Used Camera Database Blog

In The Scanning Problem Revisited, I outlined the basic construction of a do-it-yourself scanning project that would allow me to digitize my 35mm and medium format negatives.  This post describes the polished version of the idea: a combination light table / transparency scanning apparatus that gets my film photography into the computer for minimal cost.

Honestly, this project is really only applicable if you are incredibly strapped for cash.  A more permanent solution (and better quality) is to just buy a medium range flatbed scanner with a transparency attachment.  For instance, the Canon CanoScan 8800F, Epson Perfection V500, and HP Scanjet G4050 are all very capable film scanners for under $200 (my preference would be the Epson, FYI).  Granted, they are not suitable for scanning something you want to post in an exhibition, but for basic film scanning and printing at 8×10 or smaller, they are perfect.

And that is my goal for this project; to put off the purchase of a scanner for a little longer with minimal investment.  My basic requirements are to allow me to print shots at up to 8×10 resolution (approx 8MP), handling 35mm, medium format, and contact sheets.

The end result is simply a light table augmented with flash.  The light table lets me examine the negatives, and when I want to digitize something, I can just take a picture with my camera.  I’m quite happy with the end result and image quality!

Basic Construction:

The image above shows the basic idea of the project (as with all images, click to see it larger).  Materials are minimal if you already have a decent digital camera with an off-camera flash setup (Strobist is a great resource for that kind of stuff).  Of course, if you don’t have a camera and flash, it would be much cheaper to buy the camera!

Materials and Tools:

• Digital camera
• Macro lens
• Flash with off camera trigger (wireless is very useful)
• Sturdy cardboard box
• Plexiglass (I got an 8×10 sheet at my local hardware store for $2.75)
• Fluorescent bulb and mount with plug (I had one from Ikea that I removed the shade from — I believe I paid less than $6)
• Standard office paper
• Standard white school glue
• Scotch Tape
• Scissors, ruler, knife, etc.

Total out of pocket cost for me (since I had the camera equipment, tools, and lamp) was less than $3.

The entire device is enclosed in a large box (approximately 10″ L x 11″ W x 18″ H).  The flash (and fluorescent light) is at the bottom of the box, then there are two layers of diffusion material, and finally a clear viewing window is at the top of the box.  The camera is connected to the flash with a wireless trigger to allow high quality images with minimal blurring from camera shake.   The flash sits (unattached) on the bottom of the box, and a fluorescent light is mounted on the side of the box (not shown in the diagram or these first shots) to allow negative viewing and to aid the auto focus of the camera.

The box I chose was soymilk box from my local Costco — quite sturdy, and a perfect size and shape.  I cut off two of the top flaps and trimmed the other two to provide a sturdy place to mount the plexi. Then, I covered the inside of the box with white office paper — this was easily the most time consuming portion of the project since I ended up doing two layers over pretty much the entire inside surface.  It took me a couple of hours of work (while watching a movie).

Once the paper dried overnight, I taped two layers of office paper across the inside the box for diffusion.  The lower layer is about 7 inches from the bottom of the box while the top layer is about an inch from the top (although I honestly should have put it about an inch lower — more on that later).  The result is nice even diffusion of light when the flash is centered in the bottom of the box:

Admittedly, the continuous light source was an afterthought, but a very good one.  At first, I thought about just laying the bare light bulb in the bottom of the box, but quickly decided against it because even fluorescent lights get pretty hot.  Please don’t burn down your house with this project!

So, instead, I cut a hold in the side that was off-center, towards the top of the lower cavity.  This location is designed to avoid blocking the flash and to put more direct light on the first diffuser to make sure enough light reaches the top of the lightbox.

The light itself was very easy to mount since it comes with a plastic screw-on flange (this part normally screws onto the plastic shade).  Here is the inside view:

I chose a 11W fluorescent (60W equivalent) for my box, but I think you can easily bump up the power to a 100W equivalent using this mounting scheme without danger of fire.  Incandescent bulbs might produce a more pleasing white balance, but be careful because they generate a lot more heat and the box is very flammable!

Usage and Results:

So, how does it work?

Surprisingly well!  The two diffusion surfaces provide nice, even light across the entire viewing area.  In hindsight, I probably should have gotten a bigger box so that it’d be possible to do a full proof-sheet (approx 8×10) in one shot.  But it is not a big deal to just shoot each sheet of negatives twice — once for each side (three by two 6×6 medium format negatives).  Here is a proof sheet where I squeezed in three by three frames with minimal editing:

A 60W bulb provides plenty of illumination as for continuous viewing as long as the room is relatively dark.  In brighter rooms or outside you might like a brighter light.  Considering the light has to pass through two sheets of paper, it is quite good.  The paper itself though does not provide a completely uniform diffusion surface.  For instance, in the full frame shot below, you can see the mottling and texture in the paper:

The general design (placing the top diffusion sheet an inch below the film surface) is designed to place this mottling outside of the depth of field.  But, for large area shots (i.e. proof sheets) and medium apertures (f/8 to f/16) an inch away does not eliminate all the texture.  If I had to do it again, I’d place the top sheet two inches down to give me a little more leeway.  For now, I’ll just keep this in mind and try to use a lower flash power and larger aperture (to reduce depth of field).

