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JamesF

Beginner's guide to stacking planetary images with AutoStakkert!2

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The file sizes you recorded make no sense to me, or at least they seem to be the wrong way round.  Also 300MB for a 2 minute, 30 fps, 1920x1080 video is tiny!  There is no way that is lossless!

Cheers,

Chris

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If you look at things the other way around, a raw (ie. still in bayer format as it came off the sensor) colour video at 30fps and 1920x1080 resolution of two minutes duration should be about 7GB even if it's only 8-bit colour.

I agree with Chris about the onion rings.  I think it's an indicator of lack of dynamic range in the data.  You probably need more exposure time per frame though it's entirely possible the camera will not do that for you.  They're not really designed with planetary imaging in mind...

James

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I will try later with different exposure...what I don't undestand now is should i record with FINE or NORMAL? Normal seems to be bigger file (better data?)

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I tried to record a video now at home in FINE, and it's bigger than the one i posted here...i guess it was only 30mb because except for jupiter all around were only black?

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can u suggest me what should i do with this option? if i activate it it does a slight zoom, i can choose auto as u see or is2 (horizontal) and is3 (vertical) i can choose from 8mm up to 1000mm as in the picture...what should i set?

ok0hXAq.jpg

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I tried to record a video now at home in FINE, and it's bigger than the one i posted here...i guess it was only 30mb because except for jupiter all around were only black?

Ah yes, the size of the compressed data will depend on the subject in the video,  That could explain the strange file sizes.

From my reading on the internet, FINE is the setting you want.

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okay thanks =) as for the image above, IS it's the image stabilizer, right? im gonna set it to auto but don't know how many mm i should set...

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I tried to record a video now at home in FINE, and it's bigger than the one i posted here...i guess it was only 30mb because except for jupiter all around were only black?

Could be.  Does the manual not explain the difference between the two settings?

James

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I'd turn image stabilisation off.  Not sure about focal length I have to admit.  I'm not at all sure how that will work out.  It may work in your favour if you use something rather shorter than you did for the image you've already posted.

James

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I'd turn image stabilisation off.  Not sure about focal length I have to admit.  I'm not at all sure how that will work out.  It may work in your favour if you use something rather shorter than you did for the image you've already posted.

James

I'm reading on the internet that u shuld choose the focal length of ur lens or the most similar, in this case i would leave 1000mm as my telescope is 1500mm (3000 with the barlow) ...gonna make some video test in one hour on jupiter. there is an excellent seeing, finally.

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Although these programs generate lossless AVIs, they do by converting lossy video (or a series of JPEGs) into a lossless AVI.  The damage has already been done to the data and I doubt there is any quality advantage to working this way.

Edited by cgarry

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Although these programs generate lossless AVIs, they do by converting lossy video (or a series of JPEGs) into a lossless AVI.  The damage has already been done to the data and I doubt there is any quality advantage to working this way.

wait, isn't this the method everyone uses with the ccd cameras using icap, sharpcap etc?!? i'm confused

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"Proper" CCD (or other planetary imaging) cameras give you the data read out of the camera sensor unit.  They don't mess about with it to reduce the data size or anything like that.  As I said a few posts back, if you had the raw data for a 1920x1080 frame at 30fps for two minutes you'd be looking at 7GB-ish of data.  That's exactly what a dedicated camera would give you in that situation.

James

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Consider:

The average user of the video mode of a consumer grade compact or DSLR camera is interested in the overall result.  They won't be too fussed about noise or a bit of lost data unless it affects the video as a whole.  They're certainly very unlikely to go pixel-peeping individual frames of a video.  Manufacturers know this and take advantage of it to allow them to increase the resolution or produce frame rates that would otherwise be impossible with the same kit.

When you want to use a camera for planetary imaging however, every pixel of every frame counts.  You're after the most accurate record of the light that hit the camera sensor.  That's somewhat at odds with the situation above.  If two adjacent pixels are different colours, even only very slightly different, you want to know.  You don't want some camera firmware deciding that they're close enough that in a 25fps video no-one will notice if they're made the same colour to reduce the required storage space for the frame.

