How I 3D printed a ground glass back for use with my Lomography 4×5 Instant Back

In one of my recent videos I share how I shot with the 4×5 instant back (Lomograflok ) from Lomography. In that video I shot with my Chamonix 4×5 camera and I mentioned that we need to use a spacer every time we compose a shot.

That is to take into account of the different film plane on this back. The Instax Wide film plane is further away by 19.4mm from the usual sheet film plane. Another point I mentioned is that if I were to mount this back on the camera, I would need to remove the ground glass frame. The Chamonix ground glass frame is easy to put back ( one hand to slide the frame in)but difficult to remove ( you need 2 hands to lift out the 2 spring arms) and that is kind of troublesome if you have to do that for every shot.

So I decided to 3D printed a ground glass frame that already has the spacer built in and it’s also much easier to remove and put back. The new ground glass frame that I 3D printed is very similar in size to the spacer that came with the back. The only difference is the height which is about four mm higher to take into into account where the ground glass should be. The other thing I added was the grooves along the long sides so that it can be locked down. In contrast, there is no groove on the original spacer because will be held in place when you insert it into the groundglass frame

3D Design in Fusion 360

The 3D design is done in Fusion 360, nothing too complicated as the shape is quite regular. It is a matter of measuring the original spacer and transferring the measurements into the design. One of the thing is I nearly missed out are the 2 raised bars on the right side of the frame. These are used to align the entire frame on the camera back to prevent it from being inserted too much or too little.

I 3D printed it using my Anycubic Mega S printer with the following specs (for reference):

Layer : 0.3mm
Infill density : 20%
Extruder temp : 230C
Support : Everywhere
Time Taken : 5hrs

Printing on my AnyCubic Mega S 3D printer

The STL files can be downloaded here ( DO note this is a Work in Progress project)

Ground Glass

Acrylic ground glass

Instead of making my own ground glass, I opted for a piece of 3mm acrylic that is frosted on one side. I have a piece lying around from my Afghan Box cameras build so I decided to use it. There are also four corners that I used to hold the ground glass in place. The 2 bottom pieces are glued to the main body using superglue while the other 2 are secured with screws. This will make it easier to swap ground glass in the future by unscrewing the top 2 pieces.

Test shoot

So what was left is to do a test shoot to make sure the ground glass image plane is the same as the Instax Wide back film plane. I chose a still life setup and focused on the label on the orange. The results shown the there is no shift in focus switching from ground glass to instant back.

Resultss


Improvements

The radial locks to catch the groove are not well aligned. Although the 3D frame is still held in place, it is something to look into.

Conclusion

While the 3D printed back is not perfect, it certainly make using the instant back easily with my Chamonix camera. Other 4×5 cameras may not require this if the back can be slotted under the ground glass.

DIY Photo Enlarger from an Afghan Box Camera

In my previous post, I shared how I converted my Afghan Box Camera into a slide projector. The principle of the slide projector involves putting a light source at the back whose light passes through some condenser lens. The light then goes through the slide and finally pass the projector lens and be projected big on the the projector screen.

Typical enlarger design Used under CC license

I thought that would be about the same principle as a photo enlarger in the dark room. In the enlarger we have also the light pass through some condenser lens (depending on the design) and it will pass through the negative, go through the lens and it will be projected big on the photo paper so I thought maybe I would try to use my Afghan Box Camera again to convert it into photo enlarger  in this case it will be horizontal enlarger where I will project the image horizontally onto the wall surface.

Negative Carrier

Negative Carrier

I decided to use my photo paper holder inside the Afghan Box Camera for this conversion. I taped up a 6x7cm window using some black PVC tape. If this is to be a more permanent setup, I would make a proper negative carrier for now. For now, this will do and I used some small pieces of masking tape to secure the 6×7 negative flat against the glass. To focus I would move the focusing rods per the usual way when using the Afghan Box Camera which move the negative towards or away from the lens.

