SiD the Turtle

Thanks for this, working out this stuff melts my brain. Have I got this right though, that because of the 127 MAK's focal ratio compared to a faster scope, the field of view is reduced, the galaxy takes up a larger amount of space on the camera sensor and therefore you get more pixels making up the galaxy? However, that's the light spread across more pixels and therefore more, longer exposures are required. With a faster scope the galaxy is spread across a smaller set of pixels therefore you need less subs, but the size of the galaxy is much reduced. Correct?

Thanks all for the advice. Just got to wait for them to come back into stock now!

Hi all, I'm tempted to put an order down for the Sky-watcher 80ED for when they come back in stock but I'm bewildered by all the add-ons and parts I may need, or not need, to do astro-photography on this OTA. I'm currently using a Canon 600D which is connected to my OTA using a t-ring (M48 I think?). Nothing else. What would I need to do something similar with the 80ED? Here's what I think I need: The Sky-Watcher reducer/flattener. The Sky-Watcher DSLR-M48 Ring Adapter. - Why can't I use my existing t-ring, is it a different thread? Do I need anything else to achieve the correct back-focus? If I went down this route and if I save my pennies here's what I might do: Switch to a dedicated astro camera. Would that change the above? I guess I'd just need to lose the t-ring? If the focuser can't hold the weight of the camera replace it with an aftermarket one. Would that change anything? If I used something like the Baader SteelTrack (which is super pricey but let's see) that's got an M48 thread so you wouldn't need the Sky-watcher specific t-ring? Thanks!

Hi all, just wanted to say thanks for all the input and advice. Especially regarding over-sampling which I hadn't considered in the past. One question- can I bin using a DSLR? Surely as it's a colour camera with a bayer filter if I bin i'd be mashing together a random combination of R, G and B pixels?

Hi folks, I've been practising, practising, practising on M101 with my setup below to try and hone my capture workflow before I start scanning the sky for more targets. Let alone the image workflow- my trials for Photoshop and Pixinsight have now expired so I'm now down to Paint.net until I decide which one I prefer and can afford! This image is very lazily stretched and curves applied, I haven't spent any time with star reduction, setting the blackpoint, reducing noise etc, I just wanted to get input at this point: The images are still very noisy which I think is down to imaging on very warm evenings (sensor was between 25-35 degrees Celsius). I know in PixInsight there is a de-banding filter that will get rid of the Canon banding at least. I'm tempted to switch out the OTA to something faster but I do like the ability to get up close with the galaxies for now. Thoughts? I have ~£200 to spend now that next in line is either going towards Pixinsight or some dew heaters, USB hub etc, or I can put it towards a new, faster OTA. My reticence is (if I understand correctly) the increased FoV on the faster scopes would mean smaller galaxies, and I'm really interested in galaxy photography for now, before I move on to nebula etc. Setup OTA: Celestron 127 SLT Mount: Skywatcher HEQ5 Camera: Canon 600D unmodified Guiding: SkyWatcher Evoguide 50ED + ZWO 120MC-S + PHD2 Computer Hardware and Software: INDI/ASCOM/EKOS on a Raspberry PI4 Imaging Software: Deep Sky Stacker, Paint.net (crop, levels and curves). Images Lights: 62 x 300s Darks: 53 x 300s Bias: 431 (for comedy value, I took 200, lost them, then took another 200-odd then found the original. On another forum someone suggested this number of bias frames could be creating noise) Flats: 60 (missed flats on the final night) ISO: 1600 Bortle class 5 Across 3 nights of imaging.

Thanks, completely didn't notice that right at the bottom of the window!

Quick update in case anyone finds this thread. I ended up buying the Canon 600D via MBP. Really good decision, I've been really chuffed with the images it's been snapping, works fine with INDI and Backyard EOS (as you'd hope) and having the pop out screen is indeed a lifesaver. One warning on second hand, though I went for one with a relatively low shutter count the battery it came with was pretty knackered and wouldn't last an hour. Not expensive to replace though, I got a third party pair of batteries and charger for ~£15 that have a longer life that the official Canon batteries and so far have lasted a few nights of long exposures.

Over the last three months I've had three attempts at photographing M101 from my backyard. I now have: Lights from each night Darks from each night (excessive as the temperature was pretty constant?) and a master dark for each night. A set of 200 biases and a master bias. Flats for the second night (need to do some flats for the third night now) and a master flat for that second night. How can I put these all in the pot and get a decent master file in DSS? I know for example I could in theory create one master dark and use it across all as it shouldn't have changed much, but I would want each flat to correspond to each set of lights, as the dust etc will have moved. I also assume I don't want to create a master for each evening and then try and combine them as I'll lose a lot of data. What's the 'best practice' here?

