New Scope considered for EAA

[Astrith]

Hello All.

I shall be ordering soon the Skywatcher  Evostar 80 ED Pro .  After seeing many of the fist class images on this forum , I would like to try my hand at some wide-field images .  I was wondering ..especially on nebula would a narrowband  H-alpha 7nm filter be useful . Owing to its cost , I would be grateful for any advice . My Lodestar XC 2 is my default camera. Many thanks for reading. Alan.

[happy-kat]

Bump as you haven't had a reply 

[HiloDon]

Hi Alan,

The NB Ha filter is a great item to have for EAA.  It works best with a mono cam, but I have gotten good results with my LS X2c as well.  It only works for emission Nebulae.  Attached is an image of the Trifid using an LS X2c and 7nm NB Ha filter.  Note that the reflection portion of the nebula is gone.  Only the emission portion remains. The only color you will get will be red.  You lose some resolution with the color version of the LS because of the Bayer mask, but I found the results quite acceptable.  

Another thing you might consider is to get a 50mm Orion Mini guide scope to complement your new 80mm.  With the 80, you have about 600mm focal length.  With focal reduction you might get that to 300 or 400.  That's still not wide enough to get some of the really big emission nebulae like California, North America and Rosette.  The Mini has a focal length of 162mm at F3.2 and gives a really wide field of view.  And, it's cheap.  I posted an example of one of my captures with the Mini and X2c.

Another thing the NB Ha filter does is eliminates all light in the spectrum except that very narrow band at 656.3nm.  That means it cuts LP and moonlight.  Does wonders for star bloat, too.

I know the filter is a bit expensive, but it's well worth the money and the resale value is very good.

Don

[Astrith]

Thanks Don .

As it happens it was your images that prompted the question .  The 50 mm Orion mini guide scope would that equate to the same as the Skywatcher 50 mm guide scope , if so I have one that I can use. Thanks for the assurance on the NB HA filter , I shall invest in one. Best Regards..Alan.

[HiloDon]

Alan,

Any 50mm finder/guide scope will work.  I started out by converting one of my finder scopes by taking out the eyepiece and putting in a 2" to 1.25" adapter.  You can get it to fit by using some electrical tape around the barrel of the adapter and pressing it into the tube of the finder.  I went with the Orion because the focal length was the shortest I could find at 162mm.  Most finder are around 200mm.  Another thing you can try are camera lenses.  I also use an old Nikon 105mm F2.4 that works well, too.  You just have to figure a way to mount it.  Like this:

Don

[Astrith]

Great !! I have the eyepiece adapter so will rig it up next cloud free night . I now have to re-think over the outlay for the 80 ED . But then again...... . Thanks for the pics don. Cheers. Alan.