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A friend let me have a go on his Star Tracker so that I could have a stab at capturing the Orion Nebular.
This DSO photography could get very expensive should I carry on with it.
It's 15 exposures at 60, 30, 15, 8 and 4 seconds on my very noisey GH6 + 35-100mm lens.
https://www.flickr.com/photos/the1lemming/51908370594/in/dateposted/
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In reply to The Lemming:
nice one, nice picture.
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In reply to The Lemming:
Hmm, there looks to be quite a bit of mistracking (or a wobbly tripod) there. However, this sort of fun doesn't need to be very expensive. I built my own barn-door tracker years ago and it's giving good service with ordinary non-astro photo equipment. The only bit of astro-specific equipment I actually bought was a UHC filter.
https://drive.google.com/file/d/10o1PEeamATXjjQLWYdLAGxPYJzn43Yjv/view?usp=...
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In reply to Marek:
> Hmm, there looks to be quite a bit of mistracking (or a wobbly tripod) there.
Yep the stars are elongated but I'm not sure why. The stars are the same shape from the 60 second to 4 second exposures.
In reply to The Lemming:
Beautiful picture!!
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In reply to The Lemming:
Awesome photo. Looks like something NASA would release.
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In reply to The Lemming:
In that case it'll be distortion in the lens. Astrophotos are VERY good at showing up flaws in lens and zoom lenses in particular have compromises in their design. Was it a crop from near the top-left of the frame? It looks bit like what call 'coma' abberation. Try and use the middle of your sensor if possible. It's hard to predict which lens are good/bad - my best lens is a relatively cheap Samyang 135mm f2 which is pin sharp corner to corner wide open. Most Canon lenses are quite poor, although the 70-200 f2.8 is good (but heavy). On the Lumix side I've had good results with the 100-400mm lens, but it's very slow and the G9 isn't particularly good for astro (noise).
For worse thing about astro for me is that here in the NW, you get very few decently clear nights. I consider myself lucky if I manage a handful of sessions per year (summer is useless - it just never get dark enough), I spend more time tinkering with the tracker and software than I do actually getting pictures.
Orion is a great target though: Right in the middle (the biggest blob in your photo) are four very bright blue stars (the 'Trapezium') that you should be able to resolve with careful exposure. They basically are the power source for the whole nebula. Near the belt is the 'Horsehead' nebula (small dark horse head shape in the bottom left of my picture above). And then if you go wider there's a structure called 'Barnard's Loop' all round the left side of Orion that's worth try to capture, but it's quite faint and you really need a decently dark sky.
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In reply to Marek:
I didn't know that was the location of the Horsehead. Is it a feasible visual target or is it only discernible in stacked images.
( I can just about get the Trapezium with my ST80 but it's an easy proposition with the ST 120)
In reply to Tom Valentine:
> I didn't know that was the location of the Horsehead. Is it a feasible visual target or is it only discernible in stacked images.
I don't know - depends on how dark your sky is, how good your eyes are and practice. Some people claim quite impressive visual capabilities (e.g., the relativistic jet in M87 https://britastro.org/node/20783. I can't get even close to imaging it in the UK), but I just do stacked imaging (the gear does the work and I stay in the warm indoors!) It's not *really* faint, so I'd give it a go if you can get somewhere reasonably dark like Kielder.
Edit: The horsehead nebula is in the southern sky for us, so you really want to get somewhere which has open sea to the south (and no oil rigs), e.g., tip of the Llyn peninsula or the Hebrides. Should be easy then (weather permitting).
> ( I can just about get the Trapezium with my ST80 but it's an easy proposition with the ST 120)
Post edited at 10:09
In reply to Tom Valentine:
> I didn't know that was the location of the Horsehead. Is it a feasible visual target ...
It's always been reckoned to be feasible with a 12" (or greater) mirror, and dark skies.
In reply to Marek:
> Hmm, there looks to be quite a bit of mistracking (or a wobbly tripod) there. However, this sort of fun doesn't need to be very expensive. I built my own barn-door tracker years ago and it's giving good service with ordinary non-astro photo equipment. The only bit of astro-specific equipment I actually bought was a UHC filter.
That's a very good image.
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In reply to Rob Parsons:
This suggest it's just about doable with a 120mm scope and a UHC filter...
https://www.cloudynights.com/topic/488405-how-many-have-visually-seen-the-h...
