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The Astro-Imaging Thread


ProtoJeb21

Astro-Imaging Questions  

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  1. 1. What's Your Favorite Solar System Body to Image?



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3 hours ago, Veeltch said:

Man, my syntax is poor. But yeah, that's what I meant.

http://astrosolar.com/en/

Why risk health and material ? Yeah, you can burn your eyes. It is not the bright light, that will make you turn away quickly, avoiding damage.

If you use a homemade film it may look dark so that your pupils are wide open, but hard radiation is eventually getting through, you cannot see it directly but you damage your eye background while looking through. So, clear answer, do not tinker with untested material if you value your health :-)

Edited by Green Baron
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I have three new albums of images I took on three separate nights - January 5th, January 21st, and January 30th. There were all taken through my 8" SkyWatcher collapsible Dobsonian. However, the images from the 21st were taken at a darker site than where I usually observe.

ZeOwrmz.jpg

http://imgur.com/a/1fuRi

wcCzUvp.jpg

http://imgur.com/a/Qjc7g

Cu1PFS6.jpg

http://imgur.com/a/SNGqb

 

@Green Baron I want to make some of these images better by making at least 3 dozen copies and editing each one in a subtle but different way via GIMP before stacking. Will this work, and what stacking program should I use?

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41 minutes ago, Green Baron said:

http://astrosolar.com/en/

Why risk health and material ? Yeah, you can burn your eyes. It is not the bright light, that will make you turn away quickly, avoiding damage.

If you use a homemade film it may look dark so that your pupils are wide open, but hard radiation is eventually getting through, you cannot see it directly but you damage your eye background while looking through. So, clear answer, do not tinker with untested material if you value your health :-)

I've said I won't be risking my eyesight though. Only camera imaging involved.

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51 minutes ago, ProtoJeb21 said:

I have three new albums of images I took on three separate nights - January 5th, January 21st, and January 30th. There were all taken through my 8" SkyWatcher collapsible Dobsonian. However, the images from the 21st were taken at a darker site than where I usually observe.

ZeOwrmz.jpg

http://imgur.com/a/1fuRi

wcCzUvp.jpg

http://imgur.com/a/Qjc7g

Cu1PFS6.jpg

http://imgur.com/a/SNGqb

 

@Green Baron I want to make some of these images better by making at least 3 dozen copies and editing each one in a subtle but different way via GIMP before stacking. Will this work, and what stacking program should I use?

Just take video and use Registax. If holding your phone to the eyepiece is difficult you can get an adapter for $20.

 

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@ProtoJeb21: like @_Augustus_ said, Registax and hundreds of exposures or a few minutes video. At least that is how people do planetary imaging. You need a high magnification and a videocamera. A cheap one is enough or maybe your phone can do video. I must admit i still have a phone that i use just for calling

If "copies" mean that you copy a single photo that will not work, they must be different. A tracking mount is helpful as at the high magnification the planet will just race through the field of view. Maybe you will become a master in greasing the rockerbox of your dobson and pushing it manually. Should work with video sequences.  You can experiment with the moon to see the difference between a single shot and the stacked video sequence.

I have not done it myself yet but it's on my list for the spring, maybe we can exchange our knowledge then :-)

@Veeltch, well, try it out.If it works ... i didn't mean to talk old ...

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7 minutes ago, Green Baron said:

@ProtoJeb21: like @_Augustus_ said, Registax and hundreds of exposures or a few minutes video. At least that is how people do planetary imaging. You need a high magnification and a videocamera. A cheap one is enough or maybe your phone can do video. I must admit i still have a phone that i use just for calling

If "copies" mean that you copy a single photo that will not work, they must be different. A tracking mount is helpful as at the high magnification the planet will just race through the field of view. Maybe you will become a master in greasing the rockerbox of your dobson and pushing it manually. Should work with video sequences.  You can experiment with the moon to see the difference between a single shot and the stacked video sequence.

I have not done it myself yet but it's on my list for the spring, maybe we can exchange our knowledge then :-)

@Veeltch, well, try it out.If it works ... i didn't mean to talk old ...

I'll give it a shot tonight at the First Quarter moon...which I ALWAYS seem to be imaging. But it does have some fantastic surface features during that phase, so I can't complain.

