Tuesday, November 3, 2009

Gakken kit 25 - Twin-Lens Reflex Camera

I apologize if any of the photos fail to load. I'm using Media Fire to host the photos because they have unlimited storage space (Photo Bucket charges for storage over 1 gig, or bandwidth usage over 1 gig per month). And, for some reason, Media Fire has really been screwing up lately. From past experience, the photos tend to load properly within a few days of when the problem starts, so be sure to scroll down the page the next time you come back as see if they're showing up yet.


Kit #25 is the 3rd camera from Gakken in the Otona no Kagaku (Adult Science) series so far. Is there really that much to plumb from cameras to justify yet another one?

The answer is "yes", of course. Kit #3 was just a simple pinhole camera and (apparently, since I haven't bought this one and only looked at the online magazine) you were given instructions for making your own photographic paper. The concept is very straightforward. The paper is placed inside a sealed box. Light passes through a small hole in the box and hits the paper. The nature of light and the size of the hole work together to allow the image to be focused at the plane of the paper. The sharpness of the image on the paper depends on the exposure time. For room-lit conditions and 100 ASA paper, figure a 3-5 second exposure (bright sunlight, about half a second). So, you'll also want a tripod or a stable surface to set the camera on.

Kit #14 brought us the stereo pinhole camera, which actually has 3 pinholes. A rotating lever raises and lowers a piece of plastic within the sealed box. This time, we're using standard 35 mm roll film and a little crank for advancing the film. When the plastic piece is rotated up out of the way, and using the central pinhole, you can take panorama pictures across two frames of film simultaneously. When the plastic piece is rotated down, it separates the two frames and the two outer pinholes essentially allow you to take two photos at a time with the parallax slightly offset in each. Looking at the stereo photos with a special holder, you can get a kind of 3D effect. Again, the focus depends on the exposure time, the speed of the film and the amount of ambient light.

There are several drawbacks to pinhole, and stereo pinhole cameras. First and foremost is that you can't focus them. The best you can do is time how long the film has been exposed and make an educated guess. The second is that you MUST have a steady mount for the camera. With such long exposure times, any jiggling of the camera will smear the photo. Third, you can't be exactly sure of how the shot is being framed. You can look over the camera at the subject, but you can't see what the film sees.

(Former prime minister Aso.)

This is where we start getting into mechanics and real optics. The twin-lens reflex camera adds two focusable lenses, one in front of the aperture and the second in front of a mirror that bounces the light up to a smoked plastic screen, allowing you to see the subject as it will be framed on the film. Pressing the shutter lever down exposes the film to the incoming light. Exposure times are reduced because the lens is focusing the image for you, so you don't need to worry about jitter as much (letting you hold the camera in your hand during the shot). Better yet, because the film is advanced by hand, you can choose to play with optical effects by double- and triple-exposing the film. (If you can get the film shop to develop the paper without cutting it, you can have lots of fun with multiple exposures across the entire roll.)

(Triple exposure; two friends in front of a white building, moving, on top of a shot of the street).

The instructions suggest a 1-hour construction time, but it took me 90 minutes largely because I wasn't exactly sure what I was doing. There is an error in the book, where springs A and B are mislabeled, but it's easy to tell that this is a mistake because they're different-sized springs. Be careful about over-tightening the main shutter lever - there's supposed to be a 1mm gap between the lever and the screw to allow the shutter to snap properly, but you don't want it too loose either. When you put the camera case panels together, don't tighten the 6 screws down right away; the case needs to be able to flex to snap all of the panel pieces into place first. You'll probably need to use the included screwdriver to reach the hard-to-reach screws at the end when you do tighten them all down. The one thing that threw me was the view screen. It's a clouded plastic sheet, which I initially thought had gone bad. Actually, it's supposed to be clouded in order to give the image of the subject from the mirror something to project on to. My main suggestion is to keep testing the shutter lever and other moving pieces as you assemble the kit to ensure that they're working correctly at each step. And, make sure that when you put the double-sided tape on the mirror, that the tape goes on the side with the clear plastic protector sheet (the blue side doesn't get the tape).

(Shooting towards the sun. Very washed out.)

For actually using the camera, the book suggests 400 ASA film outdoors and 100 ASA indoors. (You can't adjust the shutter speed to match the ASA rating of the film). Put the film in the camera, close the camera up, and advance the film to the end of the roll. Then, looking at the "counter" dial, rewind the film 24 or 27 frames before taking your first shot (so that you have enough leader at the beginning of the roll to avoid ruined frames from when you put the roll in the camera; actual number will depend on the roll you bought). It's a very sturdy package and generally you don't have to worry about stripped screw holes unless you take the screws out and put them back in too often. The protector panels over the view screen fold down when the camera's not in use. Pull the little tabs of the top panel outward in order to open the panels up for using the camera. There are no lens covers so you may want a protective case for the camera during storage.

