# This is why I never really depend on light meters



## fjrabon (Nov 9, 2012)

Zack Arias talked about light meters the other day on his blog.  It's all stuff that I think people sorta kinda know, but seeing it all written out right there on one page, to me indicated why you really can't just get a light meter value, program your settings and roll with it today.  I use light meters to get me in the ballpark, but after calibrating the LCD and knowing how to read a histogram, I use those more than the light meter as a 'final guide' to how I want things.  Even after having a great Sekonic, pro level L lenses and a 5DIII, sometimes light meters are just off by 1/3 of a stop when you look at the image.  Or a half stop, or on very rare occasions more.  If a half stop of exposure variability isn't a big deal to you, then I guess, fine, eh whatever.  You can probably just stop reading.

There are just way too many things in the chain that can be slightly off, that then add up cumulatively to your overall image being a bad exposure to just get out the Sekonic, see what it reads, and then set your camera and pop it.  

Even after you take all the painstaking steps that Zack lays out about knowing every single lens you have, at multiple focal lengths and multiple apertures, knowing every body you have, knowing every filter you might use, etc, there are still too many variables that could be off by a half stop to just run with a light meter's readout.  

Anyway, thought it was a great read for multiple reasons.  Perhaps the biggest being the 'so you want to be a pro photographer, well here's the crud you gotta put up with...' aspect.  

Photography Q&A -Ask Me Anything About Photography &bull; Zack, I


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## Robin_Usagani (Nov 9, 2012)

Yeah, I got drilled pretty hard a few months ago for saying you dont really need a light meter for a simple setup.  Anyway, all of my shots I share, I usually use off camera flash and no, I dont use or own a handheld lightmeter.  Do I want one?  Yes.  Will I use one? Probably if I use complicated setup.. maybe indoor.  Do I think it is not necessary to use one on ONE off camera flash setup?  Yes, it is not necessary.  It is not that hard to dial your ONE flash to the right power without a light meter.


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## Derrel (Nov 9, 2012)

I laughed at his improper use of the word "incidence" mode... there is no such thing as an "incidence"mode. The word "incidence" is a noun. The proper word is incident... There ARE,however, such things as incident-light meters. Meters that offer both incident- and reflected-light metering modes do NOT have a mode called the "incidence" mode.

"*I use meters in the &#8220;incidence&#8221; mode 99% of the time. There&#8217;s basically two types of metering modes. Reflective and incidence.* "

Maybe the guy ought to hire somebody who knows the proper terms.

Google the term "incidence light meter".


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## ann (Nov 9, 2012)

that is why one tests their equipment.


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## Derrel (Nov 9, 2012)

His conclusion was interesting: "_I&#8217;m only touching on some of what a good meter can do. You can take several readings to find an average in a scene. You can figure out the ratio of ambient vs. flash in a mixed situation. You can add filter compensation into the mix. There&#8217;s a lot you can do with a meter beyond finding what shutter speed you should use at ISO 800 at f2.8.__Is all of this overwhelming? Does it all sound like it&#8217;s too much of a pain in the ass? Get over it. It&#8217;s called professional photography. Be good at your craft. Begreat at your craft. Think a pastry chef trusts a new oven to be exactly 350 degrees when they set that on the dial? No. They test it. 350 on the dial might mean 380 degrees in the oven. You need to know that. You need to know your cameras. Your lenses. Your lights. Your exposure. Your screens and monitors. You need to test this ****. It&#8217;s boring and tedious and all of that. I know. It is. Get over it. Wait till you build color profiles for all your cameras, lights, and modifiers. Be a professional and do it. Don&#8217;t be another mediocre photographer. There&#8217;s millions of those. Don&#8217;t be one. Be great at what you do. Know what you are doing. Do the hard work to learn all this stuff. It&#8217;s worth it. It&#8217;ll save your ass one day._"

Or....you can just f&&k around, and wing it off the back of the LCD. Shoot, chimp-adjust,Shoot, chimp-adjust,Shoot, chimp-adjust,Shoot, chimp-adjust,Shoot, chimp-adjust--ahhhh, *NOW you have it figured out!!!* Which is plenty accurate right? It's the professional way to do it! The wild-ass-guess,shoot,chimp-adjust method. It impresses the chit out of art directors and discerning clients!


