I've recently taken an interest in astrophotography and thought I would share my misadventures!

I thought it'd be a useful experience, both for myself and for other newbies for me to document my shoots (and any results if they are even a little noteworthy), along with notes on what I done, where I done it, why I done it that way, and most importantly - where I feel I can improve! Not only will this provide a visual record of my progression from really bad absolute novice into hopefully better images, but it may also allow both myself and other newbies to learn from my mistakes!

2018-12-24 @ 2154
Target: Moon
Conditions: Clear skies, low temperature (<0°C), frost, very light breeze (Beaufort 2), Class 4-5 Bortle
Shots: 2 groups of 10x images
Equipment: Pentax K-50 with 300mm lens (75-300mm f/4.0-5.6 Sigma) (crop factor 1.52) mounted on basic tripod
Exposure: 1/50s, f/11, ISO100
Notes: Individual images were likely slightly soft; attempt to compensate with wavelet controls introduced and exaggerated noise in image
Development plans: practice focusing technique using 3D printed bahtinov mask, learn how to better use registax




2019-01-09
Target: Vega
Conditions: Broken clouds, low temperature (<0°C), strong breeze (Beaufort 6), Class 5 Bortle
Shots: 3 groups of 50x images
Equipment: Pentax K-50 with 300mm lens (75-300mm f/4.0-5.6 Sigma) (crop factor 1.52) mounted on basic tripod with sandbags
Exposure: 1" to 1/5s, f/8, ISO6400-ISO12800
Notes: A few test images with longer exposures showed stars invisible to naked eye. Issues with the shorter exposure - even when stacked, details remained invisible. Wind caused vibration during shot resulting in peculiar circular streaking around bright stars (vega looks like a tight ball of spaghetti - unless it wasn't vega, in which case I may have photographed the flying spaghetti monster).
Development plans: Rebuild heavy-duty tripod/stand, continue practicing focus. Maybe avoid shooting in strong breezes in future.

Planned:
Target: Starfield (any)
Shots: Groups of 10x images
Aims: Practice focus, learn more about correct exposure for stacking.

A heavier more sturdy tripod will help a lot in windy situations and shooting in general. So setting the wind aside without tracking of any kind I would say with a 300mm you are getting fairly close on exposure. Personally I would shoot at 0.6s of exposure and use ISO 1600 or 3200, others may suggest shooting at 1s but shooting at .6 will produce round stars not egg shaped ones.

Unfortunatly I don't think Deep Sky Stacker would have been able to stack those Vega images with that much shake but had that not been the case DSS should be able to stack them without much issue. Then once I have a stacked image I would open it in Photoshop or Gimp and start adjusting. You will be amazed at what you can pull up from the shadows once you get the hang of it. Using a lower ISO also prevents clipping of data at either end so you should be able to retain more color information for the bright stars and still be able to pull up the non naked eye visible stars this way as well.

Also for star fields go wider unless you want to shoot a globular or open cluster in which case you really are shooting a deep sky object (DSO). A handy list of fairly easy to shoot items are the Messier Objects and with that 300mm going after M42 (the Orion nebula), M45(the Pleiades), M31(the Andromeda Galaxy) are good starter objects. They are bright and easy to find, especially M42 and M45. M31 may be problematic now given where it is and how close it is getting to the horizon but if you location allows it to be in a dark area of the sky (good chance it might, I looked where Irvine, Ayrshire is). For finding things I would suggest either using a paper sky map, or using a cellphone app, like Sky Safari (recommended to me by another user here after trying others and not being pleased).

Get yourself an O-GPS1, which should run you less than $200 (for example) and that sturdier tripod MossyRocks recommends and you'll be able to do 40 second exposures with that lens at 300mm. Enough practice and you could potentially get results like this (not mine!). Using your lens at 200mm might get you a result like this. Note that this was from my first night using Astrotracer, so the feature is not hard to use.

PS. I didn't at first notice that link you included in the first post. So MossyRocks and others already introduced you to Astrotracer (with links to reviews of it by users) but you didn't bite. At all. Any reason you don't seem to be interested? IMHO the O-GPS1 will be the best $200 (less) you will ever spend and if you are like me you will still be using it after you get a full telescope-based rig (here's mine). And you don't have to spend tons on a sufficiently sturdy tripod that is still portable. Look in the used market. ThIs is what I use. Mamiya 1507, Japanese, all metal. I have seen them sell for as little as $50. (I got mine at a swap meet for $25, but the altitude bearing did require some major work.)

Money! I lack it! I've got an ebay alert set up for it, but none of them have came within my price range yet =/

The O-GPS1 is on my wishlist, but I want to try and nail the absolute basics before buying any more equipment (namely because I'm not sure I'll go very far in astrophotography - and if I do, I can build a lot of it myself; surprisingly including tracking mounts (I am into electrical engineering after all, and I have access to well-certified welders and machinists).

I also want to be sure that it's not just a photography-phase that I'm going through - in other words, I want to be certain it's for me before buying any expensive* gear that doesn't have much use outside one particular field.

