Remember the Seagull 50mm F1.8 MC Minolta MD-mount lens I had for my infrared-modded Fujifilm Digital Q1 camera? It now has a prime companion, the Vivitar 24mm F2.0 Olympus OM-mount lens.

Assuming ISO400 sensitivity:

Compared to a 50mm F1.4, it has the same darkness performance, giving steady shots at absolute EV4.66. How so? The F2.0 would be one stop darker than the F1.4… but because it is one stop wider (to be exact, 25mm is one stop wider) it can use one shutter speed stop slower. Bokeh is two stops smaller, but it’s a practical walkaround lens. The Nikkor 28mm F1.4D is the most expensive wide prime, which can shoot in EV4, merely 2/3rds of a stop darker than this 24mm F2.0. (A Canon 50mm F1.2L lies halfway between, in terms of dark performance at EV4.33.)

Top, from left to right: Fujinon 50mm F1.4 EBC lens (Fujica mount but without lens body), Seagull 50mm F1.8 MC Minolta MD-mount lens, Vivitar 24mm F2.0 Olympus OM-mount lens, Cosina 19-35mm F3.5-4.5 MC Pentax K-mount lens, 35mm-equivalent manual focus webcam lens.
Below: The Seagull (left) is joined by the Vivitar.

This time around, I made an effort to document approximately where I should set the manual focus to camwhore at arm’s length.

The Olympus OM mount is unique – the depth-of-field (DOF) preview button is on the lens, not the body; the lens release button is on the lens as well. However, the lens I bought had a problem – the DOF preview button did not work. So I’d be stuck at F2.0 all the time. And so, I opened the lens, taking care to separate screws of different layers, by putting them on different filters (top row).

The underside of the rear-most piece; on top is the DOF preview button, which pushes the lever; below is the lens release button.

I then removed the aperture ring (on left) and a tiny ball bearing dropped out onto the lens. Arrow denotes where it came from; the ball runs along the notches on the lens, to make the clicks you feel on your aperture ring.

Finally, the root of the problem! It took me a while to figure out what controlled the aperture, since a DOF preview system is complicated and has a few springs. The problem was that the spring on the left was supposed to pull a lever (in the middle, nearer to the lens) that closed the aperture blades. The spring did not have enough tension to pull the lever!

Note the loose spring in the bottom-left corner; the hook was loose. This lens had 6 circular aperture blades.

After toiling about, I decided to superglue the spring solidly to the mechanism! I removed the other spring that returned the lever to open the aperture blades. The downside was that once I had pressed and released the DOF preview button, the aperture would stay closed. Fortunately, I could open the aperture by turning the aperture ring.

I suppose the spring weakened because the previous owner tried to forcefully press the DOF preview button while the lens was at F2.0. The DOF preview button, I found, was supposed to provide resistance; it should only travel all the way down if the aperture was at F16. You should only be able to half-press it at F2.0, at which point the springs would stop you.

I also suppose that the previous owner (or someone unfamiliar with the camera) tried to press the DOF preview button while at F2.0, thinking it was the lens release button. Since it didn’t dislodge he/she would’ve pressed harder, breaking the spring. Ouch! I wonder if any other Olympus OM system users have this problem. I hope Google leads all you broken-DOF-button-Olympus-users here!

I prefer the rear diaphragm lever method used by every other non-digital lens.

And now, a group photo from left to right: infrared-modded Fujifilm Digital Q1, and them lenses in order of brightest to darkest, coincidentally going wider, too.

The infrared-modded Fujifilm Digital Q1 puts on the 24mm F2.0 after the fixing. Note the screw in the rear lens cap; it locks the lens in place. The button with grooves is the lens release button. I don’t know why, but with this lens-to-sensor distance I can focus closer than the lens says, and yet focus beyond infinity.

I had to reopen the lens when I pressed the DOF preview button and weakened the spring. More superglue!

I had to reopen the lens again when it seemed to be focusing close; the lens was too far out despite being screwed all the way back in. The giant screw thread that connects the lens to its housing has a few entry points! Enter the wrong one, and the lens will have the wrong distance and thus lack the correct focusing range.

Alright, enough of the tech talk. I’m stoked to have opened and fixed my own lens mechanism!

24mm with a crop factor of 6x gives a 144mm equivalent focal length.