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## kundalini (Nov 9, 2012)

fjrabon said:


> Zack Arias talked about light meters the other day on his blog. It's all stuff that I think people sorta kinda know, but seeing it all written out right there on one page, to me indicated why you really can't just get a light meter value, program your settings and roll with it today. I use light meters to get me in the ballpark, but after calibrating the LCD and knowing how to read a histogram, I use those more than the light meter as a 'final guide' to how I want things. Even after having a great Sekonic, pro level L lenses and a 5DIII, sometimes light meters are just off by 1/3 of a stop when you look at the image. Or a half stop, or on very rare occasions more. If a half stop of exposure variability isn't a big deal to you, then I guess, fine, eh whatever. You can probably just stop reading.
> 
> There are just way too many things in the chain that can be slightly off, that then add up cumulatively to your overall image being a bad exposure to just get out the Sekonic, see what it reads, and then set your camera and pop it.
> 
> ...


B00l0cks.


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## bhop (Nov 9, 2012)

Derrel said:


> Or....you can just f&&k around, and wing it off the back of the LCD. Shoot, chimp-adjust,Shoot, chimp-adjust,Shoot, chimp-adjust,Shoot, chimp-adjust,Shoot, chimp-adjust--ahhhh, *NOW you have it figured out!!!* Which is plenty accurate right? It's the professional way to do it! The wild-ass-guess,shoot,chimp-adjust method. It impresses the chit out of art directors and discerning clients!



That's what i got from the link, and the OP..  

I always depend on light meters if I don't want to waste time.  It's _stupid_ not to.. the catch is, I know how to use my experience to make adjustments when needed depending on the lighting conditions BEFORE chimping.


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## Ysarex (Nov 9, 2012)

ann said:


> that is why one tests their equipment.


:thumbup:

Yep. I depend on all of my equipment right after I thoroughly test it.

Joe


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## kundalini (Nov 9, 2012)

fjrabon said:


> There are just way too many things in the chain that can be slightly off, that then add up cumulatively to your overall image being a bad exposure to just get out the Sekonic, see what it reads, and then set your camera and pop it.
> 
> Even after you take all the painstaking steps that Zack lays out about knowing every single lens you have, at multiple focal lengths and multiple apertures, knowing every body you have, knowing every filter you might use, etc, *there are still too many variables that could be off by a half stop to just run with a light meter's readout. *


I'll be the first to admit that I am far too lazy with post processing.  Any photo that I have posted on TPFis the result in minimal post work.  If you can't adjust your image in post by one stop, then there are larger issues you need to address.  My Sekonic has always set a reliable base line exposure for me.  It has always been true.  The fact that I decide to go one way or the other after the reading has nothing to do with NOT relying on the information the light meter gave.


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## Derrel (Nov 9, 2012)

A WAG is more-accurate than a light meter...is that the takeaway some people are getting from the article???

For those who have not heard the term WAG in a photographic context, it means wild ass guess...whereas in the British tabloid press and on the web, it means (hot) Wives And Girlfriends.

Sorry, but I will trust my Minolta flash meter over my own 38 years' experience when I need to *KNOW* the *EXACT* strength of a flash pop. And I'm a damned good guesser too...but the Minolta reads down to the tenth of an f/stop...all the excess precision and chit...and I mean, it takes like 5 seconds too...such a hassle!!!!


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## Tee (Nov 9, 2012)

If ya wanna chimp and use the histogram then party on, Wayne!  I like using a light meter and it has drastically sped up my workflow.  Less time fiddling, chimping, and histograming.  But then again, I'm practicing using 2-4 studio lights and when I'm paying for studio time, I'm not wasting it chimping and fiddling.  Your OP reads like a manifesto against using light meters...or rather they are untrustworthy.  I find this to be troublesome as many members are new (such as yourself and myself) and will swear off light meters when, in fact, a light meter may be what they need.  Or perhaps you don't know how to use one?


