Digital light meter.

[ignatiusjk]

I recently went to Zion and Bryce Canyon and tried using my digital 35mm camera as my light meter for my 4x5 and the negs came back a little thin. Someone told me that you can do that that's why I tried it but my negs proved otherwise.So I'll have to go back to my Luna Pro.What meters do you use????

[urs0polar]

a used Minolta flashmeter IV is awesome (you can get a spot attachment for it); I also have a sekonic 558 which is also great.

[Professional]

What do you mean by thin?
I used my 35mm DSLR to meter for my 4x5 negs for my first time in my life to shoot LF, it worked fine, just i give that LF say about 1-2 stops more due to DR and large area of the film size so it will take light almost more than 35mm DSLR, maybe some will say that both formats will see same amount of the light under same settings, but i just took a risk and exposed less about 1-2 comparing to DSLR metering.

[ic-racer]

It should work if you set the iso on the digital camera so the lowest area on the histogram gives 0.1 above film base & fog when that low area of the scene is exposed by the [negative] film camera at the same f-stop and shutter speed.

[Andrew O'Neill]

It'll work for you but you will first have to find which ISO setting works best...just like when we calibrate our regular metres to our own process. I prefer to use my Minolta digital spot metre. It's way more accurate.

[David de Gruyl]

Pentax digital spot. Works fine when I don't screw up (just like any other meter).

I suspect that if you are shooting E-6, and you get the right ISO setting, the digital camera would be the best lightmeter available. For B&W negatives, it probably would not work for me unless I was using it in spot mode.

[jeroldharter]

It does not matter what meter you use, but you must calibrate any meter to your processing and film.

If you have a known meter that works well, you can compare the readings from the known meter with the DSLR's meter and make any adjustments needed to equilibrate them. Otherwise, you have to test your meter to your film processing to arrive at an effective film speed.

[Leigh]

I also have a sekonic 558 which is also great.
I love my Sekonic 558. Use it all the time.

For those unfamiliar with the product, it's an ambient meter AND a 1° spot meter in one package. Looks kinda odd, but works great.

It also has a Pocketwizard transmitter built in so I can trigger my strobes with it.

- Leigh

[Frank Petronio]

It could be as easy as lowering the ISO of the "digital 35mm?" camera.

It could be as hard as reading a book, running tests and measurements.

But switching meters won't fix your immediate problem, unless your LunaPro measures a couple of stops worth of added exposure more than your digital 35mm camera in the same situation. Have you ever compared the two side-by-side to see if they match or not?

[Jeff Bannow]

A couple of well-known photographer friends use a digital camera for their light meter. They are "morally opposed" to using a real meter.

The result - all of their negs are consistently underexposed. Thin shadows, ugh. It's really too bad. My opinion - use a real meter.

[Bob McCarthy]

Light meters calibrate to middle grey (18%).

Digital cameras calibrate to prevention of highlight clipping, a moving target at times.

So, it might match or it might not depending on the conditions.

Scene selection also dramatically impacts a digital camera and therefore the correct settings.

If your camera offers "raw" that is the lowest contrast and a reasonable match to the DR of a negative given the limitations mentioned above.

I have a manually exposure capable P&S that gets me in the ballpark for really low light (Canon G12) but in daylight it can be fooled easily and my spot meter is much more accurate as to what shows up on film.

I found my film Nikons (F5) more accurate than my digital Nikons (D2x) for use as a meter, especially with transparency film.

bob

[Andrew O'Neill]

A couple of well-known photographer friends use a digital camera for their light meter. They are "morally opposed" to using a real meter

That's funny. I could understand someone being morally opposed to using a digital camera as their light metre, but an actual hand held one?? Stupidity, if you ask me.
I know a guy who uses his digital camera, but he calibrated it to his system, and gets decent results.

[Jeff Bannow]

That's funny. I could understand someone being morally opposed to using a digital camera as their light metre, but an actual hand held one?? Stupidity, if you ask me.
I know a guy who uses his digital camera, but he calibrated it to his system, and gets decent results.

The silly thing is that they take those negs, scan them in and spend dozens of hours in photoshop to correct the problems.

[engl]

Light meters calibrate to middle grey (18%).

Actually, meters are calibrated to 12% gray. There is an article about this here:
http://www.bythom.com/graycards.htm

It is mentioned in several other places as well, such as Beyond The Zone System.

