First light with Ultrastar C

[jorman]

Hi folks,

I have been an astro - photographer for over 10 years now. I know nothing about live video astronomy, but I came across an article in Sky and Telescope and

decided to give it try since I belong to SCAS (Southern Cross Astronomical Society) here in Miami and we do a lot of outreach programs. As you all know with a live telescope once you have shown the moon, Jupiter, Saturn and sometimes M42 a million times, people tend to lose iinterest.  I purchased an Ultrastar C camera which arrived yesterday. So tonight I decided to try it out. I had my big SCT C14 set up outside so I put a Meade 3.3 reducer on the visual back and tried the camera with StarLive V3. I had seen some pictures on these forums , but I was not prepared for the Wow factor when the 10 seconds and 15 seconds image of M42 popped on the laptop screen. I have attached a mono and a color image for you to comment if you so choose. Do not mind the focus of the stars for I do not have any kind of focuser on my scope, it is just the coarse knob that comes with the SCT. The images are not stacked or process in any way. There was no Light Pollution filter either. Images taken from my pool deck in Miami,Fl.

On the other hand I was disappointed with the Jupiter image. I just could not get any detail on the planet. Just a big bright blob. I went down to the lowest exposure allowed, but to no avail....Play with all the buttons, but nothing. Probably either I do not know what I am doing or the C14 just gathers too much light. Also I could not use the stacking function. After two stacks, the stars became very elongated. The scope was perfectly level and my polar alignment was within 1 second. Thanks for listening.

PS: I could not attached the color picture. It is too big and I am too tired to play with it.

 

[HiloDon]

Hi Jorman,

Great to see success on the first try.  Although M42 is an easy object, seeing it with these cams is always inspirational.  When you get to some dimmer stuff, you'll see the importance of stacking.

Just a minor thing, but the Meade 3.3 will probably introduce some vignetting and corner coma.  Not a big deal for outreach, but if you eventually want some presentation images, it could be a negative.  I think you're interested in getting Hyperstar and that would be ideal with the Ultrastar, especially with the C14.

The Ultrastar is not a lunar/planetary cam.  It's sensitivity combined with the lack of short exposure time make it unusable for planets and moon.  These objects are better viewed visually anyway in my opinion.  There are too many beautiful DSO's to see.

Your stacking problem may be related to either the defective pixel removal being on or having the max pixel displacement set too high.  I think there may be a problem with the DPR with the Ultrastar.  I experienced a similar thing yesterday and reported it to Paul.  Just uncheck the box and try again.

Thanks for sharing your first experience.

Don

[jorman]

Hi Don,

Thanks for the quick response. Yes, there was some vignetting with my set up, but I am going to use this camera for live video only on our outreach programs. I have an XCM2000 from SBIG for my serious photography.

I believe that I have both the Max pixel displacement at 0 ( I did not even think about that function )  and the defective pixel box checked off,but I am not sure. Maybe I should have put some value on the MPD box ??

As far as Hyperstar I had one for years and actually ended up selling it. Just not worth the risks associated with it. Many times it got stuck to the corrector plate and I had to either remove the plate with it hanging from it or I needed to use an oil strap to turn it and more often than not it would turn the secondary assembly causing a horrendous collimation problem. I have mentioned this to Dean in Starizona in the past, but I do not believe there is a solution for the problem. Many other users have had the same problem.

PS: I have attached the reduced color image of M42

Regards,,,

M42_2016.3.31_21.01.42.png Size reduced

[Martin Meredith]

Hi Jorman

Great first image with SLL. I think your problem is with the Max Pixel Displacement being set to zero. It is best to set it to something like 8 or so (and then occasionally monitor the actual pixel displacement value that SLL reports when aligning subs; for longish stacks it can increase, and the solution is to increase Max pixel displacement accordingly).

Looking forward to seeing more images from your impressive setup.

Martin

[RobertI]

Hi Jorman,

Welcome to the forum, that's and impressive setup and I'm looking forward to seeing what it can do.

Rob

[aparker]

Nice first light!  As you found, the planets are BRIGHT!  Several options exist for viewing them with the SX cameras.

1. Use a narrowband filter.  This will cut out most of the light, but gives a mono image.

2. Use a neutral density filter at like 95%

3. Use a sub-aperture mask, probably 2-3 inches in size.

4. Gat a camera that has adjustable gain and turn it way down.

 

also, if your seeing will support it, use a Barlow lens to crank the image scale.

[laudropb]

Very nice first light.

[jorman]

Thank you all for your response. Frankly I did not know about the Maximum Displacement adjustment. Remember, I do not have any experience at all with live imaging or with Starlight Live. I am basically an astrophotographer.

Weather permitting I will try again tonight . This time I will use my Hutech LPS filter and play with the Max Pixel Displacement. I will let you know how it goes....

Jorman

[HiloDon]

Jorman,

I believe that the max pixel displacement setting set to 0 will stack images without registration, so any tracking errors will elongate the stars.  I believe Paul recommends starting with a setting of 15 to 30.

Re: Hyperstar.  Dean has a replacement secondary gasket available that will prevent the secondary mount from turning when installing or removing the Hyperstar unit.  If the mount does turn, it can be returned to it's original position by aligning the Fastar emblem with the scope.  The notch is typically at three o'clock.

Look forward to seeing more of your results.

Don

[Paul81]

Yep max pixel displacement set to 0 will just stack images without re-aligning them. I recommend a setting in the 16-32 ish range, but as Martin recommends check the value coming out on the stats display, and at least 2-3x it.

The camera and SLL are not designed for planetary imaging, only DSO.

Nice first light!

[jorman]

OK Great ! That probably explains the stacking issue. I will try again tonight.

Thanks,

Jorman

 

PS: By the way Starlight Live software is unbelievably intuitive and user friendly. Keep up the good work! I have attached the color picture that I could not before.M42_2016.3.31_21.01.42.png size reduced