Using a DSLR as a light meter?

<p>My P67's prism meter seems to be about a full stop off (overexposed). I have some important pictures to take this weekend and no time to take more test shots at different speeds/stops/etc. However, I do have utmost confidence in my D200's matrix metering ability. So, would it be feasible for me to meter the scene with my D200 and then just transcribe the exposure readings over to my P67? My 50mm f/1.8 Nikkor very closely matches the FOV of the P67 165mm f/2.8 that I will be using for the photos. I'm shooting Provia 400X slide film, so I don't want to take any chances with missing the exposure by a stop... Thoughts?</p>

<p>Certainly do-able, but clearly not the most efficient method. However, if it causes you to be the most comfortable, there's a lot to be said for that. JR</p>

<p>Absolutely! I use the histogram of my DSLR (and even my Canon G10 - if that's all I have with me) to measure the light for my Large Format Photography. Frankly, I think it works better than a traditional light meter. I can see clearly when clipping occurs and dependent on what film I am using (color neg, vs slide, vs B&W) I expose to the right, middle or left of the histogram. It makes for very predictable results.</p>

<p>Digital is inherently off. It works great for digital but film is a different animal. Digital meters tend to underexpose by as much as a full stop to obsessively try to avoid clipping highlights. The details get lost in highlights faster than in shadows so protections are built in. SO your meter in your D200 may be perfect for your D200 but the ISO settings are not always exactly accurate. The best way to test your film camera is by using a hand held meter or very controlled lighting situation or sunny 16. Though if you aren't familiar enough with Sunny 16 you may be off in your estimation of the light you are trying to capture. If you have full light no clouds point your camera at some grass that is fully lit by the unfiltered sun. Set your aperture to f/16 and it should be telling you the shutter speed should be really close to the inverse of the film speed you are set to. If there isn't any film loaded it is usually like 100 or 200 unless there is a manual film choice knob. Meters are tested for ISO standards for meters by using lux meters to test sensitivity. Sunny 16 is based on a certain lux scale. So if you don't have a lux meter that is as close as you can get. </p>

<p>Even given your similarity in field, it's just so difficult to make sure you're metering the same thing. That, of course, is the strength of a TTL metering system.</p>

<p>However, my personal experience does not correspond to Christopher's suggestion that digital metering systems are preset in some sort of compensatory way. When I meter through the digital camera, or my old TTL film cameras meter, or with my Gossen Luna Pro SBC, the readings are in the same ballpark. I often have several cameras along so commonly get to compare the readings.</p>

<p>That being said, it IS probably wise to avoid clipping highlights in either digital or film, the latter especially if it's to be converted to digital for post-processing at some point.</p>

<p>To do this without prior testing is to invite problems.</p>

<p>For what it's worth, my D200's matrix meter exactly matches the TTL meter of my old Pentax K1000 when both are set for the same film speed and when metering the same scene (low contrast), so I do have some comfort level that the Nikon will meter the scene accurately. I just wanted to make sure exposure readings were transferable between film and digital media. Conventional wisdom would suggest that they are, but without any empirical data, I am still concerned.</p>

<p>A meter is a meter. I've been using my D200 for a meter for 4x5 for a year and find that it works quite well.<br /> If you haven't tested your DSLR sensor and histogram against a specific film's response, that's another matter altogether. (I tend to use the histogram to look more at the dynamic range of the shot than as the final arbiter of exposure.) The roll off of digital sensors is more drastic than with film, generally speaking.<br /> Spot metering is tremendously useful, and the Nikon RGB metering sensor is the equal of any handheld meter with which I'm familiar. That said, I'm always a little cautious of the D200's Matrix metering because the internal databank of comparative images may bias toward overexposure with a digital sensor, which is great for negative films, but not what's needed for transparency. (The old F5 Matrix for film was uncanny in it's ability to not blow highlights with transparency film, however). First generation DSLRs like the Nikon D1X or D100 may not have used this same metering regime or else the sensor may have had very poor roll off compared to film, but everyone else I've heard from who's reported using a Nikon DSLR of more recent vintage seems to be getting terrific exposures.</p>

<p> </p>

<p>Thanks for the great replies. Let me ask this, is it at least safe to assume that if I take an exposure with the D200, and it looks <em><strong>good</strong></em>, then I should at least expect a similar (not identical) response with film, negative or slide, using the same exposure settings? All things being equal, of course (same scene, same lighting, etc.) The thing that worries me the most is the D200's interpretation of ISO vs. the actual film emulsion...</p>

<p>You might have more consistent results if you meter a gray card with your DSLR instead of metering the scene. Then you wouldn't have to worry about your camera messing things up trying to save highlights.</p>

<p>"A meter is a meter." Ah, a truism duel at ten paces...Anyone ever consider why there are incident and reflective meters and how they differ? Just asking.</p>

<p>If you're sure it's a full stop off, why don't you just set your ISO one stop off accordingly so that it exposes properly?</p>

