noisy blue channel

PerroneFord said:
What do you mean by preset?
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Every 2/3" camera I've owned has a 3200K preset and A and B white balance channels. Most require optical filtration for 5600K scenes. Clearly, these cameras
are setup with tungsten light as the baseline.
 
Ah, ok. Gotcha. Were these mostly studio-themed cameras or ENG style? I'd think ENG type cams would be more at home in daylight.
 
PerroneFord said:
Ah, ok. Gotcha. Were these mostly studio-themed cameras or ENG style? I'd think ENG type cams would be more at home in daylight.
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PerroneFord,

These were all ENG and studio companion portable cameras, all setup just like a studio camera--the studio companion portables have to match a studio camera to live up to the name. It isn't a CCD only issue, same with tube cameras, same with EX1/3 and other CMOS cameras I'm aware of--except RED ONE.
 
Facts

Facts

While I am not sure about the Panasonic 3CCD systems, here are the facts I know to be true:

Echoing what Dino said, I have worked with several Sony Betacam SP and HDCAM cameras (ENG-style shoulder mount) that have sensors balanced for 3200K. They have optical filters (85) to correct for daylight, and lose some light using them.

Every still camera with a single CCD or CMOS with a bayer pattern that I have ever looked at (and I used to work at a camera store and repair shop - I've seen hundreds of point & shoots and DSLRS) has a sensor balanced for daylight, and uses white balance to correct for tungsten, thus increasing the noise in the blue channel, which is already the noisiest to begin with.

The RED Mysterium sensor has a published spec of being natively 5000K.

I have completely redesigned my lighting kit to be natively 5000K fluorescents, and not only does the RED ONE like it, my good ol' DVX100A seems happy with it, too.

If you want to test it out on your camera, set it up in a tungsten-lit scene, white balance, and record some footage.
Do it again, this time hold a blue 80A filter (an optical one, not a lighting gel) in front of the lens, white balance, adjust your shutter speed to get the same exposure, and record some footage.
If you got your exposures matching, look at them on your computer. If your sensor is daylight balanced, you should see more noise in dark areas on the white-balanced shot, and by looking at individual red/green/blue channels, the blue channel should be noticeably noisier.
 
Thank you all for your wise input, but I am a bit unclear on something...

Perrone seems to think cameras are daylight balanced or equally balanced, whereas Dino says many or most are tungsten balanced.

Which is correct?

Is my 170 equally sensitive to all colors? If so, does tungsten lighting still pose a threat to the relatively clean image I see under daylight balanced?

This whole daylight balanced camera issue worries me, seeing that I just invested in an expensive tungsten kit.

You see, I'm shooting a feature this winter where almost half of the shots take place in a hotel room at night.

I purchased this lowel kit assuming I would be able to balance to daylight no problem, without having to resort to the light loss of filters or gelling my rifa88 (pain in the arse)

if it IS an issue with this camera, should I just purchase all CFL bulbs and balance to 4400k or whatever they are? (for indoor shoots)


Once again, thank you all.
 
Your HPX170 is fine. I use tungsten all the time, this is not an issue for this or frankly any other CCD camera that I have ever worked with. Please just use the camera with the tungsten lights, white balance, it will be fine.

Merry Christmas,

Jan
 
DanHD said:
Thank you all for your wise input, but I am a bit unclear on something...

Perrone seems to think cameras are daylight balanced or equally balanced, whereas Dino says many or most are tungsten balanced.

Which is correct?
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Please listen to Dino. I have no experience with the 170. My comments stem from my experience lighting for the EX1, and from Panavision's technical info. These may well not apply to your camera.
 
Hi,

The 170 camera has 2 white balance settings built in, 3200K and 5600K. It operates equally well undert either setting with no pronounced blue channel noise. CCDs are very different from CMOS, good to know the difference as the rules are not the same for both.

Best,

Jan
 
DanHD said:
Is my 170 equally sensitive to all colors? If so, does tungsten lighting still pose a threat to the relatively clean image I see under daylight balanced?

if it IS an issue with this camera, should I just purchase all CFL bulbs and balance to 4400k or whatever they are? (for indoor shoots)
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Dan,

Blue channel is noisier than green and even red in all cameras I've ever seen. This is due to blue being the lowest luminance value of the three channels. Because blue makes up such a small percentage of the luminance, the noise will not be apparent. When it comes to luminance noise, the green channel will be
the culprit. With chroma noise, it's usually the red channel that is most obvious.

The one feature I'd love to see added to an HPX170 via firmware is a -3db setting, like the EX1/EX3 and every 2/3" camera I've owned. This will reduce noise in any lighting situation.
 
Good point Dino. My Ex1 never leaves -3 unless I absolutely HAVE to. And it is here that I notice providing daylight balanced lighting really keeps the blacks clean.

Did you find in your experience when shooting with the larger cameras that providing light with more blue in it, and shooting at -3 improved your images? Or did you find that since the cameras were tungsten balanced, it hurt your images using daylight?
 