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## panblue (Nov 9, 2012)

A method for scenes lit by incident light using a reflective meter is to divide the shutter-speed
by ten (..from a 1950s Sekonic instruction manual). e.g, point the meter directly at window-light, 
giving say 1/250. Expose for inside the room (light source out-of-shot) at 1/25. :thumbup:



Derrel said:


> I laughed at his improper use of the word "incidence" mode... there is no such thing as an "incidence"mode. The word "incidence" is a noun. The proper word is incident... There ARE,however, such things as incident-light meters. Meters that offer both incident- and reflected-light metering modes do NOT have a mode called the "incidence" mode.
> 
> "*I use meters in the &#8220;incidence&#8221; mode 99% of the time. There&#8217;s basically two types of metering modes. Reflective and incidence.* "
> 
> ...


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## Overread (Nov 9, 2012)

The thing is if the light meter gets you accurately to within 1/3rd or 1/2 of a stop of the correct exposure in a quicker time than chimping would then I would argue that the meter is actually being of great use. Yes you might make a final judgement call that the exposure can be adjusted just a little more once you see the histogram - however that means you've just taken 2 shots (one to chimp and one with the correction) instead of maybe 10 or 20 shots where you were adjusting lights each time - because you used the meter to set those lights in the first place.


I can see a great benefit to reduced chimp shooting. I'm not even thinking of the image it creates of the photographer, but simply the photographers workflow. Firstly taking lots of shots and chimping works, you can check the histogram and adjust without worries provided the light remains constant and the subject in place. However its a nightmare if you come to edit and you've dozens of wasted test shots - one can easily end up mixing up their test from their real shots and deleting in camera is always a slow process and one I aim to avoid (last thing I want to do is delete the wrong shot and put a card out of action for later restoration of the lost shot and that's if you notice at the time).


Sure not everyone uses an external light meter, heck I tried to justify one months ago and really couldn't get much of a justification for owning one for my kind of photography (over using the meter in the camera+some histogram chimping) - or at least not enough of a justification to invest in one at that stage. 
If I were shooting studio lights and wanting good light balance then yes I can certainly see a need for a lightmeter.


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## KmH (Nov 9, 2012)

Like a camera and lens, a light meter is just a tool, and learning how to use it effectively is as important as learning to use a camera and lens effectively.

Good light meters can and should be calibrated, and the good ones can measure light to 1/10 of a stop.

Three 3 types of light worth measuring - incident, reflected, and strobed.


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## fjrabon (Nov 9, 2012)

Pretty sure I said I use the light meter to get within a third of a stop quickly, and then adjust with a bit of fine tuning after that.  I don't know where I ever said that I'd just take a WAG right off the bat.  

My big problem is a sort of complete trust some people put in light meters.  I've seen people literally look at a bad exposure and just say "well, that's what the light meter said."  That's what I was taking a position against.  I think people don't realize how far off light meters can be in certain situations.  

Direct quote from the OP:

"...why you really can't just get a light meter value, program your settings and roll with it today. _*I use light meters to get me in the ballpark*_, but after calibrating the LCD and knowing how to read a histogram, I use those more than the light meter as a 'final guide' to how I want things."

For any very serious number of shots with multiple lights I'd use my light meter every single time.  I'd just make the *final* adjustments based on looking at the calibrated LCD and histogram.  

Although, on the other hand I have talked to a pro who pretty much never uses a light meter...  Joe McNally. ​


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## Ysarex (Nov 9, 2012)

fjrabon said:


> Pretty sure I said I use the light meter to get within a third of a stop quickly, and then adjust with a bit of fine tuning after that.  I don't know where I ever said that I'd just take a WAG right off the bat.
> 
> My big problem is a sort of complete trust some people put in light meters.  I've seen people literally look at a bad exposure and just say "well, that's what the light meter said."  That's what I was taking a position against.  I think people don't realize how far off light meters can be in certain situations.
> 
> ...



