M45 Pleiades Seven Sisters Subaru Matariki - 15/10/2018 (Processed Stack)

First Light test with Pentax SMC Takumar 200mm f/4 M42 lens at f/6.9.
Chromatic aberration less noticeable then f/4 and vignetting gone with sharper stars in the corners, however bridge edge stars show internal reflection flare. See f/4 and f/5.6 variants. f/5.6 is probably better for economy of exposure time, but flare reduced at f/6.9.

DeepSkyStacker 3.3.4 Stacked 100% (3) of 3 Images at 200mm f/6.9, ISO 1600 @ 30 Sec, 0 DARK, 0 BIAS, 0 FLATS, Post-processed with Adobe Photoshop CC 2018

Pentax SMC Takumar 200mm f/4 M42/EOS adapter, No filter, Baader BCF modified Canon 70D DSLR field 381' x 254' , Ambient ~15C. SkyWatcher Star Adventurer EQ mount unguided sidereal drive.

MessierM45 Pleiades Seven Sisters Subaru Matariki

From 2018 Refocusing 2