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JGM1971

The "No EQ" DSO Challenge!

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Take a look at the rotation links on the last page or so I found very interesting on how many seconds depending on where looking and it was not what I was expecting.

Really like the second image.

StarTools my PC is 32 bit and not hugely fast so to reduce crashes massively the first thing to do is crop generously and then bin 50%. After that it is faster too.

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51 minutes ago, Nigel G said:

A beautifully clear night last night gave me the chance to get some images of M51 & M13. 

These are both about 40 x 50s @ 1600 iso lights 30 dark and 50 bias stacked and once again these images are straight from DSS, unfortunately StarTools runs incredibly slow, I was 2 hours into processing and it crashed ? But still I'm very happy with these.

M51 tosend.JPGM13 tosend.JPG

50 seconds exposure and being able to keep 75 %, I think with high altitude objects I'm getting better results as the mount moves slower, I recon 60 - 90 seconds will be possible.  Low altitude objects 30 seconds is max, M42 last night failed with 20 seconds max. I did get a 70 second exp of M13 though ☺

Clear sky's 

Nige.

Yes Nige, ST is extremely resource intensive and you ideally need a fast PC running 64-bit. There are of course other specialist programs, some of which are very expensive and require substantial study if you are to get anything decent out.

Getting the optimum exposure is a bit of trial and error, in the knowledge that at high altitudes the mount may not need to make such great movements, but field rotation is at its worst, and at low altitudes you have to contend with poorer seeing.

Your images have come out rather well; I like M13 best.

Ian

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2 hours ago, happy-kat said:

Take a look at the rotation links on the last page or so I found very interesting on how many seconds depending on where looking and it was not what I was expecting.

Really like the second image.

StarTools my PC is 32 bit and not hugely fast so to reduce crashes massively the first thing to do is crop generously and then bin 50%. After that it is faster too.

Thanks for the information,  I have tried cropping then binning and StarTools works much faster, ☺

Another step forward,  Great ? 

Nige.

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This is a single frame image from Canon 750D (T6i) at 400mm, ISO 1600, f7.1 for 15 seconds. Some minor Photoshop adjustments. Seeing conditions were marginal at best with major light pollution from the city. I used the mount in Alt/Az mode.

A2642448-4C53-484F-8B74-BAD8F4E47BF1_zps

This is the rig used to take the shot. It was my first test.

IMG_3277_zpst4va8em5.jpg

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Very nice image,  I like the colours that have come out. 

Nige

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This was taken using a NexStar 5i with a Meade 6.3 FR/FF and 1100D Canon 25X30s ISO3200 processed with DSS and PhotoShop cs2

 

M51.jpg

Edited by BrianClark
better example
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9 hours ago, VSOP said:

This is a single frame image from Canon 750D (T6i) at 400mm, ISO 1600, f7.1 for 15 seconds. Some minor Photoshop adjustments. Seeing conditions were marginal at best with major light pollution from the city. I used the mount in Alt/Az mode.

A2642448-4C53-484F-8B74-BAD8F4E47BF1_zps

 

 

That's a good start VSOP, very vibrant for just a single frame. Are you planning on taking a few dozen and stacking them?

Ian

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Hi Guys,

Total newb here, I've only been taking pics for a few months, but I'm starting to have some success.  Using a 10" Meade LX200-ACF with the stock alt-az goto mount.  Camera is a Canon T3i attached to a Moonlight focuser.  Using Deep Sky Stacker for processing, haven't gotten the hang of taking bias's or flats yet, only using darks.  I've been limited to 10-15sec exposures max due to the tracking errors in the mount...sometimes I can use 30sec exposures if I take a tonne of frames and cherry pick the best ones.  Biggest revelation for me so far has been to buy a $30 intravolometer for the Canon which allowed me to start taking the quantity of shots needed quickly and easily.  Below are some of my best shots to date:

 

Orion Nebula - 20160105 - 4 - downsampled_1.jpg

Great Orion Nebula.  4 frames @ 10 seconds exposure each, 3200 ISO, 4 dark frames.  One of my early attempts and first successful final image.  There is more noise with this shot than the others because I was trying to stack jpgs :s  Rookie mistake I guess.  With the next couple of shots I converted the jpgs to bmps before hand, which may be why they look a little pixilated.  Next time out I'll just shoot RAW images and work with that. 

