ONIKKINEN

5 minutes ago, StuartT said:

Which cables though? I have a lot! One long one from the house out to the Ultimate Powerbox, then a bunch of them out from there to my equipment.

And how would I know what type of chip a given cable has? (I didn't even know cables had chips!)

The seller and/or packaging will tell you which chipset and which chipset drivers you need. The pegasus astro EQMOD cable will have an FTDI chip in it for example. Only these special purpose USB to serial connectors have a chip whereas a usb to usb cable is just a cable.

Take a look at astrobin to see what others have done with the scope: https://www.astrobin.com/groups/162/skywatcher-evostar-72ed/

Some have fat stars, some dont. Some have purple halos, some dont. Its hard to say from just looking at pictures posted by others because processing is key anyway, but i would say its going to be an improvement. If for nothing else, the focal length and the ease of using an actual telescope with a focuser instead of fiddling with a lens.

7 hours ago, bomberbaz said:

Noooooh don't do that, the high powered jets can blast dust so quickly it effectively becomes a sand blaster.

I definitely don't have a 5cm long scratch on my primary mirror coating because a pressurized air can launched a projectile towards it while "gently" cleaning my secondary. Small scuffs probably wont matter for mirrors, but still lesson learned.

I flocked my VX8 not that long ago with the same mat as yours. Measure twice, cut once is what i would suggest. Not what i did, just what i should have done 🤣. It stays put very tightly once you rub it in, so make sure its where you want it to be. I accidentally cut mine a bit short so there was a gap of about 1cm. I then had to surgically insert the remaining strip in place which was a lot harder than just doing it properly in the beginning.

Both mirrors and the secondary spider off and its not that difficult to apply otherwise. You should probably unroll the mat and let it sit for a while under some weight, as it is rolled the wrong way around in the package.

Another vote for SIRIL. Easy to learn (for an astronomy software ayway) and works well as a linear stage processing tool.

There is an Asinh stretch function in siril that preserves colour well. There is also the "regular" histogram transformation tool that i feel like works much better than fiddling with curves and levels in PS or gimp when it comes to colour retention. Also includes a photometric colour calibration tool which works pretty much every time. 

Sure youre not overstuffing your boots with socks and insoles? For winter use your boots should be very loose with just regular socks, perhaps even unusable. Cutting blood circulation because of too many layers/too thick even in good boots will be ineffective at keeping the warmth in.

Ensuring a good seal between your boots and pants are also as important. Longjohns in the boots (not tightly) and 1 or 2 layers of pants over the boots will work.

Did plenty of stargazing and imaging at -20 or colder last winter. Cold feet and fingers really kill the mood so its an important issue to fix.

For me here in Finland it is unfortunately wrong. Says not good to stargaze and 60% cloudy, when i cannot see a single cloud anywhere 🙄. Clear outside is less wrong at 40% cloudy interestingly.

Still thanks for the heads up, added this to my pool of weather data to check.

All part of the charm for the hobby. I think it makes the mediocre result after months of imaging look so much better when these "why am i doing this-nights" are in the mix.

Possible: yes

For what purpose is this, planetary or DSO? For planetary you would want a barlow with more oomph and for DSOs you really wouldnt want to use the barlow at all as it makes everything worse. One of my earlier imaging attempts was with a barlow since i could not reach focus otherwise. Terrible experience and there is no more detail in the picture compared to no barlow.

Maybe if guiding and the atmosphere were exceptionally stable, but otherwise not a good idea.

Getting the smartphonecamera-holder-eyepiece-focus train aligned and focused is really fiddly and tricky to do in the dark. I started just like that and found it annoying, but if you shine a light in to the telescope you can get things aligned faster. For focus a still distant streetlight is the easiest. If none are available, pick an obvious and bright target. Polaris is pretty good too since it hardly moves. Once aligned and focused, try not to touch anything in the vicinity of the focuser.

As for finding things to shoot its no different from visual astronomy in general. Pick bright targets that are easy to find and shoot away (thousands of shots probably). The moon, Jupiter and saturn (might be too late, they are low in the sky) and M42, the orion nebula are pretty good targets and easy to find.

I have this one: https://ecoflow.com/products/ecoflow-river-portable-power-station

Has never run out of power during a night so far. I expect it to not last quite so long if its very cold, but at -5C i ran everything for 6 hours and still had some juice left over. I am running a Go-to mount, cooled astro camera, guide cam, 1 small dew strip for the guidescope and a Mini-PC from the power stations USB-C 100W output connection. I used to run my mini-pc from the AC 230V outlet, but that is quite power hungry. Still, if you want to use an AC outlet in the middle of nowhere, you can.

