October 7, 2015
Observing with PVS-7 and 100mm f/7.4 refractor. First time with this scope.
Good views with 610nm Longpass filter. FOV around 1 degree.
First target was U Lyrae, a deep red faint carbon star. Visually it forms a tiny equilateral triangle with two stars of similar magnitude. In the PVS-7 U Lyr is much brighter than the other two. Faint OC NGC 6791 is visible close by.
I tried the 0.5x focal reducer. Unable to reach focus with 2" diagonal. Need about 1/2 inch more.
I removed the diagonal and tried straight thru. Works with a 2" extension tube. Nice wide 2-degree FOV with a teeny bit of vignetting. Great views of Stock-2, Double Cluster, M31, 32, and 110. The last was much brighter than expected.
Advantage of straight thru: better brighter image, correct view orientation.
Disadvantage: neck pain and tripod hugging.
I can't wait to try that 1.25" c-adapter + .5 focal reducer combo.
Replaced the diagonal for viewing at f/7.4
M33 - faint, barely visible with 32mm eyepiece against bright urban sky. With PVS-7 and 610 LP : very slight enhancement. Worse with H-a. I hoped one of the H-a regions might light up, but just saw the core. Barely.
M76 - faint bi-lobed with H-a. Very faint with 610. No structure.
M103, NGC 663, 654, 659. Very nice with 610 LP, but need more magnification.
Minkowski 1-92 , The Footprint Nebula. Visible as a tiny faint star w/ 610 LP . Too dim with H-a.
PK 064+5.1 , Campbell's Hydrogen Star. Bright and slightly non-stellar with 610 LP. Similar view as visual in 18" dob.. Crazy bright with H-a. As bright as 9 Cyg. Visually it's nebula appears orange from H-a.
NGC 6960, Western Veil. Not visible with 610 LP or H-a.
NGC 6995-6992, Eastern Veil. Barely visible with 610 LP. Similar to visual unfiltered view in 4". With H-a it's brighter with a little structure, similar to a visual view with OIII fiLter in same aperture.
With Cygnus losing altitude I decided to return to f/3.7 straight-thru viewing. The skies are increasingly hazy, and some clouds are coming in from the north.
The Western Veil is now faintly visible with H-a. The Eastern is much brighter with improved detail. NGC 6974 is now easily visible.
The Gamma Cygni clouds are large and bright with H-a.
North American, Pelican have detail but not like in the 18" dob.
NGC 7027 and 7026 are just stars at this low power. No detail or disk to be seen.
IC 5146, the Coccoon. Visible as a faded round patch with 2 faint "eyes" with H-a. Barnard 168 was not seen. In a visual scope the reverse is true.
clouds came in fast. It's like they resent night vision!