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Hehe, i shortly read a humorous text that tried to answer the question "Why are the vast majority of moon photos from a crescent waxing moon ?" (sorry, bad english, i meant the phase between new and full moon ...)

As far as i am concerned, the morning hours are not my most active phase ...

 

Edited by Green Baron
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2 hours ago, Veeltch said:

I've said I won't be risking my eyesight though. Only camera imaging involved.

But you can also fry your camera. I bought two solar filters from Thousand Oaks Optical for my camera lenses in preparation for next summer's eclipse. If you don't want to spend the money for glass filters, you can also just get a cheap plastic membrane like the stuff they put in eclipse viewing glasses.

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Or you can always use a pinhole.Remove the lenses.

On a second note, if you decide to buy some sheet filters, keep in mind not to touch the filter material itself. Back in the solar eclipse here I made a big mistake on thinking "ah, just like aluminum foil" and tested it up by holding it by my arms. Safe to say it went very wrong the day when I want to make the finished filter to fit on my telescope - luckily someone got a spare.

2 hours ago, Green Baron said:

Hehe, i shortly read a humorous text that tried to answer the question "Why are the vast majority of moon photos from a crescent waxing moon ?" (sorry, bad english, i meant the phase between new and full moon ...)

As far as i am concerned, the morning hours are not my most active phase ...

... And the fact that the full moon is as featureless as any sand.

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@Green Baron I have RegiStax 6.0.0 and three videos of the Moon ready for processing. How do I separate a video into all of its individual frames?

EDIT: I've also found that RegiStax has quite a lot of trouble with the images that I have, which are 4K resolution.

Edited by ProtoJeb21
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Good news :-) I wanted to do this in spring, but i did a search now. There seem to be a lot of registax tutorials. Example http://www.astrotarp.com/Registax_basic_tutorial.html

Also i believe registax has some sort of manual, the foreword in the link says that.

It seems like there is a frame grabber for avi built in registax, so i hope you have avi. If not maybe you need a conversion software, or registax can extract the frames out of other formats as well ? Hint from an amateur: before you gather data be sure that your planned workflow (the steps from data aquisition to presentation) understands your data or you might get stuck in the middle of processing, contemplating the evil in the world :-)

Sorry for not being more helpfull right now, if the tutorials do not help and you get stuck i'll try and dig deeper.

 

Edited by Green Baron
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6 minutes ago, Green Baron said:

Good news :-) I wanted to do this in spring, but i did a search now. There seem to be a lot of registax tutorials. Example http://www.astrotarp.com/Registax_basic_tutorial.html

Also i believe registax has some sort of manual, the foreword in the link says that.

It seems like there is a frame grabber for avi built in registax, so i hope you have avi. If not maybe you need a conversion software, or registax can extract the frames out of other formats as well ? Hint from an amateur: before you gather data be sure that your planned workflow (the steps from data aquisition to presentation) understands your data or you might get stuck in the middle of processing, contemplating about the evil in the world :-)

Sorry for not being more helpfull right now, if the tutorials do not help and you get stuck i'll try and dig deeper.

 

I'm following the tutorial, and I've found the issue. With the Moon you're only supposed to use around 150-200 APS. I accidentally used over 1,800. Oops. :confused:

Right now I'm attempting to stack some images of Venus.

EDIT: It appears to be having issues with the Venus images as well. I think I need to scaled them down quite a bit...

Edited by ProtoJeb21
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1 hour ago, ProtoJeb21 said:

I'm following the tutorial, and I've found the issue. With the Moon you're only supposed to use around 150-200 APS. I accidentally used over 1,800. Oops. :confused:

Right now I'm attempting to stack some images of Venus.

EDIT: It appears to be having issues with the Venus images as well. I think I need to scaled them down quite a bit...

Don't scale them down! It'll ruin the resolution.

Registax is slow with high-res video. Just give it a bit of time.

I went back through my phone and found I took some other lunar photos than the full Moon, and I processed them in Registax.

U5f4Rob.jpg

87% Moon on October 18, I don't remember taking this (it would've been probably midnight by the time it was above my house).

7iUMSW9.png

Half Moon in November. If you look closely you'll see the Lunar X and V.

 

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21 hours ago, ProtoJeb21 said:

 

21 hours ago, ProtoJeb21 said:

 

 

@Green Baron I want to make some of these images better by making at least 3 dozen copies and editing each one in a subtle but different way via GIMP before stacking. Will this work, and what stacking program should I use?

