fast achros are useless for double star work

[raymo]

I was messing about with a range of filters, and focal lengths, and thought I would see if I could get enough magnification to image a couple of doubles.
The seeing was appalling, stars roiling and boiling, so experimented with different exposures and ISOs. At the ridiculous focal length that these
images were obtained, I had to use ISO 6400.

102mm f/5 with 2x and 3x barlows stacked, and 6.4mm EP = 3,000mm f/length, and a stupid 468x mag.
First one is aCru, and the second is aCen.
raymo

[RickS]

Nicely split, Raymo :)

[raymo]

Thanks Rick, It was just a bit of fun; actually, I might try again when the
seeing is reasonable.
raymo

[Camelopardalis]

I see your skills with Photoshop are improving raymo ;)

[Atmos]

Quite nicely done considering quite terrible seeing conditions :) Well, except for the unnatural green stars :P

[raymo]

They are straight from the camera except for cropping and resizing in PS
Dunk.
The colour is due to the fact that I was using a no.11 yellow filter at the
time Colin. I was playing at CA reduction.
raymo

[Camelopardalis]

Sorry raymo, that was my dodgy sense of humour at work :D

Nice split :thumbsup:

[raymo]

I have to admit that two greeny yellow circles are not exactly visually
awesome. After further consideration I think your comment is amusing.
:lol::lol::lol::lol::lol:
raymo

[Camelopardalis]

:D

Folk use filters in planetary imaging and DSO imaging all the time, so why not this!

[Robh]

Hi Raymo,

They are pretty good splits using two barlows. I think both pairs are around 4 arcseconds apart. I'd be happy with that result.

The poor seeing would really be noticeable below 2 arcseconds.

Regards, Rob

[raymo]

It was just a bit of fun Rob, with aCen being harder to get nice round stars
from due to it's lower altitude. They are a bit dim because I used fairly high shutter speeds to get rid of the diffraction rings, leaving clean edges.
raymo

[skysurfer]

Recently I took a video of aCen en aCru during daylight.
Just a Canon Powershot S100 behind Nagler 13 eyepiece in an ED110.

aCen starts at 1:40.

http://skysurfer.eu/jwplayer/video.php?v=L1ZpZGVvcy9za3kvUGxhbmV 0cy0yMDE2MDIyNS5tcDQ6Ojo2MDA=

[raymo]

Hi Skysurfer, I saw the still frames, but gave up waiting to see the video
after about 3 or 4 minutes. I don't know whether it was just glacially slow
downloading, or not downloading at all.
cheers raymo

[Merlin66]

Raymo,
Interesting stuff....
If you can get a hold of a webcam (or similar) then Florent Losse's excellent software can be used to measure and analyse the images....
http://www.astrosurf.com/hfosaf/uk/doeva1.htm
florent_losse(at)yahoo(dot).fr (at@yahoo.fr)
Drop him an email, mention my name and get the latest freeware version.

[raymo]

Thank you Ken, I might just do that. I do have a webcam.
raymo