(My favorite shot. A double exposure with a close-up of a pot of flowers followed by a long distance shot of a truck on the street.)

The mook starts out with a number of photos taken by various amateurs using the kit camera, and then switches over to professional shots with antique boxes. There's another round-up of various styles of cameras, and a feature story on how to make your own daguerreotype images on glass plates. One article discusses JAXA astronaut Koichi Wakata's shots of Earth from space. A second suggests modifications to the kit, which largely consist of gluing pictures or glass beads to the case. A third article shows a disassembled scanner being used as a camera, and there's also a piece on a laptop-driven pencil (used for automating "hand-written" letters). There's also a "how-to" for making models of giant robots using rubber erasers, the history of roll film (starts out in 1889), an overview of how 3D TV screens work, a manga describing the H1N1 influenza (swine flu) and a second manga exposing the secrets of some "diet supplement" in Japan (it's actually the stimulant ephedrine).

Links in the mook include:
Nature photos, Arizona
Space photos
Scanner camera

Overall, this is a good kit and a good mook. The photos of old cameras aren't as interesting as, say, the photos of old gramophones or synthesizers, from some of the other kits. But, it's still a good introduction to film-based optics. It is getting harder to justify the costs of developing roll film when digital cameras are so cheap and easy to use, but film cameras will probably never really go away because they're so cool. The shutter mechanism on this kit is a fun combination of a couple of gears and springs, and the way the image shows up on the smoked plastic screen is almost magical (even though it's just the 1 lens and a mirror).


A comment on the photos I took. Granted, this is the first time I've used this kind of camera, and that the film had passed its freshness date. But, I can say a few things here. First, I used 400 ASA film, which really does not like being used indoors. Even under bright lights, indoor shots turned out underexposed and very grainy. Second, when something's focused at the center of the shot, everything else goes out of focus as you go towards the edges of the frame (a problem with using an inexpensive lens). But, this is a good thing if you want a soft focus around the subject. Third, shooting facing the sun will give you washed out photos. Shooting away from the sun gives you better colors. Fourth, if you're going to go for trick shots and multiple exposures, there's an all new set of rules.

First, for multiple exposures, if you want the subject to move and the background to be solid, make sure that camera is bolted to the ground. Any movement when you're pressing the lever will mess up the shot. Being on a tripod is NOT the same as being bolted to the ground. Second, don't do more than 2 or three exposures - any more than that will just create a mess. Probably, you should shoot the darker image first, then the lighter ones on top of it. Third, play around and have fun. The best shot of my first roll was completely accidental.


Next up, kit #26, a mini electric guitar, due out in December.


Rackweaver said...

I am looking to buy a Gakken kit 25 on eBay for my daughter; is it fairly easy to assemble even though instructions are in Japanese? Are there photos in the instructions? Your blog provides excellent information - just don't want to buy her something she can't put together.

TSOTE said...

Hi Rackweaver, here's the link for the instructions PDF. http://otonanokagaku.net/magazine/vol25/pdf/vol25furoku.pdf Lots of pictures. There are a fair number of pieces, so it can be a bit of a challenge, and there are a couple places where you're being told not to tighten the screws down right away. But, if you're careful and take you're time, you can build this without understanding the text. How old is she?

Chris said...

Do you know where I can find this in the U.S.?

TSOTE said...

It's probably not available there yet. Expect a couple week delay to allow import shipments to make it over by ship. If you want to try buying from a Japanese shop and then wait for the kit to arrive a couple weeks later, (http://hlj.com/product/GAK05594) Hobby Link Japan has it now. Otherwise, keep an eye on Amazon, EBay amd Maker's Shed (http://www.makershed.com/SearchResults.asp?Search=gakken+camera)

mikhailah almalvez said...

Thank you for this very informational post. I've been wanting the blackbird fly camera for a while now, but because of the price, I'm still working on getting one. :) This will be an excellent gift for myself. Great pics by the way! Keep it up!

Juice said...

sorry asking a weird qn. how do we actually know if the film is loaded properly and how many photos have we taken??? ?_? totally don't know how to load the film in. thanks.

TSOTE said...

Juice, that's actually a good question. This is an extremely simple camera, so you end up having to be more careful with how you use it.

