Lunar: Janssen + Fabricius

[iceman]

Hi all

This image of Janssen and Fabricius was captured on the 11th October 2006, but processed over the last few days.

It's made up from 6 avi's, taking the best parts from each avi to create the composite mosaic. The seeing was only average, so the 3x barlow was used with the DMK21AF04, my 10" dob on the EQ platform.

The attached version is reduced in quality for posting, the uncompressed version can be downloaded here (500k jpeg) (http://www.iceinspace.com.au/images/images/moon/20061011-janssen-full.jpg).

btw i'm trying out a new presentation style (top left of the image) which includes scale, resolution and region. Feedback welcome.

Thanks for looking.

[h0ughy]

looks good mike!

[Dennis]

Hi Mike

That is one of the best Janssen images I have seen. I like the "information panel" very much although I'm not too sure of the mixed fonts. You seem to have used 3 styles and I think with fonts, less is usually better.

How do you perform the metres per pixel calcs?

Cheers

Dennis

[iceman]

Thanks for the feedback, Dennis.. you're right.. I really struggled with font selection (downloaded about 15 new fonts this morning looking for something suitable) and still have some work to do there ;)


I used known crater sizes, and measured the length of those craters in pixels. Simple maths after that :)

I compared both the width of Janssen (190km) as well as the width of the Rille (5km at the wide part and 2km at the narrow part), and they both came out accurate (given the metres/px) so i'm pretty sure it's close to accurate.

[RB]

Excellent image Mike, very high standard as usual.
I agree with Dennis the info pane looks great but a simple/single font would be better.
A great idea though and looks very professional.

[John K]

Sweet image Mike.

[Dennis]

Thanks for the details Mike. I guess that at the Moon's central meridian (whatever it's called) that should be okay, but as you get towards the limb, there is increasing foreshortening in one direction, so using the non-foreshortened dimension will help with accuracy.

Cheers

Dennis

[iceman]

ah good point, Dennis..

I guess after a while i'll know the resolutions and scale for my various combinations of imaging train - ie: 2x, 3x and 5x magnifications and then it will apply for all images.

[bojan]

Superb!!!

[Robert_T]

Mike, add "master of presentation" to you "master of the moon" title... the map in top left is a great idea!!!

cheers,

[mill]

Wonderfull!!
Looks like i have a lot to learn from you iceman (mike).:help:

[Harb]

G'day Mike,
I agree with evryone else re the one clear font is the way to go....
I think the info panel is just the most important feature of a displayed image such as this.
I gives everyone a reference, old hands and newbies to the sort of gear needed to achieve these type of results and also the skill of the astronomer at the controls.............
I have seen some very impressive images come out of this forum.........It certainly has got my astronomy engine running again after quite a few years away from the hobby, and stuff like this just adds to the fuel supply!!

cheers
John

[sheeny]

Excellent image Mike! Love that detail!:thumbsup:

It's not too hard to calculate the resolution for each setup Mike. With the ToUcam on my C8, each pixel of a moon image is about 1km at f/10, 500m at f/20 and 400m at f/25. Of course that's round numbers, and the moon's orbit is elliptical, so it does vary a bit but not significantly enough for a general scale on an image. If we were trying to do some precise science with the image that would be a different matter!

Al.

[[1ponders]]

Top notch Mike. Great Mosaic. I'd love to know how that nicely semi-circular rill formed :shrug:

Ditto the font. Definately don't like the "Hand written" Style. It also took me a while to work out what you were scaling too, with that line under 400 m/pixel. Yeah I know sometimes I'm a bit slow on the uptake ....however ....how about placing the scale measurement in the image rather than in the legend. Use a larger scale maybe. Or in Photoshop or paint do up an image you can reuse with intervals of 10|25|100 kms. JAFI

[sheeny]

I'm guessing you were just asking this question out of interest, Dennis. I imagine you know what I'm about to say...

To calculate the resolution per pixel (Maths Warning! Maths Warning!) the simplest way is to apply similar triangles...

Therefore:

Pixel size (in mm)....... Distance per pixel (in kilometres)
------------------- = --------------------------------
Focal length (in mm) ..Distance to subject (in kilometres)

(Edit: oh, what a mess! So much for writing equations!)

Actually the kms and mms don't specifically matter, just as long as the sam units are used on top and bottom of the same side of the equation.

Rearranging:

Resolution (i.e. distance per pixel) = (Distance to subject) x (Pixel size) /(Focal length)

FYI in case someone didn't know.:D

Al.

[[1ponders]]

Thanks for that Al.

[FNQ_View]

Mike,
Awesome imaging:eyepop:. The map idea is brilliant. I have to echo others when I say font selection is an issue:shrug:. Something to keep in mind. The western world has been so exposed to the times font that it is offically the easiest font to read for abot 75% of the english speaking world. ( I work in document production ) Try finding a novel in another typeface......

Mick

[Moonman]

Moonman approves

great stuff!

I'll be dabbling soon with some lunar shots as soon as I get organized with a Toucam. Just got the lap top so only a couple of hundred dollar to go!

[iceman]

Thanks for the feedback guys - the font will change :)

[ving]

not bad! :)