Light Source

Unlike a light source for a slide projector, the enlargement is smaller so light source for this enlarger can be relatively less powerful. So I use a simple 11W warm color LED bulb. As I do not have a timer, I simply use the on/off switch for the bulb during printing to control the exposure time.

Lens

I do not have a dedicated enlarger lens so I use my trusty Fujinon 210mm lens as the enlarging lens. For a safe filter, I dug out an old Cokin red filter and a Cokin filter holder. I would just slip the filter and holder over the lens if I need to block the light from reaching the photo paper.

Paper


Arista Edu 5×7 inches Resin Coated paper

I use the Arista Edu 5×7 inches Resin Coated paper. Being a variable contrast paper, I could use the Ilford Multigrade Contrast filters to control the contrast of the print. Again, this is done simply by taping the filter on the rear element of the lens during printing.

Results

The results shown that the box camera can be easily turned into a photo enlarger by making a few changes to it

  • Add in a light source
  • Replace/convert the photo paper holder with/into a negative holder
  • Add in safelight filter and contrast filter

Improvements

Nevertheless,  a few improvements can be made

  • Better way of holding the paper on the wall instead of just using masking tape.
  • Some method to confirm the squareness of the enlarger to the photo paper
  • Better way to hold the safe filter and contrast filters

Conclusion

Vintage Solar based Horizontal Enlarger

Horizontal enlargers have been around for a long while and box camera users can consider turning their box camera int0 an photo enlarger if they need a quick print from a negative.

How to Get Large Format Film Look with a Mobile Phone Camera

Remember my previous post where I turned my Afghan Box Camera into a 4×5 slide projector? Today I have another idea around the Afghan Box Camera – that is to make use of my humble mobile phone camera to create a large format look by making use of the box camera and its lens.

This is much inspired by other fellow photographers who have designed similar stuff such as this by
Olexiy Shportun and another by Tim Hamilton. The main idea behind this is to make use of a digital camera to take a photo of the projected image made by the large format lens.

Design

In my design, I decided to make use of a mobile phone camera rather than a DSLR or mirrorless camera. However how would I control the mobile phone camera if the phone is placed inside the box? Luckily there are various apps that will help us.

Remote Control

IP Webcam app

For my Android phone, I decided to go for the IP Webcam app for its versatile. It is free, can be used via Wi-Fi and easy to use. Hence by using this app, the mobile phone camera can be controlled and hence trigger off remotely.

After some testing, I realised that the phone camera cannot be too near the ground glass otherwise the phone camera will produce an image with a hot spot. The best position I found is to place the phone all the way to the back of the box camera. The ground glass image will only occupied about half of the camera phone photo framesize. This can be easily overcome via zooming in via the control interface or cropping during post processing.

Webcam Control Interface

The IP Webcam control interface is easy to use, I usually play with the following settings

  1. Zoom – to zoom on the ground glass image as mentioned above
  2. Exposure compensation – this settings can be adjusted from -12 to 12 steps (not sure how 1 step is equivalent to a photographic stop)
  3. Effects – like any phone digital camera filter , you can set it to Black & white, sepia , negative. My favorite is black & white simply to minic the usually monochrome photo we take with black & white photographic paper.
  4. White balance – for shooting in color, Daylight settings seems to boost up the colors saturation quite a bit.

Some Sample Photos

In conclusion, this method of hybrid shooting has potential to be explored further. My best use of such way of shooting was in an educational workshop during this pandemic time where safe distancing is encouraged so to be able to show what is happening on the ground glass remotely is particular useful.

Making a 4 x 5 slide projector

My build video on Youtube
4x5 slides on a light table

4×5 slides on a light table

I have been shooting 4 x 5 color transparencies or commonly known as color slide film for many years but the best that I could enjoy them was to put  them on the light table and  viewing them  through a loupe. Unlike my 35mm and 120 slides, I have never seen them projected big simply it is not easy to locate a 4×5 slide projector.

