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-   -   Budget Light Meter (https://www.dvinfo.net/forum/photon-management/503544-budget-light-meter.html)

Ray Turcotte March 18th, 2012 07:50 PM

Re: Budget Light Meter
 
Thanks Gary for setting me straight!

I did some testing with my A65 & AX2000 cameras. I set up a controlled lighting setup and pointed both of my cameras at a 18% grey card.

Using the A65, I confirmed the Sekonic metering in incident and reflected modes (if held close to the 18% card) was accurate in both photo HD_cine and photo metering modes with the TTL metering of the A65.

I then mounted my Ax2000 at the same distance from the grey card, and by experimentation, found out that at 0db gain the AX2000 is shooting at an equivalent of 400 iso. As 6db gain is a doubling in the logrithmic scale, Iso 800 matched 6db gain and ISO 1600 matched 12db gain.

So I can use the Sekonic as I originally intended.

Now doing this test with the CX550v is not possible as the 550 will not display the exposure data on screen, so I'm going to assume its about the same.

Boy did I learn a lot from this discussion...thanks.

PS. Hype advertising and poor product documentation will always get my blood boiling. It wasn't too long a go when manufactures would include detailed and well written documentation that helped the consumer get the best out of a product. With the global shift to "lowest cost production" and very short product cycles, the manuals have become useless.

Gary Nattrass March 19th, 2012 02:39 AM

Re: Budget Light Meter
 
Good to hear you got somewhere with it and your tests showing 0db as ios 400 also tallies in with my -3db for iso 320.

I know what you mean about manuals and I suppose they have to be seen as reference manuals these days as manufacturers seem to assume that you know how to operate their kit or still write them thinking that a salesperson is there to give you advice as well.


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