Infrared-modded Digital Camera With SLR Lenses!

I had read about tilt/shift lenses, and how you could move the focus point. And so, I unscrewed the manual focus lens from my infrared-modded manual-focus Fujifilm Digital Q1, and held the Fujinon 50mm F1.4 lens in front of it like it was an SLR.

(The lens was stuffed inside my Canon Powershot A520 lens adapter, hence the appearance of a black tube.)

Viola! I could tilt it, and move the lens closer or further from the body to focus. (Of course, having space between the lens and sensor means that dust can get in. A safer way is to have a tube in between, or a bellows, or get yourself a Lensbaby.

Inspired by this macro infrared digicam project, I went around looking for wide old lenses with aperture rings and manual focus. (The Q1’s sensor is 6 times smaller than a full-frame sensor, giving it a crop factor of 6x. Thus, a standard 50mm lens would look like a 300mm.)

After finding YL Camera in Pudu Plaza, I saw a box that caught my eye – A Cosina 19-35mm F3.5-4.5 MC wide lens. The label above said “Nikon mount 19-35mm F3.5-4.5 like new“, so I checked it out. It was a clean lens, and I bought it for RM350.

A 19mm wide lens was rare in film SLR days; the widest it would usually go was 24mm. Any wider, and the lens would have to extend backwards into the mirror box, not a pleasant surprise when you find the mirror smashing into the rear element of the lens. I suspect that this 19mm lens achieved the wideness on the front, as the screw thread diameter was a whopping 77mm!

I asked for an extra back lens cap for the project. They tried a few Nikon caps, but none worked. A brandless one did, so I took that.

As I sat in Uncle Lim’s, Berjaya Times Square, inspecting my purchase, I read the instructions. Apparently, only the Nikon mount version had an aperture lock switch. Mine didn’t.

I checked the underside and then the side of the box – P! P for Pentax! The shop had mislabelled it. Thank goodness *I* bought it, and not some Nikon newbie who did not bring his/her camera along while buying this lens. No wonder none of the Nikon back lens caps worked!

I was originally thinking that I finally gave in and got a Nikon-mount lens (which would then make me get a Nikon.) Then when I found out it was a Pentax, I was disappointed that I could not mount any Nikon lens my friends had!

(Canon EF/EF-S lenses are out of the question as they don’t have aperture rings. Olympus has certain lenses that require you to press them to do stop-down metering; it does not lock for some reason.)

Left: The box; top-right: the back lens cap, which I sawed with a Swiss Army Knife ala V for Vendetta; bottom-right: the rear end of the lens, with the Pentax K auto-focus mount.

Pentax and Nikon were the only camera manufacturers to retain the same mount when introducing auto-focus lenses. A manual-focus lens would fit on their new auto-focus camera bodies. This lens also had a screw so that the camera could turn it and thus change the focus.

It had 8 circular aperture blades. Unfortunately, it closed down to a teardrop shape instead of a perfect circle, just like my Fujinon lens.

The ghosts from the table lamp I used above were interesting! They were… holographic? I wonder if I could count the number of ghosts and calculate the number of glass elements in the lens from that.

Anyway, it was time to marry the Q1 to the Cosina. Dr. Albert (Frank)einstein shaved off some plastic so he could glue a 55-52mm step-down adapter parallel to the sensor (top-left picture). The 55-52mm was picked over a 52mm to reduce distance from the sensor.

I then screwed on a 52mm filter, followed by a 52mm-to-Series-VII ring adapter. It looked like a 52-55mm step-up ring, but it is not compatible with 55mm rings (probably different thread thickness.) Anyway, the ring gave me enough space to swallow more of the rear lens cap I had cut earlier. (Refer to bottom-left picture.)

The rear lens cap was superglued to the 52mm-to-Series-VII ring; I could then screw them all together. The top-right picture shows it all in, minus the lens.

