Don't Judge A Strobe By The Number of Watt Seconds: A Direct Comparison

PacAce wrote in post #7635608
Vadim_C, if you have numbers or references to prove your point about Robert's tests being flawed or the results incorrect, please present them. You have heard the phrase, "put up or shut up", right? Otherwise, as far as I can tell, your arguments are based on assumptions, conjectures and/or speculations and have really taken this thread off course.

I do not believe I find myself trying to prove that a reflector can grossly changed the light measurement of two lights with the same light output.

Essentially what OP did he compared the guide numbers of the strobes in a nonstandard manner since the position of the lightmeter was not in the usual location. But that does not change the essence of the test.

You need references ? Good.
Here is one from all our favorite Paul Buff site:

http://www.alienbees.c​om/specs.html

We get a lot of questions asking, what is the "guide number" of your flash unit? This term is not wholly reliable because it relates more to the angle of the reflector than to the actual amount of light produced. For example, a flash unit with a given amount of light output will register a much higher guide number (f-stop at 10') if it has a narrow angle reflector (for telephoto lens) than if it has a wide angle reflector. But the actual amount of light is the same in both cases…it just covers more area with the wide angle reflector (at a lower guide number). In comparing flash units, the max GN of a flash unit is usually given for ISO 100 film. When it comes to choosing a flash unit, you have to be careful, as these measurements can be altered. It is common practice within the flash unit industry (for marketing reasons) to provide the max GN at the smallest coverage, as this will provide the longest focal length. Such a focused flash unit is more powerful, which produces a higher Guide Number, implying a more powerful output. Therefore, the max GNs of different flash units are usually not directly comparable. Studio flash units are designed to be used in many different configurations, with different accessories. The angle of coverage will be different in each case as will be the achieved guide number for a given amount of emitted light. As merely an indication of output, we publish the max guide numbers, noting that they are not true measurements of what you can do with our lights, as the real output will be determined by how you choose to modify the light.

The OP presneted the Elinchrom as two times more powerful than Visatec Solo. Sure it could affect the decision of a casual reader when considering Elinchrom versus some other lights.
I hope I presented my point in easy to understand manner. If not so be it I am not going to spend my on this.

vadim_c wrote in post #7638661
Essentially what OP did he compared the guide numbers of the strobes in a nonstandard manner since the position of the lightmeter was not in the usual location. But that does not change the essence of the test.
.

What is 'non standard' about taking a reading a short distance (48") from the flash tube? You mean I cannot position my light 48" from a tabletop product (or shoot with a small softbox 48" from my human subject) and make a reading with an incident light meter at subject position, because it would result in my coming to an invalid conclusion?!

I can't comment on the technical stuff as I don't understand it all, but I can comment on the attitude. We've all seen others that display the same rude attitude, and we know they don't stay for long; either by his/her own choice, or the choice of a moderator with the power to ban someone.

I'd sure hate to see relevant information and resources disappear because the source is bashed repeatedly.

vadim_c wrote in post #7638661
The OP presneted the Elinchrom as two times more powerful than Visatec Solo. Sure it could affect the decision of a casual reader when considering Elinchrom versus some other lights.
I hope I presented my point in easy to understand manner. If not so be it I am not going to spend my on this.

Photographer is not a science. Anybody that pretends it is and talks like a pseudo-scientist is always a poser.

Every working photographer knows that two brands will often meter very differently even if their WS are advertised as being equal. WS are just a general guideline. In fact, meters only provide general guidelines too. Meters aren't all calibrated to the same standard. The way that the meter is used will also vary between photographers. The aperture of a lens a photographer is shooting with may claim to be 2.5 but may actually be 2.4. The subject a photographer is shooting might meter at a certain F-stop but may actually require a completely different F-stop to preserve detail in the highlights or shadows. The camera might be set to daylight balance but the file captured might appear colder than daylight. There are a million variables. This is not a science. The best photographers know that it's an art and not a science and they learn to work with their gear by being very practical. They ignore theory, and rely on practical experience.

The only thing that matters to the photographer is how his gear is going to work in a practical studio setting. That's it!!! None of pseudo-science matters.

BTW - I love the references to guide numbers. Only rank amateurs even worry GNs. Nobody else cares about them. And the link to ABs...that's a good one...Maybe some lectures on speedlites are coming next?

