How to find framing and focus on a Non-Reflex Bolex without an eye level viewfinder?

Owen Felton · May 8, 2023

I am a film student interested in shooting on 16mm for the first time. I recently inherited what I believe is a Bolex H16 Supreme. Since this is a Non-Reflex model, it doesn't have the built-in eye level focuser, and it didn't come with an attachable one either. I only have the viewfinder that attaches to the side of the camera door. I have no way of seeing what the actual filming lens is capturing unless I put my eye right up against the circle that is intended to connect to the eye level focuser, and it is very difficult to see this way.

I could only find one person selling an eye level focuser on Ebay and I can't afford to buy it. So, my question is, is there any way to figure out how to focus on this camera by only using the viewfinder on the side door? I am also worried about framing because surely this viewfinder won't give me an accurate representation of what is in frame since it is in a different position than the actual lens.

I am also quite new to the mechanics of focusing and finding the right aperture on a film camera. I have shot still photography on a 35mm film camera before, but I've always just kinda winged it.

If anyone can help me out and explain some of the mechanics of framing, focusing, and finding the right aperture on a Bolex Non-Reflex with these lenses please let me know!

If this is of any use, on my Bolex H16 Supreme, I have two lenses: a YVAR f/2.8 AR lens, and a LYTAR f/1.9 lens.

Jon O'Brien · May 8, 2023

Just some quick ideas off the top of my head. You can't figure out the focus from the side viewfinder. You could measure the distance to the subject with a long tape measure for the closer shots, and estimate the distance for subjects/scenes further away. The focus scale on the lens may not be accurate but it should be reasonably close to accurate. The side viewfinder should be good enough for framing. It should have a dial marked in feet or meters for changing the angle to the camera so that the framing is close enough to the final image that appears on the film. You can focus, can you not, by peering into the opening for the eye level focuser? Then you have everything you need! I wouldn't be worried, just take courage and start shooting -- there is really no other way to learn how to use what you've got to work with. Mistakes and things that could be done better are inevitable but you will learn fast, as film as you know is expensive. One thing you could try to check the framing is to put some kind of slightly opaque material in the film gate area and look at the image formed on it. Some kind of plastic sheeting material with a frosted look or even a bit of baking paper in a pinch but it might leave paper fibres in the gate area. It would be very fiddly to do and I don't think I would bother. Best of luck with getting started in real film!

For exposure you should try and get some kind of good, second hand exposure meter. Sekonic make good ones. You may find that you will need to open up just a bit more than what the exposure meter indicates, perhaps half a stop or so, but this can really only be known from your own tests, and depends on what you're shooting. I'm tending to find that a slight bit of over exposure can be a good thing, and can be corrected for later in post. But by all means make your own tests and probably best to start out by adjusting the aperture to the indicated level on the meter.

Edited May 8, 2023 by Jon O'Brien

Dom Jaeger · May 9, 2023

I don't want to crush your enthusiasm, but if you can't afford $120 for a fairly essential part of the camera, how are you going to afford the film, processing and transfer costs? Have you looked into the costs of shooting film? You'll spend that much on your first 100', which will give you a couple of minutes footage.

There was a small magnifying eyepiece part that screwed into that opening for the viewfinder so you could use the top focus port without a viewfinder, but they are hard to find too.

You can simply use the lens focus distance scales to focus and hope that they are reasonably accurate. For framing the side finder has parallax correction as Jon described. You can use a phone app for exposure rather than buying a meter if you are very cash-strapped.

As a tech, I generally advise people to have their newly acquired vintage camera and lenses at least checked over, and ideally serviced before they spend money on film and transfer only to find an issue after the fact. Unfortunately film is an expensive hobby..

Jon O'Brien · May 9, 2023

G'day Dom, I can't remember if I've asked you this before but do you service Kodak K100 16mm cameras? I have two. One, the single lens version, seems fine and works well so far, and the other with a turret winds but doesn't run at all.

Dom Jaeger · May 9, 2023

Hi Jon,

I pretty much service anything except Super 8 cameras. But I'm very booked up, minimum 2 month turnaround, and I will shortly stop taking on new jobs to catch up.

Dom Jaeger · May 9, 2023

6 hours ago, Owen Felton said:

I am also quite new to the mechanics of focusing and finding the right aperture on a film camera. I have shot still photography on a 35mm film camera before, but I've always just kinda winged it.

If you have a Supreme, you need to meter for an exposure time of 1/60 sec if filming at 24fps, or 1/40 sec for 16fps. Err on the side of over-exposing, ie a smaller f number on your lens.

