Lyra in June 2014 from the backyard as seen with an unmodified DSLR with a portrait lens.

Taken over several nights as a part of testing to prepare for GSSP 2014, I put the Pentax K10D camera on a non-goto Losmandy GM8 mount and let it track guided for 5 minute exposures at 100 ISO and in-camera noise reduction enabled.

Used two lenses:

smc PENTAX-A* 1:1.4 85mm

S-M-C Takumar 6X7 LS 90mm f/2.8

Both were at F4.

The 67 lens was coupled with an adapter and an IDAS HEUIB-II filter was attached. This seemed to help control out of focus NIR.

Blue halos abound, even with the ED elements in the 85mm lens. I tried using a B+W 486 filter on the lenses but this caused additional flare with Vega. Might be a worthwhile addition if imaging in areas with fewer bright stars.

Made some efforts to capture flats but the stacking in DSS over compensates and I opted to just drizzle stack and crop afterwards.

The total data set is 36 subexposures at 5 minutes each for 180 minutes of integration over June 3, 5, 7, and 9. Additional exposures were made on other nights and were removed from the final stack due to issues with tracking or focus.

Stacked with DSS with a custom rectangle and 2x drizzle. Processed in PI with DBE, slight saturation curve boost, Masked Stretch Script, Histogram Stretch, and final masked curves to drive the background skyglow down.

Here is the platesolve from PI:

Referentiation Matrix (Gnomonic projection = Matrix * Coords[x,y]):

-2.52208e-005 +0.00203001 -4.0094

-0.00202616 -7.44414e-006 +5.45273

+0 +0 +1

Projection origin.. [2683.786448 2008.407150]pix -> [RA:+18 51 07.02 Dec:+36 07 35.74]

Resolution ........ 7.301 arcsec/pix

Rotation .......... -89.591 deg

Focal ............. 170.93 mm

Pixel size ........ 6.05 um

Field of view ..... 10d 50' 29.3" x 8d 6' 57.3"

Image center ...... RA: 18 51 02.630 Dec: +36 08 54.61

Image bounds:

top-left ....... RA: 18 29 50.437 Dec: +41 26 24.88

top-right ...... RA: 18 31 57.287 Dec: +30 40 30.52

bottom-left .... RA: 19 12 56.398 Dec: +41 24 15.63

bottom-right ... RA: 19 09 30.962 Dec: +30 39 09.13