Astro Waves

it feels like theres more to think about than when shooting a DSO! hah.

On 18/02/2022 at 18:23, drjolo said:

All the things vlaiv described plus monitor the histogram, so the image is not saturated in highlights - there is no way to recover details in saturated areas. 

What scope do you plan to use?

I would just be using my Redcat 51 to shoot with.

2 hours ago, happy-kat said:

For the Moon tend to take video so no calibration files used.

What will you be shooting the Moon with?

ahhhh I see. I'll be using the ASI294mc-pro as I'm pretty sure you can do video on that. Would you recommend any software to process the video?

Are there any differences in stacking video frames and imaging frames? 

I wanna have a proper go at shooting the moon rather than just taking a single image and working on that. Is it necessary to take calibration frames? 

Cheers

11 minutes ago, ScouseSpaceCadet said:

This project seems to have caught the public's attention. Yesterday my boss put me on the spot during the morning meeting, "Peter you're an astronomer, tell us about this telescope..." After wishing for MS Teams to disconnect, a fifteen strong team of nurses, healthcare assistants and admin staff received a three minute lecture about JWST. Slightly embarrassing. 😬

I bet they loved it! when you can see someone has a passion about something people will be interested regardless. I bet it was a good 3 minutes.

Personally I'd say go for the Star Adventurer Pro 2i, if you end up wanting to get into doing some deep sky imaging which I think may happen once you realise how awesome it is to shoot space I don't think the mini would be able to handle the weight of a larger 135/200mm lens.

In terms or targets 14mm is pretty wide, you could just point it at the sky in general and get some interesting shots to practice with but something like Barnard's loop would be a good one thats very much coming into full view soon.

Hi all,

Think I might need to get a bit more of a decent/reliable dew heater and was wandering if anyone has any recommendations? Had a look on the FLO site but they seem to be all out at the moment. Not exactly in a major rush but something I do need to sort out.

Cheers

Every so often when I'm just pottering around I always go to myself "it would be ace to live in the artic circle when it gets dark for a few months, then you could just go out and shoot any time".

bloody lovely that is!

8 clear nights in a row? I wouldn't know what to do with myself if that happened over here, haha, I'm lucky to get a few hours at most!

I really like it, let the artist in you loose! 

21 minutes ago, discardedastro said:

Basically banding is in the sensor and is a result of how the camera/sensor reads out pixels/data or inconsistency in the sensitivity of specific pixels in the sensor. Lots of things can cause it, but it is tied to camera/sensor, so calibration helps. Calibration can't magically restore missing data, though - hence why dithering is important, to put those objects on "good" pixels often enough that you actually get data for those regions of the image.

With that much banding you need to at least move 10-20% of your image size over the course of imaging, I'd say. So work out roughly how many subs you're doing and adjust dither movements accordingly!

How many darks/biases/flats you need is best experimentally determined, but yes, more is almost always better. I do 25 flats per filter, 100 frames of bias, 50-100 frames of dark on an ASI183MM-PRO (which is cooled, so that all gets done at -15c)

 

nice, thanks for the help, definitely given me lots to think about. 

On a side note I'm looking into CCD cameras and was eyeing up the ASI183-MC and noticed in your sig that you use the MM version, how do you find the amount glow with this camera? I feel like I'm spending for ever trying to read about what cameras to match with the redcat 51 and the 183 seems to be a good fit, don't think I get enough sky time to go down the mono route yet and would probably be easier and more consistent when I know I can frame much easier over multi night shoots using a go-to mount when that time comes. 

29 minutes ago, CloudMagnet said:

Given you still have that banding, it would be worth doing more dithers. The fewer frames that share the same position as each others means that the chances of banding persisting will drop. It might also be worth increasing the size of the dither to make sure there is visible movement between frames. It might be the case your dithers now just aren't large enough.

Next time I get out there I'll give it a go with making the dithering more frequent and se if that makes a difference. Is banding something that in ingrained in the actual camera or is it something that changes each time you shoot if you get my drift? tried to make a pun out of that but hopefully it makes sense, haha. 

