EX3 lens flare adjustment queries? at DVinfo.net

Go Back   DV Info Net > Sony XAVC / XDCAM / NXCAM / AVCHD / HDV / DV Camera Systems > Sony XDCAM EX Pro Handhelds

Sony XDCAM EX Pro Handhelds
Sony PMW-300, PXW-X200, PXW-X180 (back to EX3 & EX1) recording to SxS flash memory.


Reply
 
Thread Tools Search this Thread
Old January 27th, 2010, 12:31 AM   #1
Major Player
 
Join Date: Nov 2008
Location: Melbourne Australia
Posts: 604
EX3 lens flare adjustment queries?

I have been experimenting with the lens flare adjustment menu with the hope of improving the performance of one of my Nikon prime lenses. The EX3 Field Guide says to use an appropriate lens test chart while the Sony Manual does not mention a target at all.

I have tried a black and white lens resolution chart left over from 16 mm days. I have used the full range of adjustments available (-99 to +99) and noticed very little, if any, difference in the viewfinder image. I have also tried various coloured patterns and objects with the same unconvincing results.

I am getting confused, because of the R,G & B adjustments I assumed that flare was something to do with chromatic aberration. However according to Wikipedia lens flare is more to do with unwanted light bouncing around the inside of the lens possibly because of an inadequate lens shade or ineffective lens coatings etc.

I now have more questions than answers: -
1. In the context of this adjustment what is lens flare?
2. What is an appropriate test chart or target?
3. What aperture should one use?
4. Does the viewfinder provide a good enough image with which to make any adjustments?
Alastair Traill is offline   Reply With Quote
Old December 13th, 2010, 04:29 PM   #2
Major Player
 
Join Date: Jun 2005
Posts: 264
Not sure if you are still interested but I can tell you basically how this is done. The process is known as flare tracking and is designed to reduce any spurious light between the elements of a lens or between the back lens element and the CCD optical block. Such light leaks, if I can call them that, can effect the blacks in the picture when you open up your lens causing them to rise up and go gray.

To make the chart get a piece of black Velcro about 1" X 1". The side with the soft hairs. Stick this to the center of a piece of show card about 8" X 10". Light the card as evenly as possible. A small light on each side should work fine.

Connect your camera, any camera, to a waveform monitor and frame up the chart. Open the iris about 25% and adjust the waveform monitor to place the center black signal on the 7.5% line.

Now, open the iris up until the white of the card reaches 100% on the W.F. monitor and see if the black block stays on the line. If it does you have correct flare tracking. Racking the iris up and down the black block should remain on the line or very close to it.

If it comes way up off the line then flare needs to be adjusted. Normally you would do this as R,G, B out of the camera and watch the flare of each channel. If you only have composite out then what you will see is the black signal getting wider as one or more color channels is out of whack.

Only adjust to get the block to just say put or not expand in width. More than that will crush your blacks and you may not see detail in the shadows

That's all there is to it.
__________________
"the difference between an amateur photographer and a professional is the amateur shows you all his pictures"

Last edited by George Odell; December 14th, 2010 at 09:24 AM.
George Odell is offline   Reply With Quote
Old December 14th, 2010, 05:01 PM   #3
Major Player
 
Join Date: Nov 2008
Location: Melbourne Australia
Posts: 604
Hi George and thanks,

I am very surprised that this topic has not caused more interest than it has.
I would have thought the forum would have been full of tweakers.

What do you use for a wave-form monitor?

PS I have tried to email you without success. Is your address still current? f
Alastair Traill is offline   Reply With Quote
Old December 14th, 2010, 05:14 PM   #4
Major Player
 
Join Date: Jun 2005
Posts: 264
Quote:
Originally Posted by Alastair Traill View Post
What do you use for a wave-form monitor?
PS I have tried to email you without success. Is your address still current? f
I corrected my email. Try it now.

Any waveform monitor will work. I have a few Tektronix 528A's and a Magni. They can be had rather cheaply nowadays. With the switch to digital and HD stations and production companies are dumping their old SD equipment.
__________________
"the difference between an amateur photographer and a professional is the amateur shows you all his pictures"
George Odell is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Sony XAVC / XDCAM / NXCAM / AVCHD / HDV / DV Camera Systems > Sony XDCAM EX Pro Handhelds

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 08:47 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network