For the last few years, I tried searching online on how to do it yourself (DIY) and build a 4x 5 slide projector  but no one seems to have make them before.   There are commercially  produced 4×5 slide projectors although I never seen one in real life. I have not even seen them on the used market on eBay before but even if they are available they are going to cost a lot and even more to ship.

 It was only recently that I saw this YouTube video by DIY Perks on how he made a 4K LCD projector that triggered me to think about making a 4×5 projector again.  in this video he explained how he made use of the Fresnel lens instead of the conventional thick condenser lens.

Afghan Box Camera

With this new knowledge, I started to think how I can convert my Afghan box camera into a slide projector. For those who do not know the Afghan box camera, it is a camera and darkroom built into a single box. If you need more info on how to build one you can refer to this amazing ebook by Lucas Birke on his Afghan box camera project .

Light source

Philips 12B LED light bulb

Philips 12B LED light bulb

The most important part of the side projector is a powerful light source. The conventional projector will use powerful  but hot incandescent or halogen light bulb. However for this project I went to the store and find the highest wattage LED Bulb.  This turned out to be a 12 watts LED light bulb from Philips. It is also warm light which is what slides are usually projected with. It was said the slides usually come with a blue tint to balance out the warm light.

I wired with up with a socket (WARNING : live wire is involved. DO NOT do this yourself if you are not confident or trained. ) and attached it to the back of the box camera using 2 screws.

Fresnel lens

Fresnel lens sold as magnifying sheets

I went online and bought 2  magnifying reading  sheets  that are usually use for reading but I guess they would work for this purpose. On every sheet there will be one side that is make up of the Fresnel lens which is a series of concentric circles and the other side will be smooth so it is important the place that sheets in the right orientation.  The one nearest to the light bulb have the Fresnel lens facing away from it and the other piece will have the concentric circles facing the bulb. In this manner, the light from the bulb will be collimated By the first piece and converged by the second piece.

It is also important to find out the true focal length of the Fresnel lens. TheDIY perks video shows you how. My 2 lenses have focal length of 90mm.

Fresnel lens separated by a narrow strip of plywood
Fresnel lens separated by a narrow strip of plywood

To mount  the lenses I just got two pieces of plywood with a window cut in the center and I  3D printed some corners to mount the lenses to the plywood. To attach the 2 Fresnel lens plywood in the Box camera I just   use 2 narrow strips of plywood and 2 elastic bands to act as a spacer between the 2 boards. The idea here is  to be able to convert this back to a box camera instead of turning it permanently into a slide projector.

Lenses


Fujinon 210mm lens

For lens I continue to use my Fujinon 210mm lens which is my
large format photography shooting lens . I find that it still do a decent job in projecting the image however I’m not sure sure if there is a difference in projection quality if I were to use a enlarger lens or projector lens.

Focusing

In order to focus the image on the screen I use the focusing rods that is already part of the box camera system. This box camera is designed to take 5×7 inches photo negative so I removed the existing ground glass and made a 4×5 slide mount to hold it to the holder and to block off excess light .

Testing

For testing I set up a piece of 5feet white fabric backdrop mounted across two light stands and was placed see about 3 meter from the slide projector in the darken room with all the lights off. Hooya! I was able to get a good image on the screen! I was certainly very impressed and I to be able to see my large format slides on such a big screen finally !

Conclusion

While this slide projector is not bright enough to be used in an auditorium, it is good enough for personal viewing of 4×5 slides at home. You will need a very dim room to enjoy the slides at a view distance of 3 metres. There are certainly room for improvements but that will be for another DIY made.

Building a ULF 16×20 camera with a massive aerial lens and cardboard

A few years ago I built a ultra large format camera that is 24 inches by 24 inches. While it was a pretty huge camera, it was a simple build it was just two square standards, one for the front and one from the back which were connected by a big bellow.