In reply to Marek:
Good to know, though there's probably very little point trying in my Bortle 6 back garden
In reply to The Lemming:
Did you use a remote shutter/ time delay? The elongated stars could be a jiggle from pressing the shutter.
> Yep the stars are elongated but I'm not sure why. The stars are the same shape from the 60 second to 4 second exposures.
In reply to The Lemming:
That's how it all starts! It's a very addictive pastime. Your image is certainly a lot better than my first attempt at AP. It does look like you've got some sort of wobble going on though to create those star shapes, it doesn't look like coma to me.
In reply to andi turner:
You may be right (about the coma), but it didn't seem likely to be shutter release wobble (it would be much more obvious on the 4s exposure then the 30s exposure) and it also didn't fit the pattern of random mount wobble. Also the angle of the distortion spread seem to vary across the image, which is why I guessed it was optical (rather than mechanical) and that the image was cropped. I suppose tangential astigmatism is a possibility - I struggle to differentiate them unless they're very obvious.
Post edited at 17:49
In reply to The Lemming:
sweet. i'm thinking of getting the samyang 12mm/f2 for astro - but may as well buy a telescope for the price of your long 2.8 lens?
could you give a single shot comparison to see what the software does?
In reply to magma:
> ... - but may as well buy a telescope for the price of your long 2.8 lens?
Ooh, slippery slope! Telescopes tend to be very slow (compared to photo lenses) which means you need a decent mount (which will cost as much as the scope). There are fast 'astrographs', but we're talking serious money (£5k+). A lot of chaeper scopes are also design more for visual use rather then astrophotography, so then you need to add 'field flatterers' and all sorts of other (expensive) bits. And if you got that, you might as well go for narrow band imaging (the filters are only another £1k). And so it goes...
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In reply to Marek:
I hadn't heard of UHC filters before (my basic set is 3 colours and ND) but it sounds like a good buy
Post edited at 18:54
In reply to magma:
> could you give a single shot comparison to see what the software does?
Evening everybody. I wasn't expecting so many people giving me such helpful advice for my first ever attempt at a DSO.
I will most definitely give all this another go, just not with my Lumix 35-100mm f2.8 lens.
I'm guessing that the lens is more the problem that anything else because every single shot from 60 seconds through to 4 seconds looks the same. Everything was shot with the 2 second delay before the images were taken.
Sadly I also have to contend with a MFT camera and being very noisy. Such is life
Here's one of the 60 second DGN files with no editing or cropping.
https://drive.google.com/file/d/12VdNGFhjlHfO1s33MR1YP6dwFyPhU7Nu/view?usp=...
In reply to The Lemming:
And for anybody interested, here's the 4 second DGN file
https://drive.google.com/file/d/177wYfJNkf4Qf2LwEuau9ixajCqzQIZol/view?usp=...
In reply to Tom Valentine:
> I hadn't heard of UHC filters before (my basic set is 3 colours and ND) but it sounds like a good buy
I have one of these: https://www.rothervalleyoptics.co.uk/explore-scientific-uhc-nebula-filter-1...
UHC *used* to be very effective against urban light pollution - till they replaced the narrow-band sodium lights with broad-band LEDs. Nothing much works against those, but the UHC filter is still good at bringing out some of the colours in emission nebulae like M42 in Orion. Bear in mind that The UHC filter won't help at all with reflection nebulae nor with galaxies.
Also, these filters are designed to fit into telescopes just in front of the eyepiece. You have to get a bit 'inventive'* to use them with an ordinary lens-and-camera combo. They also don't work very well with wide-angle lenses (for a number of mechanical and optical reasons).
* I can fix a 1.25" filter to the rear of most of my astro-relevant lenses (unfortunately not the 70-200mm f2.8, nor the 35mm f1.4) such that it doesn't foul the flappy mirror. YMMV, buyer beware and all that.
In reply to The Lemming:
The noise is ok, nothing to worry about - the way around that is to stack more exposures. Amazing results have been achieved with far noisier sensors. Also, nothing wrong with a 4/3 sensor - a larger sensor is not necessarily any less noisy, it just covers a larger field of view for a given focal length.
I wonder if the streaks on the image were due to the stacking program you have used not registering and aligning the images properly. I'm not familiar with that program, maybe some setting is not correct there. It looks like all the subframes have just been added without the software tracking the small shifts between each frame. The stacked image shows worse trailing than either of those subframes. The stacking program should shift each frame so that all the stars line up between each image. It might not like the exposures being different. They can be worked with like that but it's a different approach.