For loading the film, place the lead edge of the film into the slot on the take-up roller and turn the take-up crank enough to get the sprocket holes of the film to match up with the sprocket pins of the roller. Keep turning the crank a little more to ensure that the film won't unwind on you when you close the case (maybe 2 or 3 full wraps around the roller). Now, as you advance the film, you'll feel the tension in the crank - that's how you know it's advancing correctly. If you watch the counter dial as you turn the crank, each half-rotation is one frame, so when the notch on the inner dial goes to the next notch of the outer dial, you've advanced 1 frame correctly.

As for keeping track of how may shots you've taken, you just have to remember that yourself. To make this a little easier, when you first load the roll, advance the film all the way to the end, then count off the number of frames as you rewind back to the front of the roll using the rewind crank (ie - 24 or 27 frames depending on the roll). Record each picture in a memo pad, and remember to advance the film one frame before taking the next shot. You'll know when you've reached the end of the roll when it becomes much harder to turn the crank any further. When you're done, just rewind the film until the tension in the crank drops to nothing.

Tina said...

okay, so i bought the camera and i'm setting it up right now. I have a question: what do i do with the mirror? do i rip off the protective paper on both sides and attach the double sided tape to the side with the transparent paper? and then attach it to the piece shown?

TSOTE said...

Tina, thanks for dropping by. Essentially, the blue film is there to tell you which side of the mirror faces up, and it's also there to keep you from getting fingerprints on the mirror during the assembly. First, remove the clear plastic film from the one side of the mirror, put the double sided tape on that side of the mirror, and attach the mirror to the support plate as shown. Put the support plate in the camera case, also as shown. When the assembly is completely in place, use a piece of cellophane tape to help you peel off the blue film, and you're finished (with that part).

Tina said...

Thanks so much! I was a bit worried I would ruin it altogether.

Patricia said...

hi! :D first off, thanks a lot for this post; it helps us non-japanese reading people a lot in assembling the gakkenflex. :D

i have a question though: after loading the film, is it really necessary to advance the film to the end AND THEN rewind it back to shoot? or is it only done if you want to count the frames? (btw, i loaded a 36 exposure film) i haven't used film in a LONG time (and it's my first time to use a DIY cam. haha) so i have to refresh my memory :D


TSOTE said...

Patricia, glad to be of help.

"Is it necessary to advance the film first?" No. If you keep track of how many shots you've taken, you'll be fine either way. The reason for doing so is that when you put the film in the camera, a small amount of light does get inside the roll and semi-exposes the first couple of inches of film. So, when you take the first 1 or 2 shots, they won't come out that well. And, when you get to the end of the roll, there may be 1/2 of a frame at the end that goes to waste. Advancing to the end and then counting back reduces the effects of these two issues. Hope this makes sense.

Vix said...

bought this kit off the local Kinokuniya store, and it's pretty cool! Assembly took approximately 1.5hrs, probably because i was partially watching TV at the same time.. :)

About the film loading, let me confirm if what i understand is correct:

load the film into the camera; i have 2 options:

A. the normal method (load, snap, advance), or the
B. reverse method (load, advance, snap, rewind)

TSOTE said...

Hi Vix,

Actually, the idea for advancing the film first is that when you get to the end of the roll you then rewind, counting frames and when you get back to frame 1 you stop rewinding and then start taking your photos from that spot and advance normally. Theoretically, you could do your two approaches, but approach 2 is a bit inconvenient because the rewind lever isn't as easy to handle as the wind lever is.

Approach 1:load, snap, advance

Approach 2: load, advance to the end of the roll, rewind 24 or 36 frames (depending on the roll), snap and advance 1 frame.

If there's still some confusion I guess I could write up an illustrated description of what's going on.

Vix said...

ahh, so let me get this correct, the idea to advance first then rewind is not to over expose the first 1/2 frames?

so i should:

1. load the film
2. reset the "counter"
3. place the lead edge of film into take-up roller
4. turn the take-up crank to get the sprocket holes of film to match with sprocket pins of roller
5. close case
6. advance all the way to the end of the film
7. rewind back to start of film, counting off.
8. once back to start of film, just shoot normally, and crank up per shot.


TSOTE said...


Vix said...

thanks! i'll give it a go later today :)

Vix said...

hi, i brought my first roll of film for developing, and none, not one, of the 36 shots i've taken could be developed at all!

I just checked the negatives, nothing but a few blots and lines... nothing at all..

this is sad!

what could be wrong? the shutter?

TSOTE said...

Vix, it may be easier if you contact me directly in e-mail. The two things I can think of are a problem with the shutter not opening properly, and a mismatch between the film speed and the amount of ambient light in the shot. For the second case, what were you shooting, what's the film ASA and how much light had there been?

