Basics Advice: ND Filters, Iris, Saturation, etc. at DVinfo.net

Kevin Wild · December 27th, 2004, 12:01 PM

I've only had the XL2 for about a week and have been doing some testing. While the picture is very good, I have a couple basic questions about what people are doing for the best picture:

Before I go further, note that I did all outdoor tests at -3db gain and 1/60th shutter. For this set of tests, I did 4 x 3 and 60i.

-Is there a rule of thumb about when to use ND filter and irising up vs not using it and irising down? For outdoors shots, I can usually get away with the 1/6th ND setting if I iris down...but can also open iris on 1/32nd ND. What are the benefits to doing it either way?

-Any tips on improving the saturation levels? I haven't yet tinkered with the menu-based controls, but so far, I've found the colors to be a little flat unless the object you are shooting is very saturated. I've shot outside with a variety of settings and have yet to be satisfied with the amout of blue in the sky. A polarizer filter helped, but still the sky isn't very "rich" in tone. Advice or tips?

Thanks in advance for this review of basics!

Kevin

Barry Green · December 27th, 2004, 02:02 PM

Quote:

Is there a rule of thumb about when to use ND filter and irising up vs not using it and irising down?

Irising down, vs. using the ND filter, are two ways to accomplish the same goal, which is to cut the amount of light entering the camera. But the ND filter doesn't affect the image in any other way, whereas the iris does: changing the iris changes the depth of field (how much of the shot is in focus). So there is a bit of artistic aesthetic decision-making to come into play when choosing whether to ND or to iris.

Also, on a camera with tiny CCD pixels such as the XL2, you have to beware of using small apertures. On an XL2 I'd avoid F/11 whenever possible. F/8 is pretty safe. Smaller apertures can lead to problems with diffraction, where the iris is too tiny and the light "scatters", making your shots quite soft. The smaller the CCD pixels, the more the problem seems to appear; the XL1 had comparatively huge pixels, and it entered diffraction territory around f/32; the XL2 has comparatively tiny pixels and can run into diffraction trouble at f/11. The Sony FX1 has even tinier pixels, and they've even implemented an auto-iris limit to control diffraction.

So stay at f/8 or smaller and you shouldn't have any diffraction trouble.

Quote:

Any tips on improving the saturation levels?

The XL2 is quite capable of a wide variety of looks, due to the extensive menu settings. Learn the settings and what they do, and you should be able to boost the color saturation significantly. Also, tend towards underexposing and you'll bring out richer, deeper color.

Here are some shots I did on the DVX, which has similar menu settings to the XL2. My goal was to simulate some of the looks from Magic Bullet Movie Looks, but do it all in-camera. All these shots were done entirely in-camera, no post-processing whatsoever, but this gives you an idea of what you can accomplish if you use the menu settings to their full effect:
http://www.dvxuser.com/articles/dvxb...%20(WinCE).jpg
http://www.dvxuser.com/articles/dvxb...%20(WinCE).jpg
http://www.dvxuser.com/articles/dvxb...%20(WinCE).jpg

Now, for color saturation, check out this "color reversal film" simulation shot:
http://www.icexpo.com/MagicalProjectileColorRev.jpg
Look at the blue in the sky -- much richer in saturation. This shot was underexposed by 1.5 to 2 stops.

Joseph Tran · December 27th, 2004, 02:26 PM

Hi Kevin,

Here's what works for me:

I use the ND filter and iris up when I need a shallower depth of field (subject in the foreground is sharp, background is blurry). This is especially useful for certain cinematic situations where I want the extra emphasis on the actor and less on what is happening in the background. In this situation, the ND filter is used to manipulate the depth of field.

I'll also use the ND filter and iris up when there is something in the shot that is waay overexposed or "blown out". Usually, that happens when 1.) I am shooting indoors in correct light, but there is a window giving overexposed light in the shot, or 2.) when I am shooting outdoors and the background, usually sky, is very bright. In this situation, the ND filter is used to control the amount of light entering the camera. Sometimes if you do not use the ND filter in very, very bright situations, and set a small aperture setting, your picture may appear blurred.

There isn't really any rule of thumb I know of. The above examples are my basis of using the filter; but I think the best rule of thumb is to try the different conbinations and see which one works best for you.

Regarding saturation levels, I've tweaked the color settings under the custom preset menu. I think that since you have so much control of the color settings in the XL2, Canon erred on the conservative side with the default color. For a warmer, more vibrant color, I bumped the color gain a couple of notches, the R gain a couple of notches, and the G gain equal to, or a notch behind, the R gain. The B gain I turn down a notch or leave as is. Conversely, for a cooler tone, I turn the B gain up a notch and reduce the other two a notch. I take full advantage of the three preset settings -- one for a very warm, romantic setting; one for a colder, perhaps bleek setting; and one for a normal cine color setting. I always tweak little things from there.