 

Asking again does not change the answer :wink: you really do need multiple lights, tweaking a bunch of copies isn't going to do what you want.

 

And sorry about the weird quotes, again, forum ui on mobile is rather horrible :(

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4 hours ago, ProtoJeb21 said:

EDIT: I've also found that RegiStax has quite a lot of trouble with the images that I have, which are 4K resolution.

Use this https://sites.google.com/site/astropipp/

Functions:

Load a sequence of images from supported video files, SER video files or TIFF/BMP/FITS/JPEG/RAW camera image files.

Calibrate frames with dark, flat and dark flat calibration frames.

Debayer raw frames from colour cameras to produce colour frames.

Check each frame contains a planet that is completely on the image and discard any frames that do not.

Check for and discard overexposed frames.

Centre the planet in the frames.

Offset the centred planet.

Crop each frame around the centred planet.

Apply a fixed gain to each frame.

Apply a fixed gamma correct to each frame.

Apply a median noise filter to each frame.

Stretch histogram for each frame (equalising R, G and B channels for colour images).

Estimate the quality of each frame and reorder the processed frames in order of quality.

Keep only the number of best quality frames specified by the user.

Split colour frames into R, G and B frames.

Save processed frames as a sequence of TIFF/BMP/FITS image files, as a single AVI/SER video file ready for stacking or archiving or as an animated GIF for sharing online.

 

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Well, a webcam is what many people still use for moon and planets and in principle a guiding cam is nothing more than a good webcam with a little more software. Single shots do look like that. Try a video sequence of a few minutes, push your dobson manually, the bad frames will be discarded later. And then feed it into registax.

Maybe i try it too today with the guiding cam, just to be able to keep up with you guys :-). I only don't want to dismount my equipment because it's all adjusted for DSOs. I'll have to get the old newton out of the cellar, free it from dust and adjust it ... where is my laserpointer ... ?

Edit: oh, this may be a stupid hint, but give your reflectors at least a few hours to cool down when you take them out of a heated interior into the cold. That'll make a big difference. If you have an adjustable main mirror mounting the main mirror should rest with a little clearance, so that it could be turned by hand or a thin sheet of paper fits between mirror and rest. Most people fix the screws tight just because they think that is the way ...

I hope this wasn't too impertinent.

Edited by Green Baron
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Don't use heaters, you only cause turbulences in the tube. Leave it in a dry and cool place during day to reduce the cool down time.

Here the difference is only 5-10°C between in- and outside, yet i put my stuff out in the shade when the sun goes down and give it 2 hours, and refractors are said to cool down much faster than reflectors. If there is too much moisture in the air then i try another day. The seeing conditions will be bad anyway. In this climate here water may be dripping from the tube, time to give up and do something reasonable instead like play ksp ...

 

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I am using a 1.25in eyepiece on my 10in astrograph (1000mm focal length f 3.9). I have not noticed any coma. Is that because it is being cropped out? Would I have to worry about it with a 2in eyepiece? I know cost is not all of it, but what should I pay for a good coma corrector? 

Edited by munlander1
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2 hours ago, munlander1 said:

I am using a 1.25in eyepiece on my 10in astrograph (1000mm focal length f 3.9). I have not noticed any coma. Is that because it is being cropped out? Would I have to worry about it with a 2in eyepiece? I know cost is not all of it, but what should I pay for a good coma corrector? 

With a 2" eyepiece you'll see coma.

Astro-Tech makes a nice coma corrector for a low price.

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3 hours ago, munlander1 said:

I am using a 1.25in eyepiece on my 10in astrograph (1000mm focal length f 3.9). I have not noticed any coma. Is that because it is being cropped out? Would I have to worry about it with a 2in eyepiece? I know cost is not all of it, but what should I pay for a good coma corrector? 

If that earns it's designation of being an astrograph than some sort of field correction is built in ... ?

Edit: hm, orion offer a corrector for their newtonians. I would take that one.

The televue paracorr has a good reputation. But take your camera with you to get the right set of adapters and correct distance. This is submillimeter work. Maybe try without first ?

Sorry for being short, am on my tablet ...

 

Edited by Green Baron
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