Samsung NX mini for Astro- + Landscape-IR-Photography
How could this small CostLess digicam become an IR Must-Have ILC ?
2015, the Best Canon APSC Camera has got a 1" BSI Sensor : Click Image, Ctrl+ to enlarge more
Despite tiny sensor 33% the area of APSC, the 1" BSI shows 70% of the DxoMark-ISO Sensitivity of Renown Canon Eos 60D(A), 600D... PowerShot G7X & Samsung NX-mini both have the Sony imx183 BSI sensor ~> Sensor's main page for more detailed informations : SensorCompare.html ~> Samsung NX-mini tests : https://www.dpreview.com/reviews/samsung-nx-mini www.imaging-resource.com/PRODS/samsung-nx-mini/samsung-nx-miniA.HTM https://www.ephotozine.com/article/samsung-nx-mini-expert-review-24605 . ~> Sony imx183 BSI CMos sensor specification sheet : https://www.sony-semicon.co.jp/products_en/new_pro/may_2014/imx183_e.html ~> ProCam : https://astronomy-imaging-camera.com/product/asi183mc-pro-color ~> Scientific (Spectro.) use case : http://www.astrosurf.com/buil/asi183mm/ Few years ago, you'd have to be a Fortunate Professional Researcher to get a BSI CCD sensor with High Energy Waste, and High Dark Current Level, and No possibility to get the Signal Cleaned, then Digitized "on chip" : The Exmor Bonus ! AstroPhotography-DSO : https://www.dpreview.com/galleries/tags/nx-mini chassimages.com/forum/index.php/topic,236962.125.html https://en.astronomike.net/u/6809.html . DPReview : Nikon1v3, Nikon1v1, 1j1, PentaxQ7, Samsung NXmini, SonyRX100 - Nikon 1 (1" FSI), Pentax Q7 (1/1.7" BSI) : lower Raw & Low-Light-ISO scores - Samsung NX-mini, Sony RX100 (1" BSI) : higher Raw & Low-Light-ISO scores Click Image, Ctrl+ to enlarge more . The Drawbacks of the Samsung NX-mini with its 1" imx183 BSI sensor – ISO 1600 shows Amp-Glow localised in the Bottom Corners of the frame, but the 240 sec. Bulb Exposure was enough. I just once had to set at ISO 800 : wind and Turbulence were so strong that Guiding over 30 sec was very difficult ! I Never subtracted nor Bias-Maps (Offsets) neither Dark-Frames from my subs, even during this Summer 2019, where nights Temperatures climbed over 25° C ! U do need ISO1600, it's not so bad to reduce the format ratio from 1.5 to 1.4 or even to 1.33. That means from 8.8 x 13.2 to x 12.44, even to x 11.74 mm wide. . More Advantages to the Samsung NX-mini over other 1" BSI cameras – the NX-mini is the unique 1" BSI cam. to support Interchangeable Lenses. – MA4NXM optional Adapter opens the NXmini to the whole NX lens system. – NX-mini has a Huge 2330 mAh Battery : lasts a whole night in worse conditions. (– As nights become warmer, could be very easy to cool this camera from inside) – Bulb Mode holds 240 seconds long exposure, the top for AstroPhotography. – the NX-mini is a Costless camera : I bought mine for €183 in spring 2015. – the IR-Cut filter inside the NX-mini is very easy to remove (read next). – IR-Cut removed, the Auto-Focus is still Reliable with 9 & 9-27 mm lenses, the NX-mini could be the Best for Landscape-IR : nor High-ISO, neither Tripod, get ten times, 10x the Light, for twice, 2x the Price of 1 R72 IR-Filter : https://www.google.com/search?q=landscape-IR-photography&tbm=isch . Click Image, Ctrl+ to enlarge more I superimposed the curves of Relative QE from 3 Zwo BSI mono Astro-Cams : the Asi178mm is very sensitive toward the Blue, the Asi290mm which sensor is advertised as Near-IR by Sony, and the Asi183mm which seems the very best compromise between the 2 others ! At 656 nm, their Relative QE is : ~60% for the 178, ~80% for the 183 and ~93% for the 290 ! If I could achieve the same "easily readable graph" for their Color Version with a Bayer Filter, I'll do it. But, there is no reason things will change dramatically. What we can see here is their Silicon response to different wavelengths and the effect of deeper photodiodes : the deeper, the more IR sensitive. Asi183mC & Samsung NX-mini could reach an Absolute Peak QE of 80+% in both Green channels, an excellent sensitivity !
Adding a M48 x 0.75 Mount Thread on your NX-mini
How to Add a M48 x 0.75 Mount Thread on your Samsung NX-mini Please, don't begin doing it if you don't feel able to achieve it... It's Your Own Full Responsability to do it... Or not to... You have to find a M48 x0.75 T2 Mount Adapter of any brand, with the thicker 8mm M48 threaded Inner-Ring + a M48 to M42 Adapter – 0) remove Battery & Lens + Protect the Sensor from Glue, Scratches – 1) unscrew the 3 screws that hold the Inner-Ring in the T2 Adapter... – 2) remove this Inner-Ring : « 48mm conon » off the T2 Adapter... – 3) Remove the Latch, Button, Spring off the Samsung NXm Mount... ( 3 & 4 need to remove the Front Panel : SamsungNXminiTopIR.html ) – 4) Cut the Aestetic-Ring off the Front Panel at diameter of Inner-Ring – 5) Verify the Inner-Ring slips around the NXm Mount of the NX mini... /!\ Crucial : the Inner-Ring to be firmly glued around the NXm Mount /!\ – 6) Screw the M48 to M42 Adapter in the Inner-Ring from its marked ... side, letting 4mm free M48 Female Thread at the Non marked side... – 7) Cut a 48mm Paper diameter, put it at bottom of the 4mm free M48... – 8) Prepare some Araldite glue, apply it on the 4mm free M48 Female : ... the Paper at bottom prevents the M48 to M42 Adapter to be glued too – 9) Slip the 4mm free M48 Female Thread around the NXm Mount... ... keep parts quiet ~24 hours at ~22°C... unscrew M48 to M42 Adapter put the Front Panel w/ enlarged hole back : SamsungNXminiTopIR.html
/!\ No Glue, No Scratch on Sensor /!\
Any brand M48 x0.75 T2 Mount Adapter w/ its 48mm conon Inner-Ring : this Inner-Ring must be at least 8mm thick Click Image, Ctrl+ to enlarge more . If your Reflector, Refractor is an Up to Date instrument with a M48 thread... ... go to Adjusting the Focusing Distance... at the bottom of page . If your Reflector, Refractor is a Classic instrument with a M42 thread... ... you'll have to screw in the M48 to M42 Adapter M48 male to M42 female Adapter : Click Image, Ctrl+ to enlarge more
Adjusting the Focusing Distance with Extensions : – 1) The distance from the Sensor to the NXm Mount is ~ 7.5 mm ~ – 2) Backfocus Distance of your instrument minus 7.5 = ~ the lenght to add... – 3) With the Moon / a Bright Star, verify the Right Focusing on the Sensor... Backfocus Distance of a T2 instrument or lens = 55mm