The Cosina, with its 77mm diameter, hides almost all of the camera! (Bottom-right picture.) All the more so with the lens hood attached.

From top, the complete setup, lens to camera: Cosina 19-35mm F3.5-4.5 MC Pentax K-mount lens, Pentax K-mount back lens cap (with a triangle cut), 52mm-to-Series-VII adapter ring (superglued to cap), Hollywood 52mm SKY-1A Skylight filter (glass removed), Hoya 55-52mm step-down ring (superglued to camera), infrared-modded Fujifilm Digital Q1.

The Hollywood filter was required to give the correct distance from lens to sensor so that I could focus apparently near and far. I did not measure how accurate it was, but it gave me the best range.

Through the LCD screen, it looked like a 114-210mm film equivalent zoom lens. Yes, the LCD screen. It was a SLR lens attached to a digital camera with Live View! No other digital camera, prosumer even, had true manual focus! It was great fun. Interestingly, the lens can focus nearer at 35mm than at 19mm.

(Click image for bigger version.)

Adding distance between the lens and sensor makes the camera short-focused (which is great for macro; stack a few rings so you can focus nearer still!)

These rings do not cause vignetting; as long as there is an infrared filter, adding polarizers and color filters would have no effect to the exposure.

Also note the added Hoya 2x Teleconverter (which I got from the friendly Jeff of Leos Com Trading in Ampang Park). It was dirty on the inside and was for manual-focus Pentax mount (it had corrective optics but no auto-focus screw) so it was quite… unwanted. Adding this made my lens a 38-70mm F7.0-9.0 zoomer.

But wait, that’s not all!

It was quickly joined by a Seagull Minolta MC-mount 50mm F1.8 lens which I found in Foto Selangor, Pertama Complex for RM100. However, being a Minolta MC manual-focus mount, it would not fit on Minolta AF mounts like the Alpha mount. smashpOp tried it on his Sony Alpha A100, and it was too loose.

Seagull was a Chinese company that made loads of imitations, often with aperture, zoom and focus rings turning the opposite way of normal lenses. In this case, everything was reversed compared to the Cosina.

Top-left: The Minolta MC mount; top-right: I cut a triangle in the back lens cap and superglued it to a 52mm Toshiba SL-1A Skylight filter; bottom-left: 6 straight aperture blades, more even for nice bokeh; bottom-right: it could loosely fit on the Pentax K-mount Hoya 2x Teleconverter, to make a 100mm F2.8!

The standard setup; Seagull Minolta MC-mount 50mm F1.8 lens, Minolta back lens cap (with triangular cut), 52mm Toshiba SL-1A Skylight filter (superglued to cap), Hoya 55-52mm step-down ring (superglued to camera), infrared-modded Fujifilm Digital Q1.

This baby was even more fun to play with. The lens was a real manual lens, not an auto-focus lens by build. Auto-focus lenses aren’t so fun because they’re lighter and often made of plastic (so the motor can focus them faster); they go from macro to infinity in a smaller turn of the focus ring; they don’t have depth-of-field scales to help you do hyperfocal focusing; and they don’t have that silky, viscuous dampened feel.

This was metal, and took a smooth 180 degree turn. Orgasmic.

The extended version with rings for extreme macro.

Speaking of macro, the Seagull reversed looks about the same to me on a reverse macro setup as my Fujinon 50mm F1.4.

But enough theory talk. We now go live, behind the screen of the Fujifilm Digital Q1.

Clockwise from top-left: Tilt/shift lens testing; more testing; the Fujinon 50mm F1.4 gives a 300mm equivalent crop, from ground level; it also crops the scenery.


…and busy bee.

I love how the Q1’s CMOS sensor distorts images when moving.

Clockwise from top-left: The first ever picture every SLR buyer takes (the lens cap!); the box taken with the Q1 and webcam manual focus lens; the box taken with the Q1 and Cosina lens at 19mm; me trying to camwhore at arm’s length at 19mm.