Mind you, I've been using XL2 a little differently than you -- I've mostly shot at 16:9, 24P and 1/48th shutter. But the rules are the same, I've tried the above in 60i, and it looks just as wonderful.

Hope I have been of some help.

~ Joseph

A. J. deLange · December 29th, 2004, 08:19 AM

Before boosting saturation levels be aware that the public loves vibrant color and the manufacturers are aware of this. If you and enough other people complain that the camera's colors are too dull the manufacturers will respond by upping chroma gain still further. As it is the XL2 reproduces the 18 colored patches on a Macbeth card at an average saturation 3.1% greater than the saturation of the patches on the card. IMO one is best off leaving the camera settings alone and increasing saturation in post when and where you think it is required.

David Lach · December 29th, 2004, 11:36 AM

Increasing the saturation on-camera is a great risk to run into color troubles, like bleeding for example.

I did have some while shooting an actor with a blue projection screen in the background. The blue bled on his face.

I guess I should have used a vectorscope. I think with DV it's best not to saturate your colors in-camera too much and tweek the look in post.

You can tweek the warmth of your image by adjusting the individual RGB gains to your liking (nothing more than +1, for example I set the R at +1 and both G and B at -1), but leave the overall color gain alone.

Anthony Lee · July 4th, 2005, 03:15 PM

As far as color and image quality goes would it be better to boost saturation in camera or in post? There are other issues that each one brings up but from a pure quality standpoint which is better?

Rainer Hoffmann · July 5th, 2005, 12:49 AM

Anthony,

if we were talking about digital still photography the answer would be simple: do it in post because you have access to 12bit uncompressed raw data. DV is another story because it is already heavily compressed. When you do any color correction in post and the clip(s) has (have) to be rendered (i.e. to be compressed again), the overall quality is degraded (cascaded compression, eeek!).

Having said that, I don't see much difference between a first generation clip and a second generation clip as long as the original clip is of good quality, i.e. not too noisy. In that case I personally prefer doing the color correction in post. As others have pointed out already, if you overdo it in camera you are stuck with less than optimum quality clips that you can't correct in post.

Ash Greyson · July 5th, 2005, 12:43 PM

DV in general is oversaturated and produces illegal colors. This only really become a factor when you get to broadcast or VHS, sometimes even DVD can be an issue. The XL2 has all the color info there and can be easily tweaked in post. The DVX produces WAY more saturated colors in camera, as did the XL1s, however, these can be a real problem, especially red, in many situations.

If you are looking for blue skies on the XL2 in camera, you need to get the camera back to blue and away from green. Turn down the green in the custom settings a couple notches and bump the red and blue.... also make the color phase go in the red direction.

Another HUGE factor in the color is white balance which effects the XL2 more dramatically than many other 3CCD cams... try WB to blue, grey, pink, cream and white... see what you like and how it effects the picture...

ash =o)

December 27th, 2004, 12:01 PM	#1
Kevin Wild Major Player Join Date: Dec 2004 Location: Raleigh, NC Posts: 540	Basics Advice: ND Filters, Iris, Saturation, etc. I've only had the XL2 for about a week and have been doing some testing. While the picture is very good, I have a couple basic questions about what people are doing for the best picture: Before I go further, note that I did all outdoor tests at -3db gain and 1/60th shutter. For this set of tests, I did 4 x 3 and 60i. -Is there a rule of thumb about when to use ND filter and irising up vs not using it and irising down? For outdoors shots, I can usually get away with the 1/6th ND setting if I iris down...but can also open iris on 1/32nd ND. What are the benefits to doing it either way? -Any tips on improving the saturation levels? I haven't yet tinkered with the menu-based controls, but so far, I've found the colors to be a little flat unless the object you are shooting is very saturated. I've shot outside with a variety of settings and have yet to be satisfied with the amout of blue in the sky. A polarizer filter helped, but still the sky isn't very "rich" in tone. Advice or tips? Thanks in advance for this review of basics! Kevin