 

M13_2016-03-29_1.jpg

M13, 24 frames @ 15 seconds exposure each, 6400 ISO, 10 dark frames.

 

Whirlpool Galaxy_2016-03-29_1.jpg

Whirlpool Galaxy, 17 frames @ 30 second exposure each, 6400 ISO, 20 dark frames. Probably shot close to 100 frames that night, but had to discard the vast majority of them due to tracking errors and streaky stars.

 

I'm a firm believer that you CAN do photography with an alt-azi mount!  If not somewhat limited.  Going to try and push my rig to the limits before I purchase a German equatorial mount.  

Anybody try using an autoguider with an alt-azi setup to try and remove some of the tracking errors?  Is it worth it to try and get consistent 30 sec exposures?

 

Thanks!

Ahmad

Edited by amumin
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5 minutes ago, amumin said:

Hi Guys,

Total newb here, I've only been taking pics for a few months, but I'm starting to have some success.  Using a 10" Meade LX200-ACF with the stock alt-az goto mount.  Camera is a Canon T3i attached to a Moonlight focuser.  Using Deep Sky Stacker for processing, haven't gotten the hang of taking bias's or flats yet, only using darks.  I've been limited to 10-15sec exposures max due to the tracking errors in the mount...sometimes I can use 30sec exposures if I take a tonne of frames and cherry pick the best ones.  Biggest revelation for me so far has been to buy a $30 intravolometer for the Canon which allowed me to start taking the quantity of shots needed quickly and easily.  Below are some of my best shots to date:

 

Hi Ahmad, welcome to the forum.

That's a great start, and yes, one can take astro-photos with an Alt-Az mount. And of course it's a great introduction to the subject without the extra complications of an EQ mount, but you can always migrate to that later. The principles will be much the same. With 10" of aperture you should be able to hoover up photons and make short exposures more profitable, and you should get some decent resolution too. The down-side of course is that at f/10 you have a very long focal length which will magnify any mount tracking errors. Have you thought of using a focal reducer with your kit, for astro-photography?

Setting up your mount initially can make a big difference to its performance, like levelling, precisely setting your location and time, and centring your alignment stars. There are 2 aspects really, the general tracking performance, i.e. how well it keeps the object centred, and the fine-ness of its movements.

One thing I have read is that if you don't have many darks then you are likely to introduce noise into the image, rather than reduce it. I think you'll need 50 or more. Likewise, the more subs you take the better your result.

Another improvement you can make is to use the RAW output of your camera rather than JPEGs. I think DSS will process your Canon RAWs directly. The downside though is that you'll need a heck of a lot more hard disk space :icon_biggrin:. What do you use for post-processing? There are a number of specialist applications around, varying from cheap to darned expensive, and there will always be a learning curve, but generally you can download a free trial, which I'd thoroughly recommend.

I'm not sure that you can get an autoguider for Alt-Az mounts, unfortunately.

I can recommend this book as an introduction to short exposure astrophotography< "Astrophotogrphy on the Go - Using Short Exposures with Light Mounts " by Joseph Ashley ISBN 978-3-319-09830-2.

Anyway, there's lots of good advice here on the Forum.

Ian

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On 4/10/2016 at 10:25, happy-kat said:

There is much more to this no eq mount potential then first assumed. With careful object selection and obtaining long exposures the need for hundreds of subs must surely diminish.

Hi happy-kat,

Yes, an alt-az set up will open up a lifetime of objects to image and that's good news when your local light pollution is bad, your budget is limited or you just want to see if imaging is going to be an interest without making a large outlay of money. I'd go so far as to say it can be the difference between reading about imaging and being able to get out and do some while learning all the time.

