate remains of course). I carried mine in and had it done but obviously people all over the world are using Hyperstar so it must be user-doable, I just don't know the particulars.

Best,
Oly

 

[olyinaz]

A stupid question as I know zero about astral imaging technique...

Can you take one exposure and then create multiple layers of it, or do you have to blend physically separate exposures, and why?

Both.

In this case I developed two different versions of my raw files - one for max brightness and one much less so to preserve the detail in the bright middle of the object - and then layered/masked them together.

In another case one might capture a series of exposures at different lengths, create several layers from those exposures that were blended for noise (median combine in other words), and then blend those different exposures with layers (similar to what I did but using better data and more exposures to start with).

In yet another technique one captures many exposures of a very very faint object at the maximum length that one's equipment can handle (in my case about a minute but with a separate guiding CCD I could go for as long as the G1 can handle - multiple minutes) and then you stack those images not as a median combine but as an additive combine in order to simulate having taken a very very long exposure. The Hubble uses this technique quite a bit.

Using the last technique one might capture 40 "subs" (as they're called) and stack them 10 at a time (additive) and then merge those 4 images (median) for noise reduction. The choices and combinations are endless and I am only just getting started at this but often times it's the time factor - one only has so much time per night (or in life) to get this done - that limits what one can do.

Still, with that said I've seen images from local astronomers that needed 12 hours of exposure captured over the nights of a week in order to bring a "dark fuzzy" to life in a final image. These guys live out in the boonies (or sometimes drive to New Mexico for dark skies), have tens of thousands of dollars invested in their gear ($15,000 telescope, $15,000 mount, $10,000 camera etc. etc.) and they take the "hobby" very seriously indeed.

One's pocketbook and imagination seem to be the only limitations but as you can see by visiting HyperstarImaging.com it's possible to do this for about the cost of a good camera lens.

Cheers,
Oly

 

[monza]

It's truly amazing how far things have progressed in this area...

Talked to Starizona today. They can convert the scope, I'll probably ship it to them and have them do it.

There is some question about using the G1 on a 8", the guy I talked to didn't seem to think a standard DSLR would work due to the flange distance. The G1 isn't a standard DSLR as we all know. Of course, the G1 may block too much of the light on an 8" anyway.

What kind of adapters are you using on your G1?

The G1 being small I'm hoping it would be usable on my existing scope. If I have to buy something, it's probably best to buy a bigger scope and use my existing cameras (D700 also) instead of buying a specialized CCD camera.

Thanks again Oly!

 

[psurfer]

Wow!
I think I'm having a flashback!

Y.B.III ... nocti... can't feel my brain...

 

[olyinaz]

It's truly amazing how far things have progressed in this area...

Talked to Starizona today. They can convert the scope, I'll probably ship it to them and have them do it.

There is some question about using the G1 on a 8", the guy I talked to didn't seem to think a standard DSLR would work due to the flange distance. The G1 isn't a standard DSLR as we all know. Of course, the G1 may block too much of the light on an 8" anyway.

What kind of adapters are you using on your G1?

The G1 being small I'm hoping it would be usable on my existing scope. If I have to buy something, it's probably best to buy a bigger scope and use my existing cameras (D700 also) instead of buying a specialized CCD camera.

Thanks again Oly!

If you do ship your C8 to Starizona you might consider having them fit it with a counterweight system that allows you to balance the scope with everything (including a DSLR piggybacked) attached to it. They make one that attaches to the bottom, has a sliding rail weight system and works really well.

Definitely a G1 will not have a flange-back problem but the Hyperstar needs to position the G1 in exactly the right place (the Hyperstar's focal plane) and perhaps they don't have an adapter already made for the proper distance? In my case, with the C11, it was easy because I ordered my Hyperstar with a Nikon mount and then I use Nikon-4/3rds adapters to get the G1 in the right position but perhaps the C8 Hyperstar does not come with a Nikon (or Canon) mount? I dunno. One thing's for sure, if they know the distance they need to make it they could make you a T-mount adapter but I do see how this is a possible hurdle.