Okay, so the depth of field is nothing to shout about.

However, reversing the 24mm in front of my Canon Powershot A520 at 140mm equivalent, closest manual focus, gave the image on the left. The right-side image is from the reverse Fujinon 50mm F1.4.

This might put a scale to things; text was typed on my phone; focus was not changed with lenses.

So how’d I choose the lens to use?

The Seagull 50mm F1.8 is great for performances and shooting candid shots from a distance. The Vivitar 24mm F2.0 is usable, twice as wide, but not a stalker lens. The Cosina at 19mm is the widest I have… but F3.5 seems rather dark, and it seems sharper at the 35mm F4.5 end!

I say it’s dark because the Fujifilm Digital Q1 is very basic, lacking ISO sensitivity control. It will only go to ISO200 if it is at 1/15th of a second and can’t budge (the slowest it will go.)

Perhaps when I’m free, and it’s bright, I’ll compare the Cosina at 24mm at F8 versus the Vivitar at 24mm F8.

You could also say that I don’t have an allegiance to any camera/accessories brand; I have:

Cameras: Canon, Fujifilm, Nikon Coolpix 2200 (in repair)
Filters and rings: Hollywood, Hoya, Pixel, Raydawn, Toshiba, Vanguard
Lens mounts: Fujica, Minolta MD, Olympus OM, Pentax, 52mm screw thread
Lenses: Cosina, Fujinon, Seagull, Vivitar
Memory cards: Fujifilm, Kingston, Nokia, Olympus, Transcend

Oh, and GP batteries. Yeah.

Stock clearance of more pictures from ages ago.

Food for thought.

What lies beyond?

Fans of fans.

Light a window.

Brick truck.

Ampang Park LRT station looks gorgeous.

Titiwangsa LRT station.

Is there anybody on the line?

Communicating through phone lines.

Why’d they have such a big toilet in Avenue K?

…I wonder.

Later outside.

Show your support.

Some camera pr0n.

My version of camera pr0n; the infrared-modded Fujifilm Digital Q1 with a Seagull 50mm F1.8 MC lens, 49-52mm step-up ring, my usual set of 52mm filters, the adapter to Pentax K-mount, the K-mount Hoya 2x Teleconverter, and a Cosina 19-35 F3.5-4.5 MC K-mount lens.

Similiar, but replacing the Cosina with Xian Jin‘s Tamron 70-300 F4-5.6 Nikon F-mount lens.

Mercury recently passed the Sun, a rare astrological event, which I could’ve captured from dawn (6:57am), 9th November 2006 until uh… well, I can’t seem to be able to Google the exact time, for once.

I stayed up, taking a quick nap (thanks Athena for staying up with me and giving a wake-up call!) I took a stroll around my neighborhood at 6:30am. It was already bright, but I could not find the sun anywhere!

But first, some shots around my place.

Coconuts!

Old cars!

Cranes!

Birds up for the sunrise!

The moon! I used the infrared-modded Fujifilm Digital Q1 with the Seagull 50mm F1.8 Minolta MC-mount lens on the Pentax-mount Hoya 2x Teleconverter with the Hoya R72 infrared filter, shooting with an EV of -2. Yes, they are not the same mount and are loose but I held them together anyway. Equivalent to 600mm, then cropped the sides to 960mm focal length.

In comparison, the Canon Powershot A520 went only this far with just cropping and not resizing.

Dammit, I thought, the sun was hiding behind clouds.

As it turns out, it really only came out at 6:57am.

The sun shows on the Fujifilm Digital Q1!

I could not capture the blip, not even with the Canon Powershot A520 with Hoya R72 infrared filter at 1/2000th of a second, F8.0, ISO 50 (as fast and dark as possible.)

Mercury could only be seen if you had the sun filling up at least 2000 pixels, where Mercury would be one pixel. I wish I thought of somehow getting the sun projected upon a surface which I could then capture in full resolution!

Different apertures make the sun look different; the CMOS sensor makes severely overexposed highlights… black. Stopping down the F1.8 lens shrunk the black part of it.

Areolas anyone? 😀

I then sat at this mamak, which never looked grander in daylight…

…or infrared. The sun flare came from the infrared filter, and cannot be avoided by putting a lens hood since the sun is in the picture too.

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.

Superfly!

…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!