How much far! How much close! a C11 SCT is?

We examined a random star field near to galactic band using Exoplanet Blue Blocking filter (The spectrum of the Astrodon ExoPlanet-BB filter is shown Below). It blocks UV and blue light.  It starts transmitting light near 500 nm, corresponding to the shape of the conventional V-band filter and continues to transmit light into the near-infrared.

The purpose of using this filter was to achieve the best possible focus at red end. The 40 sub frames of 120 seconds were taken using PRiSMv10. The image stacked and photometrically calibrated using star catalog ATLAS and Tycho8.0. We achieved the best possible average magnitudes at V band (conversion) to +21.50

Image:
Object: Random Star Field
DATE-OBS: 2021-04-18T21:28:25
EXPTIME(Seconds): *B/*V/*R/*I/*g’2/*r’2/*i’2/*z’2/4800ExBB
SUBFRMS: *B/*V/*R/*I/*g’2/*r’2/*i’2/*z’2/40ExBB
OBJCTRA: 18 19 30.15
OBJCTDEC: +09 28 07.1
Instrument:
Astrometry Catalog: ATLAS: Y, UCAC4: N, GAIAEDR3: N
Photometry Catalog: : UCAC4: N, APASS: N, ATLAS: Y
Johnson/Bessel: (B): *.*, (V): *.*, (R): *.*, (I): *.*
Sloan: g’2: *.*, r2: *.*, i’2: *.*, z’2: *.*
CCD: ATIK-383L+
FILTERS:
Sloan: u’2: N,g’2: N,r’2: N,i’2: N,z’2: N, ExBB: Y
Johnson/Bessel: U: N,B: N,V: N,R: N,I: N,
TELESCOPE: C11, 1623.0mm
PRiSMv10, Tycho8.0
Site:
ORIGIN: Cepheid Observatory, India, Vorion Scientific, India
SITELAT: +24:55:00:00
SITELONG:+75:33:58:99
Observers:
K.V
Measures:
S.M, B.K, V.A.
Remark:
Sky Clear, 
End

Random Star Field (Star Spikes are artifact only to make image interesting)
Original FITS
Astrodon Exoplanet BB Filter