Hi all, sorry for the longer-than-expected break from this thread. I decided to reembark and complete a few overdue projects that have been on and off for the past 1-2 years. One of them is that I finally finished building a custom PC desktop all by myself. Anyway back to the point, this topic I actually did and completed during April. I wanted to share during July but then decided to put it on hold as I'm trying to get a Sekonic L478D and hopefully a Gossen Digipro into the myth test so as to get a better conclusion. After months of asking around, that seemed no luck in finding and borrow either one. I decided that I will just proceed to post it today. I will update this topic in the future if I can borrow one.
First, I would like to make things clear:
Why?
It all started many months back when I met a person (claimed to be a Professional Photographer) said that his light meters (supposedly a Minolta IV and a Sekonic L308, based on his description) can read a flash exposure from his Nikon SB flash @ 1/64 power from 10-15meters distance. He sort of implied my own Sekonic L408 and Minolta V are both defective since it can't detect his SB flash from a distance about 11-12 meters away.
During that time I was baffled by his claim, and it sort of put me in a serious doubt thinking whether my own meter's light sensor might be deteriorating and losing sensitivity. I have never came across this situation before as I have never taken a flash reading this far and @ such low flash output. My Sunpak 120J lowest is 1/16, Minolta 5400HS is 1/32. And normally if I am at this far a distance, I just chimp from my camera.
After pondering about this for a few days, I decided I will find out myself with a test. On hand I have a few flash meters and I got permission from the owners to use it for testing. I also went ahead borrowing a Sekonic L358 to add into the test as it is fairly new as compared to the other meters. Surprisingly it cleared away my worrying doubt and made me learn and know more about light meters.
Disclaimer:
Please note that this is not a Scientific Test. I try to be as accurate as possible and I only did the test once. It took me 4 hours and 30+ mins when I did it outside my long narrow corridor @ 1am. This is to ensure that the test setup will not be disturbed as everybody is sleeping except me.
4 measuring points @ 2m, 4m, 6m and 8m. Flash output from 1/4-1/32 for Minolta 5400HS and 1/4-1/16 for 120J. At each exposure reading, I will take a reading 5 times to ensure the exposure is accurate and constant. The Sekonic L408 and Polaris don't have rotatable dome heads thus I need to tilt the meters backward so I could see and record the reading. From time to time both meters may have 1-2 reading with 0.01-0.02+- differences. I will than average out to get a reading from the 5 exposures. All flash meters have been reset to default factory setting. If a EU (Under Exposure) is recorded I will pump up the ISO to 400 to read again. If 3 EU readings is shown. The test will end at that record point.
(FYI, Sekonic L358 is a light meter created during the DSLR era. It's reading @ 1/3 stop is cater to DSLR user. I have put the 1/3 increment down so you have an easier time comparing to other meters which are analogue film camera based.)
Besides Flash Exposures, I also mounted a LED panel to test ambient reading. It show something interesting as compared to flash exposure reading. Once a EU reading is recorded I will increase the ISO from 400 to 800. If EU reading still show at ISO800. The test will stop at that point. Also attached a simple diagram on how the setup is been done. Now for Minolta III, according to manual, its flash exposure range is F1.4-F90.9. However when it comes to ambient it show EV1-EV18.2 instead of Fstop. So based on result, I guessed it's ambient reading range is F1.0 to F90.9?
What I gathered based on the data collected:
Lets put the minor 0.03 – 0.01 (1/3 stop) difference between the meters aside. As I mentioned before, this is not a scientific test and some margin of human error and different factory calibration in each meter may contribute to the 1/3 stop difference. The main purpose is to find out -
“Is it possible that a Flash Light Meter can read a flash exposure from a Hot Shoe Camera Flash @ 1/64 power and @ a distance of 10 meters or more?”
Now based on testing with a hot shoe flash zoom @ 35mm, 120J @ wide spread. I am confident to say that the statement from that photographer is absolutely bogus.
Now you might think - hey! how about if that pro photographer zoomed his hot shoe flash @ 105mm or even longer? It might increase the flash output and register a read on his meters? Yes, maybe? But frankly speaking who will shoot like this in most situation? I know I don't, thus I am not interested to find out. I wanted to do a test that is more commonsense, tuned with more logical setting that can be applied to what most photographers may use in most portrait shoot situations.
My conclusions and final thoughts,
1. Know your light meter well, read the manual! Really! Read your light meter manual thoroughly. Each light meter has its exposure range limit. Some have the same reflected/incident ambient/flash range and some have a total different set of range limit. A good example is the Polaris Flash 2. Its flash limit is F2.0 to F90.9 but when come to ambient incident it can measured a surprising low F0.5-F90?
2. Once it went under its flash exposure limit range, increasing ISO would yield the same EU result. However for ambient exposure it does work (1 stop max). Not sure about this... maybe the constant light has a bit more room for the light sensor to detect as compared to the super fast flash burst of light?
3. There is nothing wrong with my Sekonic L408 and Minolta V. Both are functioning properly.
4. Side note: I noticed that my SUNPAK 120J with its reflector set at the standard wide angle produced a similar amount of light with a lesser powered 5400HS zoom @ 35mm. Interesting... (FYI: 120J standard/zoom angle is to pull out the reflector a bit outwards using the circle to circle symbols as guide)
Important: For anyone who have read this sharing and wish to discuss more indepth, please start a brand new thread. You can use the charts I created and discuss from there. I do not want to turn this thread into a heated argument between individuals. I did a test with much effort and time spent and this is where I would like to stop at. Thank you for your understanding.
Lastly a teaser pic for
Polaroid Gals – HONG KONG EDITION! Amazingly I managed to do a personal shoot alone in Hong Kong during a four days visit last month. It is wet, cold, many long recce walks and a few discouraging encounters at times. Anyway I manage to pull it off. I will share more about it during New year eve, so stay tuned everyone.
Oh Christmas is near, wishing everyone a happy happy holiday and Merry Merry Christmas.
Another photo using the same setup. Model is Kaela, a very talented cheery model who can emote and react to art directions extremely fast and very well. She emoted so fast that I had a hard time catching up with her speed. Impressive I must say, as this made my job much easier with less art directing.