The histogram on the camera LCD is derived from the camera/software processed JPEG and as such does not represent the sensor raw capture. I'll take my meter reading, my assessment of the lighting condition and the sensor raw capture and swat down anything the camera software produces all the time and every time.

Joe


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## unpopular (Nov 10, 2012)

That article is a bunch of gibberish.


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## gsgary (Nov 10, 2012)

bhop said:
			
		

> That's what i got from the link, and the OP..
> 
> I always depend on light meters if I don't want to waste time.  It's stupid not to.. the catch is, I know how to use my experience to make adjustments when needed depending on the lighting conditions BEFORE chimping.



Its hard to chimp on a film Leica


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## pgriz (Nov 10, 2012)

unpopular said:


> That article is a bunch of gibberish.



I respectfully disagree.  The basic message of the article was to test your equipment, so that when you take a reading, you will know what that translates to in the final image.

As for using the handmeter (or not), it gives me an additional bit of information about the light, specifically the light intensity hitting the spot that I'm metering.  The camera light-meter tells me what happened to the light after it was reflected/modified by the subject.  Depending on the tonality of the subject, and the artistic intent of the image, I may choose a setting that should allow me to achieve the look I'm going for.  But that is based on my having tested my equipment, and my knowing how the readings and histogram data relate to the final image, which was the point of the article IMO.


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## Robin_Usagani (Nov 10, 2012)

Got to love TPF.  Even an established photographer get drilled here.


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## fjrabon (Nov 10, 2012)

Robin_Usagani said:
			
		

> Got to love TPF.  Even an established photographer get drilled here.



Yeah, I mean I understand pros can be wrong about things, but I'd love to have seen one of the posters here walk on a set and rail Joe McNally for not using a light meter when he was the only staff photographer for Time. Or when he was shooting a product ad for Nikon.


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## Tee (Nov 10, 2012)

Ummm....I'd bet a dozen donuts, a pint of blood to the Red Cross and Robin's triplets that a light meter has graced Joe McNally's hands in the last 30 years.  Only a newb would be bold enough to question him without rationally realizing that this guy has years upon years of years of deckplate level experience.  I don't hold any negative towards Zack Arias and his article (in fact, I've referenced him as someone to study) but rather to your original post with the underlying theme that light meters aren't as cracked up to be as everyone makes them.  You made your point and I'll respect that but I also made mine.  Getting within 1/3 stop using a light meter and having to painstakingly move the command dial a whopping one click to the right or left does not mean the light meter failed.    

I also think we should look at the two sides of camps people are on.  In my very informal and observational thoughts, I've found that those who work primarily with speedlights don't use light meters while those working in studios or using studio lights on location do use a light meter.  I truly feel that influences our thoughts.


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## unpopular (Nov 10, 2012)

My problem with the article is as follows:

1) I am very opposed to SOOC.
2) He does not seem to understand the difference between f-stops and t-stops
3) The ISO does not "permit 1/3 stop" of "wiggle room" for f-ratio. That would be a ridiculous tolerance suggesting that over the last two centuries lens manufacturers haven't figured out how to actually determine their exit aperture. This I've never heard of before and clearly shows an embarrassing misunderstanding of f-ratio and it's limitations.
4) He's stuck using digital as if it were slide film and doesn't appreciate or seem to clearly understand reflectance metering
5) His calibration method is wonky, imprecise and completely unscientific - and then has the audacity, in typical Arias fashion, to go on a patronizing diatribe about "getting over being lazy".
6) He doesn't answer the OP question about "controversial" meter reading, an issue which has never been controversial in the past. This question would have been an excellent segway into lighting ratios - that is, if Arias is even aware of the concept.

In Arias' biography I've read that he got into photography because it was an "Easy A". Well. I think that says a lot here.


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## Tee (Nov 10, 2012)

BTW, in your talking with McNally did he explain the technical reasons why he doesn't use a light meter?  Hint: has something to do with the CLS system.


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## unpopular (Nov 10, 2012)

fjrabon said:


> Robin_Usagani said:
> 
> 
> 
> ...



