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?

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.

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

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.