Another Horsehead Experiment

[MarkS]

Here is another attempt at the Horsehead - it's my first ever attempt at guiding and my first experiment with the CLS filter.  It was taken from my back garden in Sidcup using an unmodified Canon EOS300D on a C11/EQ6 combination.

1)  For guiding I used the unmodified SPC900 webcam with PHD Guiding software.  In general it's very difficult or impossible to find a star bright enough for guiding with a basic webcam but there are plenty near the Horsehead.
2) The moon was very close (just above Orion) so conditions were far from ideal for imaging a faint object.
3) I used 12 subs of 10 minutes each but stupidly left the ISO setting at 100.
4) The guiding worked with no problems
5) I have a severe case of vignetting.  John, you were right, I should have bought a 2" CLS filter.
6) The mount was overloaded (I used my old Celestron 130SLT Newtonian as a guidescope) but seems to have coped well.

I'm looking forward to trying again.  I'm stubborn enough not to give up on pushing the Canon to it's limits!

[Daniel]

That's quite inspirational! I've never been able to image the horsehead nebula, but the last of my guidescope setup should be with me by tuesday, I'll only be imaging through a C8n but the webcam you used to guide with is the same and I'll be using pretty much the same camera too. your right last night though actually having pretty good seeing (i took the best moon pic i've ever taken) was pretty crappy because of the moon everything I imaged had a lot of blue in it, though i think i may have topped my best M42 aswell.

You must have some mega mount even to attempt using a C11 AND a 130SLT just hoping that having a smaller apeture on my guidescope (im using a ED80) isn't going to affect the amount of stars I can use to guide with too much.

Anyway, once again, great work, good to see what can be achieved with unmodded cameras!

[JohnP]

Excellent Mark - I'm impressed... Guiding 10min subs first time out is very impressive.. I suspect that if you had gone to higher ISO say 800 or 1600 then even with CLS things may have started to get overexposed (due to moon etc.)

Well done - John

[Rocket Pooch]

Mark,

If you want to borrow my unused Baader "2 UHC-S filter you are more than welcome, I'm interested to see if the field issues are the filter or the secondary causing the field issue?

In return can I use you C11 for a planet for an hour at DSC some time?

Chris

[MarkS]

Chris,

Thanks for the kind offer but I've already got a 2" on order.  The field issues are mainly due to the optical design of the OTA but the 1 1/4" filter exarcerbated them.

But you're welcome to try out the C11 at DSC.  It would be interesting to see what can be achieved with your DMK.

Mark