How to Increase Depth of field?

L

liextreme

Active member
I know you can move away from the object set the object from far away and there you go, I'm shooting a still interview and I need to create major depth of filed look. What is the cheapest solution?
 
1) Set your subject as far from the background as humanly possible. Really far. Really, really far.

2) Zoom to your maximum focal length and leave it there. Frame your shot by moving the camera rather than adjusting the lens.

3) Set your aperture wide open and never stop down. Instead, use ND filters to adjust exposure.
 
Move your subject as far away from the background as possible. Try to open the iris as much as possible without adding gain. Use ND filter if needed in order to open iris up.

EDIT --- Ahhh you beat me to it :)
 
FYI, you've got it backwards. You want to DECREASE depth of field. "Depth of field" is a term that many people use interchangeably with "shallow depth of field", which is wrong and confusing. To increase depth of field, do the reverse of what's suggested above... usually by adding a lot more light.
 
The problem is that I have to shoot in a small office, and how can I do wide and sill have the depth on the object? any lenses?
 
you can also "fake" it in post production creating a mask around the subject and then make the background gaussian blur , this al can be done in FCP
 
Not to be too picky with the language, but as dougspice pointed out, you appear to be asking about how to *decrease* depth of field, not increase it. The term "depth of field" isn't synonymous with "shallow depth of field". It describes a range of choices between shallow and deep, also sometimes described as short and long. Here's a brief summary of what affects it:

First and foremost, the aperture size, or F-stop of the lens is the primary means of control over DOF. Larger aperture sizes (with lower F-stop numbers) have inherently shallower depth of field, and smaller ones (with higher F-stop numbers) have longer DOF. So if you want a "shallow" effect, use a low F-stop setting, like 1.4 on the HVX, which is the lowest available. It also affects light input, so a low F-stop will require much less light on the subject than a high one. So a low F-stop number = shallow depth of field and higher light sensitivity, a high F-stop = long depth of field and lower light sensitivity. You can counteract excess light at low F-stops by using a faster shutter speed, reducing light (when possible) or using an ND filter. For higher F-stop situations where you want long depth of field and need more light, well...add more light.

The HVX like many camcorders is inherently limited in its available range of DOF on the shallow side. It has mainly to do with the small sizee of the CCD light sensors. Even with the aperture wide open it's not going to give you the kind of super-shallow focus effect you might be looking for. This is why there are a number of aftermarket products like the Redrock M2 35mm adapter. The main reason such products exist is to allow shallower depth of field than the stock lens, although they also allow the use of many other types of lenses to enhance zoom, wide angle etc.

As some have mentioned, there is one other way to get the shallow DOF effect with an HVX's stock lens, and that is with zoom. Put the subject as far as possible from the background you want soft focus on. Zoom in (magnified) all the way on the subject, move the camera as close to the subject as proper framing will allow, and use as low an F-stop as possible. It will give you a nice shallow DOF effect. Among other downsides though, it will distort the perspective of the background due to the zooming. Background objects will be blurry, but will look disproportionately large/close due to the magnification effect of the zoom. This is nonetheless the best that can be done to achieve the effect with the stock lens.

For myself, having completeted assembling a very nice HVX "starter kit" this year (camera, tripod, lights, field monitor, shotgun mic, lavs, FCP, P2 cards, powerbook...etc, etc, etc...whew!), one of the first things I'll likely add next year will be a 35mm adapter kit and lenses.
 
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To add depth of field = add more light so you can stop down, use wider lens.

To decrease depth of field = less light so you can open up apurature (can also use ND), use longer lens.
 
liextreme said:
The problem is that I have to shoot in a small office, and how can I do wide and sill have the depth on the object? any lenses?
Click to expand...

Shooting in a small office your options become much more limited. You can set the camera up in the hallway and shoot through the doorway, but there's really no way you'll be able to get your subject far enough from the walls for them to go out of focus. You might be able to position him in front of a window and use the outside as your backdrop, in which case you would have to light your subject to match the exterior and then use lots and lots of ND.

Something I've never done but always wanted to try is hanging some sort of frosted/transluscent material (like a shower curtain, maybe?) behind the subject to blur it. I actually recall finding a link to a product for that specific purpose a few years ago, but I can't find it or remember what it was called. Does anyone here know what I'm talking about?
 
Look for the asthetic that works best. Dont go in just thinking extremely shallow. Check the best angles, background in the space you have.
 
If you dont have any camera movement in the shot, a simple and cheap solution would be to take a green screen into the office and set it up behind your talent. Shoot the scene, remove the screen and then shoot the backing plate out of focus, combine in post.
 
Mark A. Beal said:
Something I've never done but always wanted to try is hanging some sort of frosted/transluscent material (like a shower curtain, maybe?) behind the subject to blur it. I actually recall finding a link to a product for that specific purpose a few years ago, but I can't find it or remember what it was called. Does anyone here know what I'm talking about?
Click to expand...

