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DOF evaluation with Super 8 cameras?


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#1 Marc Oberdorfer

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Posted 25 July 2009 - 08:05 AM

I am going to buy a Super 8 camera soon, there are so many out there and I have noticed that most of them use split image focusing.
What I couldn't find out for most of the cameras that I'm interested in is if you get a live view of the image so you can evaluate the DOF before/when shooting.

If you look at the specs of cameras in this shop:
http://super8arena.c...om-1-p-164.html

you will see it says rangefinder which I associate with rangefinder cameras where you are looking through plain glass and not the lens and can't evaluate DOF. Is that the same for Super 8 cameras?
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#2 Peter Dean

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Posted 26 July 2009 - 08:51 PM

I am going to buy a Super 8 camera soon, there are so many out there and I have noticed that most of them use split image focusing.
What I couldn't find out for most of the cameras that I'm interested in is if you get a live view of the image so you can evaluate the DOF before/when shooting.

If you look at the specs of cameras in this shop:
http://super8arena.c...om-1-p-164.html

you will see it says rangefinder which I associate with rangefinder cameras where you are looking through plain glass and not the lens and can't evaluate DOF. Is that the same for Super 8 cameras?


Most super 8 cameras, including the R10, have reflex viewfinders, meaning you can see the same image that will be captured on the film. There are a ton of websites devoted to super 8. Check out super8wiki.com, http://home.pacbell....nyberg/super8mm, super8aid.net, etc.
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#3 Marc Oberdorfer

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Posted 26 July 2009 - 11:12 PM

Most super 8 cameras, including the R10, have reflex viewfinders, meaning you can see the same image that will be captured on the film. There are a ton of websites devoted to super 8. Check out super8wiki.com, http://home.pacbell....nyberg/super8mm, super8aid.net, etc.


I have checked the whole lot of Super 8 websites, including that one but couldn't find anyone mentioning what kind of viewfinder is used. Or I didn't see the forest because of all the trees? :)
Thanks Peter, that info helps a lot.
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#4 jacob thomas

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Posted 30 July 2009 - 05:20 AM

I have checked the whole lot of Super 8 websites, including that one but couldn't find anyone mentioning what kind of viewfinder is used. Or I didn't see the forest because of all the trees? :)
Thanks Peter, that info helps a lot.


Most super 8 cameras use beam splitters in front of the aperture so that as the lens stop down the viewfinder stays bright, however this means you won't have any indication of DOF through the viewfinder. It will always have the DOF as if the lens was wide open.

If you want a true mirror reflex viewfinder seeing what the film will capture get a beaulieu or leicina.
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#5 Marc Oberdorfer

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Posted 31 July 2009 - 04:22 AM

Most super 8 cameras use beam splitters in front of the aperture so that as the lens stop down the viewfinder stays bright, however this means you won't have any indication of DOF through the viewfinder. It will always have the DOF as if the lens was wide open.

If you want a true mirror reflex viewfinder seeing what the film will capture get a beaulieu or leicina.


Thanks for your info Jacob. I already bought a Sankyo XL620 which uses the said beam splitter. At least I get wide open DOF preview, better than a rangefinder where you get "nothing".
I wanted to go with a Beaulieu first but didn't want to spend so much for my first Super 8 camera.
The Leicina's were very tempting since I have lots of M glass but they don't seem to shoot 24fps which stopped me from buying.
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#6 Lloyd Freidus

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Posted 02 August 2009 - 02:12 PM

The virtual image you see with most beamsplitters are "direct View" and don't have a ground glass. You can not preview DOF without a ground glass viewfinder. Your eye can change focus to see other parts of the image that are not in the focus plane. The ground glass creates a "real" image which allows you to judge focus. It may be possible with a lot of experience and discipline to keep your eye focus on the frame markings and judge the depth of field. I'm not familiar with specific Super 8 models. The reflex Bolex 16mm cameras have a beamsplitter and ground glass. But it is small and hard to judge anything but framing.

Depth of field is a function of image size, all other things being equal. This is widely discussed in relation to small chip video cameras and is true here. Super 8, with a small image size has very great DOF. If shallow depth of field is a goal, Super 8 would not be a good choice. (As with video I'd use longer focal lengths when possible, and make sure my subject is closer to the camera than to the background.)

Also, even with the large bright viewfinders of modern professional 35mm cameras, it is not safe to judge DOF by eye - so much more can show up when projected on a 40' screen. In most of my work in 16mm or 35mm we would always refer to depth of field tables. The ASC manual has them for 16mm and 35mm. Most ACs who have the responsibility to know what parts of an image are in focus, have a simple circular calculator that for a given focal length and focus distance shows the DOF. If I wanted extreme DOF I would use a wider angle lens and/or increase the lighting for a smaller aperture.

While you have little control of DOF you may have some piece of mind if you have a set of DOF tables. I have seen a number of online calculators (several on still camera websites) with which you may be able to construct your own custom tables.
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