New to AstroPhotography...Filter tips/help please...

[AlexxxAA]

Hi everyone. I just purchased a CG-5 mount in order to start taking some better photos at night. However, i have no experience and no one in the Los Angeles area to really help me... Here is a single shot i took of M42. 30 seconds, ISO 400, on a typical horrible night of light pollution. I slightly processed it on Aperature on my Mac. Eventually im going to try to take longer exposures, like of 2 minutes... (im using a Canon EOS Rebel T1i)

-Will getting a UHC filter help with this glow issue???

-Also, Im using a C8 on a CG-5 mount and i just installed an f/6.3 reducer-corrector... Do i buy a 1.25" or 2" filter for this set-up? Where does the filter go installed???

I cant just walk in to a local dealership to ask these questions because the closest one to me is 25miles away and the traffic to get there is like a 2 hour drive

Any help would be greatly appreciated... thanks

[steppenwolf]

Hi Alex and welcome to SGL.

An Astronomik 'Clip Filter' like this one would certainly help you and I have no doubt that they are available in in the States. This literally clips into the 'throat' of your Rebel camera - brilliant!

I would also recommend that you do a search on the Internet to find out all about 'FLATS' as they will make an enormous improvement in your images by getting rid of the vignetting' that is apparent in your image.

[AlexxxAA]

Wonderful!

Thanks for the warm welcome

-Is the flattener going to go attached to the reducer?

-Those two items should be enough to get started with some good images right?

-Lastly, I just purchased a Williams Optics ZenithStar 80mmAPO... Will all these items be necessary as well, eventhough it has great optics?

[steppenwolf]

-Is the flattener going to go attached to the reducer?

At this stage, I am not talking about a 'flattener' at all, I am talking about taking additional calibration images called 'FLATS'.

Here is a brief description from my book of what a FLAT is:-

FLAT

A subframe taken through the telescope at exactly the same focus position as the image subframes but with the telescope pointing at an evenly illuminated surface. This is used in the calibration process to compensate for pixel to pixel variations in sensitivity, to remove dust halos and to aid in combating the effects of vignetting.

With regard to the the 'flattener', this is an optical adapter that fits in between the camera and the focus tube. The one I have linked to would work with your Zenithstar 80.

[Rossco72]

Alex,

I have a CLS Clip filter permanently installed on my Canon 450D.

It does a good job at taking out the worst of the skyglow.

This is a 5 minute sub from the light polluted skies of Glasgow in the UK.

Bear in mind though that for longer subs you will need to autoguide your mount as well....

[AlexxxAA]

Amazing! thanks guys

i already ordered a clip for my canon. Cant wait to try it out when it arrives!!!

Lets see what the result is in a couple of days

[steppenwolf]

Let us know how you get on Alex and in the meantime while you are waiting for that delivery, read up on FLATS - boring but oh what a difference they make!

[AlexxxAA]

I finally got my clip filter today! Cant wait to try it out, but unfortunately the skies are cloudy most nights, including tonight

Got myself a remote shutter for my Canon as well. Gonna test out the tracking limits of my CG5.

I know the CG5 cant handle that much weight, so mounting my

zenith star on my C8 is no longer in my plans. So for guiding, i was planning on getting an Off-axis adapter... Do you recommend getting an autoguider such as the NexGuider or Orion StarShoot and guiding in this manner???

Regards,

[Sparrow]

Good choice Alex - I have the CLS Clip filter in my EOS1000D - couldn't image without it here in Chester as the LP is truly dreadful. Just so it doesn;t come as a shock, all your subs will be very bluish because of the filter - don't worry - If you use Deepskystacker to stack your subs, there's a setting that will balance the colour so the stacked result is correctly colour balanced.

Best wishes

Sparrow

[Rossco72]

Off axis guiding is tricky as very little light gets to the guide camera, you really need a sensative one and getting focus and a lock on a star can be difficult.

I am not an OAG user myself so hopefully someone will be along soon who has eith got an OAG system or who used to use one before going parallel or piggyback

[AlexxxAA]

ill probably post a new thread asking about the autoguiding... Thanks though

-Another question, i have a mac laptop, i think the only program i can use is Photoshop, which i already have... Will this work stacking and getting the color to normal from the filter images???

If not, i can probably get a program on my mac to run windows programs if you guys recommend other program besides PS like DeepSkyStacker???