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-   -   16x How best to achieve focus? (https://www.dvinfo.net/forum/canon-xl-gl-series-dv-camcorders/66375-16x-how-best-achieve-focus.html)

Oliver Horn May 1st, 2006 10:31 AM

16x How best to achieve focus?
 
Hi. Just got me the 16x manual lens. Love it! I really just want to confirm/question my method of focussing. If shooting 'on shoulder' at wide angle, I've been zooming to the point in the scene which is relevant/average distance, then zooming out to wide and leaving the focus there. I then use as small an aperture as the light will allow to get depth of field. I ask because at the wide angle, anything beyond a couple of meters or so seems in focus wherever the focus ring is. Any thoughts?
Best wishes,
Oliver.

DJ Kinney May 1st, 2006 05:10 PM

Let me be clear on what you're looking for here... you want everything to be in focus? Or you want a shallow depth of field, with only the subject in focus?

Perhaps there's a miscommunication, because if you close down your aperture, then you'll get a deeper depth of field and everything will be in focus.

Perhaps I'm assuming that there was a mistake in your question.

DJ

Jeff McElroy May 1st, 2006 06:13 PM

Are you asking about macro-focusing, Oliver?

Greg Boston May 1st, 2006 07:20 PM

Quote:

Originally Posted by Oliver Horn
Hi. Just got me the 16x manual lens. Love it! I really just want to confirm/question my method of focussing. If shooting 'on shoulder' at wide angle, I've been zooming to the point in the scene which is relevant/average distance, then zooming out to wide and leaving the focus there. I then use as small an aperture as the light will allow to get depth of field. I ask because at the wide angle, anything beyond a couple of meters or so seems in focus wherever the focus ring is. Any thoughts?
Best wishes,
Oliver.

That's pretty much how it works, Oliver. Congratulations on getting the 16x manual lens. It will do wonders for your camera technique. The other recommendation if you can afford it would be to add the FU-1000 b/w viewfinder. This finder has a 'peaking' control which will generate an artificial highlight on objects in focus. Using it with the 16x lets you really snap things in focus quickly and accurately.

-gb-

Tony Davies-Patrick May 2nd, 2006 02:24 AM

Quote:

Originally Posted by Oliver Horn
...I then use as small an aperture as the light will allow to get depth of field...
Oliver.

This is correct for still photography, but not such a good idea when shooting digital video. In still photography a good lens will allow you to shoot scenes with increased depth of field closed down to f/16, with only slight loss of image quality through diffraction at f/22-f32 (depending on lens quality and technique). The diffraction element kicks in far sooner with camcorders. I've found that shooting at small apertures (high f/stops) is a big no-no for most Dv cameras. It is better to maintain the aperture/iris setting of the MF 16X lens at F/5.6-f/8, as this will place the lens at its peak performance, yet still maintain enough depth of field for scenes. Open up to a wider aperture (lower f/stop) when you want to provide shallower depth of field or emphasise a subject from an out of focus background. If light levels become brighter than the F/8 setting, then increase the shutter speed or use the ND filters (or a polarizer filter) to maintain correct metering.

Oliver Horn May 2nd, 2006 12:25 PM

16x How best to achieve focus?
 
Thanks everyone! I do now remember seeing an article here on diffraction, so I'll stick to f5.6/8. Sorry if I worded the question badly DJ, but Greg got what I meant. I do already have the FU-1000, peaking is my friend!
Now when is the Universal Binary of FCE HD coming out? That's why I've just got a brand new shiny slinky Macmini dual core! Any other NLEs for the Mac apart from iMovie?

Cheers, Oliver.

Ash Greyson May 2nd, 2006 03:28 PM

With the tiny sensors on video cameras you always want the aperature WIDE OPEN when possible, less noise, sharper pictures and small DOF...



ash =o)

Curtis Cates May 2nd, 2006 03:40 PM

As for NLEs for the Mac, there's Final Cut Pro, but I'm guessing that you already knew this.

The FU-1000 sounds great -- except for the seemingly many reports of fried circuits on cameras using these. A prone-to-fry 3x lens has me already skittish (I've experienced the infamous "Check Lens" message of 3x death, I had it repaired, and I'm anticipating a recurrence at any time).

I'd love to have the manual lens, but I don't trust my focus ability with the standard viewfinder, and I don't trust the FU-1000.

