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JGM1971

The "No EQ" DSO Challenge!

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Couple from me, both taken in LP backyard at home , UV/IR filter, Skywatcher 80mm Espirit Triplet, Alt/Az Evolution goto/

Horsehead & Flame 15x45 sec, Part Veil Nebula 20x 30 sec, Camera Atik Infinity OSC

EIGHT.JPG

veil 1xxxxx.jpg

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Veil part little more colour same exp and set up

VEIL NOV 18X.JPG

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I recommend mid altitudes (45-60) as alt-az mounts find it harder to track closer to the zenith, and the Evo mount doesn't have a generous clearance so you often can't even reach higher altitudes (or I couldn't with my refractor/camera).

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2 hours ago, rotatux said:

In fact I have seen that cropping also zooms in the remainging image, and so magnifies inner star trails to the point the whole image is mostly unusable. So you may be better off keeping exposure limited to a smaller value and take+process more subs.

It's actually a combination of altitude and azimuth, but yes globally more alt = faster alt-az-relative rotation = less exposure. Rotation starts at a given speed low on horizon then raises to a common maximum speed (lowest possible exposures) at zenith. Azimuths East and West give the lowest rotation speed on horizon, while South and North are higher.

There's a PDF with graphs depending on your latitude somewhere in the thread... PS: I don't have it at hand, but it should be pinned somewhere as the question comes in frequently.

Thanks for the info, I'll have a look for that.

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A couple weeks back but did have a go at Wirtenan in the fog with Capella.

Autosave group reorder v2 stars.fts stars and comet v2.jpg

Christmas Eve shrouded in swirling fog oh and Moon was 98%. Still with the weather like it was can't be fussy so setup anyway, this time using the 85mm f1.8 Canon lens at f4 on 1100d with a flocked flower pot shield. Using a Virtuoso mount and Android tablet rattled off 110 lights of 30 seconds ISO 400, 24 flats , 23 dark flats and 23 darks and bias files. Stacked in DSS using the best placed image for the comet rather then the highest scoring light made a stack on the stars and one on the stars and comet, comet only did not work due to the lack of clear sky around the comet. The processing was in StarTools with a mix of layers and masks. I have tried to keep more star data in this process rather then isolate away the background too strongly. The fog did make the data a bit more murky then i had hoped for especially with 110 light frames, took quite a while marking the comet on every frame. I reprocessed having another go again using StarTools I created three images. Stars stack for the stars and then healed out the comet area. Stars and comet stack for the comet and subtracted the stars using layers and then used the life module do subdue the stars and then the heal module to remove Capella area. Then worked on the colour in the comet and lastly combined the files again using layers module.

I am currently trying to create a time lapse of 11 images from DSS each stack having 10 images with the reference file starting with the first then advancing 11 frames before the next batch's reference frame ending with the last frame ending as the last reference frame in the last batch. But these batches are hard to process as the fog and cloud are much more evident. Work in progress.

Thought to share the effort here as well as the challenge.

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Hey guys! I have just tried out my new dslr camera on my SLT 130 Telescope. This image of the Carina Nebula consists of 44x30s subs at iso 1600. This was stacked with 15 dark frames.  I might add an extra hour of data and some flats tomorrow to see how it will turn out.

I tried my best in processing with gimp as this is my first ever dslr exposure of a dso and I plan to take some better images in the future. 

5043D3FA-051B-47FA-B2D9-9130D38D35C9.jpeg

Edited by Define_existence
Telescope name
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Well done, it must feel like an unexpected bonus in your new hobby. I hope you have many great hours of observing too.

Is that a mirrorless DSLR or did you use a barlow?

Edited by happy-kat

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Thanks a lot! I never knew that I could capture nebula like this. To answer your question, I did not use a Barlow as it it would have doubled my focus ration from f5 to f10.

I used the slt 130 at prime focus, with the primary mirror moved up 5cm. 

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I'd assumed as a new member you wouldn't have known about or done the mod to move your mirror.

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22 hours ago, Define_existence said:

This was stacked with 15 dark frames.  I might add an extra hour of data and some flats tomorrow to see how it will turn out.

Nice to see some Southern objects on here!

I'd be careful with darks on a DSRL unless it is cooled. You're more likely to add noise rather than remove it. I'm guessing from the target you're imaging from the heights of summer and probably somewhere relatively hot, even at night. DSLR's run quite hot without the addition of air temperature and unless you can exactly match temperatures of your darks to your lights you could make the image work. I'd recommend testing bias frames only.

Flats will make a huge difference. You have quite a gradient though not quite centred (it seems to be centred in the SW quadrant). I notice the stars are elongated in that quandrant too. Do you have tilt in the system?

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On 26/01/2019 at 03:06, Filroden said:

Nice to see some Southern objects on here!

I'd be careful with darks on a DSRL unless it is cooled. You're more likely to add noise rather than remove it. I'm guessing from the target you're imaging from the heights of summer and probably somewhere relatively hot, even at night. DSLR's run quite hot without the addition of air temperature and unless you can exactly match temperatures of your darks to your lights you could make the image work. I'd recommend testing bias frames only.