The shutter angle changed around this time due to a new pulldown claw design, so this information is correct if your camera has the newer trailing claw. It should have a serial number above 100401.

Owen Felton · May 9, 2023

3 hours ago, Dom Jaeger said:

I don't want to crush your enthusiasm, but if you can't afford $120 for a fairly essential part of the camera, how are you going to afford the film, processing and transfer costs? Have you looked into the costs of shooting film? You'll spend that much on your first 100', which will give you a couple of minutes footage.

I have done a lot of research and planned out the money I'll spend on film stock as well as developing and scanning and I'll be okay with those expenses, but what I meant was that I don't want to also spend an additional $120 on the viewfinder if it's not totally necessary and I can find a way to work without it. It seems like it'll be hard, but I think I can work around this issue and I'm just going to be extremely thorough in my storyboarding and planning of shots to make sure I don't waste film. You're right that I probably should get my camera checked out before I use it, so I'll probably show it to one of my film professors and see what they think, but I might just take the risk anyways since it seems to be in great condition, the motor runs properly, and everything seems to be in place. Perhaps I am a bit overambitious and pushing my luck, but it will be a good learning experience.

Simon Wyss · May 9, 2023

The sidefinder is accurate enough for general shooting. Do look for an eye-level finder tube with ocular, it will give you a magnified view of the frosted front of the prism that sits behind the upper turret port. A little patience and perseverence

For more exacting work a rackover support is used that looks like this:

If you have one, let a technician adjust camera and support to each other. From then on you will be able to frame and focus until an object touches the lens (extension tubes). An advantage of the rackover system is that nothing interferes with the optical path meaning you can use almost every C-mount lens there is.

You didn’t tell the focal lengths of those lenses. The classical set would include a moderate wide angle, 15 mm, a normal lens of 25 mm, and a double or triple normal focal length tele lens, thus 50 mm or 75 mm (0.7"/1 inch/3 inches).

I’d advise that you have the camera and the lenses serviced before use, too. That’ll cost money but defects will be revealed and possibly remedied. Perhaps the mainspring has become tired. That depends on whether the spring had been left wound up for a long time or not. Your model is over 65 years old. I can tell something about the state of the spring within a minute when I have the camera in my hands.

Robert Hart · May 9, 2023

If your drive spring is weary, you may only get about 15 seconds before the frame rate drops off the governor.

A quick and dirty method of checking the spring is to load a roll of junk film. set the governor frame rate to whatever your local power supply frequency is, 50Hz for PAL TV countries and 30Hz for the US and many others. Place your camera under an old-school flourescent tube lamp and watch the frame counter dial on the side of the camera.

You should be able to just see the marks as they move. They may hold steady or creep. Any speed change will be apparent as the creep forward of backward will alter. You can also take the lens out of the Bolex and through the lens mount opening, view the shutter blade whilst film is pulling through an older-non-reflex camera.

The screen light from old-school CRT television sets was also good for checking the camera governor. New LCD televisions/monitors do not flicker as much.

If you have a video-camera which has a high shutter speed, you can use that to view the frame counter though a close-up lens/macro by setting the governor to as near to the video frame rate as you can get, ie., 25P, 24P, 30P.

I used a similar hack to set the governor speed on a generator.

Shooting with the parallax-adjustable side-finder in well lit conditions is not hard but requires the discipline of a mental check list every time you use the camera.

As long as you are patient, you can use the eyepiece out of an old pair of binoculars to view the groundglass screen of the upper view port which you use by rotating the lens turret to bring the selected lens into view. Take care to press the lens turret disk rearwards. Sometimes the weight of lenses pulls the turret disk forwards and the focus will then be off.

This method is fraught with possibilities to waste film as the lens aperture has to be opened wide for accurate focus and to be able to see anything on the dull groundglass.

A few folk have made video-split hacks with small CCTV security cameras, 50mm lens and about ten 5mm CS- to C-Mount spacers stacked behind the 50mm lens and a bodged spacer between the front of the lens and that upper viewport. this means adding wires, power supply and a viewing monitor which rather defeats the agility of the bare camera.

Dom Jaeger · May 9, 2023

7 hours ago, Owen Felton said:

I might just take the risk anyways since it seems to be in great condition, the motor runs properly, and everything seems to be in place. Perhaps I am a bit overambitious and pushing my luck, but it will be a good learning experience.

Fair enough. I hope you get back results that inspire you to continue!