Speaking of depth of field and flash power, I was actually very surprised by efficiency of the flash in this setup and the evenness of the illumination.  Yes, near the edges it loses a tiny bit of intensity (see the above image), but the center of the shot is quite uniform, especially over a single medium format frame.  And most of these shots were taken at 1/8th power on my Sunpak 383 with ISO 100 and f/16!  Yes, f/16!  So, in the future, I’ll probably drop proof sheets to f/11 and 1/16th power to reduce the mottling artifacts, but keep using 1/8th power and the smaller aperture for single frames to decrease issues with film flatness.

All my proof-sheet shots were taken with my Tamron 17-50mm f/2.8 and the single frames were taken with an antique Canon 100mm f/4 Macro (with FD-EOS adapter).

Processing:

Scanning negatives in this way puts a lot of the load onto processing, which tends to be a bit finicky.  Yet, at the same time, it is rather forgiving.

The basic idea is simple: take the shot keeping everything in the histogram, invert the image, then adjust the shadows, highlights, and contrast accordingly.

The finicky aspect comes in when thinking in terms of the dynamic range of the input image.  Based on how your negatives are exposed, I think you’ll find that 24-bit color (8 bits per channel) from JPEGs will not give you enough flexibility to adjust the exposure to your liking.  Shooting RAW (12 bits per channel) is pretty much a must.  In some shots, I found I needed to expand a very narrow range (sometimes an eighth of the available intensity range) and in other shots I found that I had to adjust the exposure a stop or more.  While you can fine tune that as you take the picture, I think it would be hard to really nail it consistently without using RAW.

For processing, I use Bibble Pro.  Of course, Bibble does not have a dedicated ‘invert’ option — I think most RAW processor programs don’t support negative inversion.  But, Bibble Pro 4.10 does have “Andy”, a black and white simulation with multiple types of film, paper, and the all important ‘See Neg’ button that lets you invert the image.  While I could do the same thing with Paintshop Pro or Photoshop, I find it a lot easier (and faster) to process the images in Bibble without dragging around huge TIFF files.

Also, I DO NOT recommend using this type of scanner for color negatives.  Sure, go ahead and try it, but office paper produces a bit of a blue color cast and I expect it will be very difficult to get color correct from a film negative.  Honestly, I’ll probably try it at some point, but I expect it will result in some very strange color images!

For black and white though, there are a ton of settings — everything from intensity curves in Bibble to the BW conversion options to exposure on my digital camera to exposure on the film camera to the film developing!  Luckily, you can usually compensate digitally from a RAW image and tune it to look like you want it.  For example:

I’m pretty happy with the scanner and the images that result, and I’m going to get started making digital proof sheets and scanning specific images I like over the next few days.

And, of course, shoot and develop more images!

This is the final post in a series of four related to cleaning my used Yashica Mat 124.  The first post in the series describes the task in more detail and includes links to all of the other posts.

A common complaint with used Yashica Mat 124 / 124G cameras is that that meter is inoperative.  On my camera, the eBay auction stated that the meter no longer worked, but I suspect the seller never even bothered to try a new battery in it.  So, it is often worth asking if they’ve tried the meter with a good battery before you determine that it no longer works.

The problem is that the 124 and 124G are designed to run off a mercury 625 cell (generating a nominal 1.4 volts) that has been banned due to mercury content.  As a result, it is very hard to find 625 batteries for these cameras, and even if you can find one, can you really deal with the guilt of putting poison into the environment?  The replacement 625, if you can even find one, is typically alkaline with a nominal (and unstable) voltage of 1.5 volts, which causes the 124 metering to read incorrectly (too high, I believe, causing under-exposed photos).

The best replacement (chemically) is a zinc-air battery, but zinc-air batteries are not commonly sold in the 625 size.  A readily available alternative is the zinc air 675 battery, that produces the needed 1.4 Volts stably across its life cycle but does not fit in the Yashicamat 124(g) straight out of the box.  The image below depicts this physical difference:

625 mercury battery (left) and 675 zinc-air battery (right)

As you can see, the 625 has a much larger diameter and slightly more height.  There are a variety of strategies to get the 675 zinc-air batteries into older cameras – this great page at KYPhoto describes many of the ways.  Probably the easiest are Wein cells — newer zinc-air batteries with the right size specification.  But, Wein cells tend to be harder to find and more expensive than similar batteries because they are a specialty commodity.

The approach I’ve taken is to adapt a 675 battery to fit the space of a 625 battery — Rick Oleson has a good page on this which is similar to my approach.  The basic idea is to increase the diameter of the battery (by placing a spacer in the battery holder) and increase the height slightly since the 625 is usually held by the lip around the outside (not the positive terminal face) but the 675 does not have the lip.  In the image above, you can see the battery holder on the 124 (which includes a metal screw-in top).  But, where Rick Oleson uses wire, I use one of these and some aluminum foil:

Your local hardware store has a wide variety of faucet O-rings that work great for the spacer with the bonus of well-calibrated size and non-conductivity.  I used a 7/16″ I.D. and 5/8″ O.D. ring and it cost me less than $1 for two of them.

