Just tested my flashes with results I was not expecting

[bhursey]

Ok so I have always wondered what exact equivalent my flashes were because I shoot really a mixed bag of flashes. I thought this would give me a rough estaminet on how to use my setup in the future.

My friend let me barrow his Polaris flash meter to test this and I am in an way excited with the results and in an way surprised. Note this was not a scientific exact setup.

This is not direct flash power or anything and no I did not test the different zoom settings because I was on my lunch brea and personally I don't care because I was doing it just for me in my real world setup.

In the real world I shoot my flashes normally into an bounce umbrella at like 5 - 6 feet. at 24mm zoom setting into an 43 inch convertible umbrella.

I tested at 100iso 1/250 normally I shoot anywhere from 100iso to 800 iso. I normally start at 400 iso but I wanted to get the fstops full power at 100iso and the max shutter speed. my camera goes to with strobes.

All were shot at full power.

There are a total of 9 ticks and I believe 3 ticks = 1/3 it looks like

Nikon SB-24: f5.6 and 1 tick
LumoPro LP160: f4.0 and 6 ticks
Canon 580EXII: f5.6 and 6 ticks
Yongnuo YN 568EX: f5.6 and 4 ticks
YN568EX+580EXII+SB24 on tri bracket: = f8.0 and 9 ticks
YN568EX+580EXII+SB24+ LP160 on quad bracket: = f11 and one tick

Large softbox direct...
AlenBee AB400 at full power: = f8.0 and 9 ticks.

This is what the quad setup looks like. For the tri bracket just remove the bar and put a flash in the middle.



What do you all think of the results of my tests?

[i speak in math]

What result was unexpected? They all look about right to me.

[sk66]

I am lost..."3 ticks" what is a tick other than a nasty bug? =1/3 what? EV? + or -? The apertures and adjustments are all over the place..if you open the aperture you will have to reduce the power for equivalent exposure...
I'm just not understanding what you were doing or why. F/4-2/3 would seem to be very close to f/5.6-1/9...

[i speak in math]

I am lost..."3 ticks" what is a tick other than a nasty bug? =1/3 what? EV? + or -? The apertures and adjustments are all over the place..if you open the aperture you will have to reduce the power for equivalent exposure...
I'm just not understanding what you were doing or why. F/4-2/3 would seem to be very close to f/5.6-1/9...

I think he means tenths of EV for ticks. Like 5 ticks would be 1/2 stop.

And he's measuring the light output of the flashes, not changing apertures on his camera

[bhursey]

Found out a tick was 1/10th a stop.. Basically what was surprising to me was that the LP160 568EX was advertised generally to be as powerful as the 580EXII or the SB900. Now I never trust guid numbers hence the test. The results of the LP160 was extremely surprising. After testing all my flashes it seems the least powerful at real world portrait setup test. I tested also my 80$ DF400MZ my first flash which I thought was under powered and it tested better than the LP160. Now if you zoom them all the way in have no clue but the majority of the time I use them is bounce in an umbrella. I also was surprised at the tri bracket results being the same as the AB400. I mainly did this test to know what I had to work with and what best to use in certain situations and what flashes to use in combination.

Nikon SB-24: f5.6 +1/10th a stop
LumoPro LP160: f4.0 +6/10th a stop
Canon 580EXII: f5.6 +6/10th a stop
Yongnuo YN 568EX: f5.6 +4/10th a stop<-- December 2012 batch
Vivitar DF400MZ f4.0 and 9/10th a stop

Large softbox direct...
AlenBee AB400 at full power: = f8.0 + 9/10th a stop

And yes measuring the light output of the flashes. Flash meter was set at 100iso and 1/250 shutter speed. So that gives you what the flash would be able to get at that to get a proper exposure.

[scootermcq]

I'm a little surprised by the lack of output. I can get two SB600's to give me f11 at ISO 100 using a shoot through umbrella from 5'

[Rentham]

Interesting. I have a few LP160s and a 580 EXII. I'll see if mine exhibit the same.

[inkista]

... Basically what was surprising to me was that the LP160 568EX was advertised generally to be as powerful as the 580EXII or the SB900.....

I keep seeing this stated over and over, and it's wrong. It's always been wrong. People accept the spec. guide number, and think they're comparing apples to apples, without understanding how zoom works and can cheat the guide number. The LP160 and Yongnuo 5xx flashes have always been around the SB-600 or 430EX in output. The speedlights.net testing (similar to yours, only the aperture settings were then converted to guide numbers) pretty much proved it to me. They tested everything @35mm zoom.

[bhursey]

Interesting. I have a few LP160s and a 580 EXII. I'll see if mine exhibit the same.

I tested at 24mm full power however I realized something I had the spreader cap on it that I think puts it at 14mm. So can you check to see if im right in that the difference is a full stop of light between the two?

The way I set up was 43 inch bounce convertible white umbrella with the black cover on it at 6 feet toward the light meter. I gave the meter back so I can not re test without the cap. I always leave the cap on it so I did not think about that.