M13 19-07-2020

Dovnar Ivan

1121935

Deep Sky

Jul 20th, 2020

2276

NGC 6199IC 4613IC 4615IC 4616NGC 6194NGC 6196NGC 6197NGC 6205NGC 6207IC 4614IC 4617

Resolution:: 2933x1907 px
File size:: 2204 KB

Show astrometry on hover

Technical information

Telescope/Lens: ZM-5SA 500mm f/8 Lens
Camera: Canon EOS 550D (astro-modified)
Mount: Sky-Watcher Star Adventurer
Guide Scope: Finderscope 50mm
Guide Camera: T7
Software: PHD2, DeepSkyStacker, FITStacker, Photoshop, Fitswork

Location: Rudensk, Belarus

Light pollution

Orange, Bortle 6 zone

Exposure

49 × 120″ · ISO/Gain: 320

Total exposure: 1 h 38 m

Comments

alex_ob

Nice photo. Ivan, did you have any issues with astigmatism (triangular stars) on this lens? How does it perform in winter, did you modify it, loosen the mirror and meniscus mountings?

Sep 6th, 2020

Dovnar IvanReply to alex_ob

Astigmatism was present. I almost completely loosened the mirror and meniscus mountings, and it became normal. Last winter, we didn't have severe frosts, so there were no issues.

Sep 13th, 2020