Just bumped into this thread as I'm looking at buying the Pegasus Powerbox Advance. Indeed is it 'just' the early model Pi 4s? Mine are new-ish and I am running Astroberry and an ZWO guide cam off of a random Anker power bank that I used to use as an emergency mobile phone charger. That outputs at 2.4A if I am correct, and it's stable with no issues in the last few months I've been using it. Sorry if that doesn't help you if you have an older revision.

Hi all, my current beginner's setup has a Canon 600D connected to my Celestron 127 SLT, by way of a t-ring. Finally got clear skies last night and the beginnings of an image. I was curious about buying a light pollution filter like one of these further down the line: https://www.firstlightoptics.com/light-pollution-reduction-imaging/astronomik-cls-ccd-filter.html. Now they come in various shapes and sizes and of course I can get the Canon specific one and clip it in, job done. However, I know in the far flung future I'll probably want to fully automate my process move to a dedicated astro-camera and filter wheel. These seem take 1.25" filters, which (even better) are substantially cheaper than the canon-specific filters. To avoid having to 'double-dip', is there any way on my imaging train I can get the DSLR with it's 2" t-ring to connect to a 1.25" filter? Problem I see is that the OTA has a 2" connection so I'd need to reduce and then increase the width somehow. I think at least the camera sensor wouldn't get clipped.

I'm in a similar position and hovering over the buy button on a second hand Canon 600D (which in the States I believe is known as the Rebel T3i). It seems to be well regarded by the big astro photographers online, even though it's now quite an old camera. Prices are around £160 depending on condition. That's obviously a mirrored camera, rather than a mirrorless.

Thanks everyone for your input. Lots of love for the 600d I'll start saving my pennies!

Hi folks, I'd love to one day invest in proper astro CCDs but budgets are tight and I'm still very amateur, so I was thinking of getting a cheap second hand DSLR. I can see through sites like MBP I can get a decent used Canon 450D for about £100, then the next step up is something like a 600D for £200. For a beginner is the doubling in price worth it? Am I ignoring other cameras in the same budget? Requirements are a DSLR that I can connect to BackyardEOS and INDI (I've been tinkering with Astroberry) over USB I'd assume. Current OTA is a Celestron 127 MAK, but a new OTA is on the cards maybe towards the end of the year. I don't really need a daytime DSLR, that's more of a bonus and would likely try to astro-mod it further down the line anyway.

Hmm this is the etching I have: https://www.cloudynights.com/topic/653431-new-polar-scope-reticle/. There's no small circle in which to align Polaris. If I rotate the RA axis to the correct date and time, that clock face is at a seemingly random orientation. If I put Polaris at the right 'time' according to that orientation, I believe it's in the wrong place. If I simply place Polaris within the rings assuming 12 is 'up', I think it's correct.

Thanks all. Still not really getting the point of the whole clockface thing, but as you say it doesn't seem to be having an impact yet. Putting Polaris in the right place as per what the handset says (which agrees with mobile apps) seems to work, though not had enough chance to play with it to see how precise it is.

Similar question. While it's been cloudy I've been playing with Raspbian with Kstars and Ekos (all new to me) on my Raspberry PI 2, with the mount indoors to understand how it all works. The 2 is pretty slow by modern standards so looking to buy a 4. Power has tripped me up: The mount is powered by a https://www.celestron.com/products/powertank-lithium, and I had the Pi connected via a wall charger. I was thinking about using the power tank's USB sockets to power the Pi, but of course this is the first time I've realised the power tank can supply on the 12v line, or the USB, but not both at the same time 🤦‍♂️. So I can power the scope, or the Pi, but not both. Really trying to avoid further astro-related expense right now after just getting the mount (HEQ5) and other goodies so any way I can use the power tank? Somehow split the 12v line, but then do I risk under-powering the mount?

Apologies for yet another polar alignment thread! This is my first EQ mount and I'm struggling to understand the basics. I'm trying to follow guides from the likes of Astrobackyard and here: http://www.astro-baby.com/astrobaby/help/polar-aligning-the-skywatcher-heq5orion-sirius-mount/ but just don't get it! So if I've got this right: Polaris is not precisely at the pole, it orbits in a circle that is represented by circular etching on the polar scope. Either through the hand controller or through an app Polaris should be somewhere on that circle, let's say 3 o'clock. I need to put Polaris at the 3 o'clock position on the etching. If I put it at say 6 o'clock, over the night Polaris will drift off as the circles are not aligned. Right so far? If so, why do I need date and time dials? Surely I just need to spin the scope on its axis so 12 is at the top and move the scope and the altitude screws so that Polaris is in the right spot? Why do I need to spin the scope to the current date and time so the clock spins? I also guess I need to calibrate somewhat- when the date and time circles are lined up at 0, the clock is not 'the right way up'. Any super beginner articles or videos appreciated.

