Andrea B. Posted May 9, 2018 Share Posted May 9, 2018 Does anybody have any experiences with converting a cellie?Any links to cell conversion?I remember seeing something somewhere but cannot find it now.Thanks in advance for any suggestions. {{{My Secret Wish: To convert my cell phone so I can photograph Pokemons in UV. Pikachu would be so UV-adorable.}}}{{{......j/k, really j/k......}}}Pokémons? Pokémen? Link to comment
enricosavazzi Posted May 9, 2018 Share Posted May 9, 2018 I don't know of any specific mobile phone conversion, but I know that the IR-cut and UV-cut filter in cheap webcams (and also not-so-cheap action cameras) is often a vacuum-deposited coating on one of the lens elements, and there is in this case no separate filter one can remove or replace, short of replacing the whole lens. I posted a few years ago in this forum my experience with a GoPro Hero. I don't think it is a problem to build one of these filters on a plastic element, so this construction is not restricted to lenses with glass elements. Small IR- and UV-cut filters (apparently made of thin glass) for videocams are continuously advertised on eBay by Chinese sellers, so maybe surveillance videocameras are still largely using these separate filters. Mobile phone cameras, webcams and many action cameras typically use very small sensors and there is little space for a separate filter between lens and sensor. The C or CS lens mounts of surveillance videocameras provide more space. Link to comment
Andy Perrin Posted May 9, 2018 Share Posted May 9, 2018 Andrea, this was my first converted camera! The iPhone 4 had very weak filtration and I converted it for infrared by removing the window in the case (which blocks IR) and replacing it with Hoya R72 which I cut down by hand with a dremel tool. Link to comment
Guest Posted May 9, 2018 Share Posted May 9, 2018 Interesting. I'd love to see what the actual spectral response range is of a typical cell phone camera. Link to comment
Andy Perrin Posted May 9, 2018 Share Posted May 9, 2018 Not great. I tried UV also, using an Omega 330WB70, and it didn't get anything no matter how long I exposed. This was an iphone 4, so very primitive camera at that time and lots of line noise (streaky lines that come from sensor readout, not the random kind of noise) that would not go away with longer exposure. It was okay for IR, though. I had bad hotspot issues but didn't care at that time. Link to comment
Andy Perrin Posted May 9, 2018 Share Posted May 9, 2018 Here is what the UV attempt looked like (on iPhone 4): Top is visible (just monochrome), and bottom is UV: There was really bad focal shift as you can see also. Link to comment
Andy Perrin Posted May 9, 2018 Share Posted May 9, 2018 Here is the phone itself. I replaced the whole back panel so I could just swap back in the original panel if I wanted to. (I never ended up wanting to, but it was just as well because I cracked it a bit...): Link to comment
Andrea B. Posted May 9, 2018 Author Share Posted May 9, 2018 Thank you Enrico and Andy for the input. :) I think I'll skip this conversion until some future iteration of cell/mobile tech. Link to comment
OlDoinyo Posted May 10, 2018 Share Posted May 10, 2018 I have taken cell phone photos both through B+W 093 and Baader U2, without conversion. I cannot say quality was high, but the blocking on some of these cameras is not always up to the level seen on more serious gear. Hotspotting issues are of course a crap shoot. But the tiny optics often have very little total lens thickness, so that works in one's favor. PS: I think the correct plural might be Pokemontachi. Link to comment
ulf Posted May 10, 2018 Share Posted May 10, 2018 It is likely that more recent phone cameras get better filtering as the aim is to approach the quality and replace normal cameras. Link to comment
ulf Posted May 10, 2018 Share Posted May 10, 2018 Surveillance videocameras are still largely using these separate filters. Mobile phone cameras, webcams and many action cameras typically use very small sensors and there is little space for a separate filter between lens and sensor. The C or CS lens mounts of surveillance videocameras provide more space. The reason for using separate filters in some surveillance videocameras is to be able to mechanically remove the filter when switching to night mode.The filter is often quite thin and can be shifted in and out by some type of electromagnetic device.That give a better gain by including more of the spectrum for low light situations. The Bayer filter is still in place on the sensor. Link to comment
otoien Posted May 10, 2018 Share Posted May 10, 2018 Thank you Enrico and Andy for the input. :) I think I'll skip this conversion until some future iteration of cell/mobile tech. Perhaphs you could get yourself one of those FLIR cameras that plug into cellphones just to satisfy you desire at using you cell phone for the invisible spectrum? :D Link to comment
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