If you're in the US (like in the signature) you also have an option to get a Jackery. Lots of US folks seem to like theirs, and they would appear to be very similar to the Ecoflow river but perhaps cheaper.

My Mini PC is some amazon variety of a NUC, so a lot cheaper. It has an old i5, 16gb ram, 256gb SSD, 4 USB3 ports, preinstalled windows 10 PRO (very important for remote desktop!) and can be powered with USB-C. The last part is the dealmaker here, i can power it in the field from any fast-charge rated USB-C powerbank.

These come and go quickly from amazon so its pointless to link to any specific one. But i believe it was around 300€ at the time of purchase earlier this year which is a lot cheaper than a "real" nuc.

Focus is off, stars are hollow donuts. Since this is the center of your shot and stars are misshapen its a good idea to check your guiding. If your stars are misshapen only in the corners, that would mean backfocus issues.

1 hour ago, wimvb said:

Jurassic park was hardly a documentary. Pretty impressive CG effects though, at the time.

So this diving Bronto would be more accurate? Or didn't they swim at all? At least the image has correct orientation.

I see a left facing dinosaur now, head and short neck, leg(s) in bottom and long tail with a macehead thingy in the end. Im sure ive seen a dinosaur like that somewhere.

8 hours ago, vlaiv said:

See these threads:

I would personally avoid binning in drivers - as binning in software offers more flexibility.

If you lack simple way to bin - download ImageJ - you can bin image easily with that tool.

Good reading here, definitely learned new valuable info but the sift bin mentioned in the first thread really doesn't work for me as there are already hundreds of subs, each of which are 300mb after calibration and conversion to 32-bit meaning that it takes forever to complete. Also i found that there is no way to know which sub is of which color after saving the new stack from the sift bin plugin? Also found that imageJ binning removes color data, the fits file becomes mono, but i found that ASTAP has a binning feature that retains color. Think ill use that on the linear stack from now on.

5 hours ago, vlaiv said:

When binning stacked color image after debayering subs and stacking them - SNR improvement won't be the same as binning individual subs in adequate way for OSC subs, then debayering them and finally stacking them.

Interesting, yet another imaging misconseption of mine you have pointed out😄.

How big of a loss (or how much less the improvement) would resampling in post do? In SIRIL there are a few options like bilinear, bicubic, lanczos, pixel area relation etc. I would love to pretend i can see a difference between them but i dont.

If there is a big difference, would it be better then to capture binned by setting the driver to bin2? I can see straight away from HFR readings that the night is not good enough for native resolution and lose nothing of value by binning on camera.

11 hours ago, petevasey said:

So, the crunch question!  Is anyone out there binning an ASI OSC camera?  As I say I'm considering the 294 or even the 2600.  But would definitely want to bin the 2600, certainly 2x2, perhaps even 3x3.  Yes, if binning can be done correctly the colour data won't be lost.  But does the ASI camera driver look after that?  Or is it done by the capture program?  I use MaximDL 5, and wouldn't want to change, it does everything I want without complaining.  I should mention I'd be using the ASCOM driver in Maxim - from tests I know that works with the ASI533 in Windows XP.  I have also installed the ASI camera driver, although of course that isn't 'seen' directly by Maxim, but I presume that ASCOM interfaces with it.

Cheers,

Peter

Not a ZWO product, but still an IMX 571 sensor camera (by rising cam, manufactured by touptek). I always bin 2x2 which is just a 50% resampling in post as far as i have understood and i perceive no lost colour data. Read noise gets "read" from each pixel regardless if your capture software captures native or bin x whatever resolution. There is no need to do binning during capture with CMOS other than reducing filesize, you can do this in post in whatever software you use to post process.

Here is what i came up with from the linear file. I don't think i improved it, its just different. In the linear phase i do background extraction and colour calibration but looks like these were already well enough done on the stretched stack. Colour calibration is really tricky and i almost entirely rely on SIRIL photometry to do it for me. In this case SIRIL only found a handful of stars, whereas i usually use hundreds - that's the only 8 minutes here that does it. Still amazed how stars are mostly round untracked!

Untracked and 8 minutes? Looks great, probably better than my tracked M42 which i pretend never happened.