The 60s frame looks OK tracking wise, so it looks like the tracker is OK for 60s images at that focal length. Do more at that exposure. Try 1/2 hour's worth.
There is some small distortion in the image, as Marek says, astrophotography is hard on the lens. Stop it down to F4 and it might be a little better.
All in all, it's not bad at all! Experimentation is the key.
I'd check the software first though, something seems not right there.
In reply to richard_hopkins:
I may try stacking in GIMP rather than the astro software, which is great for star trails.
In reply to The Lemming:
Other point for comment: do you have a lens hood? I'm not sure if the bright "star" at the bottom right of the image is actually a star. It might be a lens flare from something. The bottom left one is Sirius, but there is no bright star at the bottom right!
Or maybe it was a plane.
Edit:
scratch that. My mistake, I've got the scale wrong. The bottom right is Rigel and the bottom left is Saiph. I thought the field of view was wider. Sirius is not in the image.
Post edited at 20:20
In reply to The Lemming:
Here's another example of what software can do:
https://drive.google.com/file/d/10og86cfFZ6Zz_Mz5kp-iGZunOwmbd6X5/view?usp=...
On the left is a single 60s image, straight out of the camera, converted to a linear tiff and stretched (gamma=5) and cropped to 100% to show the low level noise. As you can see, there's some detail there, but it's all buried in the noise. There are also some 'hot pixels' (red dots) which are sensor flaws.
The middle one is a calibrated and white-balanced stack (~30 lights), again stretched to show detail. You can see the effect of 'darks' (hot pixels gone). Flats and biases are hard to see here - more obvious in the full image. The noise level is much lower, but the center of the nebula is completely blown out (saturated). The dynamic range in M42 is just enormous.
The final image is a merge of the previous plus a number of shorter exposures (down to 1s) to try and show some detail in the center. Not very successfully, it must be said, the trapezium stars are still saturated (and unresolved) and the white area in the middle should really be a pale cyan colour. Merging such a wide dynamic range convincingly is hard. This picture contains about 15 stops of linear dynamic range and could do with more.
In reply to The Lemming:
You need software that specifically identifies the stars in the image and realigns each image to keep the stars steady. The tracker is not perfect, and the image will drift slowly over time. Stacking of these images is different to making star trail images. The processing is different to AVOID making the trails.
The traditional software for basic stacking is Deep Sky Stacker. It's been around for years and has many tutorials showing how to use it. Other more sophisticated programs are available, but DSS is fine for starting out if a little unintuitive.
In reply to richard_hopkins:
> The traditional software for basic stacking is Deep Sky Stacker. It's been around for years and has many tutorials showing how to use it. Other more sophisticated programs are available, but DSS is fine for starting out if a little unintuitive.
Indeed, I use DSS. It's good value for money (free). Pixinsight is considered by many to be the best amateur astro software. but the $400 price tag is just too high for me.
One other thing to look out for: If you lens has any noticeable geometric distortion (a given for any 'wide' lens) then simple stacking (adjusting for shift & rotation) won't work very well particularly if there's a big shift between images. You have to correct the distortion first before stacking (I use Hugin). I don't think it's the issue here, but it's worth bearing in mind if you ever try very wide field imaging.
In reply to richard_hopkins:
> The noise is ok, nothing to worry about - the way around that is to stack more exposures. Amazing results have been achieved with far noisier sensors. Also, nothing wrong with a 4/3 sensor - a larger sensor is not necessarily any less noisy, it just covers a larger field of view for a given focal length.
In principle that's true, but whenever I've compared my G9 (m4/3 sensor) with the 550d (astro modded APS-C) and 6d (vanilla FF) it's been seriously disappointing (same target, same night). Pity, the 100-400mm lens is surprisingly good (for abberation). Given the limited clear-dark-sky time I get, I can't afford to image for multiple nights to get the same noise level as I can get with the 6d in an hour or two.
The G9 & 400mm is better for planets though!
In reply to Marek:
> The G9 & 400mm is better for planets though!
I left my 100-400 lens at home yesterday thinking it was too slow. maybe if I get access to the tracker again, I'll give it a try.
In reply to The Lemming:
I've got an Astrotrac that you are welcome to borrow if you're wanting to try something different. Also, if you ever want me to batch process any of your subs then you can send them over and I'll run them through Pixinsight.
In reply to The Lemming:
I've not done an M42 for 8 years or so, but here's mine when I did:
https://www.flickr.com/photos/anditurner/12019878253/in/album-7215765040304...