There was no support base or focusing rails and I just support the two standards by using two tripoda so it was not the most stable camera. After a while I dismantled the whole setup and recycled the wood and the bellows so I thought that would be the end of my Ultra Large Format (ULF) camera building adventures but who knows a while back, my friend passed me a big lens and it got me thinking of rebuilding a ultra large format camera again.

Lens

The lens compared to a Nikon film SLR

The story was that my friend came across a camera collector near a local market during one of his walks and spotted this big lens. Money changed hands and he bought over the lens.

After some research, I discovered that it is a aerial lens. It was used in aerial camera mounted on aircraft for surveillance photos probably during World War 2 or later. The lens weighs eight kilograms and the focal length is 36 inches and has the biggest aperture at f6.3. However no brand or maker’s mark can be found on it. it may be one of the few lenses that were made by different companies during the war.

As the lens is so heavy so I built a wooden lens support for it. It is made with a few pieces of wood and cut some curves that will fit the front part of the lens. I also designed it so that there are two height adjustments as my camera design will be of a rectangular shape and there may be a need to mount the camera at different heights for landscape and portrait orientation.

Watch the video about the lens here :

Camera

As I do not have the space for for a ULF camera I decided to just make one from corrugated cardboard boxes. I opted for a sliding camera design but with a twist in the back design. It has 2 sleeves holes cut out at the sides so that I can put my hands inside to load the paper. The “dark slide” would be at the back of the camera covering up the ground glass when I need to load the photo paper and doing exposure. With no removable film holder, I would load the paper would by sticking it on the ground glass using magnets. I am not sure is this considered innovative but I must say I never come across similar design in other cameras.

Watch the video about the camera building here :

Shutter

Flap Shutter

While the camera has a working aperture, there is no shutter control for it. Initially I built a simple cardboard lens cap for it and use it to control the exposure. That is a ‘remove and place back’ the lens cap for exposure. This is a common method to control exposure in barrel lenses. However this method will not work if I were to take my own self portrait.

As the lens is so big (diameter ), it is hard to find a commercial shutter like the common Packard shutter for it . Again I built a flap shutter for it. The I just use rubber bands (or elastic bands for longer lasting elasticity) . I tied a long string to it so to open the shutter just pull the string to pull down the flap. When the string is released, the flap will be pull back by the elastic bands.

Watch the video about the shutter building here :

Conclusion

Overall this is a successful prototype build that help me to test

  1. the lens itself
  2. the camera design

Hopefully I will have the resources to build a more permanent ULF camera in the future.

Film Photography : Black and White Paper Reversal

This post is about black-and-white reversal  for paper. We are going to use this  expired 5×7 Ilford photo paper . We will need to trim it down for use inside this 4×5 film holder in the darkroom . 

We will use a Chamonix 4×5 large format camera to take the shot.

Youtube video

Exposure :

For shooting photo paper as a positive, we need to add 2-3 stops to what the meter is reading.

The light meter is giving a f5.6 aperture and the shutter speed now is 0.6 second . For photo paper if we are using it as a positive  we probably need to overexpose it by  2-3 stops

Chemicals

First Developer : the Ilford multigrade developer  (1+9)
Bleach : Part A – 1 g of potassium  permanganate and add up to 250 ml water 
Part B – 13.5g of sodium  bisulfate and add up to 250  ml of water. 
This will mix up to

Only mix the 2 parts to form the bleach when we are ready to use as this potassium permanganate based bleach does not keep well. Remember we always ADD ACID to Water so Always add the part B (which is a diluted sulphuric acid) to part A.