[engl]

A couple of well-known photographer friends use a digital camera for their light meter. They are "morally opposed" to using a real meter.

The result - all of their negs are consistently underexposed. Thin shadows, ugh. It's really too bad. My opinion - use a real meter.

I know a guy that uses a hand held meter and gets uneven exposures. Does this make hand held meters bad?

Any meter that is consistent when operated correctly can be used to get exactly the desired exposure every time (presuming it is of the type you want, if you need a spot meter, you need something that can work like one). Of course, you need to know your tools, and how they interact with the rest of your workflow.

[Andrew O'Neill]

Of course, you need to know your tools, and how they interact with the rest of your workflow.

...and that's it in a nutshell.

[Preston]

engl & Andrew: +1

I prefer using a handheld digital spot meter because I work primarily with color transparency film.

--P

[walter23]

What do you mean by thin?
I used my 35mm DSLR to meter for my 4x5 negs for my first time in my life to shoot LF, it worked fine, just i give that LF say about 1-2 stops more due to DR and large area of the film size so it will take light almost more than 35mm DSLR, maybe some will say that both formats will see same amount of the light under same settings, but i just took a risk and exposed less about 1-2 comparing to DSLR metering.

I don't think it has to do with film size; exposure is sort of an area-independent measurement - afterall, a small sensor is equivalent to a cropped portion of a large sheet of film. Each unit of area has to get the same amount of exposure regardless of film format (otherwise 35mm 100 ISO film like FP4+ would be rated lower than the same film in 4x5...). But there might be slight differences between actual & reported apertures on lenses, actual vs. theoretical digital ISO, etc. And most importantly of course, film (perhaps other than high contrast slide film) can take a lot more exposure to get shadow details whereas digital has to be exposed somewhat less to avoid blowing out highlights.

I'd say if you meter with your DSLR just add a stop for good measure if you're shooting negative film. For transparencies the exposures should be pretty close.

[walter23]

A couple of well-known photographer friends use a digital camera for their light meter. They are "morally opposed" to using a real meter.

The result - all of their negs are consistently underexposed. Thin shadows, ugh. It's really too bad. My opinion - use a real meter.

It just occurred to me what issue might be at fault. I just mentioned that digital must maintain highlight detail (once the sensor meets the maximum exposure threshhold it simply cannot store any more information and the highlight is blown)... and so a lot of DSLRs use matrix / evaluative metering modes which analyze the scene and expose to keep the highlights from blowing. Perhaps switching the DSLR to "center weighted average" or spot metering with the spot function if available would get around this? I know that if I shoot center-weighted averaging mode (which I prefer because it gives more control while not being as finicky for digital snapshottery as spot metering would be) and I'm not careful, I blow highlights on the DSLR, which would be reigned in by the "intelligent" / algorithmic metering programs.

[Alan Davenport]

So I'll have to go back to my Luna Pro. What meters do you use????

Good decision. Me, I use my Luna Pro F. The only thing it might lack (and that's only if I decide I need it) is that tiny 1 degree spot reading.

As for accuracy, analog meters are MORE accurate than digital meters. Why would anyone choose digital?

[Professional]

Any light meter free-battery?

[Bob McCarthy]

Actually, meters are calibrated to 12% gray. There is an article about this here:
http://www.bythom.com/graycards.htm

It is mentioned in several other places as well, such as Beyond The Zone System.

Thanks, havent seen this before...

Interesting, but doesn't change the point, that a meter calibrates to a fixed standard and a digital camera does not.

Since I have my meter and development times/temps calibrated to a result (the negative I desire) I guess somewhere in there I have compensated for the 12% vs. 18%

bob

[Bob McCarthy]

What I found does work in a pinch.

set the camera to

raw
spot meter
manual control
full time histogram on a P&S
read the histogram on the back and use it as a meter

very few digital cameras allow this, the Canon G12 does

bob

[Frank Petronio]

As for accuracy, analog meters are MORE accurate than digital meters. Why would anyone choose digital?

What makes them more accurate?

[Gary Tarbert]

A couple of well-known photographer friends use a digital camera for their light meter. They are "morally opposed" to using a real meter.

