Back to topic.
I did some small experiments to try and boost light input from afar too do 2 things, so as to raise the low end light levels above noise and so I can move the sensors further away so I can avoid the sensor case casting a shadow on the screen. With a slightly boosted signal overall possibly will help readings in general.
I tried using some small toy binoculars. These as predicted by some reduced the signal.
Next I tried a lens from an old slide projector. This had potential, but has the issue of being sensitive to tuning to a focal length. Too hard for us in the long run.
Next a neat bit of DIY. Cheap and effective. A light funnel.
Working on the principal that light bounces off surfaces at acute angles, ie greater than 15deg I found a piece of 45mm round clear plastic bar 90mm long. I then lathed it into a cone shape with an angle of 15deg down to 8mm at one end. The final shape looks like an icecream cone. I polished the whole finnished piece as to aid reflectiveness internally.
How it works. The large end area is the collector and the small end is the funnel which is placed in front of the sensor. Basically its about ratio, the collector has a 31:1 ratio in surface area. This is about light traveling in straight lines off a surface, the most powerful for us here. This collected light is funneled to the small end area increasing the light intensity.
The funnel doesn't need focal tunning at all, only direction, but we have to do that anyway.
I ran a proof test on my PC screen with the sensor placed 300mm from the screen.
All lights were off in the dark.
Interestingly I used the device to try a calibration and found it easier to get results, dispite the extra range of 300mm from screen, whereas a sensor on the screen left me off target at the bottom end.
Anyway the proof of the exercise.
In the attached file check the "measures" run I did.
The first half of measurements is without the funnel, then it spiked as I placed it upon the unit, then notice the luminance values go from 0.47 to 0.65 and since this value is not linear the result has potential of my aim of raising the low end response above noise so one can set black point brightness and get low end balance figures.
I was pleased to see the other figures, delta E, temp not change although there was a slight change in red. Maybe responding better.
I suspect by using larger round material and making a larger collector you could gather more light. Dishing the collector end may help collect wide angle light coming from wider afield, without the need to go wider material.
All in all a cheap and effective result and worthy of further tuning. The only thing I don't want to do is get to sensor saturation and haven't really looked into that as of yet.
btw Laric, With the V1.1.5 DVD I did find a small error in the 00IRE part of the "contraste". It strangely worked in v1.1.4 now doesn't in v1.1.5.
I just used the grey scale 00IRE instead.
If it was on auto from probe it would crash.
Opticrun001.zip 1.71875k . file