31 minutes ago, discardedastro said:

Random dithering every frame is pretty common. Also worth checking how much you're dithering by in practice, i.e. with widefield you may need to be dithering a fair bit to move the image around a meaningful amount.

I find dark frames are easy to sort - pick a cloudy night when it's cold and just run the camera doing darks all evening. I usually do around 100 120s exposures for darks, which is probably overkill but can't hurt! Alternatively, put it in your fridge if you can't wait and are confident that the optical train/telescope itself isn't introducing any constant light sources. I'd definitely look to do more biases, too, or use a tool like PixInsight's superbias to extrapolate.

Looking good regardless though!

I had a funny image of putting the entire set up my tiny fridge and my partner coming home and opening going "what the heck are you doing?"

I've never really been sure of how many of each darks, flats and biases to take, is it kinda like the more the merrier?

21 minutes ago, CloudMagnet said:

Still a lovely image, taking some more darks would be helpful to reduce that banding. 7 is a bit on the low side, I would aim for around 25 if possible. You also have the disadvantage of an uncooled camera. For the best results, your darks need to be at the same temperature (or as close as possible) to work the best.

I haven't used the skyguider pro, but I would look to introduce dithering into your process as well. It will shift the image around a few pixels between images and have the effect of cancelling out any banding as well, might be worth looking into.

Ta very much. I know, I know need more darks and I never take enough of them as it usually gets on being too late/being too tired to have the patience to wait for them to tick over even though I should do. I have been looking a cooled camera as this would definitely help so I could do them any time. Had thought about upgrading the mount first to a go-to but now I can plate solve with ASIAIR pretty quickly its really to too bad at all. 

So I do set the ASIAIR to dither every 5 images I think but is it worth it doing it more frequently than that? 

20 minutes ago, newbie alert said:

Nice image, its called horizontal banding

Thanks

Finally had a super clear night here in Edinburgh last night. Got to my usual shooting spot, did the standard setup which is getting much more swift including PA and finding target now I gots the ASIAIR Pro (which I'm loving for its simplicity and ease of use). Also received the Optolong L-extreme so thought I would give it a go. I feel like I'm getting there more slowly than I'd like with the imaging results and everything that comes with it etc.......but I'll tell you whats not great, when you forget to turn on your dew heater and also to charge your phone thats running ASIAIR app but regardless I had a nice time. 

The is the first edit I've tried for this image and pretty happy with it I'd say, definitely more on the orange/red side but I like it so stuck with it and sacrificed some whispy detail for a smoother image.

I do have a couple questions, I'm shooting on DSLR and used a pretty low ISO of 800 but I feel the amount of noise I'm getting in the image is pretty darn high as you can see from the results below. I only got about 2 hours integration time but would more time mean a smoother final result? and also the second pic is of the stacked data form Siril I've found since I've started guiding and being able to take longer exposures that I'm getting these consistent lines when shooting, any one know what they are/if there's anything I can do to get rid of them via processing?

Any comments or critiques more than welcome.

Edinburgh - Bortle 7 -  Redcat 51, Canon 750D Mod, iOptron Skyguider Pro, ASI120mm Guide, Optolong L-extreme, ASIAIR 

Lights - x46 180 seconds

Darks - x7 180 seconds

Flats - x25 1/40 Seconds

Biases - x25 1/4000 second

19 hours ago, Budgie1 said:

The ASI294MC Pro is a good camera. I upgraded to it from a modded Canon EOS 1300D in January and only touched the EOS again when I was testing my Samyang 135mm F2 lens.

As @AKB has said, it does have amp glow on the subs but the Darks calibrate this out. I also found that using Bias frames caused a residual of the amp glow to remain in the stacked image, so I don't use Bias frames, just Darks, Flats & Dark-Flats. Some have reported issues with taking the flat frames or getting them to wok correctly but if you stick to an ADU of about 25,000 and exposures of 1-3 seconds then they work fine (for me!). 