The result - all of their negs are consistently underexposed. Thin shadows, ugh. It's really too bad. My opinion - use a real meter.I did this for two weeks after my beloved meter was lost presumed stolen, I then aquired a new Sekonic , I had the opposite problem with overexposure , The other problem is my DSLR is a Nikon D3 and the last thing i need is another heavy item in my kit when i am shooting LF . Cheers Gary

[Alan Davenport]

What makes them more accurate?

A digital meter can tell you (something like) 5.1 or 5.2, but it is limited to discrete steps and cannot tell you anything about the area between those two numbers.

The needle of an analog meter interpolates the area between 5.1 and 5.2, making it arguably more accurate than its digital opponent.

[Professional]

A digital meter can tell you (something like) 5.1 or 5.2, but it is limited to discrete steps and cannot tell you anything about the area between those two numbers.

The needle of an analog meter interpolates the area between 5.1 and 5.2, making it arguably more accurate than its digital opponent.

Are all digital light meters in same class?

[Frank Petronio]

I doubt we'll ever see (or need) this more accurate meter that has a needle in which you can actually discern differences in reading of less than a tenth of a stop. That a digital readout doesn't distinguish below a tenth of a stop is likely a practical design decision than a lack of accuracy on the meter's part.

While some analog scales provide additional information to a reading, I don't recall an analog design for a light meter that ever did anything beyond simply giving us a number scale.

Most digital cameras give metering information down to a tenth of a stop, even if they set their user-adjustable increments to half- or third-stops. Most classic light meters have a wavering needle hovering over a space of 4-6mm that determines what a stop might be, it would be folly to try to determine anything closer than about a third or a quarter stop from that. Based on what is out there on the market right now, I'd expect a modern Nikon set to spot metering mode -- or the old Minolta Digital Spot Meter with it's narrower view -- to be the most accurate (and usable) of all the meters out there.

[Alan Davenport]

That a digital readout doesn't distinguish below a tenth of a stop is likely a practical design decision than a lack of accuracy on the meter's part.

Of course, you're absolutely right on this, Frank. It comes down to personal choice, as with most everything else. My first comment (intended to be over the top!) is my take on the common belief that, if something is "digital" it must be better than whatever came before.

My earliest photographic mentors were a couple of guys who both grew up -- and earned their livings -- packing 4x5 Speed Graphics and making the images that appeared in the newspapers. One of the ideas that made an indelible impression on me, was that "if your exposure is within a stop then it's close enough." That was based, of course, on the requirement to be able to make a print that satisfied the tonal and contrast requirements for a B&W halftone. And for that application, it was certainly correct. But for any application, if you're within 1/3 of a stop, you're probably OK. So obviously just about any light meter on the planet will suffice and then some.

But I stand on my original claim: you can see things with an analog display, that are invisible to any digital device. Whether we need to see those things, or should even care, I won't debate.

[Jack Dahlgren]

But I stand on my original claim: you can see things with an analog display, that are invisible to any digital device. Whether we need to see those things, or should even care, I won't debate.

This comes down to the concept of precision and accuracy. You may see the needle at a point between two marked lines and think that it is giving you a value which is between the two, but the accuracy of that measurement may not warrant making that distinction. The analog meter may have even less accuracy even though it displays it on a scale which allows an infinite number of divisions.

[Greg Miller]

But I stand on my original claim: you can see things with an analog display, that are invisible to any digital device. Whether we need to see those things, or should even care, I won't debate.

So I can't help but (politely) be curious how you would expose or develop your film differently if you had accurate exposure readings finer than .1 stop. Does the light remain that constant from the time you make your exposure reading to the time you trip the shutter? Do your shutters have the ability to set and expose with that level of precision? Is your film development process so precise as to realize any benefits? Is your printing process that precise? Is your end to end process that precise?

[Marko]

But I stand on my original claim: you can see things with an analog display, that are invisible to any digital device. Whether we need to see those things, or should even care, I won't debate.

The real question is: do the things you are seeing really exist? ;)

Given that any light meter, regardless of the display system, is based on a silicon sensor, therefore, both a "digital" and an "analog" one essentially "see" the same amount of information.

Frank has already explained that the granularity of a digital display is a matter of engineering decision, not the precision of the instrument. IOW, they are in effect limited to displaying less information than they actually see.

A needle display, on the other hand, is essentially a solenoid with a needle attached to the moving core. Where the needle stops in between the two marks is largely determined by the characteristic dissipation incurred by the solenoid AND by the mechanical inertia of the needle.