Gentleman Villain wrote in post #7639232
Photographer is not a science. Anybody that pretends it is and talks like a pseudo-scientist is always a poser.

....

and very true.

Gentleman Villain wrote in post #7639232
Anybody that pretends it is and talks like a pseudo-scientist is always a poser.

I'm not familiar with the term "poser". Does it mean A-hole?

RichNY wrote in post #7639423
I'm not familiar with the term "poser". Does it mean A-hole?

Poser according to urban dictionary.

BCRose wrote in post #7618399
Robert, do you have any affiliation with Elinchrom products? I have read many of your lighting lighting posts and you seem to always have some kind of data explaining how they are a superior product. I am not arguing with you, you are probably 100% correct in all your findings. It just seems like you are a bit exuberant with your support.

Sometimes a product simply is superior.

Also, why would anyone in their right mind bring up a quote by paul buff when it comes to measuring output on anything? This is the same guy who makes up his own measuring system to prove that his lights are more powerful than the competition. (ha!).

transcend wrote in post #7640035
Sometimes a product simply is superior.

Also, why would anyone in their right mind bring up a quote by paul buff when it comes to measuring output on anything? This is the same guy who makes up his own measuring system to prove that his lights are more powerful than the competition. (ha!).

Yeah but his white lightnings are really killer and dependable. I have 4 1200s that are almost 20 years old and have only had flash tubes replaced. They're great for location work when you don't need a ton of power. For that I've always been a black line speedotron fan....In the studio especially...

airfrogusmc wrote in post #7640133
Yeah but his white lightnings are really killer and dependable. I have 4 1200s that are almost 20 years old and have only had flash tubes replaced. They're great for location work when you don't need a ton of power. For that I've always been a black line speedotron fan....In the studio especially...

Not saying they aren't. Just saying using him as a source when talking about measuring output...probably not the wisest move.

It's amazing what one person can do to destroy a thread.

Sounds like his recipe ruining this thread was a whole lot of ignorance, coupled with too much self-righteousness along with a pinch of negativity....and voila! you have one spoiled thread.

This went from a very interesting and important thread for people to read so they too can see just how much advertising plays a part and that "specifications" put out by companies aren't always reliable.

Vadim....do us a favor and keep your negativity to yourself. Your posts on this thread have been ridiculous, and it's been many posts since this thread has been helpful. If all you want to do is bash others, then forums like dpreview and photo.net might be more up your alley.

Here at POTN, we're usually a group of smart, intelligent, and driven photographers looking to sharpen our skills and learn more about the gear and the craft. Naysayers and Debbie Downers need not apply.


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let's be done focussing on those ridiculous posts and move back to the subject that began. Robert put quite a bit of work into this, and I'd imagine he's pretty sick of the negativity as well.

So, I'd propose that given robert was pretty specific in how he setup his measurements.....maybe some of you with other lights can do the same test (ideally with the same light meter, a sekonic L-758dr, to keep this as accurate as possible) and share the results. That way we can get an idea as to who inflates their specs the most(COUGH...Paul C Buff....COUGH)

whattaya think? I'll try and free up some time to do this with my Hensel's before they're all sold in the next couple days. No guarantees....but I shall try.

anyone else?

Rob man I think you conducted a good and valid test. Your test confirms what I have seen in the studio. I have noticed that the WS second does not necessarley mean that two different brands 800 WS lights will have the same output. Some strobes have more efficent desigs than others. Keep up the great test.

A Chimera softbox catalog published back in the 1990's published the results of testing that Chimera had done with a pretty broad variety of head+power pack systems commonly found in professional studios. They were, for the most part, about 2000 w-s power packs. It was very obvious from the Chimera results that the brand to brand difference in light output, from about 2000 w-s, was NOT at all uniform in spite of the numerical ratings. All heads were put into the same Chimera softbox, which served as the 'equalizer' and putting the 'which reflector'. Some 2000 w-s units outperformed 2400 w-s units, for example.

I think this thread has gone way off topic so I'm just going to close since further discussion is not going to serve any purpose here. If anybody wants to continue the discussions unrelated to the original intent of this thread, please create a new thread. Thanks.

It's a shame this thread ended up this way because of one person.