Second Developer : Reuse the Ilford multigrade developer used in first Developer
Fixer : Ilford Rapid Fixer

Processing steps
Based on Ilford Multigrade RC paper

  1. Process for 1 minute
  2. Wash for 1 minute
  3. Bleach for 5 minutes
  4. Wash for a minute
  5. Expose for maybe 30 seconds under a normal light or natural light
  6. Fix for a minutes
  7. Final wash for a minute

Sources for materials

1. Ilford Multigrade RC paper – https://amzn.to/3dOII33
2. Ilford Multigrade Paper Developer – https://amzn.to/365Oivt
3. Potassium Permanganate – https://amzn.to/2TcVIYF or if you are in Singapore, you can get them from pharmacies like Watson, Guardian , Unity 4. Sodim Bisulfate (PH Reducer) – something like this can be used https://amzn.to/2WACBK9 or source out at your local swimming pool maintenance companies
5. Ilford Rapid Fixer – https://amzn.to/2WACBK9 or source out at your local swimming pool maintenance companies

8×10 Large format shooting

 

Eastman no 8x10 camera

My Eastman no 8×10 camera

There is a rekindled interest in 8×10 photography after a few NEW sub-$1k 8×10 cameras appeared in the scene. The most notably would be the Intrepid 8×10. As of this writing, it has far exceeded its lowly set target  £18,000 goal with 255 backers. That would means there is going to be at least 220(less those who backed for non camera reward) 8×10 cameras out there. I guess that there maybe  150 new 8×10 cameras users while the rest are existing 8×10 users who are just buying another lighter and cheaper camera.

What does this means? This means there will be an increased demand for

  1. 8×10 lenses
  2. 8×10 film
  3. tripods and tripod heads
  4. processing equipment such as paper drums and tanks

Here i share my own experience in shooting in the 8×10 format.

8×10 lenses

The most important factor to look out for when looking for a 8×10 lens is the image circle. The minimum image circle to cover the 8×10 format is 12.8inches / 325mm (the diagonal of the film size). Ideally you should have a lens that has an image circle greater than 325mm if you intend to use movements which you normally would. After all, camera movement is a unique feature of a view camera.  Next up for consideration is the focal length of the lens. A 300mm lens will be about the standard lens for the 8×10.  A 210mm lens will be considered wide on the 8×10 lens. To get its estimated equivalent focal length in 35mm terms, simply divide the focal length by 8.

While there are vintage lenses or barrel lenses out there in the used market, I would suggest getting one with a modern Copal shutter for a start. There are some good old lenses with old shutters but most of these shutters are at least 50-60 years old and  many shutter mechanism in thet are worn out. Even the well know camera machinist shop , SK Grimes does not take in any more vintage shutters for repairs or CLA.  Whereas a good Copal shutter will last you many more years to come and still serviceable.

You will be glad to know that with a big negative like 8×10, you will need less demanding performance from the lens so 8×10 lens are relatively cheaper compared to a high performance 35mm lens. After all, for the same scene, the 8×10 lens would need to resolve less lines per mm. I use the Schneider G-Claron 355mm lens with a Copal 3 shutter.  The image circle of this lens is 444mm at f22 allowing quite a bit of movements on the 8×10.  I also have a cheap Seneca 305mm f7 lens which is using a old Betax No 4 shutter.

There are other ways to work with vintage or barrel lens such as using a Packard shutter or shooting with low ISO paper negative or wetplate. However if you are new to 8×10 or just shooting 8×10 film, go for a lens with a Copal shutter first. Other lens experiments can come later!

8×10 film

If we are talking about panchromatic silver gelatin film, you only have a few choices from these 3 manufacturers  Ilford,  FOMA and Shanghai.

FOMA Fomapan 8x10 fim

FOMA Fomapan 8×10 fim

I have been using FOMA 8×10 film for the past 6 months and have been happy with it. It is a good balance between price and performance. I have also used Shanghai 8×10 before but their supply has been a bit erratic after they shifted their factory but I see that they are back on the market again. For me, I will stick to FOMA film for now. Ilford 8×10 film is about double the price of a FOMA sheet so I have not used any Ilford 8×10 film before.

Another cheaper alternative is 8×10 Xray film such as those produced by Fuji. However it is an orthochromatic film ie it is not sensitive to red light and  is also of high contrast.  Most of the Xray film are coated on both sides and making it susceptible to scratches when wet. I have tried a box and must say they are quite cheap to use and very suitable for alternative printing where a high contrast negative is desirable.