Scott Di Lalla May 3rd, 2006 10:38 AM

Quote:

Originally Posted by Ash Greyson
With the tiny sensors on video cameras you always want the aperature WIDE OPEN when possible, less noise, sharper pictures and small DOF...



ash =o)


Ash, Interesting, can you give some examples? Let's say I was shooting inside with an XL2, under normal lighting conditions, camera settings: 24p, 1/48 and and the fstop at 1.8. If you were shooting with these settings and it seems just a little bright what will you do? I'm always worried too bright will look blown out, but I guess all that can be corrected in post.

Mark Sasahara May 3rd, 2006 11:53 AM

Quote:

Originally Posted by Curtis Cates
As for NLEs for the Mac, there's Final Cut Pro, but I'm guessing that you already knew this.

The FU-1000 sounds great -- except for the seemingly many reports of fried circuits on cameras using these. A prone-to-fry 3x lens has me already skittish (I've experienced the infamous "Check Lens" message of 3x death, I had it repaired, and I'm anticipating a recurrence at any time).

I'd love to have the manual lens, but I don't trust my focus ability with the standard viewfinder, and I don't trust the FU-1000.

Just be sure that the camera power is completely off-wait a few seconds after the power is turned off and then plug in, or remove the FU-1000 plug. Same goes for when you remove, or attach lenses, and firewire cables, power the camera down, first.

All the video and audio in/outs can be plugged, or unplugged with the power on. I'm not sure about the LANC, but I shut off the camera before plugging, or unplugging the LANC controller.

Oliver, also be sure to check the back focus every now and then, especially as temperature and humidity change.

Ron Dexter has a nifty downloadable focus pattern that you can print out and stick in your kit. Lots of good info on his site too.

You can also do as Camera Assistants do and use a tape measure to check the subject distance and then set the lens accordingly. Be sure to check that the engraved distance matches the actual distance first. At the beginning of the day, after the camera is assembled, check the closest distance and then check a few other farther distances. So try 4.5 feet 6', 12', 20'.

I've noticed that with the Century W/A adapter on the lens, the focus changes, so then the engravings are off.

Oliver Horn May 3rd, 2006 01:35 PM

1 Attachment(s)
Quote:

Originally Posted by Mark Sasahara


You can also do as Camera Assistants do and use a tape measure to check the subject distance and then set the lens accordingly. Be sure to check that the engraved distance matches the actual distance first. At the beginning of the day, after the camera is assembled, check the closest distance and then check a few other farther distances. So try 4.5 feet 6', 12', 20'.

Ah, but where do you measure from? I work in a camera shop and a large number of the digital and film SLRs have a mark at the film plane, (looks like a plimsoll line) I can't find it on the XL2.

I'll also bear in mind the 3x & FU warnings. I've sent my 3x back as when you set it to manual focus and zoom, it sometimes pulls the focus with it, ireespective of the focus's orginal starting point. Also there is no way on the planet you can manually focus smoothly with the 3x, the servo always jumps and stutters. Canon said 'No fault Found', surprise surprise!
Here is my current setup (if the upload thing works.....)
Oliver.

Ash Greyson May 3rd, 2006 01:48 PM

Quote:

Originally Posted by Scott Di Lalla
Ash, Interesting, can you give some examples? Let's say I was shooting inside with an XL2, under normal lighting conditions, camera settings: 24p, 1/48 and and the fstop at 1.8. If you were shooting with these settings and it seems just a little bright what will you do? I'm always worried too bright will look blown out, but I guess all that can be corrected in post.

Never over-expose! Once you go white you cannot recover the data because there is none. I prefer to slightly under-expose but always set your knee to LOW unless you want things to blow-out. There are many ways to control light with the XL2. There are the built in ND filters, external ND filters, the shutter, custom presets and the aperature. The shutter will create an "effect" and should only be used when the effect is desired. The BEST way to control the light is with ND filters and the custom presets... you can set the blacks to press, the knee to low, and turn down the master pedestal and setup levels. You wont lose a ton of DOF by messing with the aperature so dont be afraid to dial it down a little. I personally rarely go higher than F4 or so...



ash =o)

Mark Sasahara May 3rd, 2006 02:57 PM

There is no focal plane mark on the camera. I used to use the beveled corner of the camera where the color bars button is. Once the back focus has been shifted the focus shifts. It's now somewhere in front of the body.

I use the disc on the follow focus, or I'll put white Chartpak tape in the lens and make marks there.

The lens holds focus, it's just that the lens engravings are not accurate.


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