Reducing DVX noise

Re: Reducing DVX noise

yes, I have done my own tests, sorry I don't have any grabs, but from what I can see, the filter greatly reduces noise outdoors. You can do a semi-test yourself. Just shoot using good tungsten balanced light, and then using daylight, or daylight filters on your lights and you will see the difference. make sure that your tungsten and daylight settings are equally lit, but you will see a difference.
 
Re: Reducing DVX noise

Is the #85 trick going to still going to reduce noise when shooting with no added gain? Also, is there any relationship to f stop? Thanks!
 
Re: Reducing DVX noise

yes, don't shoot with gain turned up, or that will just defeat the purpose. The reason this works is becuase the ccd's are naturally closer to tungsten (32k) than 56k. When you switch the camera to 56k you are infact boosting or adding gain to the CCd's. It is not a whole lot, mainly just boosting the blue ccd, but it does add noise. So if you use the filter, and then shoot with "gain" you are defeating the purpose.
don't quite understand what you are asking in your second question. yes it relates to the f-stop as it reduces the amount of light entering the camera, so you will have to adjust accordingly.
 
Re: Reducing DVX noise

Right. Obviously 85 reduces the light, and that would have to be compensated for with f stop.

Rather, my question about f stop was an attempt to find out if the 85 filter improvements were a global thing:

1) Noticible even with zero gain increase? Looks like the answer is yes.

2) Noticible at all light levels (obviously we're talking about noise in the shadows; I'm just asking if the improvement is noticible, say, outside when there's plenty of light and I'm running at say f11)

3) I assume when lighting with tungsten, with actual light color temp at around 3200k, you would remove the 85, right! (?) Per your comment, " The reason this works is becuase the ccd's are naturally closer to tungsten (32k) than 56k."
 
Re: Reducing DVX noise

By the way, I'm aware that #2 above might look like a dumb question, "2) Noticible at all f stops?"

And, thinking further about it, it IS a dumb question.

I guess I'm just trying to get a handle on your tip. From what you said -- I forget the words, but something like "the 85 was the best accessory investment you made for your X100" it sounds like using an 85 makes a significant improvement. I'm kind of blown away that I've never seen this tip anywhere else.

And of course it does mean shooting through another piece of glass. I'm using a matte box by Cavision, and so I'd have to get the 4x4 #85. But it sounds like it's worth checking out!
 
Re: Reducing DVX noise

1: yep you got it
2: There should never be a grain problem in you highlights, However, even when you are outdoors, you still have shadows, otherwise your image would be all midtones and highlights. The problem is not the lens, it is when it is captured from the ccd. SO even though you are getting good highlights, the ccd's are being boosted, so your shadowy areas could still suffer. Look at it like this. If you shoot 100ASA film outdoors you will use a slower shutter speed and a wider aperature. If you were to expose 400ASA film the same way you would have to close down your aperature and/or increase your shutter speed or add ND filters. The photos would look the same if exposed correctly, however, the 400ASA shot would be noticeably grainier than the 100ASA shot. So even though you are stopping down to f-11 you are still using "400ASA" film and your camera is still boosting your image. There is a lot more that goes into that, but that should just give you an idea.
3: Yes, when shooting in tungsten light you want to take off the filter, otherwise, you will just be boosting the blue CCD again when you white balance the camera.
 
Re: Reducing DVX noise

do you think maybe its possible to hack the dvx to reduce gain down to like -6dB somehow?
 
Re: Reducing DVX noise

not really my department, but if you are looking for a good hack checkout http://www.reel-stream.com.  They are working on a 4:4:4 uncompressed hack for the DVX to be out later this year.  That not only reduces noise, but it will give you a bigger frame size and a lot more lattitude, at least according to Juan.  I have yet to see any test footage but have seen some frame grabs that look promising.
 
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