Tripod & tripod head

First thing is to ditch your ball head no matter how big and strong it is. A 8×10 camera with its lens is a big camera and you do not want to the whole camera to drop off when you loosen the ball. Go for a 3 axis panning head such as the Manfrotto Junior 410 head or even better the Manfrotto 3263 deluxe geared head. Match it with a set of strong  tripod legs. Those who do not have a big budget can also look for the 2 axis Majestic tripod head. These heads are old, big and heavy and do not command a premium price on the used market, at least for now.

Do not be mislead into believing a lighter 8×10 camera means a smaller and lighter tripod. If you extend the bellows of the camera, it would turn into a sail or kite catching wind and before you know it, the whole camera and tripod will topple over.

Paper equipment such as paper drums and tanks

Last but not least would the film processing equipment, we have a few options for film processing

  1. Trays processing – just processing the film in trays in total darkness. This kind of setup would cost the less assuming you already have a darkroom or lightproof area. Just buy 3 12×16 trays and you would be good to go.
  2. Another kind of tray processing is using the Paterson Orbital processor where you will be processing one sheet at a time. It is a daylight tank where you load in the sheet in total darkness and then carry on the processing in daylight. These are hard to come by and are usually available as used in the UK ebay. Their prices have been increasing and will continue to do so.
  3. Rotating tanks like using Jobo paper drums or Expert drums.  The paper drums are cheaper as they are designed for paper development but can be easily used for film development.  You can either roll the drum by hand or build a rotary film development system

Overall any rotary system will use less chemicals than a stationary with inversion) system. I use about 250ml of chemicals for sheet for the Paterson Orbital processor and the Jobo paper drum system.

Lastly welcome to the big world of 8×10 photography.

A Protective case for my 8×20 camera

My Korona 8×20 camera is heavy but it is still possible to hand carry it by the leather handle for short walking distance. Carrying it bare will expose it to scratches and knocks as it is easy to bump this big camera into walls and such.

So I went to buy a $5 foam camping mat, some Velcro straps with tape and went off to work on a DIY protective case. As seen in the video, I have the map trimmed to the required size including the corners  and then add in the Velcro straps at the places where the different ends meet.  The Velcro straps came with tape where I  simply taped it to the foam. It may not last so I have sew a few of them in place instead. The foam is not to the best material to sew but I will monitor and see how well they stand up to the frequent opening and closing.

While this is for a ULF camera, it can be easily modified for a smaller camera.

 

 

Arduino Code for the Rotary Film Processor

In my previous post about the DIY Rotary Film Processor that I use to process my 8×20 film for my 8×20 camera, I did not go into details about the Arduino code that controls the rotation and timings. This post will explain more about the Arduino portion.

Hardware

I use 3 pieces of boards for the project :

    1. Arduino UNO

      Arduino UNO board

      Arduino UNO board

       

       

    2. An motor shield

Motor Shield

Motor Shield

    1. An LCD shield

LCD Shield

LCD Shield

 

I am not a programmer so what I did was to piece the different sample codes for the different shields in order to achieve what I need.

This is a Rotary Film Processing controller . It simply rotates a motor for 4.5 seconds in one direction before rotating back in the reverse direction for another 4.5 seconds and stop for a sec. This is considered as one cycle. Therefore 6 cycles of it will constitute 1 min.

When it is powers on, you will need to press a button (connect to the RIGHT button of the LCD shield) to start the development process. When the first step (ed Prewash for 3 mins) is completed , the buzzer will sound off and you will need to press the same button to continue to the next cycle (of course after pouring out the first and in the next chemical)

Currently, it is coded for my FOMA 200 developing needs. You will probably need to modify the code to your needs.

/* Rotary  Film Processing  
 * ------------------ 
 * This is a Rotary Film Processing controller . It simply rotates a motor for 4.5 seconds in one direction before rotating back in the reverse direction for another 4.5 seconds and stop for a sec
 * . This is considered as one cycle. Therefore 6 cycles of it will constitute 1 min.
 
