An Apples to Apples Look At Watt Seconds In The World Of Elinchrom Monolights

Comparing strobes and power output ratings from different manufacturer's is impossible because there are too many variables in each design that make it an apples to oranges comparison.

Strobes from the same manufacturer and of the same basic design can be compared and in this comparison you'll see how Watt seconds translate to a meter reading, and that reading may or may not surprise you.

I tested five different Elinchrom strobes, three of which I own and the fourth was borrowed for testing purposes.

The four strobes are the 600RX, BX500Ri, D-Lite 4it, 300RX and BX250Ri, with Watt second ratings of 600, 500, 400, 300 and 250 respectively.

Conditions were very controlled. I set up in the center of my studio. Each strobe had the Elinchrom 7" reflector mounted with the center of the flash tube aligned with the center of the dome on a Sekonic L-758DR that was mounted to a light stand. The meter and strobe position were fixed and were 4 feet apart.

Here are the numbers at ISO 100.

Strobe - Full Power Reading - Minimum Power Reading

600RX - f/45 - f/8

BX500Ri - f/32 + .9 - f/11 + .3

D-Lite 4it - f/32 + .6 - f/8 + .9

300RX - f/32 - f/5.6

BX250Ri - f/32 - f/8 + .4

If you're in the market for an Elinchrom strobe to use as your main light on location and you're either not interested in the features of the RX or they're not within your budget, then you can save yourself some cash and stop losing sleep because the measured difference between a 500 Watt second BX500Ri and a 600 Watt second 600RX is .1 EV. That's only 1/10 stop difference, folks.

Take it a step further. Let's say you don't need that maximum power output and you can get away with a little less. The 400 Watt second D-Lite 4it outputs .4 EV less than the 600 Watt second 600RX. That's 4/10 stop. Again, if features or other factors weren't playing a role in your decision and you wanted to maximize power for the dollar, then look at all the cash you save and you don't even lose 1/2 stop. Looking at it the other way.... think about how much money you're spending to get what doesn't even amount to 1/2 stop. It's an almost $600 difference.

Now don't get me wrong... there are other reasons why we buy BXRi's or RX's but when the decision making process is about power and budget then it's good to understand that while bigger may be better, the numbers aren't linear when it comes to Watt seconds and not all instances of increased power amounts to anything significant in actual usable light, but it amounts to a huge number in terms of cash. Like everything else, it's all relative based on your needs and budget.

If the top end of the power spectrum isn't important or you're more interested in how low you can power down then the 300RX is great because it gives you one more stop than either the D-Lite or BXRi. You could also use the BX250Ri or D-Lite 2it. You may have also noticed that the RX gives you the 6 stop range, as specified. The BXRi and D-Lite are a little shy of the 5 stop range specified by Elinchrom.

Great post.

Thanks for doing this Rob, this is great info. I'll add some more test results to the mix since you've got the ball rolling.

I used your same methodology, 7 inch reflector, Sekonic L358 meter, 4 feet from tube to dome, in the middle of an open room, light and meter fixed on stands for consistency. Battery packs both have a full charge, both have the "A" heads. I used max power on the A port and minimum power on the B port. I used the Quadra-EL adapater to attach the 7" reflector to the strobe head.

I'm encouraged that our tests are comparable, because I got the exact same readings for the BX500Ri.

Strobe - Full Power Reading - Minimum Power Reading

BX500Ri - f/32.9 - f/11.3

BX250Ri - f/32.0 - f/8.4

Ranger Quadra - f/32.0 - f/2.8.9

Ranger RX Speed AS - f/45.7 - f/4.0.4

The one that jumped out at me was the Quadra's output. I suspect that the EL adapter robs some of the light output by being slightly less efficient than the standard EL mount.

I did a second test at full power, this time into a 39" Deep Octa with inner diffuser to see if capturing/diffusing the light helped equalize any disadvantage that the Quadra had compared to the BX250Ri. This time, the Quadra had a 3/10 stop advantage at full power over the BXRi. That's still not very much considering that it should have 7/10 of a stop more power than the BXRi. So, either the EL adapter costs you 4/10 of a stop of power by being a less efficient reflector, or the Quadra is less powerful than specified. I guess on the flip side, the Quadra is capable of the lowest power output, beating the Ranger by 2/10 of a stop, despite specifications to the contrary.

I'd be curious to know if this is consistent across all Quadra's, or if it's just mine.

Interesting posts. Thank you very much!

Cathpah wrote in post #12680430
Great post.

zwicko wrote in post #12681173
Interesting posts. Thank you very much!

Thanks. This topic comes up a lot and I figured that rather than get into the math or overcomplicate things, I'd just express it in the simplest possible way.

Sheldon N wrote in post #12680790
Thanks for doing this Rob, this is great info. I'll add some more test results to the mix since you've got the ball rolling........

Hi Sheldon.

That's excellent that you were able to duplicate the test and results. Thanks for adding to the list.

Thanks Rob and Sheldon for running these test I am sure it will help many including me it making future purchases. I did have a few questions though.

Rob your test made a good case for the d-lite 4.
Do you think that the modifier locking mechanism and parts that mount to a stand are durable and can be used with any and all of the Elinchroms modifiers for long term use.

Sheldon I am left wondering how it is possible that the Ranger RX didn't do better in the full power test considering its rating. I believe you saw what you saw I just don't like it (being a happy owner of a RX kit). It also makes me wonder how all of the battery and head kits would do in this test PCB, Profoto etc.