And I concur that you'd be better off starting over with a new C11 or C14 (even better - if I had it to do over I'd start clean with a C14 on a Celestron CGE mount) than trying to get too crazy with a vintage C8.

I'll look into it a bit more when I get home from my current business trip! I'm curious myself now.

Cheers,
Oly

 

[monza]

Yep, the counterweights are necessary...

The problem with the G1 is the need for a custom adapter...I called again and spoke to a different guy. (They need to learn about the G1, it's a fantastic option instead of those pricey specialist cameras.)

For now, I'm going to proceed with the current equipment, see how good I am at polar alignment and such. And I can even use the G1 for viewing, I suppose, just flip out the LCD.

By summer, though, I plan to have a full Hyperstar setup...just a matter of which scope and mount.

 

[GDI]

Another great shot!

You are very kind to share your astro experiences - and even kinder to try to give folks an idea of what a commitment it is to pursue seriously! :clap:

If you don't mind I would second some of your cautions and make a suggestion or two to those considering giving it a shot.

I pursued it fairly intensely for a couple of years - trying all the while to stay in a reasonable budget. Up till 4am setting up and SCT and piggybacked refractor, drift aligning, shooting tens of 2-3 minute exposures via a timer on an Astro DSLR, then tearing down and storing it all. Then processing all of these shots to obtain an Ok shot of a DSO.

Then I decided to can all that stuff and I bought a small clock drive (Kenko SkyMemo) which I can easily align and take casual yet fairly satisfying wide field shots. I have it on a standard small scope tripod and my camera attaches directly to it. I am not going to get any great shots of the harder DSOs, but some of the bigger objects are perfectly doable with standard camera lenses on the drive.

SO anyone who is seriously considering taking up astro, may want to consider a lower tech intro. A simple clock drive, or even a "barndoor" hand driven mechanical drive and a camer and lens can give you an idea of what it is like, what is achievable and then you can decide how far to take it.

If anyone does decide to go for it - -good luck!

I took the following with this simpler setup - and either a 50mm or 200 mm on a 1.6 crop DSLR (Astro model for H Alpha sensitivity)

50mm Zeiss Planar: area of Deneb/Sadr and North American Nebula:

200mm Canon lens: closer shot of North American Nebula

 

[Bob]

I am impressed.
This area of photography I know nothing about, but I am afraid to get interested
I think I will sit back and witch the slide show.
Keep it up, this is cool.
-bob

 

[olyinaz]

Absolutely GDI! A camera and lens is all that is necessary to take some really stunning wide field views provided some basic tracking is undertaken. I found a basic equatorial mount for less than $100 on my local Craigslist.

Regards,
Oly

 

[bensonga]

Oly,

Just wanted to say how much I've enjoyed your astro photos. I've been a member of the Yahoo Digital-Astro group for a number of years and an amateur astronomer for quite awhile too. It's really amazing what folks can do with a DSLR and telescope these days....excellent work Oly!

I'm still primarily interested in visual observing myself....especially the challenge of finding objects with a sky chart.....ie without the benefit of a GOTO mount. It's like an elaborate game of hide and seek.

Of course, the Orion Nebula is a favorite. The best views I've EVER had were thru this 30 inch Dobsonian at the New Mexico Skies site near Cloudcroft, NM. If you ever have the chance to go there, it's well worth the trip! They also have a number of very high end telescopes and state of the art CCD cameras which you can rent for the night (in these Astrohaven domes). Pretty amazing stuff. I've been there five times since my first trip in 2002.

I never get tired of looking at the stars.....I only wish we had some clear and dark nights up here in Alaska when the temps weren't well below zero degrees F.

Gary Benson
Eagle River, Alaska

 

[Lupo]

...They also have a number of very high end telescopes and state of the art CCD cameras which you can rent for the night (in these Astrohaven domes)...

really crazy

.....I only wish we had some clear and dark nights up here in Alaska when the temps weren't well below zero degrees F.

I wish we had here at all times only 1 clear night ......