One downside of alt-az imaging is that the individual length of each light exposure is much shorter in duration than from a EQ set up. In his book, "Astrophotography on the Go Using Short Exposures with Light Mounts" Joseph Ashley mentions that with very short length astrophotography a total integrated exposure time of 120 minutes is desired for an object. On page 87 he gives a guidance chart comparing % frame success rate and exposure time. In practice that is a really long time to be taking light exposures involving a number of realignments due to field rotation and I don't think I have ever been able to take so many light exposures (I also need some sleep). It's worth experimenting of course but I am mindful that in the UK the weather is very much a limiting factor on how many nights you can actually image on! In the short time I have been using my gear to image I have noted that objects such as clusters and globular clusters do not need that many exposures to get a decent final image. Some nebula and galaxies on the other hand can take up as much exposure time as you can manage.

Best regards,
Steve

 

Edited by SteveNickolls
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I just had to share these 2 with you I know M 13 was favourite, I'm having a little trouble processing it so 101 and 51 after StarTools,  I never expected to get images like this when I started out. These are far beyond my expectations,  I'm over the moon.

thanks for all your advice 

PSX_20160410_180538.jpgPSX_20160411_185206.jpgPSX_20160411_184613.jpg

Nige.

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Ooo look at those, StarTools did very good for you, well done it took me several sessions to get anything going.

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You deserve to be well chuffed with those Nigel :hello2:. I've said it before, the post processing can make or break an image, it seems so much more critical with astro images than conventional images. I think a lot of folk try to take pictures with relatively modest gear, and because the results are disappointing they think they need all the fancy bits and bobs and give up. But quite often, there's so much that could still be teased out with the right processing. Star Tools has its own quirks, but it looks like you're managing to tame it. I still don't feel I've mastered it.

Ian

Ian

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On 11/04/2016 at 08:43, amumin said:

I'm a firm believer that you CAN do photography with an alt-azi mount!  If not somewhat limited.  Going to try and push my rig to the limits before I purchase a German equatorial mount. 

Yes, it certainly can be done. There was a thread on here years ago with an image of the horsehead nebula taken with a massive number of 2-second subs.

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M95, M96 and the Leo Tripets (or a lesson on if it can go wrong it will go wrong)

Step 1: Let's take the flats, darks and bias whilst the sun is up...so using the crescent moon to get a good focus...flats [tick], darks [tick], bias [tick]

Step 2: Let's align the finder scope during twilight using Jupiter and BackyardEOS to see my camera live view. Nothing. Okay, maybe the alignment is so bad it's not close to my field of view. Unclamp the scope and slew around in the hope of seeing it flash across the screen. Nope. Okay, maybe my focus has gone completely. Refocus on the Moon. Can't find it. Okay, have I messed up settings on the camera? Doh, yes it's still set to 1/8000s from taking the bias so reset the camera to manual and 30s. Slew back to Jupiter. Still can't find it. Start to pull out hair. Let's put in an eyepiece. Still can't see anything. Maybe I should remove the lens cap from the scope? /facepalm

Step 3: Let's align the mount using three star alignment and live view [tick]

Step 4: Let's get fine focus using the final star since it's bright enough and already in view. Grab mask and see focus is spot on [tick] Unfocus slightly and refocus just to make sure [tick]

Step 5: Slew to target and take a single 30s ISO1600 shot to check composition. Stars are heavily trailed. Maybe the mount needed longer to get steady? Take another shot. Still heavily trailed. Take a third shot. Still...hold on, those are weird trails. They look more like acute star spikes. Maybe remove the mask? /facepalm

Step 6: Repeat step 5. Image looks great and is centred exactly as shown in SkySafari. A first for my alignment. I normally have to adjust slightly. Lesson learnt: aligning using an eyepiece, even using unfocused stars and an 8mm eyepiece, is not as accurate as using live view. Proceed to take lights.

Step 7: Slew to Margarin's Chain to grab a few more lights to integrate with data from the weekend. Again, perfect alignment on the goto meaning I could frame my shot using SkySafari!

