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Just a Quickie!!!! Filming with DSLR


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Members,

Trying to get my head around imaging with a DSLR and read that a WEBCAM is actually better for planetary targets due to file size and weight therefore, can I hypothetically use a DSLR afocally but on the record video setting and still separate the frames afterwards, edit and stack? Or would they be too large?

9.25 AVX with Canon 550d Rebel2.

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Usually with a DSLR it is done at prime focus = no lens. Would suspect that results afocally (with eyepiece and DSLR lens) will give a poor result. In simple terms they were not ment to operate like that, although in theory they can. Half of getting a result afocally will be to have an idea of what the optics are doing.

You have to set the DSLR to take a video, then put the video on the PC and drag it into Registax, select the best frame and then stack the (say) 200 frames that best match this good one. Same with a webcam output - if you went down the webcam route you remove the lens on the webcam and again get the image direct onto the webcam sensor.

No idea why but it seems that a DSLR video tends to be less successful then a webcam, some cannot be read by the stacking software. But in general they have less success.

Theoretically you can do what you suggest but I think it may prove troublesome. Possibly brackets etc to hold the DSLR+lens may flex and in all this everything is assumed solid, unmovable and orthogonal.

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Guest Tuomo
1 hour ago, Adaaam75 said:

Members,

Trying to get my head around imaging with a DSLR and read that a WEBCAM is actually better for planetary targets due to file size and weight therefore, can I hypothetically use a DSLR afocally but on the record video setting and still separate the frames afterwards, edit and stack? Or would they be too large?

9.25 AVX with Canon 550d Rebel2.

What I have learned it is the matter of sensor/pixel sizes not image sizes. DSLR has quite large sensor thus your imaging field of view is insanely large. You end up with image with lots of nothing and just one tiny part of your actual target. Webcams in the other hand have smaller sensor and they give more narrow field of view. You end up using your sensor more effectively. Your target fills your entire image and small pixels brings more detailed view.

You could try to use good quality barlow with your DSLR. Gives you better field of fiew towards planetary imaging.

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I was going to start a topic on this, but I'm pleased to see there already is one, hope you don't mind me jumping in Adaaam. Looks like we're at the same stage in our astro-photography.

I've taken some film of Jupiter last night, for the first time ever,  using a DSLR through a barlow. At times, the image is pretty sharp, I can see cloud bands easily, and I'd like to see it stacked. I've never done stacking before, but I have Registax 5 (version 6 keeps freezing on my laptop). The first problem I have is my Canon has filmed them as MP4 files. I tried to convert to avi, but then there was a codec error.
Anyway, I did eventually get to stack an image, and was very impressed with the stabilisation, my film was all over the place. But no detail showed, but I think that's because I didn't select the best frame.

I'm new to DSLR photography, but I've seen some very pleasing Jupiter images with a DSLR, so I'm going to keep trying. If anyone's got any tips on converting a Mp4 video to avi I'd be very pleased to hear them. 

 

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Reading with avid interest, I too am at the same stage, and when I get my scope back in action want to try the same thing. 

29 minutes ago, Swithin StCleeve said:

Registax

Swithin StCleeve I've downloaded registax this morning, is it intuitive or will I need to read the manual?  FWIW I'm normally a dab hand with decent pre-built software packages.

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1 hour ago, happy-kat said:

You have a 550d so if videoing make use of the crop video mode that camera has you'll get much better results.

Happy Kat's right 640 x 480 Movie Crop Mode is what you want to use. The DSLR has smaller pixels than most webcams as well. If you use the movie crop mode you'll be able to use prime focus with a barlow instead of afocal.

http://www.astropix.com/HTML/I_ASTROP/EQ_TESTS/Canon_One_To_One_Pixel_Resolution.HTM

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12 minutes ago, JOC said:

Reading with avid interest, I too am at the same stage, and when I get my scope back in action want to try the same thing. 

Swithin StCleeve I've downloaded registax this morning, is it intuitive or will I need to read the manual?  FWIW I'm normally a dab hand with decent pre-built software packages.