There is no way you can seriously prove that a mechanical readout is somehow more precise than a digital one given the same signal.

[Leigh]

You may see the needle at a point between two marked lines and think that it is giving you a value which is between the two...
It is.

The accuracy and linearity of any decent d"Arsonval meter movement is excellent, typically 3% for non-mirrored movements and 2% or better for mirrored.

To put this in perspective, 0.1 stop = ~7%, while 0.01 stop = ~0.7%.

Analog meters do not suffer from quantization error that's inherent in any digital system.

ALL digital systems have an error of ±1 least significant digit, in addition to all other errors in the system. It's a consequence of the method used to convert analog to digital, and is completely irrespective of the nature of the parameter being measured.

As a practical example, for an exposure meter to accurately display aperture readings to 0.1 stop, the acquisition system and display would need a resolution of 0.01 stop.

Optical power measuring instruments are readily available with accuracies of 0.01% or better, so it's not a question of technology. It's just the fact that the photographic industry does not require that level of accuracy for exposure determination. Available lenses and shutters could never come close to that accuracy.

- Leigh

[Alan Davenport]

So I can't help but (politely) be curious how you would expose or develop your film differently if you had accurate exposure readings finer than .1 stop. Does the light remain that constant from the time you make your exposure reading to the time you trip the shutter? Do your shutters have the ability to set and expose with that level of precision? Is your film development process so precise as to realize any benefits? Is your printing process that precise? Is your end to end process that precise?

Did you actually read what I wrote?

[Alan Davenport]

Optical power measuring instruments are readily available with accuracies of 0.01% or better, so it's not a question of technology. It's just the fact that the photographic industry does not require that level of accuracy for exposure determination. Available lenses and shutters could never come close to that accuracy.


And one of the major driving forces in the industry's move from analog meters to digital: when you get rid of the delicate d'Arsonval movement and substitute a drop-in digital module, the meter is cheaper to manufacture! (Note that I did not claim it is cheaper to purchase, just to build...)

[Greg Miller]

Did you actually read what I wrote?

Yes, I did. You made a claim nd at the same time say you will not defend any practical purpose of that claim.

People generally don't make claims without having a purpose (unless they are a troll). I gave you credit for not being a troll and intentionally said I was asking politely about what your point was, and was intellectually curious as to why you would bother to make such a claim.

So at this point, I will abandon politeness and simply ask, regarding your claim, "so what"?

[Marko]

It is.

The accuracy and linearity of any decent d"Arsonval meter movement is excellent, typically 3% for non-mirrored movements and 2% or better for mirrored.

To put this in perspective, 0.1 stop = ~7%, while 0.01 stop = ~0.7%.

Analog meters do not suffer from quantization error that's inherent in any digital system.

ALL digital systems have an error of ±1 least significant digit, in addition to all other errors in the system. It's a consequence of the method used to convert analog to digital, and is completely irrespective of the nature of the parameter being measured.

As a practical example, for an exposure meter to accurately display aperture readings to 0.1 stop, the acquisition system and display would need a resolution of 0.01 stop.

Optical power measuring instruments are readily available with accuracies of 0.01% or better, so it's not a question of technology. It's just the fact that the photographic industry does not require that level of accuracy for exposure determination. Available lenses and shutters could never come close to that accuracy.

- Leigh

Even the cheapest digital multimeters, the $10 ones found at registers in Fry's ;), have accuracy of 0.5% or better for DC. Bench-tops are typically better than 0,01% and laboratory models reach to few ppm.

I keep referring to multimeters for a reason, because that is exactly what a lightmeter is - a device that measures low voltage DC signal generated by a photo-sensitive silicon sensor. Both analog and digital light meters are built around the same type of sensor, it's just the measuring and display systems that differ.

It's all nice and dandy as pointless discussions go :rolleyes:, but this particular application is simply too coarse and insensitive for any real differences between the two types to matter.

In other words, it's not the hardware, it's the software that matters.

[Leigh]

... this particular application is simply too coarse and insensitive for any real differences between the two types to matter.
Exactly. This is photography, not rocket science. :eek:


In other words, it's not the hardware, it's the software that matters.
In this case, "soft" = gray matter. What's between the ears makes all the difference. :D

- Leigh