Anyway, here's a processed shot of M95, M96 and the Leo Triplets using the Esprit 80 on the Evo mount and the Canon 60D. It's 57 x 30s lights at ISO1600 with 50 darks. The flats didn't work so I also didn't use the bias.

 

P.S. Step 8: Post to forum then notice I linked the Markarian's Chain and not the Leo shot. My face is getting very sore now.

large.image.jpeg

Edited by Filroden
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8 hours ago, Filroden said:

Step 2: Let's align the finder scope during twilight using Jupiter and BackyardEOS to see my camera live view. Nothing. Okay, maybe the alignment is so bad it's not close to my field of view. Unclamp the scope and slew around in the hope of seeing it flash across the screen. Nope. Okay, maybe my focus has gone completely. Refocus on the Moon. Can't find it. Okay, have I messed up settings on the camera? Doh, yes it's still set to 1/8000s from taking the bias so reset the camera to manual and 30s.

You are not alone! I did the self-same thing yesterday. Despite setting up on the RDF, I still couldn't see it on the LCD screen. I spent an age slewing back and forth until I realised I hadn't turned the wick up :icon_biggrin:

Your sky background is very black. I wonder if some fainter details are being clipped?

Edited by The Admiral

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9 hours ago, Filroden said:

M95, M96 and the Leo Tripets (or a lesson on if it can go wrong it will go wrong)

Step 1: Let's take the flats, darks and bias whilst the sun is up...so using the crescent moon to get a good focus...flats [tick], darks [tick], bias [tick]

Step 2: Let's align the finder scope during twilight using Jupiter and BackyardEOS to see my camera live view. Nothing. Okay, maybe the alignment is so bad it's not close to my field of view. Unclamp the scope and slew around in the hope of seeing it flash across the screen. Nope. Okay, maybe my focus has gone completely. Refocus on the Moon. Can't find it. Okay, have I messed up settings on the camera? Doh, yes it's still set to 1/8000s from taking the bias so reset the camera to manual and 30s. Slew back to Jupiter. Still can't find it. Start to pull out hair. Let's put in an eyepiece. Still can't see anything. Maybe I should remove the lens cap from the scope? /facepalm

Step 3: Let's align the mount using three star alignment and live view [tick]

Step 4: Let's get fine focus using the final star since it's bright enough and already in view. Grab mask and see focus is spot on [tick] Unfocus slightly and refocus just to make sure [tick]

Step 5: Slew to target and take a single 30s ISO1600 shot to check composition. Stars are heavily trailed. Maybe the mount needed longer to get steady? Take another shot. Still heavily trailed. Take a third shot. Still...hold on, those are weird trails. They look more like acute star spikes. Maybe remove the mask? /facepalm

Step 6: Repeat step 5. Image looks great and is centred exactly as shown in SkySafari. A first for my alignment. I normally have to adjust slightly. Lesson learnt: aligning using an eyepiece, even using unfocused stars and an 8mm eyepiece, is not as accurate as using live view. Proceed to take lights.

Step 7: Slew to Margarin's Chain to grab a few more lights to integrate with data from the weekend. Again, perfect alignment on the goto meaning I could frame my shot using SkySafari!

Anyway, here's a processed shot of M95, M96 and the Leo Triplets using the Esprit 80 on the Evo mount and the Canon 60D. It's 57 x 30s lights at ISO1600 with 50 darks. The flats didn't work so I also didn't use the bias.

 

P.S. Step 8: Post to forum then notice I linked the Markarian's Chain and not the Leo shot. My face is getting very sore now.

large.image.jpeg

I set up last night to photo M81 -82 , just needed to wait for it to get a little darker so indoors to have a cuppa, when dark enough I set 50 frames at 30s and pressed go. The mount is fine with 30s, can keep all images, so leave scope and camera doing there bit. 25 minutes later Check images, all blank. Scratch head, ahh take scope cap off. Oh well darks done ☺

Nice image , keep it up. 

Nige.