I've not read the manual, I've been trying to do it intuitively, and it's not working for me. I haven't a clue what I'm doing, to be honest. I'm busy today, but I intend to have a good go with it tomorrow. Looks like this thread will be useful for a few of us. I've already learnt that I can set the camera to a Movie Crop. I'll do that next time I film, but I still want to use the film I did last night, if only to practice using registax. 

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I don't use DSLR's so I'm not sure what the video format is. It's a good idea to run your file through this software:

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

Choose the planetary option and it'll automatically crop and center the planet. It can also convert to different filetypes too.

I tend to stack with autostakkert:

http://www.autostakkert.com/wp/download/

And then import the stacked image to Registax for processing with wavelets.

There's plenty of guides for both programs online, I really do recommend Autostakkert, it's a lot easier to use than Registax,

 

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I'm going to try taking some video with my LUMIX G7 and a Celestron Ultima Duo eyepiece on some double stars th next clear night we get. I'm hopeful that, after getting the video converted to the right format, Registax will do me proud. Then I'll do some post production with rawtherapee.

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Here's what I managed to get out of the short film I took a couple of nights ago.

jupesc.jpg

I put the MP4 film through Pipp, which gave me the AVI file, and then stacked it using Autostakkert, then tweaked it in Registrax. It's the first time I've stacked anything, so I think I've not done bad, but obviously there's loads of room for improvement. Extra thanks to cuivenion for the links. They were a great help!
Anyone know why it's blue on the top right? (and it's a bit brown on the opposite side).

Edited by Swithin StCleeve
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Hey1 That's not bad for a first attempt is it?  I hope I can do as well when I have a go at it.  I am still telescope-less as my base isn't back from repair yet :-(

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1 hour ago, Swithin StCleeve said:

Here's what I managed to get out of the short film I took a couple of nights ago.

jupesc.jpg

I put the MP4 film through Pipp, which gave me the AVI file, and then stacked it using Autostakkert, then tweaked it in Registrax. It's the first time I've stacked anything, so I think I've not done bad, but obviously there's loads of room for improvement. Extra thanks to cuivenion for the links. They were a great help!
Anyone know why it's blue on the top right? (and it's a bit brown on the opposite side).

You're welcome. Great first image! Regarding the blue, what scope are you using and if you are using a Barlow which one? It could be chromatic aberration caused by either. Budget barlows and refractors suffer from this.

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4 hours ago, cuivenion said:

You're welcome. Great first image! Regarding the blue, what scope are you using and if you are using a Barlow which one? It could be chromatic aberration caused by either. Budget barlows and refractors suffer from this.


I'm using a Newtonian with an 8" mirror, (Skywatcher). The Barlow came with the scope, so I'm betting it's not great. The eyepieces that came with it weren't as good as the old scruffy ones I used on my dobsonian years ago. The mirror needs collimating too, so perhaps that's not helping. I need to look at the planet through the scope without the Barlow, and see if the same effect happens. I'll get back to you.
The Jupiter image is pleasing to me, but I should imagine to the seasoned astro-photographer it's horrendous in many ways. But I'm not putting it up to impress anyone, I'm just saying "this is the first attempt" really. 

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1 hour ago, Swithin StCleeve said:


I'm using a Newtonian with an 8" mirror, (Skywatcher). The Barlow came with the scope, so I'm betting it's not great. The eyepieces that came with it weren't as good as the old scruffy ones I used on my dobsonian years ago. The mirror needs collimating too, so perhaps that's not helping. I need to look at the planet through the scope without the Barlow, and see if the same effect happens. I'll get back to you.
The Jupiter image is pleasing to me, but I should imagine to the seasoned astro-photographer it's horrendous in many ways. But I'm not putting it up to impress anyone, I'm just saying "this is the first attempt" really. 

Much better than my first attempt. I would say its the barlow causing the blue fringing. I used to have a cheap skywatcher barlow that caused the same effect. Reflectors don't have CA, only lenses.

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