11-27-2019, 08:52 PM
(11-27-2019, 04:40 PM)Ofnuts Wrote: When you use halogen, the color temperature changes with output so the spectrum changes, and the camera isn't built to be uniformly sensitive, it favors the greens.You get a better light source by switching on and off multiple tiny sources such as LED, or by feeding LEDs with a square wave (frequency high enough so that a cycle is negligible compared to exposure duration) in which you change the duty factor.
Gamma is explained here: https://en.wikipedia.org/wiki/Gamma_correction
I've had a read of the wiki page - I need to study it.
However, it seems that the control information exists.
Regarding the light source, I have a multi LED lamp as used for a motorbike running light.
I don't have the equipment setup, to switch the LED on and off, though I probably have a fast switching chip somewhere.
Neither do I have the kit to feed a high frequency square wave ... at least I don't think so.
Possibly a sonification bath, but without a tech data sheet, and I'm loath to connect my meter to the output, to see what is driving the vibrator.
What do you think about the sonificator?
Otherwise...
Would it be fair to say that an LED using an unmodified supply, will be better than a halogen?
Having said that...
I've just tested the LED assembly with my modified battery charger, that can be adjusted via a dimmer switch.
The LED can be made to go brighter, but I believe that it's circuitry includes regulators.
It wasn't a lab test, but the light seemed to peak and stay there, even though supply was increased.
Perhaps a halogen is more relevant, and easier to understand.
... it's early days.
Anyway; every experiment has its tolerance limits.
It may be, that by carrying out the tests, it will be possible to accommodate corrections into the equation, to gain a reasonably accurate result.
I will build the black enclosure, to provide light entry, and camera access.
(I'm toying with how best to achieve this)
Thereafter, we will see what we see, and make adjustments accordingly.
I've just taken a DNG image, using Open Camera - 30.3 MB
It also saves a jpg set to 100% - 8 MB
I'm now about to locate and download a DNG converter - I believe Adobe provides one FOC.
This project is set to rumble along nicely