First, I'm assuming that you advanced the film properly between shots (rather than taking 24 shots on one frame and then having 23 unexposed frames sitting on the roll). If so, and the problem is with the shutter, then try this - open up the camera and make sure there's no film in it. Push the shutter button a few times so that you can verify that it's working. Hold the camera up close to your eye and push the shutter lever again while aiming at a bright light source. Hopefully you should see a quick flash of light as the shutter opens then closes. If you're not sure because there's too much light around you, put a dark sheet over your head and around the camera to block out as much ambient light as you can and try again. If it's obvious that the shutter's not letting in enough light, then partially disassemble the case so you can get to the spring mechanism and adjust the screw tightness until the shutter starts working properly. Also, make sure that you're pushing the lever all the way down to the end of it's movement so that the shutter really is being triggered.

TSOTE said...

Conversely, and I just had this thought, the camera door may not have been fully closed and the film got overexposed as it was being wound. Were they white blobs and lines on a field of black, or black lines and blobs on a field of white?

Vix said...

i'm using a roll of ASA 200, ambient lighting of various degrees as i tried both indoors and outdoors.

i'm pretty sure that the film advanced normally, as when i turn the knob, the counter turns with it.

the problem is most likely either the shutter or the unit not being sealed properly... problem is that i have another roll inside now, a ASA 400, somewhere middle of the film.

TSOTE said...

Ok. Depends on how much work you want to give yourself. 1) You can use tape or something to seal off the camera body in case there's a crack somewhere letting light in. After you finish the roll you can remove the tape and verify that the body is fully assembled right. This may mess up the appearance of the camera, of course, especially if it's the shutter that's a problem. 2) You can write off the remainder of the roll, wind it up right now and have it developed, then check the camera for problems. 3) You can write down the number of shots you've taken, almost completely rewind the roll, then open the camera and take the film out (it'll look like you're just about to shoot the roll, with the little leader of film still sticking out of the cartridge). Fix the camera, put the film back in, wind up the film to where you're leaving off now, and shoot the second half of the roll with the fixed camera.

But, before you start, I hope that you have the negatives from the first roll. Remember, with a negative, where there was something dark on the subject the film will be clear, and where the subject was lit the film will be dark. Look at the negatives and see if they're 90% black, or 90% clear. Because that'll give you a hint for what to look for. 90% black means the camera was leaking light. 90% clear means the shutter wasn't opening.

Vix said...

thanks for the tips!

the negatives looked "Clean", aka, clear, with occasional slight blobs and very faint shapes.

so i would guess it would be the shutter problem..?

TSOTE said...

Sounds like. If that's the case, then you're better off not wasting the rest of the current roll. Wind it up and try debugging the shutter. Maybe, the shutter's not opening for some reason (such as, one of the pivot screws is tightened down too tight).

For a better understanding of how film works, try checking out this site:

Specifically the understanding of the negative's appearance:

Vix said...

thanks for all your advice! i'll let you know the outcome when i debug it after work today.

this kit is making me appreciate more on the non-digital side of photography..

Vix said...

i checked the unit last night and the shutter seemed to work fine, it did open and close...

come to think of it, how do you define "not opening properly"?

when i put my eye up against the shutter, i could see a flash of the image when i triggered the mechanism.

i reviewed the video on the official website on how to assemble the shutter mechanism, and redid the shutter following the video.

there's no way i can verify that the shutter is fine, right?

sadly, i accidentally wound back that previous roll of film too much... can't reuse that roll now..

TSOTE said...

Vix - Well, "opening properly" on something this mechanically simple is a fairly vague statement. Basically that the moving pieces seem to be moving smoothly, aren't binding anywhere, and that there's no feeling that the lever or swing is being prevented from moving through its full motion path. That means that pivot screws aren't tightened down too much or not enough. If you watch the plastic lever pieces that cause the shutter to open and close, it should be obvious that the shutter is opening right or not

If you're seeing a flash of light through the shutter, and the lever mechanism is moving smoothly, then just double check the light path so that there's nothing blocking the light from the lens to the film. Verify that the lenses are in place right and are focusing correctly when you adjust them (maybe the shots were just too out of focus to be recognizable). Check that the box is completely sealed so that there's no light leaking in from the sides. Then try a new roll of film. Worst case scenario, your first roll had gone bad before you used it...

Vix said...

i just went to collect the 2nd roll of film (the one left inside while i processed my first and discovered that that batch cannot be processed at all), and half of them turned out ok... the indoor shots were too dark, outdoor shots were fine, and the few multiple exposure shots produced interesting results...

so the problem, it seemed, to be a problem with the film....?

TSOTE said...

It's rare for film to go bad, but I guess it can happen. Just keep notes of the kind of film you're using (brand, ASA) and the age, and see if you can figure out any future problems if/when they occur.

Glad that at least half the roll came out. Go back and look at those photos, compare the results of the shots to the amount of light available at the time, and the ASA rating of the film. As mentioned in the blog entry above, the ASA of the film relates to its appropriateness for indoor and outdoor shots. This does mean that if you have "slow" film in the camera, you're kind of prevented from taking indoor shots with the camera until the roll is used up (underexposed). Vice versa for fast film and outdoor shots (overexposed).

Happy shooting!

ming yi said...

hi there, i'm curious as to how i can create a vignette effect with this camera?

also, should the image that forms on the translucent plastic sheet be a mirror image?

TSOTE said...

Hi Ming, welcome and thanks for dropping by.

First, no, the image on the screen will not be a mirror image. Essentially this is because you're behind the mirror looking down at it, so the image is right-side up, unflipped from your point of view.

Second, vignetting is an automatic side-effect for this camera, because you're using a very cheap lens that doesn't have vignette correct designed into it. The real question should be "how can I prevent the vignette effect", which is almost impossible to do. If you really want the vignette effect to be obvious, make sure that you're shooting something with a wide angle view, and a very deep background. The farther away things are at the outer edges of the shot, the less focused they'll be. You can see this effect in some of the photos I have in this blog. Hope this helps.

阿蜜 said...

i've just assembled it and taken many photo shots. after develop the film, only i found out that the films are all empty, only 2 shots taken. im wondering is it the i screwed the shutter too tight therefore when i press down the shutter, it open and close very fast and it actually doesn't exposure any exposure onto the film?
not sure am i describe it correctly but hope all the expert here can help me :) million thanks.

TSOTE said...

阿蜜 - Three possibilities, the shutter is tightened down too tight and isn't opening properly (with the camera open aim it at a bright light and look through the shutter, push the lever and see if light comes through when the shutter opens); the shutter is too loose and isn't opening at all because the lever isn't connecting right (look at the parts and make sure they're moving right); lastly, you didn't advance the film between pictures.

aslah said...

Hey, randomly stumbled upon your post. I have a Gakken and love it to bits, despite the counter not working very well and I keep having problems with the shutter.

Having said all that, I do have a question. My shutter was working fine throughout the first roll. When I started on the second, the click wasn't as fast. I don't know how to explain this, sorta like a delayed reaction.

I did reassemble it, and it was working fine before I pieced everything together. Once done, I get the delayed click again. Any idea why?

Thanks in advance!

TSOTE said...

Hi aslah - I think the reason the shutter would be delayed is that the way the interlocking teeth portions line up on the levers causes them to not disengage until the main push lever is all the way down to the bottom of it's movement range. That is, the two little spring loaded pieces making up the shutter are either tightened down too much, or something is jamming them.

You say you reassembled the camera and the shutter was working before you put the camera together again. I'm assuming the problem exists when there's no film in the camera. That implies that something is rubbing up against the shutter pieces, or that they're otherwise binding against each other.

Is there any chance that the film cover door isn't closing right? If it's hard to close, it might be twisting the case enough to affect the shutter. Otherwise check the tightness of the screws holding the spring-driven pieces of the shutter mechanism. If they're too tight, that may cause the problem.

m rizal said...

I got this one, install it... but find out mine cant work... so sad.got no lass at two circle.

LeeN said...

hi.. got it too.. but i already made a big mistake while assemble it. the focus mirror is torn apart. any idea where/how to replace it.. its kinda hard to use without it..

TSOTE said...

The mirror is essentially just a piece of mylar-plated plastic. You should be able to find replacement material at a hobby shop, although you may have to cut it to size yourself. The same material is often used for making kaleidoscopes, so one option may be to ask a schoolteacher or someone who teaches crafts where they'd go to get kaleidoscope mirrors.

SuatHui said...

hihi~ i've just bought one and have some problems with the indicator of the advancement of film.

I've checked up some of the websites, and tried to follow;

1. put some paper (adding pressure) to the back
2. pressing it while advancing
3. loosen the screw

all of those couldn't really solve the problem. the indicator shows the advancement but not really exact advancement.

hope you understand what the problem i'm facing

TSOTE said...

Well, I'm not sure of the exact problem. The indicator dial should turn one revolution for one revolution of the wind-up lever, if you have a roll of film loaded in the camera. If the roll is loaded, then the indicator dial should turn as the film is pulled out of the roll. Make sure that the roll is being loaded correctly, and the tabs of the inside part of the indicator are fitting properly against the top of the film can.

If you still have problems, send me an e-mail directly.