<p>"So, would it be feasible for me to meter the scene with my D200 and then just transcribe the exposure readings over to my P67?"<br />============================<br />No it would not be feasible from my experience. You would be better off adjusting for the overeposure n your P67. First of all it would not look very professional swtiching cameras on the fly, but that is not the major problem. The major problem is that in-camera meters differ in how they register light. I tried a test one time between the meter on my Mamiya 645 camera, the meter reading from a Nikon FM2, the meter readings from a DSLR and the meter readings from 2 different light meters. The variations surprised me. The difference between some resdings was 2+ mores stops. Try it yourself and see what you find out.</p>

<p>I use my 5DII as a meter for my Fuji Gx680 regularly. In essence I treat it like a polaroid shot and it works as well as a handheld meter. I have found that is I shoot Velvia 100 for example but I shoot it at 80 ISo on the Fuji if I set the canon to 100 ISO and then take this meter reading and add 1/3 of a stop and set this on the Fuji all works well - the same is true for Velvia 50. For B&W I just set the two cameras on the same ISO and add 1/3 of a stop to the Fuji.</p>

<p>If you want to be sure you've nailed it without the possibility of having to reshoot (particularly since you don't have time to calibrate a second camera meter to a film stock)-- shoot print film.<br>

Err on the side of overexposure and the tremendous lattitude will CYA.<br>

Or shoot digital. (Your call.)</p>

<p>Anybody every heard of bracketing? It's way cheaper than screwing up the shot and having to do it all over again. And in a pinch it's cheaper than buying a meter on a moment's notice. OTOH, as Luis said, TEST. It's the only sure way to know if you know what you're doing or not. Asking a dozen random people on a forum is not going to get you YOUR answer.</p>

<p>I've compared the metering of my D300 with my F4s which has an earlier version of matrix metering. Using a 35mm lens on the D300 and a 50mm on the F4s, the field of view is almost the same, so I put both on manual with the same ISO 200, and the metering/film speed combinations were almost identical. I then compared them to the FE2 I have and then the FM2n....all were within half a stop.<br>

It makes me have great faith in Nikons metering.</p>

<blockquote>

<p ><a href="../photodb/user?user_id=1832027"><em>Jim Simmons</em></a><em> </em><a href="../member-status-icons"></a><em>, Aug 22, 2009; 01:26 a.m.</em><br>

<em>Anybody every heard of bracketing? It's way cheaper than screwing up the shot and having to do it all over again. And in a pinch it's cheaper than buying a meter on a moment's notice. OTOH, as Luis said, TEST. It's the only sure way to know if you know what you're doing or not. Asking a dozen random people on a forum is not going to get you YOUR answer.</em><br>

<em></em></p>

</blockquote>

<p>Jim, you're right. I'm always amazed at how people complicate the simplest chores.<br>

I tested my Nikon D70s against my Sekonic meter, the camera's spot-on. If it wasn't, Id have the test results, as Luis points out.<br>

If I'm REALLY jumpy about a shot, I bracket. With the price of film these days (!) what's the problem ?<br>

How hard is that, really ?</p>

<p>Bill P.</p>

<p>p.s., Yes that film refernce is a joke. My D70s s is digital, I think....<em></em></p>

<blockquote>

<p ><a href="../photodb/user?user_id=3749458"><em>Christopher Graham</em></a><em> </em><a href="../member-status-icons"></a><em>, Aug 21, 2009; 01:25 p.m.</em><br>

<em>The best way to test your film camera is by using a hand held meter or very controlled lighting situation or <strong>sunny 16</strong>.</em></p>

 

</blockquote>

<p>... or, you could try "<strong><em>Slightly Overcast 30 Antilog base 20</em></strong>".</p>

<p>Yes, it's a joke.</p>

<p>Bill P.</p>

<p>Michael, My results were similar to Stephen's but rather than compare matrix metering I compared the spot metering of my D200 against the spot metering of two Nikon F4S cameras that I own. One with a DA20 action finder and one with the standard DP20 finder. All three cameras were tripod mounted and pointed at the same point on the top of a white plastic utility table. Settings were ISO200, f2.8, 125th using the exact same Nikon 24mm f2.8. Lighting was fluorescent. Both Nikon F4S metering systems showed the same results as the d200. From previous experiments I know that my D200 and D2X spot meter the same. Good hunting. Andy</p>

<p>I don't see any overriding reason why a dslr can't be used as a meter. Having the histogram available might help, and will certainly help more than the appearance of the image on the screen. I'd have thought that the biggest reason why you might not want to do so are to do with convenience not accuracy, and I wouldn't consider it a permanent solution from that point of view alone.</p>

<p>However there are a couple of little things to watch out for that make me believe that , especially with slide film, that I'd opt for bracketing because you haven't time to test.</p>

