depth of field

scotman

scotman

Well-known member
im waiting for barrys book on the dvx. before it comes, im trying to figure out as much as i can about depth of field. ive read about 2 ways to accomplish this. one with zooming all the way out and then changing the fstop. correct

the other way is using manual focus and getting things to line up well.

can someone shed some light on this for me. u guys are awesome later
 
Here is an ongoing discussion. It is for the HVX, but the advice will be applicable to the DVX as well. What you are trying to do is simulate a shallow depth of field.

The way to do it for real is to get a 35mm adapter and lenses.

here is the link to that discussion that is ongoing already.
http://www.dvxuser.com/V6/showthread.php?t=83394

If you run a search, you will also find many other threads that go in depth on this topic.

Later,
Jason
 
Open the iris up all the way, use ND filters, zoom in as much as possible and separate your subject from the background as far as possible. Or, get a 35mm adapter.
 
but i heard that 35 mm adapters arent good for the dvx. or is there one out there thats reallly nice.
 
Who told you that? The dvx is great for an adapter. The best adapter that I know of is the mini35 by P&S teknik. Hefty price tag though.
 
kyle.presley said:
Who told you that? The dvx is great for an adapter. The best adapter that I know of is the mini35 by P&S teknik. Hefty price tag though.
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i read about adapters and i thought it said i loose resolution or something doesnt come out as clear il take a look and see if i can find it


are there different types of dof.

under screen grabs i saw that with the dvx lens you can only achieve shallow dof. but with 35 mm you can get a different look


Whats the best method for dof expecially in low lighting. thanks


Last thing. is the dof in a dvx and a dvx 30 completly different. i tried using a dvc 30 over the weekend but got poor results in dof with low lighting. because when i opened the aperture everything was blown out and started to slow down. thanks
 
scotman said:
are there different types of dof.
Click to expand...
No. Depth of field is depth of field. It's just a term. It refers to the range of focus one has in a given composition. How deep the focus is. Great depth of field = more of the composition in focus. Shallow Depth of field = less composition in focus I.E. selective focus. It would be so much easier to show you than to tell you. When you open the iris up, you must compensate the over exposure with ND filters, basically sunglasses for you camera.

scotman said:
is the dof in a dvx and a dvx 30 completly different.
Click to expand...

It is easier to achieve shallower depth of field with the DVX than the DVC30. The DVX has larger chips, so the DVX lens has a longer focal length, allowing shallow depth of field to be more apparent in the DVX.

Hope this helps.
 
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And things start to slow down because the dvc30 exposure control also adjusts the shutter speed. Dial it too low (open aparture) and you may accidentally turn down the shutter speed as well, which causes serious motion blur below 1/30. DVC30 can actually give you better DOF than the DVX because of its 16x zoom vs. the DVX's 10x.

You don't actually lose resolution with a 35mm adapter. Depending on the adapter and the lense you use you may end up with viginetting on the edge of your image. But pretty much all the commercially available adapters already used high quality optics to compensate for this. Main thing is that you'll lose light, LOTS of light (usually around 3 stops).
 
That's not neccessarily true. Even though the DVC has longer 16x lens, it has smaller 1/4" chips, which will always make shallow DOF more difficult. The larger the CCD, the more shallow DOF. The larger the CCD, the more wide open the iris, the greater the distance from subject to bkgrd, and the smaller the distance from subject to camera, the more shallow the DOF. Using the 35mm or Nikon adapter will also reduce DOF.
 
in order to get the best DOF you have to be zoomed all the way out. So in a dvx it would be 10x zoom. Interesting
 
scotman said:
in order to get the best DOF you have to be zoomed all the way out. So in a dvx it would be 10x zoom. Interesting
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Zooming in only increases "apparant" depth of field because of the decreased field of view. Zooming is great, but is reality can be limited in use because of phsyical space limitations in being able to back up and zoom in.

The bigger chip in the DVX (and corresponding change in focal length) actually reduces real dpeth of field, and probably the DVX at 10x looks similar to the DVC at 16x.
 
Joshua Provost said:
Zooming in only increases "apparant" depth of field because of the decreased field of view. Zooming is great, but is reality can be limited in use because of phsyical space limitations in being able to back up and zoom in.

The bigger chip in the DVX (and corresponding change in focal length) actually reduces real dpeth of field, and probably the DVX at 10x looks similar to the DVC at 16x.
Click to expand...

Good answer.
 
Yeah you'd be surprised how much you can reduce DOF by zooming in a bit and coming as close as possible to the subject, then dropping in as much ND filtration as possible to open the aperture, and back the subject away from the bkgrd as much as possible. True, you don't have to actually zoom in all the way to reduce DOF, but you have to zoom in a bit, because trying to get a CU on a subject with a wide angle lens will distort perspective, make the nose look bigger, ears really small, stuff like that. Unless that's what you're after :)

The key is also the aperture. f/5.6 just won't do, which is generally where people end up when they use the 1st level of built in ND in the DVX. The second step is sometimes too much unless there is bright sun keying the subject. So the operator will simply step back to the 1st ND level and leave it there, usually at f/5.6, which is too narrow an aperture. Invest in a couple screw-in ND glass filters (72mm) at .3 and .6 ND. That will allow you to fine tune the ND amount, open the iris all the way out, and still have perfect exposure.
 
I have been using a +1 close up filter to hav a shallover depth of feild. Of course, u will loose a bit of focus range. Depending on whiting what range you will follow your subject, u can use +2 or even +3. Instead of using ND filter, I compensate on shutter speeds with a full open iris.
 
Using a CU filter can produce a cool effect, but altering the shutter speed can have negative effects on motion when all you're trying to do is alter exposure. It should be used with care so as not to remove intra-frame motion blurs. These motion blurs are what give a filmlike smooth quality, so you don't want to remove them with high shutter speed that chops up movement. :thumbup:
 
scotman said:
but i heard that 35 mm adapters arent good for the dvx. or is there one out there thats reallly nice.
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besides...why would anyone spend over eight grand for a 35 mini adapter for the DVX? if you could afford a 35 mini adapter, then why did you purchase the dvx?
 
Yup, that's why people rent the mini35 rather than buy it. But I really couldn't see why it costs 10 grand. I spoke to a DP who had a chance to use the mini35 and he told me that it easily swallows up 2k of light. It does flip the image but the Letus already done that at a much lower price point and light loss certainly isn't one of the mini35's strong point. So why is it so expensive?
 
I currently have the Letus35FE, if cost is an issue look into the letus35 original. I think there $300.00 US. You may have to flip the image in post and shoot upside down however, if your looking for an awesome film like feel to your footage and an great bokeh get the Letus35. Just do some searches here at the forum, letus35, sgpro, brevis, mini35, redock etc... you'll get hooked just like I did.
 
Try 2 use a close up filter. I have tried the +3. U indeed get a shallower depth DOF but obviously loose focus range. The best way 2 learn about apperture and shutter speed, take some photographic lessons. As a photographer, u will become a better cameraman. n also, I,ve noticed that instead of using ND filter, use the shutter speed, the DOF seems a bit shallower. But remember, the more u zoom in, the shakier ur images would get. Use a tripod, if not, a monopod can do the job
 
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