A big advantage over the DSLR is being able to take your dark frames off the scope, when you want too, and just re-use them. It means more imaging time, no stopping early to take your Darks!   I have a library of darks for the different exposure times I use, I tend to keep the set point cooling temp, gain & offset the same for all to make things easier. 

The image is cleaner than my DSLR and it picks up a lot more detail from the likes of galaxies.

If you're going to use it mainly with the Redcat 51 in your sig' then it may under sample with this scope. You may want to look at the ASI183MC Pro as another option. HERE's a link to the Astronomy Tools calculator which should help. 

Thanks for you input, much appreciated.

I think unless I'm spending closer to big bucks amp glow seems to be more or less on issue from what I've been reading, but if it calibrates out then I'm fine with that. Last time I shot on my Canon 750D there was some horrific banding going on so sadly I couldn't push the processing as far as I wanted as I struggled to get rid of it, wasn't too much as a problem.......as the image was out of focus! haha (see image below).

Being able to take dark frames off the scope would be so nice as I have no garden and use a friends allotment so the nights can get pretty dam chilly especially when you only have a shed to sit in. I always get a bit of itchy feet when I have to wait around for darks to be done (and I always have early starts in the morning which don't help).

More detail sounds good to me. Not being doing the hobby too long but definitely feel like I'm turning into a bit of a galaxy hunter. 

The camera would be for the Redcat 51, I would like to up grade the scope at some point get about another 200mm on the go but no idea when I can do that as then I'd be looking into go-to mount territory rather than my portable set up. Well....funny you should mention the ASI 183 as there is one going on the 'For Sale' section in here as well. Not sure I fully understand the Astronomy tools calculator, what is the colour bar at the bottom representing? There's a pretty decent/significant crop factor when using ASI183 which is good as well. I've popped in a screen shot from the calculator so you can have a quick look but I'm guessing my current set up would suit the 183 more?

Cheers

So, looking at upgrading from me DSLR and wanting to stick with a one shot colour rather than switching to monochrome (for now) just due to the having such limited sky time and long set up times due to no garden etc. The camera mentioned above looked like quite a good fit, basically just wondering if any one uses one and has any feedback on it? 

Cheers

Absolutely love the colour palette on the full colour version, I feel a lot of the time when you see super bold processing like that it just looks really over cooked but this looks super sci-fi! 

Being able to preview the image on something bigger than the back of the camera is the best advantage you can give yourself. As you said, if you can compare the star field or do a bit of plate solving then you should be onto a winner. Shooting over multiple nights is something I always have to contend with living in Scotland, if you do this just try and get it as close to the previous framing as you can do just to give you self a wider field of view to play with if cropping into the image is needed. 

If you're after the Veil you do need quite a bit of time on it really. Even with an astro modded camera you might still struggle to make it out for framing if you're just relying on using the camera alone, even with a a couple minute exposures. Its one of the nebulas that really caught my attention before delving into AP so I want to revisit it again but I'd really like to get minimum of about 5 hours data on it probably more really. 

Stick at it though, its a rewarding target because it looks ace and is also a tad tricky.

Skip to the end to just see the images, Kinda wrote way more than I anticipated. 

So, after moving to Edinburgh a couple of months ago I finally found a place that I can do some AP from. Got in touch with some allotments about 20 minutes walk from me (as I have no garden). such a lovely place to go and set up, I even have a little shed to sit in which is great and I can also nap a bit whilst the camera is away shooting, it feels like my own little cool observatory but a bit more rustic. The only slight down side I would say is that being in an allotment at night by yourself is a tad creepy especially when there has a been a few nights this week I've been there and you hear the locked gate open and close at about 11:45pm and then you know.....you're locked in there with some one else but its a big place so its ok, kinda.

I finally got into guiding and using the ASIAIR Pro. First couple of nights was mainly just spent trying to figure it out which I had varying degrees of success with but now I've got the whole complete set up to shooting time down to about 40 minutes which is nice. I've written a bit about each section of the ASIAIR Pro in the steps I take to get set up.

