How can I "measure to scale" the hight of a prominence on a solar picture?
I have seen this before but I can't figuring out how to get a scale value.
The picture below is not mine but this is what I mean ...
Prom measure on scale
- MAURITS
- Way More Fun to Share It!!
- Posts: 8507
- Joined: Tue Nov 27, 2018 4:37 pm
- Location: Belgium
- Has thanked: 2412 times
- Been thanked: 4787 times
- Contact:
- banjo
- Way More Fun to Share It!!
- Posts: 1465
- Joined: Sat Sep 17, 2016 12:38 pm
- Location: France
- Has thanked: 2090 times
- Been thanked: 2859 times
Re: Prom measure on scale
Hello,
one way to do this is to measure the diameter in pixels on your photo
example for me summer 6200pixels (see ephemeris sun)
1,392,684km / 6200 pixels = ~ 225 km / pixels
Prom diameter = 7000 pixels ---> (7000-6200) * 225 = ~ 180000km
Paul
https://www.webastro.net/noctua/astroph ... ires-r154/
https://pgj.pagesperso-orange.fr/position-planetes.htm
one way to do this is to measure the diameter in pixels on your photo
example for me summer 6200pixels (see ephemeris sun)
1,392,684km / 6200 pixels = ~ 225 km / pixels
Prom diameter = 7000 pixels ---> (7000-6200) * 225 = ~ 180000km
Paul
https://www.webastro.net/noctua/astroph ... ires-r154/
https://pgj.pagesperso-orange.fr/position-planetes.htm
bresser/messier 150/1200 (or 200/1800 Istar ) Mod -D-Erf 160mm intern-glasspath 1.25-etalon Pst barlow X2 ASI174
https://astropol.pagesperso-orange.fr/b ... 9/best2019
sorry for my English translators google
https://astropol.pagesperso-orange.fr/b ... 9/best2019
sorry for my English translators google
- Montana
- Librarian
- Posts: 34563
- Joined: Mon Oct 17, 2011 5:25 pm
- Location: Cheshire, UK
- Has thanked: 17672 times
- Been thanked: 8793 times
Re: Prom measure on scale
You need to use the solar ruler RegleSolaire
https://docs.google.com/viewer?a=v&pid= ... TI0ZmUyNTg
Download the PDF. Open your image in Photoshop. Open the PDF as a 'Smart object'. Copy and paste the ruler in as a layer in your image. Then free transform RegleSolaire so that the hatched lines fit your solar disc correctly. Remember to use the Shift key to keep the ruler perfectly round when you stretch or shrink to fit.
Alexandra
https://docs.google.com/viewer?a=v&pid= ... TI0ZmUyNTg
Download the PDF. Open your image in Photoshop. Open the PDF as a 'Smart object'. Copy and paste the ruler in as a layer in your image. Then free transform RegleSolaire so that the hatched lines fit your solar disc correctly. Remember to use the Shift key to keep the ruler perfectly round when you stretch or shrink to fit.
Alexandra
- MAURITS
- Way More Fun to Share It!!
- Posts: 8507
- Joined: Tue Nov 27, 2018 4:37 pm
- Location: Belgium
- Has thanked: 2412 times
- Been thanked: 4787 times
- Contact:
- grimble_cornet
- Way More Fun to Share It!!
- Posts: 3537
- Joined: Tue Jul 10, 2012 5:10 pm
- Location: UK West Midlands
- Been thanked: 47 times
Re: Prom measure on scale
Hi Maurits
As its my image you posted......... I can tell you exactly how it was done.
The scale Alexandra explained is what I used but it can be a bit frustrating as the numbered lines outside the disc are often in the wrong place. I edited the original overlay so that there are numbered layers at top, bottom, left and right - in that way there is always a set of numbers with the correct orientation close to the section of limb in your image.
Banjo's method of calculating can also be used to determine the size of the Earth - basically it is 1/109 the size of the sun. I downloaded a NASA image of the Earth from space and scaled it to match the solar diameters produced by my most commonly used scope/filter/camera combinations.
The white scale overlay has discs which represent the relative sizes of Earth and Jupiter so.............. an alternative method is to paste an image of Earth and then scale it to match the disc.
Best wishes,
Mike
As its my image you posted......... I can tell you exactly how it was done.
The scale Alexandra explained is what I used but it can be a bit frustrating as the numbered lines outside the disc are often in the wrong place. I edited the original overlay so that there are numbered layers at top, bottom, left and right - in that way there is always a set of numbers with the correct orientation close to the section of limb in your image.
Banjo's method of calculating can also be used to determine the size of the Earth - basically it is 1/109 the size of the sun. I downloaded a NASA image of the Earth from space and scaled it to match the solar diameters produced by my most commonly used scope/filter/camera combinations.
The white scale overlay has discs which represent the relative sizes of Earth and Jupiter so.............. an alternative method is to paste an image of Earth and then scale it to match the disc.
Best wishes,
Mike
.
.
.
Mike Garbett
Selection of Solar and Deep Sky images on Flickr: https://www.flickr.com/photos/mikegarbett/
.
.
Mike Garbett
Selection of Solar and Deep Sky images on Flickr: https://www.flickr.com/photos/mikegarbett/
- Ibbo
- Way More Fun to Share It!!
- Posts: 1429
- Joined: Thu Feb 13, 2014 10:13 pm
- Location: North of Nottingham England
- Has thanked: 2438 times
- Been thanked: 1650 times