 // include the library code:
#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

// define some values used by the panel and buttons
int lcd_key     = 0;
int adc_key_in  = 0;
#define btnRIGHT  0
#define btnUP     1
#define btnDOWN   2
#define btnLEFT   3
#define btnSELECT 4
#define btnNONE   5

int buttonPin=2;
int buttonState=0;
int buttonCount=0;
int EN1 = 6;  
int EN2 = 5;  //Roboduino Motor shield uses Pin 9
int IN1 = 7;
int IN2 = 4; //Latest version use pin 4 instead of pin 8
int BUZZ=3;

void Motor2(int pwm, boolean reverse)
        {
          analogWrite(EN1,pwm); //set pwm control, 0 for stop, and 255 for maximum speed
         if(reverse)
         { 
          digitalWrite(IN1,HIGH);    
         }
        else
        {
          digitalWrite(IN1,LOW);    
         }
        } 

void Motorprocess(int stepno, int noMins)
{
   int counter;
   int noRepeats;
   noRepeats=noMins * 6;  //6 cycles is one minute, so to repeat for the required no of minutes

     for(counter=0;counter<noRepeats;counter++)
                      { Motor2(255,true);
                       delay(4500); //turn for 4.5secs
                       
                        Motor2(255,false);
                        delay(4500); //reverse and turn for another 4.5 secs
                        Motor2(0,false); //stop for 1 secs
                        delay(1000);
                      }
lcd.setCursor(0,1);
lcd.print("Step ");  //write to LCD that the step is completed
lcd.print(stepno);
         lcd.print(" Done");
          Motor2(0,false);
      digitalWrite(BUZZ, HIGH); //sound the buzzer for a second
       delay(1000);
       digitalWrite(BUZZ, LOW);

  
 }  

// read the buttons
int read_LCD_buttons()
{
 adc_key_in = analogRead(0);      // read the value from the sensor 
 // my buttons when read are centered at these valies: 0, 144, 329, 504, 741
 // we add approx 50 to those values and check to see if we are close
 if (adc_key_in > 1000) return btnNONE; // We make this the 1st option for speed reasons since it will be the most likely result
 // For V1.1 us this threshold
 if (adc_key_in < 50)   return btnRIGHT;  
 if (adc_key_in < 250)  return btnUP; 
 if (adc_key_in < 450)  return btnDOWN; 
 if (adc_key_in < 650)  return btnLEFT; 
 if (adc_key_in < 850)  return btnSELECT;  


 return btnNONE;  // when all others fail, return this...
}

int val = 0;     // variable for reading the pin status

void setup() {
  
  pinMode(BUZZ,OUTPUT);
  
  int i;
   for(i=4;i<=7;i++)  //For Arduino Motor Shield
    pinMode(i, OUTPUT);  //set pin 4,5,6,7 to output mode
    
    analogWrite (10, 10);
     lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("FOMA 200 Process ");
  lcd.setCursor(0, 1);
  lcd.print("Press R to start");
}

void loop(){
  Motor2(0,false);
  int counter;
// buttonState= digitalRead(buttonPin);
buttonState = read_LCD_buttons();  // read the buttons
  if (buttonState==btnRIGHT)//change here
{buttonCount = buttonCount+1;



//if (newState==0 && buttoncount>0)
  switch(buttonCount)
  {

  case  1 : //prewash 3 mins
  lcd.clear();
   lcd.print("1. Prewash ");
      Motorprocess(1, 3);
           
      break;
  case 2 : //develop 7mins
  lcd.clear();
   lcd.print("2. Develop ");
      Motorprocess(2, 7);
     
  break;
  
   case 3 : //Stop Bath 1 Min
     lcd.clear();
   lcd.print("3. Stop Bath ");
     Motorprocess(3, 1);
   
  break;
  
   case 4 : // fixer 4 min 
        lcd.clear();
   lcd.print("4. Fixer ");
     Motorprocess(4, 4);