Battery-wise, I spent $6 at my local Fry’s Electronics for a pack of 6 Energizer 675 zinc-air batteries:

The image that started this post shows the materials used.  Just insert the o-ring into the hole in the camera (it will fit snugly), place the battery on top of the foil on the cap, and screw the cap back in.  I found it best to hold the cap up with the camera battery holder upside down keep stuff from falling apart.  The battery goes in snugly and securely and automatically centers itself.

And, the end result is a working match-needle meter:

Note the red needle, driven by the battery and sensor, that you need to line up with the yellowish-green ‘hook’.  Easy, costs less than a buck for the parts and a buck a battery, and works pretty well!

Update:  Well, I spoke a little too soon on things working well.  My meter has been malfunctioning and reading low.  Sometimes, when I open the hood up it does not turn on, and sometimes even when it does work it twitches all over the place.  I need to look into it more, but it is likely either the battery contact (which is somewhat corroded — I originally sandpapered it, but I don’t think it took) or, more likely, the switch in the hood is flaky.  I’ll open it up in the near future and see what I can do.  The camera is so much easier to use when the meter is operable, even if the meter is a little imprecise!

Update #2: (10/25/09) The foil ended up being less than reliable, since it tends to compress over time and it may cover the air holes of the battery (causing inconsistent metering).  Instead, I found a twisted spiral of copper wire (22 AWG) does a good job of spacing the battery without restricting airflow:

This is the third post in a series of four related to cleaning my used Yashica Mat 124.  The first post in the series describes the task in more detail and includes links to all of the other posts.

NOTE: I haven’t had a lot of success with this fix, but I can’t tell if it is the felt or something else.  More at the bottom of this post.

As mention earlier, my Yashica Mat 124 had some issues when I got it, specifically a decent-size light leak.  So, an important part of my cleaning task was to replace the old crumbly seals in the door.

The Yashicamat 124 uses a combination of black foam and black yarn in the light seal on the main door.  The foam fills in the larger areas at the top and bottom of the door while the yarn seals the narrow slot along each side.  In the shot below you can make out the yarn covering the sides (like all of the images, click to see it larger).

After almost 40 years, these seals tend to break down, causing areas of bright spots in images.  Luckily, fixing them is not a huge ordeal!  All you need is a little patience and a willingness to do work on your camera.

(Note: Yashicamat 124G seals are completely made from foam, even along the sides.  I have heard that they are more fragile, but that may be compensated for by the fact the cameras are not as old.)

For my light seal replacement, I used a variety of sources on the web.  The primary source of my techniques was Matt Denton’s page about replacing light seals.  It has great details about how to remove them, replace them, and what materials to use.  Of course, it uses a Yashica Electro 35 as an example and does not cover the 124, but it is close enough for me.   Also, on Matt’s Repair Tips page, he mentions materials for the light seals, including “Lily Sugar n’ Cream black cotton crochet yarn, product #CA00111″, and black Presto-felt (what I ended up using).  Another good source is David Richert’s Yashica 124 Rebuild Page, which includes some details about replacing the light seals with new foam.

As I mentioned, for my light seal replacement I only used black “Prestofelt” from Walmart — under $1 per sheet!  And to fix a single camera you only really need a fraction of a sheet.  It has a very gooey adhesive on it which definitely keeps it in the camera, but can be a bit of a pain to work with because it sticks to just about anything and leaves residue.  Just cut it, remove the backing, and stick it where you need it (I found it helpful to push it into place with a small screwdriver).  Just be careful not to get it on anything important (like the film plate!) and if you do, carefully clean it all off!

Of course, the first step is cleaning out the old seals.  For this, I used a toothpick.  The old foam seals pretty much disintegrated into black dust, while the yarn came out easily and cleanly.

While I was removing the old seals, I wrapped the camera body in standard household plastic wrap to keep any little black bits out of the film chamber.  I can only imagine how yucky that could get!

The adhesive that holds the foam in at the top and bottom of the door was very tricky to remove so I finally just gave up on it.  I figured it wouldn’t cause a big problem since the felt goes on top.  Once I had the old seals out, I just cut the felt to size and stuck it in:

Note that thin strips of felt can stretch if needed, making it easier to fit them into the grooves.  Here is the finished portion near the top of the door:

Anyway, that is it for now.  I’ll post the final page of this series in a few days, describing my solution for the now discontinued mercury batteries for the 124…

Update: Sadly, the new felt light seals really didn’t take.  I still had light leaks on my second (and third) test rolls, but I have to wonder if my leaks are somewhere other than the door seals since I sealed all around the doors with electrical tape yet I still had the light leak.  I’ll post examples in a bit.  I’ve also got a light seal kit from Jon Goodman, a very well-regarded seal maker, (see interslice’s items) on order that may help.  I’ll post and update once I have results (be they good or bad).