ONIKKINEN

I get the feeling that Ed had decided before the review that he will not like it because it seems he is a bit anti-technology for some reason, which is odd since his videos are usually pretty good and more on the objective side than subjective. I find it very odd that he decided to compare the Seestar to a Takahashi on an equatorial mount, you cant probably even get a flattener for the Tak for the price of a Seestar. Very tone deaf for sure.

I also dont quite buy the idea that you shouldn't buy one now because there will be a better one in a few years. If we followed this logic then we would never buy anything, since technology is always on the move.

I would not bother with the bahtinov mask at all, really the HFR readings from NINA are all you need and the bahtinov mask is an extra step with no benefit. As long as you arent completely out of focus and stars are visible you get a reading and can take it from there. You can mark your focuser drawtube in rough focus, so you dont need to guess when setting up on subsequent nights and can jump straight to the actual focus part.

I use 3s exposures looped in NINA and focus manually based on the HFR reading. After you have used your kit for a few nights you get an idea on what kind of HFR to expect, so it really doesnt take too long to find the smallest HFR. NINA will also plot your subs when you image through a sequence, so you can see if focus has gone out and when refocusing is necessary.

As for offset, make sure you have enough. Too much is not an issue but too little is, my RisingCam IMX571 requires at least 600 offset, so i just left it at the default of 768 and never looked back. You can measure the required offset by taking a bias frame (same gain as intended imaging gain) and seeing if the min value is above 0. If it is 0, increase until it isnt.

Another trick is to install an aperture stop (less than 1mm) to the collimation laser, which will make the laser spot on the primary large enough to cover the entire center marker. Then you can collimate using the shadow of the center marker rather than just the reflected laser. Makes it easy to see how much adjustment is needed and to what direction, since the reflected shadow is now bigger than the central hole on the target plate the laser has.

I have not had any luck with barlows on my laser, have tried 2 barlow elements and a few different methods of laser to barlow attachment and they all disagree with each other - so not accurate.

Great images once again! Always happy to see this thread updated, really a treasure trove of tack sharp extremely classy lunar RGB images.

Just now, JonHigh said:

Oh I see. I'm so used to my triplet, Oh the fun of newts 😂 ! I will have to check with my brother as he set it up initially so I am assuming he has set it up correctly. I will check if the distance is correct maybe a spacer was left off? But would that explain the birdlike stars? Sorry for going on - Just want to understand. 👍

Its difficult to tell what is the cause. Most likely there are a multitude of issues. The backfocal distance is easy to check, you just need to measure 55mm between the coma corrector and camera sensor. It is important to keep in mind here that this does not mean 55mm between the coma corrector and the camera body, this means 55mm between the actual sensor in the camera and the corrector. The adapter train you need will depend on the camera, if you have a camera with 17.5mm between the connecting threads and the sensor, then you need an extra 37.5mm of adapters in between. Some cameras have 12.5mm, in which case you need 42.5mm extra.

I dont think backfocal distance explains the erratic star shapes, that issue is in collimation almost certainly. This doesn't look like a slight adjustment issue, but some fairly obvious misalignment so i think you may be able to "eyeball" the collimation to be a bit better by just looking down the focuser without a specific collimation tool. But a tool of some kind is necessary for good collimation, but it need not be that expensive. A simple collimation cap will get you started, a cheshire is better, and a good collimated laser can be the best option. Although for the laser you do need to make sure it is collimated itself, and you need to make sure it sits in the focuser correctly and in the same way a camera would - very sensitive to tilt and de-centering issues.

Hmm, i had assumed you did not have a corrector because it looks so bad. But since you did the backwards coma could also come from incorrect backfocal distance between the corrector and camera sensor, most correctors need 55mm.

Collimation looks wrong for both the secondary and primary. Again, dont worry about possible optical defects before you have it collimated and get a useful look at its performance.

Collimation is way, waay out for sure. Your coma has a backwards pattern in the top right, suggesting your collimation is like 3cm out of field here. The coma pattern of your top right should be in the bottom left.

The birdlike stars in the bottom look astigmatic, but you should make no conclusions on optical quality before the scope is collimated.

Both cameras i have used for flats have a slight sensor vignette (EOS550D and IMX571), so dont find that too strange.

My PC has an i7 6770k with 16gb of early DDR4 ram. Its getting a bit old but still works very well. SSD for processing is a must have.

Siril is hard drive write speed limited so still very quick, i would estimate maybe 3 or 4 times faster than Pixinsight or Astropixelprocessor, so i use Siril for calibration and stacking.

Processing in Pixinsight and Photoshop. For the RC-astro tools i have setup GPU acceleration with my RTX 4070ti and any size image will finish BlurXterminator in seconds. My old GTX 1080 was also very fast, so an older model will do just fine for that purpose.

You can open and process the .SER file with Autostakkert!3 (or 4, the new beta version). You could also download SER player to quickly view the recording.

SER format is a video recording, so multiple images in the same file. Recommended for planetary, unless you want to have 10 000 images saved every few minutes. SER is also lossless raw data so you should stick with that.

MONO 8/16 is the bit depth of the recorded frames, so either 8bit = 0-255 or 16bit = 0-65 535. Most of the time you want to use 8-bit because file sizes are lower and thus capture framerates will be faster.

In short i recommend MONO 8 and SER file format and opening the file with Autostakkert when stacking into an image.