I don't think i pulled more out of it. Although i will say the TIFF in your post looks already stretched as the linear mode already is very visible (stacked files are usually almost entirely black), is it straight out of the stacker?

I did: Background extraction in SIRIL (minor effect), some photoshop masked saturation, camera raw adjustments and denoising.

5 hours ago, GalaxyGael said:

Lovely image and an interesting galaxy. I've added it to my to-do list, thanks.

The rainbow anomaly in curious, since it is reminiscent of dispersion through a glass element. The perfectly circular but thinner rainbow would confirm this. this type of issue can be tracked down and eliminated.

Are you sure it was definitively light form the mag 5.8 star? It is odd that it would cause dispersion like this. If it off-axis light from that star, it might be dispersing through a very fine mist of water droplets on that part of the sensor in order to see the circular feature.

 

Very off-axis light through a thick highly curved coma corrector could approximate a large single raindrop, but that is more typical of light hitting the curved side, which is facing the camera. these anomalies are curios to me  Did you see them before?

 

 

Thank you!

I am hesitant to try and "fix" the issue since there are so many possible surfaces to reflect from. All coated of course, but still possible. 3 glass elements in the coma corrector, both the telescope side and camera side are visibly curved (0.95x TS maxfield corrector), UV/IR cut filter, AR-coated sensor window and of course the sensor surface itself. I can probably improve the process of removing it in post if i practice, so its only a critical issue if it obstructs the actual target itself. Here is a picture showing my CC in the focus position, it does not obstruct and is sufficiently covered to not have really any "direct" reflections. (dew shield on while imaging also). The comacorrector is open only to the opposite side where there are no bright stars. Dew in the sensor would be bad news, but i don't think that's the case ( i hope not). The sensor is sealed with a desiccant tube thingy in there and the number of stars/median ADU/HFR readings from NINA i use to determine sub quality show no jumps. If there were jumps, the subs were scrapped. But very fine mist not big enough to notice? Could be, ill have to check the desiccant if its saturated.

I am not so sure at all it was the top left star in the image. It could also be 3 stars just below the image that are also quite bright. In fact it probably is, since i have not seen on-axis stars produce something like this before.

I have seen something like these reflections during go-tos to bright stars for focus. The first go-to is always a couple of degrees off and can show some reflections, but once centered they disappear. The Moon obviously also causes these when anywhere in the general direction, but not rainbow coloured.

45 minutes ago, Spitfire said:

I like your images but I prefer the first without the rainbow.

You're right, it is quite faint at Mag 10, but what is interesting is that there is another galaxy that sits on top of it (NGC4236-2) at mag 15. I took an image of them both some 11 years ago with my Vixen R200SS. It took 23 hours in Luminance and my processing then was even poorer than it is now! But just to show how technology has improved since then, I have attached my image from then. I think yours with just 5 hours is far better then mine, and you're right that some more data will improve it further.

Geoff

Thanks Geoff. I noticed this technology gap while browsing astrobin for various targets and it looks like comparing today's images to even a few years back is a very uneven playing field. I wonder how astrophotography looks like 10 years from now if the same improvements keep on coming.

23 hours is a LOT of exposure for a single target, not sure i have 23 hours in total 😅.

4 hours ago, The Lazy Astronomer said:

I like the little rainbow, it can be your signature on the image 😁

It adds some flair for sure. What im not sure if its from the HD-something star in the image or Kappa Draconis a few degrees to the bottom that caused this. Havent seen one like this before so there must be a tight spot where it can occur at a specific off angle.

I think i actually prefer the non-altered background version. Actually i definitely prefer it, so here it is. Trying to remove the rainbow reflection is probably what killed the background in the first round.

4 hours ago, alan potts said:

Not one I have seen done before, and to my eye it looks very nicely done too. Might just try this one myself

Alan

Thanks, although more southern photographers might have to wait a few months for a better opportunity.

NINAs sky atlas told me about it, otherwise i doubt i would have just stumbled upon it. At 20 arcmin should be shootable for many kinds of telescopes!

1 hour ago, oymd said:

I was advised to use ELLIPTICAL GALAXY option in PixInsight's PCC, as well as ARCSINSTRETCH to bring out some color, which it did, but very very faint.

I don't have pixinsight, but this sounds bizarre. Elliptical galaxies being round featureless mostly single coloured blobs are about as far away from M33 as possible when it comes to galaxies.

Maybe try just "normal" photometric colour calibration (if there is one in PI?). SCNR also shouldn't be necessary after a good photometric colour calibration so something is wrong.