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Last night I did manage to get the light frames of M81-M82 after removing the scope cap ☺.

I took 120 x 30s DSS used only 48 of these, it was slightly cloudy at times. 

StarTools would not improve this image so I  did a little processing in DSS and then enhanced with the Adobe photoshop app, 

If you have an android device I can't recommend this app enough, I run all my images through it to finish off before uploading. It really is fool proof and gives stunning results, the noise reduction is great as is sharpening,  only one thing is limited colour enhancement. 

It's by far the easiest photo enhancement program I've used, and it's free. 

So this image is 48x30s @ 1600 iso light, 50 dark 50 bias with 150p goto, Canon 1200d, DSS & photoshop app.

PSX_20160413_161418.jpg

Nige.

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Here's a quick and dirty look at M64, the Black Eye Galaxy. I was out taking some images of the Moon and Jupiter, testing a newly acquired x2 focal extender. After I'd finished that I reverted to my usual set-up and as there was a bit of time I turned the 'scope towards M64. I set the camera going for the first batch of 50 frames, but when I returned to the camera it was completely dead. Not knowing how many frames it had managed and as it was getting a bit late I decided to throw in the towel. In the end I did get about 50 frames, but no flats, darks or bias frames. Not really enough, but this is the result. Not great.

50sub DSS ST no fl-l-b.jpg

 

I'll need to have another go when the skies clear again. When! Usual set up, Altair Wave 102mm f7 SuperED APO, Fuji X-T1, Nexstar 6/8SE alt-az mount. 12th April 2016. Stacked in DSS and processed in Star Tools.

Ian

Edited by The Admiral
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Nigel G & the Admiral

If you have a photo-editing package with 'gamma' try reducing it to about 0.82 to 0.90 (unadjusted setting is 1.00). It will darken the background and increase the contrast in the galaxy, without losing you any detail (as long as you don't over do it).

If you have photoshop, use the levels histogram and don't tough the end sliders, just the middle one.

Gamma is a very simple tool and is fantastic for improving details in shadows or burnt out areas of ordinary photos.

 

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52 minutes ago, Stub Mandrel said:

Nigel G & the Admiral

If you have a photo-editing package with 'gamma' try reducing it to about 0.82 to 0.90 (unadjusted setting is 1.00). It will darken the background and increase the contrast in the galaxy, without losing you any detail (as long as you don't over do it).

If you have photoshop, use the levels histogram and don't tough the end sliders, just the middle one.

Gamma is a very simple tool and is fantastic for improving details in shadows or burnt out areas of ordinary photos.

 

Hi Neil, 

That's a handy tip, gamma is quite  an aggressive function and I  generally leave it alone, but I will try it now you have given me an idea what to do with it.

The only thing I have used gamma on is planetary images especially Saturn.

I'm going to see what I can do with the images I have as tonight is supposed to be cloudy.

Thanks Neil

Nige.

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1 hour ago, The Admiral said:

Here's a quick and dirty look at M64, the Black Eye Galaxy. I was out taking some images of the Moon and Jupiter, testing a newly acquired x2 focal extender. After I'd finished that I reverted to my usual set-up and as there was a bit of time I turned the 'scope towards M64. I set the camera going for the first batch of 50 frames, but when I returned to the camera it was completely dead. Not knowing how many frames it had managed and as it was getting a bit late I decided to throw in the towel. In the end I did get about 50 frames, but no flats, darks or bias frames. Not really enough, but this is the result. Not great.

Ian, 

considering there's no dark, flat or bias, I think it's a good image,  It's one of the many galaxy's  I have not seen yet. 

Thanks for sharing. 

Nige.

PS , I have just ordered a set of tube rings and dove tail bar to attempt to mount my 200p dobs on the star discovery mount, It will take the extra load but will be restricted in altitude a little by the tripod legs I think...... Hopefully it will be fine and a good improvement to my dso imaging sessions. 

 

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Thank you Nige. My mount limits the altitude of my refractor to less than 60 degrees, but I'm generally happy with that to keep rotation within limits.

Ian

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