Flats will make a huge difference. You have quite a gradient though not quite centred (it seems to be centred in the SW quadrant). I notice the stars are elongated in that quandrant too. Do you have tilt in the system?

I tried re-processing the Carina Nebula with the recommendations of Filroden. And btw, your guess was perfect lmao. The night I photographed the carina nebula it was 38 degrees c. The carina consists of 44x30s subs at iso 1600. 

The 2nd image is my attempt of the orion nebula. It is a stack of 80 x 25 second exposures at iso 1600. I really like the way they both turned out, however, I want to try and do better next time. 

carina photoshop.png

orion and running man processed.png

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4 hours ago, Define_existence said:

I tried re-processing the Carina Nebula

That is a noticeable improvement in quality! The gradient is gone so the image colours look far more natural. You have some noise creeping in on the upper right of the image. Probably temperature/calibration related. I don't use GIMP but you might want to see if it has a despeckle function like Photoshop which helps remove single pixel noise like that.

This hobby is all about finding those improvements. I never stop learning (and hopefully improving). Maybe not as fast as I would like but the weather prevents me from imaging :(

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all of these except for the last one taken with a nexstar GT mount bought from ebay for 70$.  most of these are few years old. now i have a good setup but this is how i started and fell in love with this hobby.

55-300mm lens + D5100, eta carinae

etal_3.jpg.61a8e8467f0f8e7c8887df83227d509d.jpg

55-300mm lens + D5100, lagoon+trifid

1803160505_M8M20.jpg.3f862e5020c94ff7dd99fbefbe05104d.jpg

50-500mm tamron + D5100, lagoon

M8-re-ful.jpg.bb327c8099065c4828fa701ab69bc245.jpg

50-500mm tamron + D5100, omega centauri
 

omega-1250.jpg.c60817f874da5623ee3bf96ebeaaba7a.jpg

6" newtonian + D5100, orion

Orion-Nebula-1000.jpg.6dba49afdea782a3b8b092d23800e260.jpg

55-300mm + D5100, rosette

rosette.jpg.9e78cc4f3694743ff2b09626a576be47.jpg

55-300mm + D5100

widefield.jpg.32b22825ef83462bcb8b50b5f89f5456.jpg

50-500mm + D5100, trifid

M20.jpg.8938ec1328942a8371938ea4d1ad494c.jpg

55-300mm + D5100, orion

m42-300mm.jpg.35a46449e07e2952effc999625898ff7.jpg

tripod, D5300, 50mm prime, southern sky

south-widefield.jpg.a27f94570406ec84fef7409e92abc9c4.jpg

Edited by tasheeya
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1 hour ago, tasheeya said:

most of these are taken with a nexstar GT mount bought from ebay for 70$.  most of these are few years old. now i have a good setup but this is how i started and fell in love with this hobby.

55-300mm lens + D5100, eta carinae

 

Wow, ist that D5100 astro modified? Never seen so much red with them. How many subs/@what time?

Carsten

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3 hours ago, calli said:

Wow, ist that D5100 astro modified? Never seen so much red with them. How many subs/@what time?

Carsten

thanks. no its not. all images are less than 1 hour of data. between 5min and 45min. subs are between 8sec and 30sec. i can search my data and give exact details if you want.

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9 hours ago, tasheeya said:

thanks. no its not. all images are less than 1 hour of data. between 5min and 45min. subs are between 8sec and 30sec. i can search my data and give exact details if you want.

That rough estimate is enough to make me try again with my D5100 ;) Thanks!

 

Carsten

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M42

Celestron Nexstar alt-az goto mount

Nikon D3100 DSLR

Sigma APO 70-300 @300

ISO 800

53 lights x30secs

No calibrationframes

49784262_10217894396782120_7633564367249735680_o.jpg

Edited by Peter77
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Doublecluster

Celestron Nexstar alt-az goto mount

Nikon D3100 DSLR

 Sigma APO 70-300 @300

ISO 800

34 lights x25secs

No calibrationframes

 

50224019_10217894381581740_3261793933486718976_o.jpg

Edited by Peter77
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Well done that's great. Flats would help with vignetting. Nice star shapes.

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2 minutes ago, happy-kat said:

Well done that's great. Flats would help with vignetting. Nice star shapes.

Thanks.

Really like the APO lens. Weren't that happy with the shots taken with the Nexstar 102 Slt scope, but with this APO lens the focus and the colors are fantastic. 

 

Gotta look into this with flats again. Tried it once but didn't get good results.

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I'll have a look at that lens as it's a fair price second hand.

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1 hour ago, happy-kat said:

I'll have a look at that lens as it's a fair price second hand.

Don't think you'll regret it. I got the older D version without AF. At the time I didn't care, because it was only for Astrophoto, but in retrospect I should have gone for the DG version (with AF). That way it would be more useful for daytime shooting as well but it is how it is now.

 

Was looking at the tamron 70-300 as well, but in reviews I read they suffered from CA, and besides that, I really wanted to try an APO lens. Glad I did.

Edited by Peter77

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That Sigma APO seems to fare surprisingly good ! (I like your Orion very much)

How much did you have to close the lens' aperture ? or was it full open at 5.6 ?

Seems only the DG version is available new on the market... did you hear how it compares (optically speaking) to your D version ?

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