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.