Dumbbell in 2s - 80s

[nytecam]

Despite a bright quarter moon three good night in a row at beginning of week but gave Wednesday a miss    From Monday night here's M27 in 2s exp and 20s and 80s soon after dusk  [shown in reverse order].  Don't normally expect to do summer objects this late in year - hope it's of interest. 

Used classic Meade 30cm f/2.8 LX200 SCT [via f/3.3 FR] +SX Lodestar-C camera from garden obsy

[SnakeyJ]

Single subs - Wow! Especially at low elevation.     Perhaps getting a bit bloated at 80s, but great star colour and depth in the nebula.     A dozen of those 20s exposures would stack up very nicely - would be interesting to see a single sub comparison between the mono and colour loadstars on M27, though this may have to wait until next year.

[Joves]

Loving your recent results Maurice. You certainly know how to get the best from your Lodestar!

Well done mate. Please keep them coming!!

[nytecam]

Single subs - Wow! Especially at low elevation.     Perhaps getting a bit bloated at 80s, but great star colour and depth in the nebula.     A dozen of those 20s exposures would stack up very nicely - would be interesting to see a single sub comparison between the mono and colour loadstars on M27, though this may have to wait until next year.

Thanks Jake - these are 20s subs eg 1x20s and 4x20s=80s.  Running at f/2.8 + my London LP and in certain directions like over our neighbours houses early evening, I'd saturate in 80s exp !

[SnakeyJ]

Thanks Jake - these are 20s subs eg 1x20s and 4x20s=80s.  Running at f/2.8 + my London LP and in certain directions like over our neighbours houses early evening, I'd saturate in 80s exp !

Sorry Maurice, I should have looked more closely - the lower noise and lack of sky glow were good indicators

I think I was doing 20 and 30 second mono RGB subs on M27 with my 200P/QHY5L-IIM @ F4.5, the single subs looked a lot closer to your 2sec exposures!

I would like to have a go at longer focal length next year when all the kit is running nicely, but this will be really pushing the HEQ5.

[DoctorD]

Hi Maurice

Amazing that you can still capture M27 at this time of year!

What spacing do you have between your reducer and the CCD - based on a quick experiment with Oculars in Stellarium it looks like you're operating at about 850mm focal length or F3.4.

I put in the details for the Lodestar and created a telescope with a focal length that achieved roughly the same FoV as your 20s image - mind you my measurements could be wrong.

Clear skies

Paul

[nytecam]

Hi Maurice. Amazing that you can still capture M27 at this time of year! What spacing do you have between your reducer and the CCD - based on a quick experiment with Oculars in Stellarium it looks like you're operating at about 850mm focal length or F3.4.

I put in the details for the Lodestar and created a telescope with a focal length that achieved roughly the same FoV as your 20s image - mind you my measurements could be wrong. Clear skies. Paul

Hi Paul - I make efl = 850mm / 305mm (aperture) = f/2. 786 eg f/2.8 ! I've not measured the FR - sensor distance - just play until I'm happy with fov and scope 'speed'. f/2.8 needs good flat to even out the field illumination and mine is close but imperfect :-)

[DoctorD]

Hi Maurice 

Just realised that I calculated focal reduction not focal ratio (850/2500=0.34)!! 

That's Fridays for you

Interestingly I run my SDC 435 at a similar F-ratio on my C8 (F2.7, FL 540mm) - no science, just used the spacers I had to hand.

Clear skies

Paul

[Spacedout]

Despite a bright quarter moon three good night in a row at beginning of week but gave Wednesday a miss    From Monday night here's M27 in 2s exp and 20s and 80s soon after dusk  [shown in reverse order].  Don't normally expect to do summer objects this late in year - hope it's of interest. 

Used classic Meade 30cm f/2.8 LX200 SCT [via f/3.3 FR] +SX Lodestar-C camera from garden obsy

Hello Maurice,

How are these images taken?  Are they screen grabs, photos of your monitor or have they been enhanced in anyway?

Cheers

Karl

[nytecam]

 

Hello Maurice,

How are these images taken?  Are they screen grabs, photos of your monitor or have they been enhanced in anyway?

Cheers

Karl

Hi Karl – the Dumbbell frame-grab show [lower left] a raw image seen on screen in a continuous 20sec exposure loop – no filters, flat or dark calibration frames used.  The same tweaked image

takes a few seconds longer.  The lower pics show the single USB lead from Lodestar-C cam to laptop - no other power supplies, cables etc necessary and with minimal power comsumption the cam keeps cool so no fans etc   

Lodestar-C spec @ http://www.sxccd.com/lodestar-c and my sample DSO page @ http://home.freeuk.com/m.gavin/eyelode2.html

Astro-videocams and astro-CCD-cams are both well suited to “viewing” DSOs in brief exposures.   I choose that latter and get a buzz seeing faint galaxies appear on the laptop under my light polluted skies.  I don’t seek perfection but like to “see” a lot of different objects in an evening and have a record to share with fellow SGL enthusiasts here - my cam is ready made for that.  

[Spacedout]

Hi Karl – the Dumbbell frame-grab show [lower left] a raw image seen on screen in a continuous 20sec exposure loop – no filters, flat or dark calibration frames used.  The same tweaked image

takes a few seconds longer.  The lower pics show the single USB lead from Lodestar-C cam to laptop - no other power supplies, cables etc necessary and with minimal power comsumption the cam keeps cool so no fans etc   

Lodestar-C spec @ http://www.sxccd.com/lodestar-c and my sample DSO page @ http://home.freeuk.com/m.gavin/eyelode2.html

Astro-videocams and astro-CCD-cams are both well suited to “viewing” DSOs in brief exposures.   I choose that latter and get a buzz seeing faint galaxies appear on the laptop under my light polluted skies.  I don’t seek perfection but like to “see” a lot of different objects in an evening and have a record to share with fellow SGL enthusiasts here - my cam is ready made for that.  

Thanks Maurice, looks like a great camera and you are obviously getting some fantastic results with it.

Cheers

Karl