When you have Time Magazine paying for your set, you can afford to chimp around all day. But with all seriousness, I have no doubt that photographers as proficient as McNally can intuitively predict light accurately enough to not use a meter - especially with flash photography where the distance from the subject is determined without atmospheric concerns.


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## fjrabon (Nov 10, 2012)

Tee said:
			
		

> BTW, in your talking with McNally did he explain the technical reasons why he doesn't use a light meter?  Hint: has something to do with the CLS system.



It's partly CLS and partly he just doesn't feel they're needed in the digital era very often. Even when he goes full manual he rarely uses them. He admitted that he probably should use them a bit more than he does, but he called it mostly a pure preference thing these days, regardless of if you're using SB 910s or Rangers. 

I never meant to imply that light meters aren't useful. I just don't personally like them being the final word. I use a D24 and 4 IL2500s 3-4 times per week. You can meter them once, take a few minute break, adjust NOTHING and meter them again and get a half stop difference. And this is full bore indoors, so it ain't ambient. 

I'm really just saying there are too many variables to see the reading, set it, pop it once and trust that's right. You gotta check your images (both LCD, histo and blinkies) and/or bracket. 

We have this one photographer who turned in some images that were off a full stop, when the scene had a really wide dynamic range to begin with. His excuse?  "That's what the light meter told me!"  That's all I'm railing against.


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## unpopular (Nov 10, 2012)

fjrabon said:


> We have this one photographer who turned in some images that were off a full stop, when the scene had a really wide dynamic range to begin with. His excuse?  "That's what the light meter told me!"  That's all I'm railing against.



If it was a full stop off, chances are he wasn't using the meter properly.


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## fjrabon (Nov 10, 2012)

unpopular said:
			
		

> If it was a full stop off, chances are he wasn't using the meter properly.



Yeah, I'm guessing he metered in the wrong spot. Which sure, the biggest issue with light meters is often pure user error.


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## unpopular (Nov 10, 2012)

A light meter simply reads the amount of light relative to a reference value. Provided the meter does this in a reliably way, then the meter is going to be accurate, period.

From here, we have ISO, shutter speed and transmission. The shutter speed is going to be pretty accurate, todays shutters are electromagnetically driven by accurate electronic timings. Curtain failure is going to be more likely before timing failure. So that leaves ISO and lens transmission.

I say transmission because it differs from f-ratio, at least in the real world. With a pinhole of infinite thinness, exit diameter and focal length are going to directly correlate with transmission, and in an ideal world with perfect lenses that transmit 100% of their light f-ratios would also directly correlate. But in reality, optical systems are inherently non-linear, and still photography lens manufacturers typically don't guarantee that f-stops directly correlate with transmission. Some motion picture lenses do, and you'll pay extra for this, and if you pay extra for this feature, then your t-stop lens will directly correlate with the meter reading, period, every single time, provided that the t-stop scale is accurate. But that is why your cheap-o $2000 zoom doesn't cost $20,000, because it's NOT a Zeiss CZ. Of course, you don't have it on a camera that costs $5,000/day for the privilege of using, either.

But this has nothing to do with international standards tolerances or any other celebrity photographer mumbo-jumbo. It's just the limitations of f-ratio not accounting for the lens' physical characteristics which determine how much light is actually being transmitted. If you REALLY want to determine the t-stop, you can. Set up an incident meter at the rear focus distance from the lens flange in such a way that stray light cannot interfere, and meter through the lens in such a way to read each f-stop (a film camera might be handy), make not of the change in EV on each reading, looking for units greater than or less than one whole number. With a zoom lens, you'll have to do this for ever 10mm focal length or less.

That might be a bit impractical. But ISO inacuracy and gamma correction will not influence the measurement.

And then there _is_ Gamma Correction. Which, unless you're familiar with the subject and have the ability to adjust it, kind of throws the whole calibration issue on it's heal, making the whole issue considerably more complicated - because* the camera is completely blind*. And this is why Adams invented the zone system in the first place, only to have it's concepts thrown under the rug by kids like Arias.