July 5th, 2005, 12:49 AM	#7
Rainer Hoffmann Major Player Join Date: Aug 2004 Location: Syke, Germany Posts: 249	Anthony, if we were talking about digital still photography the answer would be simple: do it in post because you have access to 12bit uncompressed raw data. DV is another story because it is already heavily compressed. When you do any color correction in post and the clip(s) has (have) to be rendered (i.e. to be compressed again), the overall quality is degraded (cascaded compression, eeek!). Having said that, I don't see much difference between a first generation clip and a second generation clip as long as the original clip is of good quality, i.e. not too noisy. In that case I personally prefer doing the color correction in post. As others have pointed out already, if you overdo it in camera you are stuck with less than optimum quality clips that you can't correct in post. __________________ Keep rolling Rainer

December 27th, 2004, 02:26 PM	#3
Joseph Tran Regular Crew Join Date: Nov 2004 Location: Los Angeles, CA Posts: 177	Hi Kevin, Here's what works for me: I use the ND filter and iris up when I need a shallower depth of field (subject in the foreground is sharp, background is blurry). This is especially useful for certain cinematic situations where I want the extra emphasis on the actor and less on what is happening in the background. In this situation, the ND filter is used to manipulate the depth of field. I'll also use the ND filter and iris up when there is something in the shot that is waay overexposed or "blown out". Usually, that happens when 1.) I am shooting indoors in correct light, but there is a window giving overexposed light in the shot, or 2.) when I am shooting outdoors and the background, usually sky, is very bright. In this situation, the ND filter is used to control the amount of light entering the camera. Sometimes if you do not use the ND filter in very, very bright situations, and set a small aperture setting, your picture may appear blurred. There isn't really any rule of thumb I know of. The above examples are my basis of using the filter; but I think the best rule of thumb is to try the different conbinations and see which one works best for you. Regarding saturation levels, I've tweaked the color settings under the custom preset menu. I think that since you have so much control of the color settings in the XL2, Canon erred on the conservative side with the default color. For a warmer, more vibrant color, I bumped the color gain a couple of notches, the R gain a couple of notches, and the G gain equal to, or a notch behind, the R gain. The B gain I turn down a notch or leave as is. Conversely, for a cooler tone, I turn the B gain up a notch and reduce the other two a notch. I take full advantage of the three preset settings -- one for a very warm, romantic setting; one for a colder, perhaps bleek setting; and one for a normal cine color setting. I always tweak little things from there. Mind you, I've been using XL2 a little differently than you -- I've mostly shot at 16:9, 24P and 1/48th shutter. But the rules are the same, I've tried the above in 60i, and it looks just as wonderful. Hope I have been of some help. ~ Joseph

December 29th, 2004, 08:19 AM	#4
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	Before boosting saturation levels be aware that the public loves vibrant color and the manufacturers are aware of this. If you and enough other people complain that the camera's colors are too dull the manufacturers will respond by upping chroma gain still further. As it is the XL2 reproduces the 18 colored patches on a Macbeth card at an average saturation 3.1% greater than the saturation of the patches on the card. IMO one is best off leaving the camera settings alone and increasing saturation in post when and where you think it is required.

December 29th, 2004, 11:36 AM	#5
David Lach Major Player Join Date: Oct 2002 Location: Montreal, QC, Canada Posts: 570	Increasing the saturation on-camera is a great risk to run into color troubles, like bleeding for example. I did have some while shooting an actor with a blue projection screen in the background. The blue bled on his face. I guess I should have used a vectorscope. I think with DV it's best not to saturate your colors in-camera too much and tweek the look in post. You can tweek the warmth of your image by adjusting the individual RGB gains to your liking (nothing more than +1, for example I set the R at +1 and both G and B at -1), but leave the overall color gain alone.

July 4th, 2005, 03:15 PM	#6
Anthony Lee New Boot Join Date: Nov 2003 Location: Kalispell Montana Posts: 22	As far as color and image quality goes would it be better to boost saturation in camera or in post? There are other issues that each one brings up but from a pure quality standpoint which is better?

July 5th, 2005, 12:43 PM	#8
Ash Greyson Trustee Join Date: May 2003 Location: Tulsa, OK Posts: 1,689	DV in general is oversaturated and produces illegal colors. This only really become a factor when you get to broadcast or VHS, sometimes even DVD can be an issue. The XL2 has all the color info there and can be easily tweaked in post. The DVX produces WAY more saturated colors in camera, as did the XL1s, however, these can be a real problem, especially red, in many situations. If you are looking for blue skies on the XL2 in camera, you need to get the camera back to blue and away from green. Turn down the green in the custom settings a couple notches and bump the red and blue.... also make the color phase go in the red direction. Another HUGE factor in the color is white balance which effects the XL2 more dramatically than many other 3CCD cams... try WB to blue, grey, pink, cream and white... see what you like and how it effects the picture... ash =o)