Thursday, July 25, 2013

Startrail : What's the max exposure time still seeing stars and not trails

Still want to see stars when taking a picture of the evening sky? So what is the maximum exposure time of your DSLR without seeing tracks of stars on your picture.
Rule of thumb : 600 divided by the focalpoint (mm) x cropfactor DSLR.

Example 1 : Nikon D60 with f 18mm : 600/(18*1.5) = 22s
Example 2 : Nikon D60 with f 200mm : 600/(200*1.5) = 2s
Example 3 : Nikon D60 with Celestron 400 : 600/(550*1.5) = 0,7s

Cropfactor Nikon D60 = 1.5

Text changed on August 5th.

Startrail around polarstar

The sky is clear and I'm on holliday. So what do you at evening? Yes, watching the sky and more specific taking some pictures of Iridium flares and trying out making a startrail.
Picture below is build up from 62 pictures each 30s exposure time, ISO 100 with Nikon D60 18mm with 30s between each photo. The first picture is edited using CS4 and "lighten".
The second picture is edited using the software Startrails - see Startrails.de website.
With a full moon and some minor clouds conditions were not optimal but as a first try out...



Edited with CS4 - 62 pictures Nikon D60 30s ISO100 18mm


Edited with Startrails.de - 62 pictures Nikon D60 30s ISO100 18mm

Iridium 41 flare

Very bright (Mag -7.0) Iridium 41 flare taken on July 24th with Nikon D60 in Raw format and edited using CS4.



Tuesday, July 16, 2013

Iridium Flare



Finally I was able to take a picture of a Iridium flare. Magnitude of -4.0 from Iridium 65 taken by Nikon D60 for 30s.

Sunday, June 23, 2013

Article from VVS on Solargraphy

Inserted are the articles from Jef De Wit publised in Heelal (VVS) oktober 2012


Article from Urania on Solargraphy

Article from Jef De Wit from Urania volume 24 / number 4 sept 2012