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In reply to The Lemming:
> I left my 100-400 lens at home yesterday thinking it was too slow. maybe if I get access to the tracker again, I'll give it a try.
You can't use that excuse! Planets don't need a tracker - Jupiter will be 1/250s at f6.3 (400mm) ISO800 for the disc and ~1/4s for the moons. All you need is a good tripod and a bunch of yet more software (PIPP, Autostakkert & Registax).
Post edited at 21:39
In reply to Marek:
> You can't use that excuse! Planets don't need a tracker - Jupiter will be 1/250s at f6.3 (400mm) for the disc and ~1/4s for the moons. All you need is a good tripod and a bunch of yet more software (PIPP, Autostakkert & Registax).
Got all that and used all that, so I will give it a try. 😀
Here's my attempt at taking a video of the moon and converting to a single image.
https://www.flickr.com/photos/the1lemming/34373552252/in/album-721576810990...
In reply to The Lemming:
Lemming, You should be able to produce an image like this with what you have:
https://www.flickr.com/photos/77393937@N02/24029372301/in/dateposted-public...
It was done with an unmodified DSLR (10 year old model now, nothing fancy), a 180mm lens at F4, and a simple tracker. That was done with 40x 30 second exposures (and some dark exposures as well). The image was stacked with deep sky stacker, and that's it. Your set up is broadly similar. The Orion nebula is bright and a great target for a non-astro camera. With more exposure (more frames) you can tease more detail.
Then when you get addicted, you can get carried away, buy a fancy telescope, camera, filters, mount and make images like Andi!
If you live near Andi, take him up on the offer of borrowing the Astrotrac, it's a great tracker for heavier lenses like your 400mm.
In reply to The Lemming:
I found that taking a bunch (86) of RAW stills rather than a compressed video worked better for me.
Jupiter with Ganymede, Europa, Io and Callisto (left to right)...
https://drive.google.com/file/d/10uqIBxyp85PIUjzeAD9eOQpAWii3sCN2/view?usp=...
Saturn with Titan @ 6 o'clock and Rhea @ 8 o'clock.
https://drive.google.com/file/d/140R9UwyZ6WvOcS_WKJH3Mmqxvj8TM7ZW/view?usp=...
In all honesty, you really need the focal length of telescope to do this properly. But I was quite impressed what an ordinary camera/lens could do.
Post edited at 21:58
In reply to The Lemming:
Great first attempt but I reckon you could get a lot more out of your data with some post-processing tweaks. There's a bit of star trailing, this could be incorrect polar alignment on the sky tracker, wind or the tripod being knocked slightly.
My attempt here:
https://www.flickr.com/photos/141680726@N06/50846451041/
Olympus E-M5 MkII
Leica DG 200mm F2.8
iOptron SkyTracker Pro
31x 50s, ISO 400 @ f2.8
1) Pre-edited lights in Rawtherapee
https://clarkvision.com/articles/astrophotography-with-rawtherapee/
2) Align and stack in Siril (2x DRIZZLE)
3) Stretch with RNC Color Stretch
https://clarkvision.com/articles/astrophotography-rnc-color-stretch/
4) Final tweaks in GIMP
All the programs above are free and open source software.
There is a wealth of very in depth information on clarkvision.com
You don't need a telescope to capture DSOs. Standard DSLR/mirrorless cameras with fast telephoto lenses can produce some amazing DSO images, I'd advise a different set up if you want to do planetary images though.
Post edited at 22:16
In reply to The Lemming:
Have a look at Andi Turners Flickr collection, lots of staggering astro shots. Not sure if he's on here to comment.
Post edited at 09:22
In reply to The Lemming:
i keep meaning to try a homemade star tracker eg
In reply to The Lemming:
nebula guy is good explaining stuff (for a newbie like me): youtube.com/watch?v=0vd6Zk5M5OA&
In reply to Marek:
I think your planet photos are a good representation of what a visual sighting might look like at around 100 X
In reply to magma:
Yes, I made one of those. And then decided I could make a slightly better one. Then thought a tweek here and a tweek there would be a good idea. Ended up with this monstrosity...
https://drive.google.com/file/d/14FF5kP5CJAb633EpwhYekrvq0bs-PYg2/view?usp=...
... plus a bunch of software you can't see.
Of course it would have been a lot simpler just to go and buy one, but there weren't any affordable ones when I started and once you start you sort of keep going. Endless evenings of fun making it though.
As people have said... slippery slope.
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