Focus: This is more being able to control I from a phone or tablet and having a larger screen which makes thing sooooo much easier as the buttons are larger than on the camera and you also don't have to touch the camera set up itself with risk of moving it. I just use a bahtinov mask and a keen eye to check the focus, though an EAF would be nice that might be something for down the line a bit. 

Polar Alignment: I did have a bit of trouble with PA to start with. I set up the iOptron Sky Guider Pro and look through the eye piece to get a pretty decent polar alignment which I can usually do in about a minute or so, then use the app to fine tune but there has been a couple of times I've done this'd and it says its aligned but when looking through the eye piece Polaris is way way off where it should be. Not sure if I'm missing something in the whole set up. Some times I just go back to using the Sky Guider as its way less faff but I do try get both done properly. I also find when you get to the final stage of PA via the app, I almost struggle to move the mount in such a minute increments to get it spot on. It gets a tad frustrating, so I've been settling for anything within 40 Arc seconds so and still works great. The William Optics Wedge would be very handy for this I reckon because it looks like you can get way more precise. 

Plate Solving: I'm not sure I'm using the plate solving to its full potential yet but it makes finding targets incredibly easy due to have the actual RA and DEC coordinates and not just hopping , some of this is still done to find the target initially but otherwise its great. Having a library of targets in the app itself makes it quick to flick back and forth to remember where it actually is. 

Guiding: The guiding is super easy to use which I like as I'm not really too fussed about bettering super technical just yet. Focusing the guide scope feels like it takes some getting used to in actually finding the stars and fine tuning them as its a fine line from being to see them or not. I think second to PA this is definitely a fiddly task for myself, its seems I have to have the guide camera almost all the way out the finder scope to see anything but not really a problem. 

Autorun: I like this feature a lot as its super quick, easy and the most simple to use with being very self explanatory. Its great that you can pre-label everything and that its in FITS files, so when it comes to getting the images onto your computer some of the work is already done. Its saved a lot of time having to faff around converting Canon CR2 files into FITS. On the imaging side I'm not sure I'm understanding this fully as in taking images, are you looking to get a good image with or having to use the auto stretch within the ASIAIR? I felt like I had to have a faith in the data being captured knowing that it was there. Any weigh ins on this would be great!

Conclusion: The ASIAIR Pro is very simple to use after a couple of goes, its pretty intuitive to use which is perfect for someone like myself who isn't the most technology abled person lets say. Because of where I live and the fact I can only image on Friday/Saturday nights I want to get up and running quickly which this I great for and would highly recommend. I've added a couple images of my kit set up and how minimal set up you can get away with/pack down into as I know the price of getting into this amazing hobby could almost put you off (but its totally worth it). The £6 magic arm for the ASIAIR to attach to the tripod is a good addition that I would recommend. 

This is the First proper go I've had at Andromeda and the edit I've done. Might have another go when I can Starnet++ to play nice as well but pretty damn happy with it especially as its just above the moon, took me a while to flatten out the background due to this. 

Edinburgh - Bortle 5/6 in 74% Waning Gibbous Moon - Shot over two nights

x74 Lights - 180 Seconds

x12 Darks - 180 Seconds

x10 Flats - Set to ASIAIR auto

x10 Biases - 0.001 Seconds (ASIAIR fastest Sutter speed choice, not actually sure how fast it is)

On 04/08/2021 at 15:36, drivera said:

 

I attempted the Veil last night.  Omg it was painful. My Redcat has been replaced by a GT71 as I broke the Redcat 😞 When I got the GT71 I also purchased the L-Extreme filter to see.

I'm shooting with a Sony A7iii and I feel theres something weird going on with the sensor - I can't get my bias/darks right. I'm trying to understand if it's okay or not by reading up on ADU values etc. 🤷‍♂️

Great point on framing! The GT71 is a bit on the heavy side, and I was using the new WO Base for the SGP and I messed up the levels, so my guiding was shot. The camera was upside down so I was taking a shot then watching it on the laptop, then moving it and it was so hard to get the framing. I was running out of time so I saw a clip and decided to run with it.

