What exactly is a 35mm Depth of Field Adapter (aka DOF adapter)?

 What exactly is a 35mm Depth of Field Adapter (aka DOF adapter)?


A Depth of Field Adapter is used to achieve shallow depth of field on a video camera whose sensor size is not adequate to achieve it native. A DOF adapter could theoretically be used on a multitude of platforms, although it is most useful on prosumer digital camcorders where high resolution is a capability but the sensor size is still small enough to elicit use of the adapter. The term 35mm adapter is common, since most designs use a focusing screen the size of a 35mm film frame (24×36 mm) and interface with lenses designed for 35mm cameras.


Do you need An 35mm Adapter to get Depth of Field?

The term is a little confusing, let me define it first: DOF is the distance in front of and behind a certain object that is considered imperceptibly in focus - everything else would be considered out of focus.

Now, with that said, a 35mm Cinema camera can give you a much shallower Depth of Field than any 1/3″ CCD camera can. People often call it “The Film Look.” You can get shallower depth of field with a video camera by opening up the aperture all the way, but you will not get the shallow DOF that a 35mm Cinema Camera can give you. That’s until you add a 35mm DOF adapter.

Other than a shallow depth of field, what else can the 35mm DOF adapters offer?

They can help to limit the amount of light hitting the CCD, so hot spots aren’t as hot. This really helps when shooting outside - since shooting outside is often video’s weaker area.

What are the cons of using a 35mm DOF adapter?

There are plenty of cons to using a 35mm DOF adapter.

1. They lose light - 1 to 2 stops, and that’s not counting the added lens!

2. They can take a while to setup.

3. They are often expensive - the better the quality, the more expensive.

4. They are bulky and can add inches/feet to the overall length of your camera.

Should I get a 35mm DOF Adapter?

Yes. But, that doesn’t mean you should use it on every shoot! Similar to using a wide-angle lens on the front of your video camera, 35mm DOF adapters should only be used in the right places.

Think of the DOF adapter as a great addition to your video arsenal and you won’t go wrong. It makes for a great “film look” and allows you to use cinema lenses. Perfect for shooting with a low-budget, when someone wants a higher quality than they can afford…

Are there other ways to get DOF from a video camera?

Using the zoom lens at its greatest zoom, and backing up from your subject will get a better DOF.

What about adding DOF in POST?

This technique works, but you are limited in many way. Different layers and mask are used to accomplish this effect. It’s doable, but not easy.

If you pre-think your shots on set then you can do DOF much easier in post. Make sure your subject doesn’t have any objects crossing behind his head in the back ground, where the mask, and layer will be use to blur the back ground or at least have a point as it crosses his head that you can use as a layer. Think about it this way your going to have a blurry Layer and a sharp layer. The less you have to mask out on your subject the better. This can be done to great effect if the actor is some distance from the background to start with.

Any of these will work, the idea is to use DOF to get a more pleasing interesting picture, and WOW your audiences.