1 hour ago, Kon said:

Great images. You have done an excellent job under the conditions as you have resolved the small craterlets very nicely. Nice delicate colours too.

Thanks, i think colour adds a lot to Lunar images. The last one was actually tricky to not overdo, the right side is strangely strong in blue which was easy to "overcook".

2 hours ago, WestCoastCannuck said:

Images look pretty great given bad seeing!    I would say seeing at least a 2.5.  Colours look great too. 

 

Mike

Come to think of it i have no idea if i have ever actually been under index 1 seeing, its possible the worst nights i have had were 2 or 2.5. In a relative seeing sense of all my past lucky imaging nights this is in the bottom 20% for sure.

29 minutes ago, Andrew rogers said:

What is the complete set-up your using?

Buying soon came here to get involved with the online community.

My scope is not really any specific brand but a mix and match DIY one, and you cant buy one exactly like it. Closest thing available would probably be a TS ONTC f/4.5 8" newtonian.

Mine has OOUK mirrors with a PV1/10 primary, but these shots are nowhere near the limit of the scope so a worse mirror would produce the same image. The tube is a Klaus Helmerichs carbon fiber tube, focuser is a Baader diamond steeltrack.

The important components here are the APM barlow and the ASI678MC, mount is an AZ-EQ6 but its not so important for Lunar imaging.

Been a while since i got the chance to do some Lunar imaging, 6 months if my logs are to be trusted, oh how (mostly cloudy) time flies. Well, got a chance on Sunday night but seeing was really not good with the Meteoblue seeing index forecasted at 1 and I'm inclined to believe that. Turbulent and breathing recordings, with a sprinkling of 14m/s wind gusts to throw the scope around, but some of the recordings are perhaps not a total waste of time.

All taken with my 8'' newtonian with an APM 2.7x coma correcting barlow and an ASI678MC, all images downsampled to 80% of capture resolution.

First one is the region around Montes Caucasus also featuring Aristoteles and Eudoxus, 20k frames with best 5% stacked:

Second one is what looked like an interesting bunch of craters, i believe these are Maurolycus, Faraday, Stofler and others. 10k frames with best 5% stacked:

Third one is Montes Caucasus again, but with a wider ROI to include parts of Montes Apenninus. Enormous recording, over 30k frames at 70 gigabytes, again best 5% stacked:

Then as the last one we have the South pole, 22k frames and best 5% stacked:

And that's it for this time. In total i captured over 300 gigabytes worth of recordings, but some of them were not worth further processing because they really were too unstable to get any decent detail out of. At least i got to try the new version of Autostakkert, which seems to be significantly faster at parsing through the gigabytes than AS!3.

-Oskari

Does affinity photo have some kind of HDR tool that can lift the shadows without touching the highlights? Photoshop has a 'shadows and highlights' tool that i found useful on my last year's effort of this galaxy (should reprocess that one as well).

Nice image by the way.

You are too harsh on yourself, its a good image! Very nice details on the galaxies, and i am not at all offended by the green glow of that bright star.

11 hours ago, WestCoastCannuck said:

Thanks much Onikkinen!   I hope you got a chance to look on a PC.

 

Clear skies

 

Mike

On a big screen the critically sampled image wins the comparison, but its still nice to be able to zoom in on the details of the big one.

If you swamp read noise by some factor at bin1, then any level of binning further will also be swamped by the same amount so you dont really need to worry about extra effective read noise at bin2.

I'd go with the mono camera, if within budget. The price on that thing makes me a bit light headed though... Better test current camera performance first and then figure out if full frame is worth it.

The full resolution image looks pretty damn good on a smartphone, sharp and detailed corner to corner. The smaller one is great too, but i agree that the details are easier to see in the big one.

Looked at some of the subs, and cant say anything other than it does look weird. Cant say i have ever seen a sudden increase and an equally sudden decrease in hot pixels with my RisingCam OSC version of the IMX571 camera.

If this is a specific QHY camera issue then try the QHY 268 thread here:

Lots of users of your camera in this forum, someone there could be better informed on how to help with your issue.

Is this a single uncalibrated sub? I'll be honest in that i have no idea what im looking at, never seen anything like this. Something looks very wrong here for sure.

Im guessing here, but this looks like a corrupted file and could be some sort of USB gremlin, or some issue with how the files were written on disk, or worst case scenario a faulty camera. Does the camera produce a normal looking image if you try now in daytime or do they look like this?

7 minutes ago, paul mc c said:

Is this what you mean.

Yep, choose the settings manually instead of automatic to have control over the rejection rate of hot pixels.

My APP subscription has run out and i dont quite recall what the options were, but i think there was a winsorized sigma clipping option for rejection. Set it to that and go for 3 sigma in kappa high. Kappa low is not too important, you can leave it to whatever it is, maybe 6 by default.

I've found APP to be a bit too relaxed with rejection hot sigma with satellite trails and hot pixels visible, if i just go full automatic on the stacking process. Chances are APP chose some silly hot sigma, like 6 which rejects basically nothing. Try setting it to 3, they should go away.

Did you let APP decide the integration settings automatically?

If APP chose to not reject anything, or chose too high a sigma for hot pixels you would see this.

M81 is a tricky galaxy to process with how bright the core is and how faint the extended outer parts are, i have processed my last year's image at least a dozen times but still dont think i got what i wanted.

Some kind of HDR process is necessary to have both the faint parts and core visible, but still this is a nice image.