DIY Metering
I usually check Worldradiohistory.com everyday to see what is new:
http://www.americanradiohistory.com/American-Radio-History-Updates.htm
Today I saw an issue of Budget Electronics magazine:
https://www.worldradiohistory.com/Archive-Elementary-Electronics/Elementary-Electronics-Budget-Electronics-1978.pdf
This was published by the same people who produced the yearly 101 Electronic Projects series (mentioned before):
https://wb9kzy.blogspot.com/2022/02/101-electronic-projects-magazine.html
Budget Electronics had fewer than 101 circuits in an issue but each one was presented more in depth rather than just a schematic and a parts list. The one that caught my eye today was this light meter on page 79:
Not so much for this particular design but just the idea of building a light meter rather than buying one.
Why would I want or need a light meter ? I have a Nikon D40 digital SLR camera which is quite nice. Originally I bought just the used body on Ebay and was planning to use some of the Nikon F mount lenses that I have. The problem is that the D40 doesn't know what the aperture ring is set to so it can't meter internally with these old lenses. So I ended up buying a pair of zoom lenses that work with the D40 meter. But they just aren't as sharp as the old metal and glass Nikon F lenses.
If I want to use the old Nikon F mount lenses like the 50 mm macro lens (nice and sharp, good for closeups), I have to guestimate the exposure and then adjust it based on the screen image and/or the histogram.
Why not just use a light meter ? I do have old light meters and in fact the old Nikomat FTn camera has a meter. But the problem with them is that the mercury batteries that were used aren't available anymore :(
So now, reminded by this article, I may try building a light meter - this would mainly be for in the house use, closeup pictures for the blog or kit documentation. There are lots of designs on the internet, just a matter of selecting and trying one out. Should be fun !
Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm
