Venus Take 2 23/04/15

Are you sure you weren't mistakenly pointed at Mars 😉

Seriously, though... that's a stunning image... cloud definition is fabulous. What filters did you use?

Thanks Mike

Are you having a go at my colour balance? Just for you I have done a colour sample from an ESA image!

Venus 2 false colour by astrograph ltd, on Flickr

Image was first adjusted visually with an ADC at 450x. I then used an Astronomik IR642 to give me a base image for the Red channel. That was featureless.

For the Blue channel I used a Wratten No 47 filter in combination with a UV/IR cut filter. This is because a #47 passes IR in addition to UV from about 350nm up to about 450nm. An Astronomik UV/IR cut deals with the IR and does not cut UV until 350nm. As the clouds are only visible at the UV wavelengths, it is important to have a fairly tight bandpass around the UV area to get the best contrast.

I do have an Astrodon 'UVenus' filter which only passes light in the 3-400nm band. Unfortunately, it renders Venus so dark at the f24 I was using it was not usable. The #47 keeps things relatively bright.

This was only a 2 minute exposure (about 15000 frames). As Venus rotates very slowly, I may well try again near elongation with double or triple the exposure to try and bring out the clouds in more detail.

Are you having a go at my colour balance? Just for you I have done a colour sample from an ESA image!

Ah yes, this is more aesthetically pleasing to my eye!

Interesting about the tight bandpass around the UV area... makes a lot of sense. Very impressed with the amount of detail you've been able to pick up using this method.