I found Keat Camera, and found this dirty push-pull zoom; it had low contrast. The second picture on the right is from another push-pull in Cash Converters, and the flourescent tubes are from Foto Selangor, Pertama Complex.

Clockwise from top-left: The Cosina at F3.5; stepping down to F22 shows how much dust has gotten on the sensor due to all my experiments; pointing at a bright light shows how bad it is; however, at bright apertures, it is not obvious.

At 35mm (210mm equivalent) and sunlight crashing in through the window, uh…

Top: camwhore is unaware that the Cosina is not very wide after all; bottom: Grace and I figure out how to camwhore at arm’s length with the Seagull.

Another mandatory shot – the look-ma-I-can-manual-focus-with-awesome-out-of-focus-areas shot. I can’t remember how I got the distortion in the lower picture.

Transformers Alternators Grimlock: Focus, dammit, focus!

I used the Seagull to take a picture of the Cosina with many rings; it appears to be white in infrared.

Seagull 50mm F1.8 shot.

45cm away, macro is pretty cool.

Shooting performances with a 300mm equivalent F1.8 on an infrared-modded camera is great fun, because of how bright infrared modding makes it! This was underexposed by one stop and shot from over 10 feet away from the performers. The camera shot at 1/250th of a second at ISO 100!

Interestingly, stopping down the lens to F2.8 (the lower picture) removes a lot of that infrared tint. It could just be enough to tip the camera’s white-balance over for this effect.

I can also shoot from across the table!

It is truly an intimate lens.

So if I have a Q1 which only does 1600×1200, could I take a picture using a dSLR on a 50mm F1.8 and crop it to the same picture?

The Q1 does 300mm at a crop factor of 6x. A regular dSLR crops at 1.5x or 1.6x. Thus, to get as much detail in that tiny area, you’d need a dSLR with 6400×4800 resolution, which is 30.72 megapixels!

Okay, fine, so a dSLR has a 3:2 ratio (I don’t understand why don’t they get closer to a square, as it uses as much of the image circle with less cropping.) Hence it should be 6400×4267 resolution or 27.3 megapixels to get as much detail in a crop as the Q1.

In case you haven’t figured it out already, I intend to get more lenses of different mounts, and unite them all at the 52mm screw thread. 😀 I can then stick filters between the lens and camera instead of in front of the lens! The exception is the Seagull, where adding any more filters will make it short-focused, so I’d have to get a 49-52mm step-up ring. My only worry is if the Seagull is so old that its front screw thread diameter is 48mm instead!

13 thoughts on “Infrared-modded Digital Camera With SLR Lenses!

  1. Albert Ng Post author

    Pinkfrog: Wait, we’ll go out in the sun with your 70-300 with aperture ring. 😀

    annoymous: Unfortunately, the Q1 does not have slow shutter; in dark places it will only go up to 1/15th at ISO 200 on its electronic shutter. The picture with Grace was shot with very dim ambient light about absolute EV 0 (to get that you need F2.8 at 1 second with ISO1600). Until I can get one of those ISO3200 1/1.8" Fujifilm CCDs, I’ll have this noise. Then again, most places I found aren’t purely flourescent-lit, so I still get fast exposure times than unmodded cameras.

  2. Tan Yee Wei Post author

    Thats fantastic! The mechanism for changing lens mounts is nifty too.

    Do consider making an M42 screw mount. Those lenses are cheap compared to newer Pentax K, Nikkor and Canon FD lenses. And extremely common back then.

  3. Albert Ng Post author


    Unfortunately, I have NEVER seen an M42 mount lens anywhere. We could technically call the 52mm filter thread a M52. 😀

    I will make a mount for every old lens that I acquire. Rear lens caps are easy to acquire (though I suspect that the CO-Y in the second picture means that the rear lens cap the shop gave was a Contax/Yashica, which explains why it’s not very tight with my Pentax K-mount lens… but still shows that CO-Y and K-mount are very similiar.)


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