Comet Jacques - Damien Peach

[Mike]

There is a picture of the comet that Damien Peach put online today. It's a great picture. But... Considering how difficult Mark found it to get an image of the tail and also considering how fast this thing was moving (in only 30 seconds you could see clear movement against the background stars). This image of Damien's is very suspect indeed. You decide:



Unfortunately he never gives any technical details of his images but I am guessing this is many hours of exposure. One of the comet and one of the nebula and then they are combined. Looks nice, but a very false image.

[MarkS]

It's a great image but it's some kind of composite and not a single sub.  Nevertheless, all credit to him.

I reckon Jacques was moving by about 3 arcsec every 20 seconds which is about 1.5 pixels at my imaging scale. So I couldn't go above 20sec for a single sub and maybe 20 seconds was a bit too much.

Robert was managing to guide on the comet head last night and successfully displayed the tail quite well in a single sub using a proper mono-CCD.  Using a supersensitive planetary camera (which Damian certainly has!) he would have no problem guiding on the comet head to obtain great detail in the comet and tail.  As long as the trailing stars can be removed from the comet image (not easy) it can then be combined with subs guided on the background stars (with the comet removed).

However he is doing it, I'm sure it's a lot of jiggery pokery!

BTW, I'm sure the tail has become thinner and less defined since it passed by the Heart and Soul Nebulae.

Mark

[Mike]

Yeah its a great image for sure. I just wish people who take images like this were a bit more upfront about how its made.

[Fay]

as we were saying, this morning, 90% is the processing , skull duggery indeed!! these days you have to be a very good processor rather than an imager!

[The Thing]

What a con. I suppose you might see something like this with a huge dob or the Keck.

I bet he used something like the EQMOD Custom Tracking rate function to get the mount to move at exactly the comets rate across the sky, that would mean longer subs possible without guiding having to correct for the speed difference as well as the usual stuff or even no guiding.

[mickw]

Getting interesting - an APOD

http://apod.nasa.gov/apod/ap140822.html

[MarkS]

Getting interesting - an APOD

Nice picture - sitting between the Heart and Pussy Cat nebulae.