M103 with Manual Guiding ( My first guided image )

[ArmyAirForce]

I've only had my scope eight months, so consider myself very much a beginner, although I've had an interest in astronomy for many years. So with that in mind, I felt this new section of the forum was the place for these images. Despite what has been a poor year for weather, since getting my scope in February, I've been out observing/imaging for 45 nights, or once every five days.

Up until late October, none of my images have been guided, just relying on the tracking of the mount, which has limited exposures to about 2 minutes maximum. I'm now just venturing into taking guided images, but as the piggy bank is still recovering from buying the scope, equipment to guide with has to come from selling off stuff on Ebay. By mid October, I'd raised enough to buy a TS 9mm off-axis guider, a slimline unit which would allow my DSLR to reach focus on my Explorer 200PDS reflector. As yet, I can't afford a proper guide camera with a guiding port to connect to the mount, so I've been making do with an old modified webcam.

Because of the limited sensetivity of the webcam, and the light pollution in my area, the camera can only see stars of magnitude 4 and brighter, which does limit where I can point the scope to image! I'm after a Lodestar guide cam when finances allow, but for now, the webcam will have to do. As normal when buying a new piece of astro kit, three weeks of clouds followed, so it wasn't until a couple of nights ago, that there was a brief window to give the OAG and webcam a try.

So, to manually guide, the webcam attached to the OAG is run through Sharpcap, with the screen set at 150% with reticle shown. I aligned my guide star with the reticle and manually guided the exposures with the mount handset, set on the slowest speed. As the star moved out of the crosshairs, the handset buttons were used to re-centre it. Inputs were necessary between one and five seconds apart. The image is photographed with a Nikon D50, operated with the "DSLR Shutter" software and the Shoestring USB/IR trigger interface.

Shoestring USB/IR trigger interface

I managed 5 x 5 minutes on M103 before the clouds came in. It is shown here. The first image is the full frame processed. The second had a 50% area selected for stacking, and then stacked at x2 Drizzle, with darks, flats and bias frames. I used a bahtinov mask for focus, though I think the focus drifted a little as the temperature dropped.

Full frame

50% with x2 Drizzle

[tone2012]

Nice image looks really good

[Matt Scunthorpe]

Although i have 0 experience with imaging (cant barely do visual atm lol) I think that image looks really good.

[Pete Presland]

well done on your 1st guided image.some very nicely coloured stars.you do seem to have a few dust specs as well

[Velvet]

well done you for a first and unguided., Keep at it and save the pennies I think you are going to

be quite good at this

velvet

[ArmyAirForce]

well done on your 1st guided image.some very nicely coloured stars.you do seem to have a few dust specs as well

Yes, dust! Most annoying. I normally photo a white surface to check for dust before imaging, and clean as needed, but was in too much of a hurry to make use of the clear sky. I took around 15 flats, but I guess the dust spots were too big to process out. I've been playing around with the processing this afternoon, and can reduce the bloating a little by processing slightly differently. I just wish my Ebay stuff would sell so my wallet would be my friend again!

[4lefts]

nicely done. can't you use phd with the webcam rather than doing it manually? i seem to remember seeing a shoestring astronomy cable that allowed you to send guiding info from phd over usb to the guide input on the mount? or can't you control the mount form eqmod without the handset and send guide signals through that connection?

[ArmyAirForce]

I've got no means of controlling the mount at present, and any spare cash is going into the guidecam fund. With such heavy light pollution here, the current webcam gives me virtually no stars to guide with near any interesting targets. It isn't much better than naked eye, so really only the main constellation stars are visible. M45 is only just visible against the background sky. A highly sensitive guidecam is the next step, and link the camera guideport direct to the mount.

[turbotim]

Good shot!

[ArmyAirForce]

Thanks for the encouragement everyone. I'm looking forwards to a proper guidecam, and being able to do some serious imaging, although the exposure times will still be limited to around 5 to 7 minutes at ISO 800 due to the light pollution, even with a LP filter. Attached is one of the M103 5 minute ISO 800 subs. As yet, I don't know how exposed/overexposed the subs can get before the detail is lost. Does this exposure look normal for a light polluted sky?