It mostly comes down to money though! I know you say it's definitely one of the cheaper bits of gear I could buy - but I would still need to save up for it; and I'm already saving for a bunch of scuba gear! I might shift the O-GPS1 up the priority list a little though

I might ask for contributions towards one for my birthday in July - that gives me time to see if I'm still into astrophotography, and will be a useful upgrade if I still am

That said... for the same price I could also get a motorised equatorial mount... I'll make that decision nearer the time - as I can also build a motorised mount using stepper motors and 3D printed parts - in fact I could even machine the parts... THAT is a definitely a discussion for another time! For now, we're sticking with what I have... practically no budget


As for tripod, I like the look of that Mimiya - looks sturdy-as! My current tripod is an amazon-basics with a 3rd party all-metal quick-release... I don't mind it - it's served me well and I like it - but it could be sturdier. If I can find something like that Mimaya in that sort of price range I'll definitely upgrade! I'm also in the process of building a smaller version of my monster ultra-heavy-duty tripod (the tripod made from 8ft lengths of 2x4s) - this one will be smaller BUT the idea behind it is that it has a very wide splay so I can get the camera close to the ground where I can shelter it with a windbreak of some sort.

I think my next upgrade will actually be a decent tripod - it's all fine and good making one, but it will always be bulky and cumbersome! As I said though, I think the O-GPS1 will be next on my list after that if I'm still astrophotographing! (You've sold me on it )

--EDIT-- The wink () emoticon looks kinda weird xD

Then build your own, I'm considering doing that. I already have 2 tripods but the sturdier one is really too short for doing astro with my bad knees and the other that is taller is no where near as sturdy or as nice. Since you are someone who builds things look around at some DIY wooden tripods for ideas. Then get what ever kind of tripod head you want for it and have a bolt with the correct thread pattern (either 1/4"-20 or 3/8"-16) attached to the tripod. I've even seen some made from old wooden crutches. Time is my big constraint now preventing me from doing that.

I would steer clear of 3d printed parts but machined ones would be better. Depending on what you are making (a dual arm barn door tracker or equatorial) you may find mixed results. As much as I like building things my plan is just to eventually buy a proper tracker as the precision to make it great is needed and I know I can't achieve that with what I make. The tripod to stick it on is a different story as I can build those types of things with ease.

Ha! I decided to do both - bought a cheap-but-better tripod second hand on ebay (£50) and I've drawn up plans for a wooden one as well - grabbed an az-el mount with slow-motion controls for £10 which I can fit on it (and also on my store-bought tripod too if I fancy it!) which I can motorise later if I so choose.

I'll post pics of my build of the wooden one since it should be fairly simple - though I could do with buying better wood... the wood I planned on using is a little bit worse for wear! That said... auch you know what, I'm going to build it anyway - BRB in a few hours >.<

-EDIT-
Ran out of the bolts I wanted - got one leg built though (it took longer than it should have because my GF hid stole borrowed my measuring tape

In the meantime, I'll 3D print a mitre block for 30 degrees - I could measure and cut it myself but I dont trust my carpentry xD - my existing mitre block doesn't have one (huh, I would have assumed that 30 and 60-degrees would have been useful ones to have... and then I thought about it for a moment and realised that they're only useful if you plan on making triangles xD)

Anyway, au revoir for now!

I don't think there are many trackers selling for $186US (also available in the UK for about the same price) and whatever you can buy at the low end will probably not track as well at 300mm or even at 200mm. As well, any full-blown, RA-driven telescope mount you can get for that money (such as this one) isn't worth owning IMO.

As for making your own tracker, I did that a long time ago. Here it is. If I were making it today I would use a stepper (electrical engineer for 35 years) rather than a DC motor (I had the latter already and wanted to make use of it) and I would make the whole thing even smaller. But I doubt I could make it track any better. Astrotracer beats the pants off it. I no longer need any external tracker, home-made or otherwise. And Astrotracer fits better in a camera bag for travel (in my case no extra space at all because it is built in to my K-3II). The O-GPS1 is smaller and lighter than even the smallest tracker.

Now that is a very good point about the size!

The trackers I had seen for a similar price (secondhand) were usually from Orion - I had (perhaps naively!) made the assumption that any tracking mount is better than no tracker, and a poor tracker could be improved.

I'm afraid I'm only an amateur electrical engineer - though to be fair I do a lot of microcontroller work and have a bit of experience building control systems for CNC. Building (or modifying) one shouldn't be too difficult for me (whether it would be worth it is another matter: what separates me from a seasoned EE is that I'm slow and don't always use best practice (i.e. - more time spent tracking down bugs on top of design and manufacture). It would certainly have fun doing it though, so that's an option for the future!)

BUT - again, that is a good point about the size - and if one factors in the time I would spend building (or modifying) my own system, it'd easily "cost" more in terms of my free time than it would just to buy something.