Payday! Looking to pull the trigger on: HEQ5 Pro Bahtinov Mask ZWO guide scope (All on my existing 127 MAK OTA with the Nikon for now). Just shy of £900 so a bit to spare further down the line or indeed for software licenses! Anything obvious I've missed?

Cheers everyone, good input! I think to pace myself I'm going to get the HEQ5, and a guide scope and pair it with my existing OTA. Can always spend the rest on the 130PDS or similar down the road. When it comes to guide scopes, any recommendations? Some of them are more expensive than OTAs! Software is a good question, I won't open that can of worms here!

Hi folks. I'm lucky enough to get a bonus this year and while most of it is earmarked for actual life needs I've put £1,000 aside as 'spoil myself money' and I'd like to start dabbling with astro-photography. Currently I have a Celestron 127 SLT on the out of the box alt-az mount. I've been using both a camera-phone mount and an old Nikon to take pictures of the moon and recently bought a ZWO ASI 120MC-S to do planetary imaging only to find in my beginners ignorance that the planets are up in the daytime at the moment so it's going to be a while before I can use it! While the Celestron is a great beginners observing mount the tripod might as well be made from bendy straws, given how wobbly it is. I'd like to try DSOs and maybe galaxies on an eq mount and setup. How should I spend up to £1,000? I am a techie so would like to slowly graduate up to dedicated astro cameras connected to my laptop or similar, rather than investing in a DSLR. Given the kit I have at the moment I was considering: HEQ5 Pro mount Some kind of guide scope + ASI camera I already have for guiding Using the OTA from the Celstron and the old Nikon DSLR while I'm learning. Keep the difference and save for an imaging OTA and/or a DSO camera later in the year. Alternatively I see the 130pds get a lot of love here so perhaps that plus the HEQ5 Pro? For context this would be mostly for backyard photography in a class 5 bortle suburb, but with the ability to throw everything in the car and find some dark skies on occasion. What do you think? Feel free to suggest alternatives completely different from the above.

Hi all, OP here. Just wanted to conclude by saying I've had several nights of play now and got this down fairly well. Keys seemed to be both choosing stars near the meridian and also accounting for backlash. I had no idea the mount had so much play and making sure I focused on ending up 'up and right' helped immensely. Thanks again!

Thanks again. Had a break in the clouds last night long enough to give it another punt with different stars, chose one close to the meridian (Capella) then over to Dubhe, the results were A LOT more accurate, so much so I was actually able to do some stargazing before the clouds made a return 😎. I think with a bit more practice I'll get it, but I'm so much closer than when I was using Polaris. Cheers all!

Thanks everyone for the friendly welcome and responses! Just waiting for clear skies to try again. Out of curiosity why is Polaris not a sensible alignment target and something close to the meridian is? Interested in the technical reason. De-focusing the star to make the star bigger is a good shout too, will give it a go.

Hi folks, complete beginner here really struggling with the basics! I bought a Celestron 127SLT a while back and every time the clouds part I'm outside trying to get it to align so that the go-to works. I'm using two-star align, the default 'point at any three stars and it works it out' simply fails . I'm at a point where with two-star align the go-to points at least vaguely in the right direction, but near the edge of the eyepiece. Here's what I've tried so far: Mount is level using the tripod's bubble. Time is set to the second using time.is and I'm not on DST. Location matches the coordinates given by both Google and SkySafari and I've made sure I'm using N and W and not mixing lat and long (that's obvious when I do, it's nowhere near accurate). Laser pointer and telescope are aligned (and regardless, I try to centre the star by eye through the eyepiece). My garden faces due north, so I use Polaris as my first star, then I've tried all the stars in the Plough, or flipping south to Orion's Belt. Running off a Celestron PowerTank Li to give it a steady power source. I wonder if my trying to get the star in the centre during alignment is not as centred as my eyeballs think! So questions: Is that kind of inaccuracy par for the course or am I not aligning with enough precision? If I align, slew from Polaris to say Dubhe (which is then off-centre) and then back again, Polaris will be in a different place in the eye piece than when I started. If use the direction buttons to reposition the star to the centre after slewing, it stops tracking. Is that normal? Would buying a laser crosshair eyepiece help? Cheers in advance!