<p>The first is that you need to lose the idea of meters being "right". Just because your dslr meter gives you good exposures on that camera does not mean that the meter is "right" and in particullar it doesn't mean that you'll get perfect exposures with other cameras using it. Actual apertures and shutter speeds vary , and all you know is that your Nikon meter matches acceptably with your Nikon. </p>

<p>Field of view is one thing , where the meter is drawing its information from is something else entirely. I have no idea how your Pentax meter works in that respect but very often MF meters are pretty unsophisticated. I would personally want to use the metering pattern on the Nikon that suited the photograph best rather than trying to mimic how the Pentax meter works. In short don't try to recreate the Pentax meter on the Nikon.</p>

<p> </p>

<p>Ok, here's where the rubber meets the road, fellas (and the reason why I asked the question in the first place...)...<br>

The P67 is new to me, just purchased on flea-bay a few days ago. I've put several rolls through it (b&w and color), but none have been developed yet. I have my own b&w darkroom, but am out of chemicals so I can't develop anything right now. Plus the color rolls were not taken with "testing" in mind. So, I have no set benchmark yet as to how this camera exposes at a given film speed. Now, my loving wife wants me to shoot some portraits of the kids, in color, this weekend. So, here I am. I need to take portraits, which I'm quite good at with the D200, but I would like to use my new toy, err... tool. And having never developed anything from the P67 yet, I don't know exactly how it exposes. So, my short term hypothesis was to use my D200 as a litmus test of sorts to compare P67 TTL readings with D200 readings and formulate a correlation that would afford me a reasonable chance at nailing the exposures with the new P67. Capisce?</p>

<p>If the answer is within a stop or two of what the TTL is telling you anyway, I'd say, Why not?</p>

<p>Want to get super-creative and be dead on with every shutter trip? It's going to take testing and metering. Want to get close enough to make a reasonable image? The stop or two from TTL will do it.</p>

<p>I've had consistently good results using the multi-spot metering feature of my Olympus C-3040Z P&S digicam to meter for my meterless TLRs and folding MF cameras. The Oly had no built in bias and matched the results of my Pentax Spotmeter V. But the digicam offered several advantages, including the ability to zoom in to meter an even smaller spot than the Pentax; to meter more than one spot, store and average the result; to use evaluative metering for simpler scenes that didn't require spot metering; and the bright LED display was much easier to see in dim lighting than the Spotmeter V's needle gauge.</p>

<p>The Oly doesn't have a histogram display and I've never relied on one (even with my Nikon D2H) as a major factor in my exposure decisions. I've heard a few claims that certain digital camera meters are biased but none I've owned and used has been - all were neutral and metered exactly as my Pentax and Minolta handheld meters did, within 1/3-2/3 EV, with the variations usually due to angle of incidence and operator bias (me).</p>

<p>My P&S digicam meters only from ISO 100-400, but that's all I've ever used in medium format. I tend to use faster films and/or push only with 35mm so it hasn't been a hindrance. But if you prefer faster films be sure the digicam you use can handle it.</p>

<p>I am probably going to go off on a rant a little but bear with me. In EVERY photographer's bag should be one, if not both of these. An ambient meter (I use a Minolta Flashmeter IV, which is one of the most versatile meters in the universe) and a Pentax 1º spot meter. I have literally gone months with dead batteries in my F2's and never knew it. Not because I don't care about my equipment, but because I don't use them. Let your batteries die in modern cameras and everything after the F3 and all you have is a very pretty PAPER WEIGHT.<br /><br />Ok, here's the rant part. The true art of photography is being lost with today's digital "auto everything" cameras. If permitted to, they do all the thinking for you. That is just plain silly in my opinion. They expose, focus, etc. for you. All the photographer has to do now is pretty much compose and push the shuter button. Maybe one day the software engineers will figure out a way to have the camera compose for you too. The true <em>art</em> of photography comes from looking at a scene, deciding what you want to do with it, what areas of the photo need to go where exposure-wise and meter them for that. If you shoot B&W film, like I do <em>a lot</em> of, you expose for the low' and develop for the highs. Ansel Adams' Zone system is the most profound, systematic, negative to finished print method for making photographs every developed.<br /><br />If you are in a hurry, like I am sometimes, I use my Flashmeter in the ambient mode and just get an average ambient reading. But for critical stuff, the spot meter is the only way to go. I honestly cannot think of the last time I used the meters in all three of my F2's, though all three are still spot on. Why? Because center weighted averaging is <em>wrong</em> a whole more often than it is right.<br /><br />I have a Nikon digital camera with all the fancy-schmancy matrix metering and all the bells and whistles. And probably 7 times out of 10, it is still completely off as far as what I want to do with the scene. So I go back to the old standard; I put the thing in manual and meter with the spot meter. I have yet to ever use it for any critical work in the automatic mode and never will. In fact, all I pretty much use it for is to check that my film camera settings are correct. It IS very good for that.<br /><br />Ok. rant off. I will get off my soapbox now and go sit back down........we now return you to our regularly scheduled program, already in progress............</p>