  break;
  
    case 5 : //Wash 1 min
            lcd.clear();
   lcd.print("5. Wash ");
     Motorprocess(5, 2);

  break;
  
   
  default :
  buttonCount=0;
  }//end for switch
}
}


DIY Rotary Film Processor

This Rotary Film Processor project has been on the back on my mind for ages but it became a priority after I got a 8×20 camera.  I managed to get a paper drum that can take up to 16×20. Usually I process one sheet (which for now is actually 2 pieces of 8×10 joined at the shorter side) at a time. Handrolling the tank for 15 mins for every single 8×20 shot is no joke.

Rotary Film Processor

Rotary Film Processor (less the connection to the Arduino box)

In terms of design, I have been looking at the various DIY designs that are found online. Of all, this youtube video looks the most interesting. However I decided to modify the design not to use a water tank for a few reasons.

  1. I do not need a water bath to regulate the temperature. I am quite happy with developing at room temperature. Even when I develop at 20C, I am fine that the chemicals go up by a degree or two.
  2. Saving of water since I do not need a  water tank.
  3. The buoyancy of the water aids the rotation of the tank but I can replace it with a roller base.
  4. A more compact design and easier to store away.

I have been doing DIY projects for a while so I have collected quite a number of parts so I am able to start the project using mostly of what I already have. Therefore pardon me for the non standardization of lengths and measurements.

Roller base

Rigid Wheels

Rigid Wheels

This is similar to the Jobo roller base.  To make this, mount 4 pcs of 1″ Rigid wheels  on 2 pieces of plywood.  The length of the plywood will depend on the length of your drum. Using my wood scraps, I have a 24″ and a 17″ pieces. Space out the wheels so that the drum will be well supported. Of course you may add more wheels if you intend to process drums of different sizes.

Roller Base

Roller Base

I connected the 2 pieces of plywood using 2 brass rails (they were from a forsaken camera project). They are locked down using 1/4″ bolts and nuts.   This will allow me to adjust the distance between the 2 rolls of wheels for catering to drums of different diameters. At this point the drum should rotate smoothly and evenly by hand.

Roller Base Rails

Roller Base Rails

Motor Arm

Motor and Shaft Coupler

Motor and Shaft Coupler (Motor cables are no connected)

For now I am using a 12V 30 rpm motor.  To mount the 3/8″ threaded rod (again another piece I have sitting around) , I use a flexible shaft coupler which has a one 6mm hole what will fit the motor shaft while the other end is a 10mm hole that fit the 3/8″ rod.

The 3″ wheels were purchased new as the old inline skate wheels I salvaged from my old skates have a bearing hole of 7mm. The hole diameter need to be 10mm for the 3/8″ rod to go through. They were then tighten with nuts on both sides. I placed a drop of Locktite so that the nuts won’t get loose from the turning . However as we do not want the wheels to be free spinning as the rod rotates,  I have to jam the ball bearings. In this way, the wheel will turn with the rod and then in turn causes the drum to rotate.

Wheels

Wheels with 2 nuts locking it down on both sides.

Automation

I have an Arduino Uno that was for my Kallitype printing which I modified it for this rotary film processor project. Basically with a motor shield and LCD shield, the sketch will go through the following cycles where the timings are customised for FOMA PAN 200 film using HC110 Dilution D.

  1. Prewash 3 mins
  2. Developing 7mins
  3. StopBath 1min
  4. Fixer 4 mins

Arduino Interface

Arduino Interface

At the end of each cycle the alarm will sound off signalling the need for me to change the chemical and go to the next cycle by pressing the Red push button. Check out this post for the sketch (code)

Update

I have made a version 2 of this rotary processor.  Here is a video to explain on the parts

Conclusion

I hope this article give a good picture on how to construct a rotary film processing on your own. There are still quite a few improvements to be made  for mine. You will need to customize it to your own needs and also the ability to source your parts at your side.