From the Sony imx183 (SamsyNXmini) up to Sony imx078 (PentaxQ, Q10) both Dima & Sony Calculation methods show a ~44% increase in Sensitivity, a ~44% increase in Sensitivity is as opening Aperture from f/5 up to ~f/4.2. For Q, Q10, Sony Calculations : 3574, 3354 are averaged to 3464 value. ~> Sensor's main page for Fully Detailed informations : SensorCompare.html One can see that it's Not its Big Pixels that make the Sensitivity of a Sensor ! It's rather the Precision of 1st the Lithography process 2nd the Etching process, down to 90nm for its brother imx118, that let Sony maximising their Fill-Factor.
Drawbacks of Pentax-Q, Q10, despite its 1/2.3" fabulous imx078 BSI sensor ~ Drawbacks in yellow could certainly be Fixed by a FirmWare Hack/Update ... Please read : Pentax-Q10 FirmWare-v1.03-Disassembly ~ Bulb + Manual Mode limited to 30 sec. Exposure w/ Pentax K2Q Adapter ~ ISO 1600 => Amp-Glow at the Bottom-Left of the frame + Random LENR ... 2-4 min. Long Exposures at ISO 800-400 to avoid Amp-Glow and LENR ... Please read : Samsung NX-mini Top-Astro-IR.html ~ No way to set the LENR, Long Exposure Noise Reduction, fully ON or OFF ~ Camera Temperature Not Recorded in EXIF Data for Exposure > ~10 sec. ~ IR Remote Control doesn't work with Bulb, nor Intervalometer – Multi-Exposure Mode outputs a JPEG file, not a RAW file – No Wired Remote Control Port on Pentax-Q, Q10, Q7, Qs1 – IRcut removed, the Auto/Manual-Focus doesn't work w/ 5-15 mm zoom lens ... except for subjects at (very) Short Distances. Ditto to expect from 15-45 mm – Tiny Pixels are in Love with the Highest Precision from Belt-Driven-Eq-Mount ... I only own an Old Black HEQ5, thus being forced to Trash ~50% of my subs pentaxforums.com/frms/136pentaxQ/212387-astroQclub-13.html#post3274556 One, 1 arc-second = 1/1 296 000 of a Circle... IOW 1/3 600 of 1 Degree... 1 degree is ~half your thumb's nail width, your arm held out to the sky... you'll have to draw 7 200 parallel fine lines on your thumb's nail ! ... That is, looking from your arm's full length... Good luck ! . Bill Claff's Photo Dynamic Range ranking : Sony 1" BSI, Pentax-Q10, Nikon 1" - FSI, some older Classic APSc cameras, iphone7, https://photonstophotos.net Clic Image, Ctrl+ to Enlarge
More Advantages to the Pentax-Q, Q10 over other 1/2.3" BSI cameras – Q, Q10 are unique 1/2.3" BSI ILCs to Support Interchangeable Lenses. – K-to-Q Optional Adapters open the Q, Q10 to the whole 'K' Lens System – Q, Q10 have 1000 mAh Battery to last 1 summer night in precise conditions – the Q10 is a CostLess Camera : I bought mine for €170 in spring 2014 – the IR-cut filter inside the Q, Q10 is Easy to Remove (read next) https://www.dpreview.com/galleries/tags/pentax-q10
IR-cut filter Removal to increase Red + IR SNR
How to Remove the IR-cut filter from the inside of the Pentax-Q, Q10 Please, don't begin doing it if you don't feel able to achieve it... It's Your Own Full Responsibility to do it... Or not to... – 0) Remove the Battery and the Lens on a clean well lit clear surface... – 1) Lock the IR-Filter-Box on 4 Sides with 4 Bent Paper-Pieces... – 2) Draw 4 Lines at 1.2mm from 4 sides of the IR-Filter-Box... ... same as the dotted-lines seen on Q10cmosIRcut.png – 3) Gently cut-off the Plastic following the 4 lines... ... it's ~1 mm thick and of Easy cutoff. – 4) Separate and Remove the just cutoff Plastic Rectangle... – 5) take the IR-cut filter, maybe you'll have to-cut a little More Plastic to free it... – 6) the IR-cut filter + Bellows will jump out, to Store in a clean paper wallet... – 7) free the IR-cut filter: cut-off its flexwire, it powers the Piezo element. The Density of the IR-cut filter is about ~1.2 Ev. Careful : No things on sensor ! . F11, Clic Image, Ctrl+ to Enlarge . For those who want to replace the original IR-cut filter with a Clear Glass or... another IR-cut filter at 680 or 720 nm, here are its exact Dimensions : - Thickness : 0.6 mm - Height : 12.6 mm - Width : 13.1 mm