January 22, 2015: Second Lovejoy image

[michael.h.f.wilkinson]

Second attempt at Lovejoy. This time 20 usable frames of 80s exposure at 800 ISO, using the Canon EOS 450D with CLS filter, and APM 80 F/6 with Tele-Vue TRF-2008 0.8x reducer. Should perhaps have stayed at 1600 ISP, because tail is only showing faint hints. DSS still flatly refusing to stack both stars and comet. Oh well, not too bad for the second ever attempt at digital comet imaging.

Still a bit of a gradient and too noisy, but hopefully I can have another go tomorrow

[Davey-T]

Set up for another crack at Lovejoy tonight, found and framed it started guiding, took two shots and it clouded over, forecast clear

Dave

[michael.h.f.wilkinson]

Set up for another crack at Lovejoy tonight, found and framed it started guiding, took two shots and it clouded over, forecast clear

Dave

Isn't that just typical. I should have got  the kit out earlier, but too many things got in the way. Hope you get another chance

[symesie04]

Very nice. In theory is DSS capable of stacking multiple targets in the same image even if there moving at different rates?

[michael.h.f.wilkinson]

Very nice. In theory is DSS capable of stacking multiple targets in the same image even if there moving at different rates?

Tried "Comet and Stars" stacking, but that tended to stack only the stars, or made a mess out of both. The rather bright background (floodlit football pitch nearby) cannot have helped. That increases the noise a great deal making correction of artefacts much harder

[StuartJPP]

I know this may start an ISO myth flame war, but I always try to get the histogram away from the left hand side. In other words I'd rather use a higher ISO to make sure I am not losing/clipping the darks/subtle data but if I can take longer subs I'd prefer to lower the ISO still ensuring that I don't clip the darks. Likewise you will lose star colour using an ISO too high if you are clipping the highlights. There isn't a huge difference between say ISO800 and ISO1600, but it is present and when you are trying to eke out as much detail as possible in the faint data I'd rather have a noisy image that can potentially be processed than have no signal there at all.

These are just my views and everybody else's will probably differ...

What I do like about these star trail comet images is that you can see that it is a totally rogue body flying in the opposite direction to convention. I also like to see how fast they move across the sky, I'd never have known it was at the speed they do. Each night you can see it in a different position to the night before.

[kenny k]

I know this may start an ISO myth flame war, but I always try to get the histogram away from the left hand side. In other words I'd rather use a higher ISO to make sure I am not losing/clipping the darks/subtle data but if I can take longer subs I'd prefer to lower the ISO still ensuring that I don't clip the darks. Likewise you will lose star colour using an ISO too high if you are clipping the highlights. There isn't a huge difference between say ISO800 and ISO1600, but it is present and when you are trying to eke out as much detail as possible in the faint data I'd rather have a noisy image that can potentially be processed than have no signal there at all.

These are just my views and everybody else's will probably differ...

What I do like about these star trail comet images is that you can see that it is a totally rogue body flying in the opposite direction to convention. I also like to see how fast they move across the sky, I'd never have known it was at the speed they do. Each night you can see it in a different position to the night before.

Hi Stuart,this comet is travelling at 37/km per second according to CDC.I think i managed to add Lovejoy to CDC last night.Was'nt too sure as it was cloudy here and did'nt get chance to check but watchin CdC for 15mins it was moving considerably.

Nice image Micheal by the way.

Kenny

[Pete Presland]

nicely imaged, i think comet images look better with the stars as streaks anyway. It gives a better sense of the movement of the comet.