It's a softscreen found at indietoolbox.com, they talk about it in this DOF thread that also has some very helpful information, here.
 
liextreme said:
ok m2 $550 I think that is the answer, now what lens and where do I get it?
Click to expand...

$550? Don't forget you'll need a lens adapter ($100), a step down ring if your using an HVX ($10), rods (the M2 is pretty heavy... couple hundred bucks), and then maybe the HD Achromatic ($400)... You might get away with only spending a little more then a grand.

I've seen some killer images using fast Nikon lenses. Try to buy them used because these can get expensive.
 
Nice Ted, you know what you are talking about :beer:


Ted Spencer said:
Not to be too picky with the language, but as dougspice pointed out, you appear to be asking about how to *decrease* depth of field, not increase it. The term "depth of field" isn't synonymous with "shallow depth of field". It describes a range of choices between shallow and deep, also sometimes described as short and long. Here's a brief summary of what affects it:

First and foremost, the aperture size, or F-stop of the lens is the primary means of control over DOF. Larger aperture sizes (with lower F-stop numbers) have inherently shallower depth of field, and smaller ones (with higher F-stop numbers) have longer DOF. So if you want a "shallow" effect, use a low F-stop setting, like 1.4 on the HVX, which is the lowest available. It also affects light input, so a low F-stop will require much less light on the subject than a high one. So a low F-stop number = shallow depth of field and higher light sensitivity, a high F-stop = long depth of field and lower light sensitivity. You can counteract excess light at low F-stops by using a faster shutter speed, reducing light (when possible) or using an ND filter. For higher F-stop situations where you want long depth of field and need more light, well...add more light.

The HVX like many camcorders is inherently limited in its available range of DOF on the shallow side. It has mainly to do with the small sizee of the CCD light sensors. Even with the aperture wide open it's not going to give you the kind of super-shallow focus effect you might be looking for. This is why there are a number of aftermarket products like the Redrock M2 35mm adapter. The main reason such products exist is to allow shallower depth of field than the stock lens, although they also allow the use of many other types of lenses to enhance zoom, wide angle etc.

As some have mentioned, there is one other way to get the shallow DOF effect with an HVX's stock lens, and that is with zoom. Put the subject as far as possible from the background you want soft focus on. Zoom in (magnified) all the way on the subject, move the camera as close to the subject as proper framing will allow, and use as low an F-stop as possible. It will give you a nice shallow DOF effect. Among other downsides though, it will distort the perspective of the background due to the zooming. Background objects will be blurry, but will look disproportionately large/close due to the magnification effect of the zoom. This is nonetheless the best that can be done to achieve the effect with the stock lens.

For myself, having completeted assembling a very nice HVX "starter kit" this year (camera, tripod, lights, field monitor, shotgun mic, lavs, FCP, P2 cards, powerbook...etc, etc, etc...whew!), one of the first things I'll likely add next year will be a 35mm adapter kit and lenses.
Click to expand...
 
Ok I went to M2 sites and hd kit - HD Edition for Nikon Lenses M2 Cinema Lens Adapter Special M2 HD Achromatic lens 15mm Rod Support System Nikon SLR lens mount M2 or LetusHD100?

and what exact lens would work the best? size make, and does it have to be made for HD?
 
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Very good explanation, Ted.

liextreme, I think you need to slow down a bit and think about what you're trying to do. jeremy is right, you're not really going to get a functional m2 package for under $1000. There are cheaper adapters available, and plenty of posts around debating which are better. But they all have a few things in common that will affect your filmmaking:

1) they require you to use additional lenses (my current Nikons cost about $2200 total. You could make do for about $500 maybe, with older used lenses.)
2) they lose light. if you're planning to shoot at night, or a lot of interiors, realize that you'll need to provide a lot more light to your scenes.
3) they're mostly specialty-built, online. This means that even if you decide on an adapter, you can probably expect to wait weeks before yours is shipped.
4) they slow you down, and can require additional crew. That shallow film look is great and professional, but you may not realize how much more time you'll spend setting up and doing takes when you have to worry about whether or not the subject was really in focus. With a 50mm lens wide-open, the area in focus might be as slim as 4 inches. It's easy to mess that up. If your camera is moving, you'll absolutely need an assistant to pull focus.
5) most of them flip the image, which means you'll usually need some sort of external monitor to be able to operate the camera, unless your shots are on tripod and don't move. There are ways to flip the image in the LCD to compensate, but I've broken a camera before doing it, and don't plan on doing it again.

So when you get down to it you're really talking about a tremendous increase in the amount of time and money needed to shoot a film, over what the HVX can do on its own. Of course, those adapters produce a quality of image that the HVX on its own can't replicate. I own an M2 and have mostly been happy with it. But I still run into plenty of situations where there's not enough time or money to use it. That's fine. Just don't think you're going to slap one of these things on your camera and instantly have a professional looking movie at no additional cost.
 
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