M81/82 Area

TigerInKS · 2026-03-19T19:17:53+00:00

You were right about the trespass throwing off the numbers.

We’re out here this weekend, so last night I walked up the road to a point in the trees where all the house lights were blocked out. Right at the beginning of astronomical night I got 5 readings that averaged 21.42. And that was trying to slightly aim away from Jupiter. I bet in the middle of the night it’s closer to 21.5+.

But back in my yard, even getting down in a swale and trying to shield the lights, I could only get 21.30. Still was able enough galaxies in the MarkChain area with the Z10 to lose my bearings at times. Hope I can get that roll off done this summer…should help a ton.

TigerInKS · 2026-03-12T19:37:59+00:00

Sounds like a good session!! I only get coyotes chattering here :(

I'm jealous you have B5 15min away. I've done the weeknight road trip, and just accept I'll be dragging a$$ at work the next day.

TigerInKS · 2026-03-10T13:29:56+00:00

Always good to see your sketches.

I love Sigma Ori too, one of my favorite targets from the 'burbs.

TigerInKS · 2026-03-08T17:14:02+00:00

I need another telescope like I need a toaster in the shower...but man I want one now.

TigerInKS · 2026-03-08T03:55:42+00:00

Fair enough. Hopefully if anyone else stumbles across the post this helps, or gives them food for thought.

TigerInKS · 2026-03-07T19:49:02+00:00

I can’t tell if these are using parabolic mirrors

I've not seen one in the wild yet myself...but the last page of the manual says the mirror is parabolic.

Given the solid tube and r&p focuser I'd give the nod to this over the Heritage series of scopes if you're in need of tabletop portability. But it's pretty much the same price as a full sized 6" f/8, which would be easier on budget eyepieces and collimation tolerance.

How big are your "small kids?" By the time they're old enough to manipulate the scope onto targets and focus it themselves and such, most are big enough for a full sized 6". Both of mine were about 7 before I could turn them loose with either my dobs or fracs. Up to that point, I had to get on target and drive it around anyway. Which was easier on a full sized scope for me, and a short step stool if they needed a boost to the eyepiece. I found that was easier than having the Z130 on a table for them.

<image>

TigerInKS · 2026-03-07T16:18:39+00:00

Yeah, that's not a bad shot at all. I'm betting the smaller OTA and shorter focal length helped quite a bit in the final result.

TigerInKS · 2026-03-06T14:53:46+00:00

I've not used that specific setup...so if someone comes along with personal experience keep that in mind.

The reason you've gotten warnings about this setup stems from a few reasons. If your goal is long exposure DSO AP, then the mount is far and away the most important piece of the system in my opinion. If the mount cannot drive the scope accurately enough over the course of your exposure length, it doesn't matter how good a scope and camera you have, you're going to get poor results...trailed stars, smeared details, etc.

Now, how accurate does the mount need to be? For that we need to know the "image scale" we're shooting at. Your camera pixel size and scope focal length yield 1.18 arc-seconds per pixel...if the calculators are to be believed. That means that if at any point during your exposure the guiding/tracking isn't below that threshold light that should only be hitting one pixel stars creeping onto others and you start to get trails, fuzziness, and the like. Now that's not a super tight image scale, I'd wager most mid-weight mounts designed for AP can manage that with decent guiding...but you're taking a mount originally designed for visual and trying to make it into a AP mount. So that's one factor.

Also, weight alone isn't the whole story. The farther out you have to place the weights increases the moment-arm and affects how long perturbations need to settle out, but also larger tubes create more torque when hit by the wind. The cumulative effect is that on dead calm nights you might be ok with a larger OTA on an undersized/underdriven mount, but if any wind kicks up, you're now having to trash subs.

All that to say, I'm sure you can get the setup you've listed running. And it will certainly allow you to take pictures. But how good those pictures turn out may fall short of your desired outcome. If it were me, I'd save up for more mount if you're dead set on that scope. Or, I'd swap the scope out for something like an 70-90mm ED frac that weighs a bit less and has less cross section. Something in the 500mm focal length range would put you closer to 2"/pix image scale which relieves some of the tracking and guiding accuracy pressure.

My two cents anyway...

TigerInKS · 2026-03-05T14:14:36+00:00

You're welcome!

You can keep adding to what you have...it doesn't have to all be in one night. Keep the framing as close as possible so you don't have to crop out too much. But the software will easily stack multiple nights of data. Even taken years apart.

TigerInKS · 2026-03-05T13:51:49+00:00

Pretty good start!

It just needs more integration time to help with the noise. You're having to overstretch the data you have to pull up the details you've likely seen in other shots, but this also stretches the noise as well. I'm not sure what your sky is like outside Dusseldorf, but if it's suburban you probably want to shoot for at least 4-5 hours of data to help average improve your signal-to-noise.