James

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wait, isn't this the method everyone uses with the ccd cameras using icap, sharpcap etc?!? i'm confused

The are various capture programs that capture raw data from fast frame rate cameras (often incorrectly referred to as web cams).  Sharpcap, FIrecapture and oaCapture are these type of programs.

Then there are various programs the appear to do a similar thing for DSLR cameras (such as 'EOS Camera Movie Record'), these are the programs I am referring to.  In general it is simply not possible to get raw (or lossless compressed) video data from DSLR cameras.  These programs give the impression that you are getting raw data, but all they do is convert the lossy compressed data into a raw AVI.

Chris

Edited by cgarry

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The 120MC takes a bit of time to get the hang of, but it's capable of good results.  This is from the same camera with my 127 Mak:

jupiter-2014-03-04-04.png

James

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The 120MC takes a bit of time to get the hang of, but it's capable of good results.  This is from the same camera with my 127 Mak:

jupiter-2014-03-04-04.png

James

im love already! Gonna focus with the moon and jupiter at first...

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I have a 120MC and a 120MM and they are both fantastic cameras.  Though you do have to work at it, great images don't just fall out of them!

Here is one of Mars that I took with the 120MC:

post-9259-0-63411100-1419888569.png

Note that there was a C14 telescope in front of the camera which does help an awful lot!

Cheers,

Chris

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I have a 120MC and a 120MM and they are both fantastic cameras.  Though you do have to work at it, great images don't just fall out of them!

Here is one of Mars that I took with the 120MC:

attachicon.gifMars_150414_0027_cgarry.png

Note that there was a C14 telescope in front of the camera which does help an awful lot!

Cheers,

Chris

<3 <3 <3 love it! I have a 12" dob and televue 2x for now, but maybe in the future i'm gonna get the 5x too, it's not so expensive... can't wait, guys <3

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*I'm in love.

What's the difference between the mono anc color version? Why would someone choose the mono?

In a colour camera each pixel corresponds to a particular colour in the image, red, green or blue.  For pixels in red positions, for example, there is no green or blue data.  It's derived from adjacent pixels of those colours and as such may not be entirely correct.  Effectively the resolution is decreased slightly by doing this.  Also, in order to make the pixels respond to the colours required you start with a mono sensor and add a filter for the required colour to the front of each pixel.  That filter causes some loss of light and reduces the sensitivity of the sensor.

With a mono camera you use a filter in the optical train for each of the three colours, so every pixel records data for each of the colours and you get no loss of resolution.  Also, the external filters tend to allow more light to reach the camera sensor, so overall the sensor is more sensitive.

Of course the (arguably) negative side of using a mono camera is that you have to take three sets of data; one for each of red, green and blue and then combine them afterwards to get a colour image rather than getting all your data in one hit.  And in the case of Jupiter you'll be trying to do all that data collection in the two-minute period before any distortion in the image due to the rotation of the planet becomes apparent.  And you need to buy the filter wheel and a decent set of filters, which could easily cost more than the camera.

But... the result of using a mono camera should be a much better image than is possible from a colour camera of the same sensor size and resolution.

James

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In a colour camera each pixel corresponds to a particular colour in the image, red, green or blue.  For pixels in red positions, for example, there is no green or blue data.  It's derived from adjacent pixels of those colours and as such may not be entirely correct.  Effectively the resolution is decreased slightly by doing this.  Also, in order to make the pixels respond to the colours required you start with a mono sensor and add a filter for the required colour to the front of each pixel.  That filter causes some loss of light and reduces the sensitivity of the sensor.

With a mono camera you use a filter in the optical train for each of the three colours, so every pixel records data for each of the colours and you get no loss of resolution.  Also, the external filters tend to allow more light to reach the camera sensor, so overall the sensor is more sensitive.

Of course the (arguably) negative side of using a mono camera is that you have to take three sets of data; one for each of red, green and blue and then combine them afterwards to get a colour image rather than getting all your data in one hit.  And in the case of Jupiter you'll be trying to do all that data collection in the two-minute period before any distortion in the image due to the rotation of the planet becomes apparent.  And you need to buy the filter wheel and a decent set of filters, which could easily cost more than the camera.

But... the result of using a mono camera should be a much better image than is possible from a colour camera of the same sensor size and resolution.

James

wow, didn't expect to buy other things, i can afford only the camera...think im gonna go with the color one lol

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