For those who don't think shallow DOF can be achieved with small chips...
 

gs100, 1/6th ccds.

http://members.shaw.ca/tjshaver/Squirrel01a.JPG

http://members.shaw.ca/tjshaver/Squirrel02a.JPG

The first link is OK, but in the second link, the background is sharper than the subject.

<<<-- Originally posted by Jeff Donald : The first link is OK, but in the second link, the background is sharper than the subject. -->>>

It probably was done on purpose, to prove that you could run focus on different planes.

In any case as an example it's a bit relative. Flat DOF is a problem in video on "normal" to wide angle lengths. With long lenses you should get more control over focus.


Carlos

Correct, it was done on purpose.

I agree with you on that Carlos but i've read some comments by people who think that there is NO way to get shallow DOF with a small camera, this was just an example to show that it is possible if not entirely practical.

I did it all the time with my gs100. Just get close to the subject, if possible.

too right. if you have light to play with it is even better. all you have to do is turn your shutter speed up to close the iris more and you will get a shallower depth of field with some great effects.

Justin

here are some grabs i took off my mx500. i had two other clips but i didn't use them because they looked terrible. There was a lot of movement in the picture so when i deinterlaced it affected the quality something cruel. anyways here are the good ones.

http://www.geocities.com/sniper_y2k2000/dof.html

Justin

I don't understand your point, Tavis. You were probably full tight on the squirrel at around twenty-five feet away, and the background was probably another twenty-five feet from the subject. Yes, this is an example of shallow depth of field, but to someone trying to shoot an interview, or a single for a short film, it means nothing. If you substituted a human being for the squirrel, you would have an extreme close-up. Eye, nose, mouth, and not much else. Hey, you're Sergio Leone!

It isn't that shallow depth of field is impossible to get with small chip cameras, Tavis, it's just that it's damn near impossible to achieve in real-world situations with actors and interview subjects. However, we'll add this shot to those of Coke cans, bugs and baby toys that have been used to show it's possible to create shallow depth of field with small chip cameras.

But it is a cute squirrel.

Wayne Orr, SOC

i was about 15 feet away. The point is what i said, just showing it is possible if not totally practical. Although i personally think that with some forethought you could achieve usable results.

Plus, i liked the squirrel. :P

I know you guys already understand DoF pretty well. But, I found this reference that illustrates DoF and the differences among cameras pretty well.

BTW, nice squirrel, Tavis!

<<<-- Originally posted by Justin Boyle : too right. if you have light to play with it is even better. all you have to do is turn your shutter speed up to close the iris more and you will get a shallower depth of field with some great effects.

Justin -->>>

I think you meant OPEN up the iris (f2.0 rather than f8.0) to achieve shallow DOF. And you want it dim to be able to do so.

That's why I keep a polariser (equivalent to ND1.5) and an ND4 close at hand for bright sunny days to achieve shallow DOF.

Recapping, shallow DOF is possible, more at the long end of the zoom (10x), and you should open up the iris more (just before digital gain) to get maximum effect. At widest angle (1x) put the cam REAL close to the subject (much barrel distortion) and focus at macro to force a shallow DOF, again with the iris wide open.

sorry my mistake.
anyway there is one problem with doing this. you are more likely to get lens flare and aberations etc. this can be a very big problem with cameras of this calibre where the lenses are of low quality and don't limit things like this. so i guess you could say that shallow DOF with small chip cameras is not very good in that sense. Heh thats a good link for the DOF thanks.

Justin

You may want to refer to DV Info's article on DOF here.

It should be noted that if you move the camera further from the subject you're increasing DOF. If you zoom in (increase focal length of lens) on your subject to get the proper framing, DOF is decreased. If the subject size (say their head) stays the same size in the frame, DOF stays the same.

If you physically move the camera forward and back you change perspective. This change in perspective provides an apparent reduction in the DOF. Changing perspective and increasing the focal length (zooming in on subject) allows for a narrower angle of view and may permit less background to be seen. This narrowing of the angle of view and reduction of background is only an apparent reduction of DOF. But if it fools the viewer and gives you the effect you want, do it.

Actually Justin I think you'll get better definition at wide apertures rather than smaller. So if you shoot at f2 (especially at the wide-angle end of your zoom where difraction losses are at their greatest) you'll get better resolving power than by shooting at f8, and much better than shooting at f11.

This surprises a great many people, but it's usually people who've come to Mini DV from 2 1/4 square or 35mm photography. So many people question this that I've shot a test film to prove it. Having seen it they all go out and buy ND filters.

Note though that modern cameras (MX300, 350, 500 etc) all employ in-built ND filters. Pushing the 'display' button and getting a readout of f16 is silly nonsence, but the display is there to sooth you. They are theoretical aperture readings with these cameras.

tom.