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## Derrel (Nov 10, 2012)

Tee said:


> BTW, in your talking with McNally did he explain the technical reasons why he doesn't use a light meter?  Hint: has something to do with the CLS system.




McNally is also a walking,talking,video-shooting *Nikon-sponsored* ADVERTISEMENT for *Nikon's Creative Lighting System (CLS)* multi-speedlight, TTL metering and flash control system. He is the fellow who shows how one can use four, or five, or six, or even is it eight??? $589 *Nikon* speedlights. He is the face of *Nikon's* entire TTL speedlight promotion network. He is PAYED to show people how NOT to use a light meter, and to demonstrate how to rely on *NIKON*'S TTL light metering and *Nikon's TTL flash metering*.

Joe McNally's job is to encourage people to buy 3 x $589, or 4 x $589 in *Nikon* speelight set-ups,and to demonstrate the capabilities of *NIKON TTL*-controlled speedlight systems. Joe's job is to show people what *NIKON's* equipment can do. In the videos I have seen, he even shows how he will shoot flash shots with the camera's shutter speed being regulated in an automatic mode, controlled by that awesome *Nikon light metering*...something that NO OTHER professional shooter, or serious amateur, typically espouses. I've never heard of a single *serious* shooter who felt that allowing the shutter speed to be controlled by a camera's automatic metering mode, was the "normal" way to work with flash illumination. Ever. Buuuuuut...Joe does it all the time in the videos he produces for *NIKON*...the ones where he does his *Nikon-sponsored* "how-to-do-it" videos. And I think I know ***exactly** why he does what he does. That *NIKON TTL* multi-speedlight remote commander *Creative Lighting System* is awesome, ain't it!!!!

(This message brought to you by *Nikon*, and the *Nikon Corporation* and *Nikon* speedlights, *NIKKOR* lenses, and the new *Nikon* D800, D800e, and the amazing new *Nikon* D600 and the incomparable *Nikon* D4.)


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## Samerr9 (Nov 10, 2012)

I didn't read all the posts here. But have you calibrated your lightmeter to your camera?


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## Mully (Nov 10, 2012)

Derrel said:


> I laughed at his improper use of the word "incidence" mode... there is no such thing as an "incidence"mode. The word "incidence" is a noun. The proper word is incident... There ARE,however, such things as incident-light meters. Meters that offer both incident- and reflected-light metering modes do NOT have a mode called the "incidence" mode.
> 
> "*I use meters in the incidence mode 99% of the time. Theres basically two types of metering modes. Reflective and incidence.* "
> 
> ...



Maybe he ment indecent mode LOL


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## Helen B (Nov 10, 2012)

fjrabon said:


> I use a D24 and 4 IL2500s 3-4 times per week. You can meter them once, take a few minute break, adjust NOTHING and meter them again and get a half stop difference. And this is full bore indoors, so it ain't ambient.
> 
> I'm really just saying there are too many variables to see the reading, set it, pop it once and trust that's right. You gotta check your images (both LCD, histo and blinkies) and/or bracket.



Not a very good advert for Normans. All I can say is that Dynalites and Speedotrons are consistent, and can be trusted to fire consistently - apart from some of the xxx5 series Speedos that can vary by about a third of a stop if you turn the variator _right_ down.


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## unpopular (Nov 10, 2012)

I have never noticed this problem with my Chinese-made, $160 Mettles c300's, though I don't use them much either.... will test.


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## fjrabon (Nov 10, 2012)

Helen B said:


> fjrabon said:
> 
> 
> > I use a D24 and 4 IL2500s 3-4 times per week. You can meter them once, take a few minute break, adjust NOTHING and meter them again and get a half stop difference. And this is full bore indoors, so it ain't ambient.
> ...



Yeah, I really am not a huge fan of Normans as far as consistency goes.  Their build quality is hard to beat though.  Our battery packed impact lights are far more consistent.  The other issue may be inconsistent power at some of the locations we use them, but the Norman's built in power conditioners should fix that.  At our studio they're fine.  You get them to schools, especially the older schools, and they're inconsistent.


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