I just can't seem to learn how to process images correctly! I did this with Siril then Photoshop 😕. 

 

This is:

- 30 Lights x 180s

- 20 Darks

- 20 Flats

- 40 Biases.

 

My first attempt!  I'm lost on the processing side.....but  guess slowly but surely? Oh yeah excuse the upside/down/wrong way image. 

Doesn't sound like you had the easiest time shooting the Veil. I really like the image though, I like the almost light sea foam green/blue kinda colour. Processing is a whole other thing, despite being a photographer for years, editing astro stuff I just had to almost start form scratch again. Its so tricky, I just watch as many tutorials I can do find tips and trick from various people and try and create my own flow that I'm happy with but it takes ages.

9 hours ago, ollypenrice said:

I think you had tighter focus for the first image but the second is still good. I would just give the colour balance a slight tweak since your background sky is a little green.

I definitely agree on both those points. I've done another edit since this post and much happier with the all round colour of it. Focus is something I struggle a bit with, have thought about an electronic focuser but not sure on that yet as I should probably get a guide scope first. 

22 hours ago, Marvin Jenkins said:

Just take in that star field, mind blowing in its intensity. I love these images, they are so honest.

Marv

When ever this happens and I'm off with the framing, I just try and pull out as many stars as I do just to blow my tiny mind of how many are actually out there. 

4 hours ago, drivera said:

That's awesome!!

It gives me hope with the same setup; SGP and a Redcat + Sony A7iii (not astro modded though).

I'm hoping I get some clear skies soon in Kent as I really want to attack the Veil nebula!

Thanks very much. The SGP and redcat are great together, been really enjoying using them. Only thing I'd say about the Veil especially when not using as astro mod is definitely shoot to laptop and proper stretch the data on the test images to make sure you've got it framed nicely other wise you might struggle as I did first time around.

3 hours ago, AstroMuni said:

Lovely picture.

How come your biases exposure timing is way different to all the others?

Thanks

With the biases when shooting DSLR, from previous tutorials I've watched a few different people have said shooting the biases should be at the cameras fastest shutter setting, works pretty well. 

Amazing, thanks for some suggestions I'll give them all a good look. 

Not sure if this was the right part of the forum to post this in.

I was just wanting to know if any one had any good book recommendations on space/astrophysics/time/blackholes etc and that fun kinda stuff and also the philosophy of science? My physics knowledge isn't exactly the greatest so anything that's really technical I might slightly struggle with but I've been really trying to learn anything I don't know and more than happy to put in the time to get to grips with it. The kind of things Ive been reading to give you an idea are:

The universe in your hand - Christophe Galfard

The consolations of physics - Tim Radford

Reality is not what it seems: The journey into quantum gravity - Carlos Rovelli 

There's a couple others as well but I'm sure you get the idea. I've been enjoying watching stuff on the philosophy of science as well but would prefer some things to read as well as its easier to make notes on get to grips with a concept. 

Hopefully this isn't all too vague, if it is pop us any questions. 

On 26/07/2021 at 09:54, powerlord said:

ASIAIR PRO number 2...

Usually buy everything from FLO.. still will. but.. well.. got ZWO sale email, didn't know FLO was gonna do it too.. and took a gamble on buying a second asiair pro direct.. looked like it might work out at about 185 quid inc postage if I didn't get stung on duty...if I did, well still might be a bit cheaper than normal price.

arrived today! and looks like no duty! oh.. and with exchange rate it didn't work out at 185 quid...

it worked out at 158 quid !! all in inc postage.

🙂

 

I've been looking at this the past couple days and getting it for £158 is a bargain, I'm the same in going to FLO but that's a pretty big saving.

Got the William Optics Dec adaptor with vixen saddle for the iOptron sky guider Pro, not a huge upgrade but oh my days its so much easier to use than the one that comes with it and is way more precise, I would definitely recommend the upgrade to anyone. Also got the saddle as well because I'm eyeing up a guide scope (finally).