PerroneFord said:
And it is here that I notice providing daylight balanced lighting really keeps the blacks clean.

Did you find in your experience when shooting with the larger cameras that providing light with more blue in it, and shooting at -3 improved your images? Or did you find that since the cameras were tungsten balanced, it hurt your images using daylight?
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PerroneFord,

My experience is with tube and CCD cameras, so maybe there is a difference with CMOS sensors, but I just can't see how a daylight balance would affect the noise in blacks unless black balance or flares are not set correctly.

There is no question that the RED ONE performs better in daylight balance, as do many DSLR cameras. The RED ONE is also very susceptible to IR shifts.

I have never seen a perceptible noise difference in daylight vs. tungsten balance with a 2/3" camera. I shoot with Kino Flos at 3200K and 5600K all the time and just don't see it.

In the days of analog cameras, it was good not to be at the end of the range of any white balance circuit or detail circuit or gamma or whatever, but with digital cameras it's not an issue.
 
Dino said:
PerroneFord,

My experience is with tube and CCD cameras, so maybe there is a difference with CMOS sensors, but I just can't see how a daylight balance would affect the noise in blacks unless black balance or flares are not set correctly.
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You know what, now that you mention it, I have not done a black balance on the EX1. Always did with my two Pannys. I'll do that Monday and do some test shots.
 
Thank you Dino and Jan you guys are lifesavers.

And Perrone, I did check out the Panavision Tech Seminar you posted, tought me alot.

It did that they focused more around blue nose issues in CMOS sensors with Bayer patterns than three chip cameras.


So, i'll take Jan and Dino's word for it and shoot tungsten.


Oh, another thing Perrone, what k temp are those CFL bulbs you're using?
I might buy those for my lowel's because of they are virtually heat free and don't cause the talent to sweat all their makeup off
 
And one more question

I know the Red has a noisy blue channel, because of the gain added to compensate under tungsten

This is a good one for Jan to help me out on

What seperates my 170 from the Red, as far as sensitivity?

Is the Red just simply less sensitive to Blue, and the three chips in the 170 are equally sensitive

It's strange to me that an 18,000 dollar camera would have very obvious problems with tungsten whereas a 5,000 camera is fine..
 
DanHD said:
And Perrone, I did check out the Panavision Tech Seminar you posted, tought me alot.

It did that they focused more around blue nose issues in CMOS sensors with Bayer patterns than three chip cameras.
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Did you happen to note that the slides were titled "Genesis" which is not a CMOS camera?


DanHD said:
Oh, another thing Perrone, what k temp are those CFL bulbs you're using?
I might buy those for my lowel's because of they are virtually heat free and don't cause the talent to sweat all their makeup off
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I use 3 different ones temps. I have some 2700k which are a close match to my Halogen work lamps. I RARELY use these as there is so little blue in them, they give off too much noise in the camera. Much better to augment practicals in a room. I have some 3200k ones that I use to color match my tungsten fixtures. And I have some 5500k ones that I use as daylight balanced.

What really sucks is that the daylight ones available at H.D. are the lowest output. I can get the 2700k in 150w equivalent. But can't get the 5500k ones in anything over 100w. There are ways around this issue, but it's disappointing nonetheless.
 
DanHD;1502004t said:
an 18,000 dollar camera would have very obvious problems with tungsten whereas a 5,000 camera is fine..
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LOL!

Given that the vast majority of the folks at a level to shoot the RED One are using HMI's indoors, I suspect they see the increased blue sensitivity as a real bonus, not a "problem".

What REALLY boggles me is why Kodak hasn't spent more time and effort developing a more solid daylight film. 5218 (Tungsten balanced 500ISO) has got to be their best seller for features, and 5219 will probably be right on it's heels.

I'd like to see what that Fuji Eterna 250D looks like without coloring.
 
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DanHD said:
Is the Red just simply less sensitive to Blue, and the three chips in the 170 are equally sensitive

It's strange to me that an 18,000 dollar camera would have very obvious problems with tungsten whereas a 5,000 camera is fine..
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RED ONE is single sensor CMOS technology with Bayer filtration, 170 is three small chips and a prism. Obviously the Mysterium sensor in the RED ONE exhibits more noise in the blue channel at 3200K, so they setup the camera to be optimal at 5600K. It is not a particularly fast camera. Even though it has a large sensor, the 4K pixel count means each pixel is small. The 170 uses small sensors, but the much lower pixel count of each makes for better light gathering.

There is no way all three CCD's in a 170 can be equally sensitive because as previously discussed, each color channel makes up a different luminance value due to the different color frequency responses.

Comparing a 170 and RED ONE is apples in oranges in almost every possible way technologically. The RED ONE does a whole lot less processing in the camera than even the most low-end palmcorder. No toe, gamma, knee or hard clip circuits--each color channel clips at different IRE. It is truly a post-production camera, not dis-similar to shooting RAW with a DSLR and finishing in Photo Shop. But it captures so much more information than any
palmcorder and most 2/3" cameras and HD formats that the extra work in post is worth it for many users.
 
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