I looked at the spec sheet again and it seems a little clearer if I am reading this right.

Ranger RX AS A output max power 733ws
Ranger RX output 1100ws

Hi David,

It certainly does make a good case for the D-Lite 4. I just picked one up to use for location work and as a spare, whenever needed.

I was going to post this to the Elinchrom thread, and I probably will, but I did a good deal of testing with the D-Lite 4 using everything from a 22" beauty dish to the 39" Deep Octa, 53" Octa, 69" Octa, and a Photoflex 36" x 48" softbox. I never had to crank down on the ratchet handle and never felt I was overtightening to lock the swivel mount in place. I also left the 69" octa set up for 24 hours to see if it would creep. It stayed in position perfectly and the actual accessory mount was just as stable. I can't see any reason not to use that combination.

Regarding testing other strobes. That would go back to an apples to oranges comparison, which is what I don't want to do.

david lacey wrote in post #12682604
Thanks Rob and Sheldon for running these test I am sure it will help many including me it making future purchases. I did have a few questions though.

Sheldon I am left wondering how it is possible that the Ranger RX didn't do better in the full power test considering its rating. I believe you saw what you saw I just don't like it (being a happy owner of a RX kit). It also makes me wonder how all of the battery and head kits would do in this test PCB, Profoto etc.

david lacey wrote in post #12682651
I looked at the spec sheet again and it seems a little clearer if I am reading this right.

Ranger RX AS A output max power 733ws
Ranger RX output 1100ws

When you run just one head in the A channel, you get all 1100 watt seconds. When you are running two heads simultaneously, then the A channel output will reduce to 733 watt seconds.

The reading wasn't too far off what you'd expect. It should be just less than one stop more powerful than the 600RX, and that's right about where it came in, give or take a few tenths. I think the BXRi's also seem to put out a little more power than you'd expect them to.

The studio strobe that seems the most attractive to me is the 300RX. Seems to have plenty of power for normal use, and goes the lowest of all the studio strobes by a noticeable margin.

Sheldon N wrote in post #12682835
The studio strobe that seems the most attractive to me is the 300RX. Seems to have plenty of power for normal use, and goes the lowest of all the studio strobes by a noticeable margin.

Agreed. I've found the 300RX to be a very useful strobe in the studio. The RX is also desirable because it does give the range specified by Elinchrom. With BXRi's and D-Lite's, they are rated at 1 stop less than the RX but that is compounded by the fact that those strobes fall short of the specified range by about .4EV, or 4/10 stop, leaving you with a 4.6 stop range.

Rob,

I understand not wanting to complicate the testing with all light kits. Hopefully someone in the PCB, or Profoto world will want to pick up the ball and try to simulate the test procedure in another thread matching the same conditions.

I am glad you worked the D-Lite over with the 69" Octa. I have read people dinging the D-Lites build quality and even though I take it with a grain of salt I do start to question if it could be true. If it holds up a 69" Octa just fine that is good enough for me. As I work my way into multiple light studio setups I plan on adding at least one of the D-Lites to the mix.

Sheldon N wrote in post #12682835
When you run just one head in the A channel, you get all 1100 watt seconds. When you are running two heads simultaneously, then the A channel output will reduce to 733 watt seconds.

The reading wasn't too far off what you'd expect. It should be just less than one stop more powerful than the 600RX, and that's right about where it came in, give or take a few tenths. I think the BXRi's also seem to put out a little more power than you'd expect them to.

The studio strobe that seems the most attractive to me is the 300RX. Seems to have plenty of power for normal use, and goes the lowest of all the studio strobes by a noticeable margin.

i really like the 300RX, i have 4 of them 1/2800 T1 time

Sheldon, I was comparing the RX speed in your test with Robs 600RX and that was where the question came from. Compared with the BX500Ri it seems OK, I guess the 600RX reading seems high but again I am sure Rob saw what he saw.

david lacey wrote in post #12682866
Rob,

I understand not wanting to complicate the testing with all light kits. Hopefully someone in the PCB, or Profoto world will want to pick up the ball and try to simulate the test procedure in another thread matching the same conditions.

I am glad you worked the D-Lite over with the 69" Octa. I have read people dinging the D-Lites build quality and even though I take it with a grain of salt I do start to question if it could be true. If it holds up a 69" Octa just fine that is good enough for me. As I work my way into multiple light studio setups I plan on adding at least one of the D-Lites to the mix.

Hey David,

Other than knowing exactly how those strobes perform, I still don't really see the point. Reason being that other brands don't have multiple lines of strobes with interim power levels to complicate things. PCB has 160, 320 and 640 Watt second strobes. They're all 1 stop apart. Profoto has 250, 500, and 1000 Watt second strobes, all 1 stop apart. Hensel has the same.

Jump to Elinchrom and you've got 200, 250, 300, 400, 500, 600 and 1200. Most people that don't understand Watt seconds and the lack of linearity don't want to know about the math or how to calculate the actual gain or loss of light based on an increase or decrease in Watt seconds.

The purpose of doing this within the Elinchrom product line was to spell out how choosing 500 or 600 Watt seconds really makes no difference in the actual output, and if someone is going nuts because they want more power and can't afford a 600RX, then no big deal. If power is the issue, they lose ~1/10 stop.

With other brands that offer 2 or 3 strobes that are rated 1 stop apart, you can pretty much count on that, give or take small percentages. That makes it easy to assess your needs and to build a lighting kit. It's not quite as easy or obvious with more choices that fall in between those whole stops.