So! What is it about the mounts with RA drives that you think isn't worth owning? I'm just curious of course - I'm not terribly familiar with the different types of drives and mounts! I mean, I know the basics behind az-el and polar/equatorial mounts - but that's about where my knowledge of mounting stops :P

Gary Seronik has some designs for simple barn door trackers.

6 DIY Star Trackers for Perfect Night Sky Photos | Make:

The periodic error on those small, cheap equatorial mounts is usually pretty poor. They may actually be worse than similarly priced trackers in that regard. Also, mechanically they are just less well made. And it won't be long, assuming you stick with astrophotography, before you want a small telescope that will be too large for such a mount, in which case you will end up selling it and spending more on something better. I always prefer to spend money on things of value that I will keep for a long time. That actually saves money over time. I bought a Vixen GP-DX mount 15 years ago and I still use it today. Quality should always be paramount.

You would not believe all the little headaches that can bedevil your photography if the mount is not up to snuff. You expressed some interest in deep-sky stuff, and that unavoidably means long exposures. (In this context, even 30 seconds is short; I'm looking at 5-10 minute ones for my nascent narrowband career!)

At even the modest magnifications that a 200- or 300mm lens will yield, periodic error in the drive, slop in the bearings, and indeed any play in the system will be painfully visible. Heh. Ask me how I know. For example, my CEM25P mount claims no worse than 10 seconds' periodic error; with my setup (336mm, K-5iis) that's three pixels right there. Your eye can easily detect that much jiggle in a high-contrast context like stars in a dark sky. And of course Murphy never allows the various errors to cancel each other, oh no they MUST always be additive!

(OK, to be fair that CEM25P spec is over ~10 minutes. Still.)

Here's a test: Open a nice sharp image in Photoshop or your favorite image-editing program. Duplicate the image, set the copy's transparency to, say, 50%, and then use the arrow keys to drag it five pixel's worth in any direction. If the result doesn't look awful, I'll eat Comet Wirtanen.

Ah, of course! It's a relative positioning system, so errors will quickly stack: Δerror = |Δa| + |Δb| + ... |Δn| so net error will grow with time (assuming the axis are independent of each other - i.e. that you can get an error in only, say, the X-axis and the Y-axis will be unaffected - if they are not independent, the errors will multiply rather than merely summing.)



Woo! I've already favourited that exact article I quite like the design of these double-arm trackers as well - haven't built anything yet though! I should probably get on that actually!

My current build is focused on improving the stability of my whole system - the heavy-duty tripod is 3/5 finished, just need to buy some bolts and secure the last two legs on it and we'll be good to go - though I plan on building another one with better quality wood.

I also have a lens-support that I want to build - just a strip of wood with a 3D printed lens-holder - bolt the camera to it via the tripod mount, set the height of the lens-support to suit the lens you're doing, and then bolt all that to your tripod near the centre of gravity - super simple, but will hopefully reduce shake quite a bit (and also put much less stress on the lens mount while we're at it!)

Huzzah! I might finally have a break in the cloud lover that will last more than 10 minutes! According to ClearOutside I should have clear skies from 2300 right through to the early morning - DarkSky suggests 0100 to early morning, so if I get up a few hours early for work (I'm usually up at 0500 anyway) I can go for a walk and hopefully grab a few shots!


Most of this is just me planning ahead but by posting it up here people can let me know if I'm doing something dumb or make suggestions :P Note that targets aren't necessarily realistic - I'm shooting targets of interest to see what I can and can't see with my equipment rather than simply trying to get good shots - I'm trying to establish a sort of baseline to work against when planning in the future

Target(s):
-Andromeda Galaxy [M31], N, nearest horizon 0500 - primary target - practice for stacking
-Arcturus, SE, 40° Elev ,anytime, may not be that interesting - secondary target - practice for focus
-Whirlpool Galaxy [M51], E, 70° Elev, anytime, likely difficult
-Veil Nebula, NE, 10° Elev, anytime, likely difficult
Expected Conditions: Clear skies/scattered clouds, low temperature (~1°C), moderate breeze (Beaufort 4), Class 6 bortle, 5 if I'm lucky
Shots: 10x frames per target
Equipment:
-28mm f/2.8 Vivitar (crop factor 1.52)
-75-300mm f/4.0-5.6 Sigma (crop factor 1.52)
-2x Teleconverter [NB: will likely introduce CA]
-Static heavy duty tripod (no tracking)
Exposure: 1" to 1/5s, f/8, ISO6400-ISO12800
Notes: Wind may be issue - consider using guy wires. Figure out where you left your bahtinov mask.
Development plans: Stacking and focus practice, start establish baseline with this equipment so I can realistically plan future targets. Start saving for O-GPS1 (you guys sold me on it! )

May I suggest M42 as a perfect target for practicing, it's visible to the naked eye. If you ask me, far easier to locate than the Andromeda Galaxy.
I guess your clear skies are blowing across the North Sea - I have perfect conditions tomorrow evening/night