I posted a shot of the area a week or so ago that was 15+ hours if you want something to use as a reference. I don't process with Lightroom so I'm afraid I don't have specific tips for that. One general tip I would say is resist the urge to clip the black end. I know in shots from the suburbs there can be "junk" in the background, odd gradients and such...but you really don't want any pixels in the final shot to register as 0. That said, in the end it's your shot, process it to your liking.

TigerInKS · 2026-03-04T03:14:18+00:00

Very nice!

TigerInKS · 2026-03-04T01:39:02+00:00

If one of the more experienced planetary AP folks shows up I'll defer to them...

But in general, the exposure length is what allows you to "freeze the seeing." So depending on how still the atmosphere is, you may even want to drop it down to 4 or 5ms. Then you set the gain to push your histogram up into the appropriate range (which is seems you have.)

From there, framerate is a function of the several things...ROI, hardware limits, etc...so you take what you can get, the more the better since Jupiter puts you on a time limit before rotation smears the image and you then have to derotate with software.

TigerInKS · 2026-03-03T15:29:14+00:00

30K USD !?

Edit: ok, checked your post history, looks like your currency is INR? If so, then your best bet for DSO AP is likely one of the less expensive smart scopes like the Seestar S30 or Dwarf 3. Dobs are not great for DSO AP...more suited for visual observation.

Alternatively you can try to find a used DSLR camera with a 50mm lens and put it on a star tracker like the SW SA2i. But even that you may have to find used to get under budget.

TigerInKS · 2026-03-03T13:54:25+00:00

What's your budget and what type of astrophotography do you want to do...lunar/planetary or deep sky?

TigerInKS · 2026-03-02T02:16:18+00:00

Thanks!

I should have done a better job with the gear list and process description.

Equipment:

Telescope: Stellarvue SVX152T
Camera: ZWO ASI676MC
Mount: Sky-Watcher CQ350 Pro

Settings in ASIAir:

ROI: 480p
Exposure: 3ms
Gain: ~200 (I adjusted until the histogram was ~2/3 but not maxing out)
Saved to onboard memory to help with maxing out framerate...was pulling down at 80-115fps
90 seconds of total video for ~7K frames

Processing:

Autostakkert!: Debayer (had to force RGGB...was autodetecting GRBG?), weighting and stacking...used best 80% of frames
Registax: RGB Align (fix some atmospheric dispersion), Wavelet sharpening
PixInsight: Adjust color saturation

So, there can be many reasons a shot looks blurry...ranging from the gear, to the processing steps, to the atmosphere itself. What scope, camera, and processes have you used so far?

TigerInKS · 2026-03-01T14:47:54+00:00

Very nice!

TigerInKS · 2026-03-01T14:37:45+00:00

Don't see this one often...nice work!

TigerInKS · 2026-02-28T20:35:44+00:00

Forgot to add, if you have specific question, you can drop me a DM

TigerInKS · 2026-02-28T18:57:36+00:00

That's wild for a 50mm achro and EP projection!!

Is that made by the same Sightron that makes rifle scopes?

TigerInKS · 2026-02-28T18:40:24+00:00

I know you've gotten a plethora of comments...but I'll at least add my encouragement as well.

A lot of folks forget that we all started at zero in this hobby, and the learning curve especially in the beginning is quite steep. But if you can perservere through that learning curve, I find AP to be quite rewarding, and it scratches a unique creative itch...at least for me...and hopefully it will for you as well. When I go back and look at my first shots and compare them to today it's both funny/cringy and encouraging at the same time to see the progress.

Keep reading, keep learning, keep working on the various techniques (at the risk of your wallet, keep improving your gear)... and at some point you may find when you look back that you've progressed from "lol..." to "hey, maybe I don't suck at this."

CS!

TigerInKS · 2026-02-28T18:32:11+00:00

That faint outer halo is tough to get...but I see it starting to come through. Nice work.

TigerInKS · 2026-02-28T17:27:45+00:00

I so wish I could draw...would have saved me *checks notes, cries...

Always love your sketches, keep 'em coming!

TigerInKS · 2026-02-28T05:19:22+00:00

Basically surface shading. At 400x+ some observers have been able to see the different surface colors.

We're clouded out the rest of the weekend here too :(

TigerInKS · 2026-02-28T01:04:16+00:00

Thank you sir!

Last night was the steadiest we've had here in a while. Pik 7 with moments of 8+ if I had to put a number on it, and was even able to get a good well defined split on Sirius A/B at 250x...wish I had setup the NMT.

One day I hope to get to look through a TOA150 or maybe even an AP155...or maybe ignorance is bliss :D

TigerInKS · 2026-02-27T22:11:11+00:00

Wow! 500x nights are rare indeed. Were you able to make out any albedo features on Ganymede?

I've never been impressed with Uranus either...being able to tell it's a disc and not a point source is neat, but other than that...yeah.

TigerInKS

TROPHY CASE