Interesting article about using iPhone apps to meter a scene

[stevelmx5]

I've just come across this article running a direct comparison between two dedicated meters and two IOS apps for metering both a controlled and non-controlled scene;

http://www.ryanewalters.com/Blog/blog.php?id=1222011888909495377

Makes for an interesting read and confirms the results I've had from the Pocket Light Meter App too. I also came across this photographer in Seattle who shoots entirely on film with some excellent results along with a very interesting blog;

http://www.sandracoan.com/

http://www.littlebellows.com/film-stocks-1/

Cheers
Steve

 

[excalibur2]

Interesting but when proof is shown that say with colour neg film you can be 2 stops under and 5 stops over and still get decent pics and with old film cameras the shutter speed are usually out as well as tolerances when manufacturing, then tolerances on lens apertures, plus tolerances on film....why get an expensive light meter, some guys are happy with sunny 16 plus experience because of film latitude.
Of course if using slide film and use spot metering or MF and LF there might be an argument but then there are some cameras that can do spot metering and are cheaper than a seperate exposure meter, so if into MF or LF you can always take this spot metering 35mm camera as backup and if lugging these cameras with heavy trioods what's the problem with a 35mm camera adding to the weight.....h'mm I would wager some guys take a digi as backup esp for exposure readings

 

[steveo_mcg]

I've always got my phone, I'll almost never have my DSLR and I'm prone to leaving my various meters with which ever camera gear I've not got with me. So the simple meter in my Android has got me out a hole a few times, I could have probably got away with Sunny 8 and latitude but sometimes its nice to have your guess verified.

 

[excalibur2]

Well I don't know when exposure meters were invented but in the old days they got by with experience. When I go out shooting on sunny days most of the day it's f5.6\f8 at 1/250 sec with 200 asa from eqiuvalent grey card reading (which would be sunny 16 or incident) and don't bother with an exposure reading...of course if the subject is in shadow you have to compensate.

 

[steveo_mcg]

Well I don't know when exposure meters were invented but in the old days they got by with experience. When I go out shooting on sunny days most of the day it's f5.6\f8 at 1/250 sec with 200 asa from eqiuvalent grey card reading (which would be sunny 16 or incident) and don't bother with an exposure reading...of course if the subject is in shadow you have to compensate.

The problem is that the level of experience needed to reliably get a good print every time with out a meter is more work than is really necessary these days. The amount of testing and calibration that some of the LF guys do with sensitometry for just one combination of film, developer and paper is would stop me from ever picking up a camera. Instead I can rely on an ISO (that's a standard for a reason) to give the film broad response, a spot meter to decide where I want to place my shadows with some confidence and 1/100 of the amount of testing that would have been required prior.

Snap shooters always got what Kodak gave them, still do only now Kodak is replaced by the brain of what ever camera the (digital) shooter is using. Same with an Asda scan really, the automation will destroy a shot that one has deliberately under exposed to try and bring it up to some presest standard (then they'll sharpen it....)

 

[StephenM]

I found the article very interesting; the most interesting part to me was probably the relative performance of meters, phones and camera. Interesting, but it won't stop me using a meter as I neither have nor need an iphone. Well, as I don't know what they do, perhaps I do have some need and just don't know it - but I only use my current mobile phone for outgoing calls in cases of dire necessity...

On accuracy and calibration etc., as far as I'm aware (and this agrees with my personal experience) you can produce an excellent print by the scan and digitally print route from a negative that would be unprintable in a darkroom. At each stage in the fully conventional process you restrict the tonal range available, and in the final stage (the print) the most severe contraction takes place. The dynamic range of the printing paper is the weak link, and taking the digital route at this stage makes things much easier. Hence, you don't need the same degree of care to get a fine print. The problem with paper is keeping the density range of the negative within the limits that the paper can handle; with digital tonal manipulation adjustments are possible that allow you to capture detail at both ends that you'd find hard to achieve with film without tailoring the exposure and development of each frame. Note - I'm a black and white photographer, and colour is a different world with different problems.

In practice, I find that I can estimate exposure usually to within half a stop of what my meter says; and have had to rely on my estimating on one memorable occasion when I left my meter behind. But normally I always meter, and as a matter of fact carry a couple of meters with me, a Sekonic spot meter and a Lunasix for dark interiors.

 

[excalibur2]

...but I would say most of us can use any decent camera, use Agfa Vista and without an exposure meter get some decent shots. But maybe I'm missing something in my logic as IMO a spot meter taken of subject in shadow is only accurate if the subjuct is equivalent of a grey card..thus e.g. snow in shadow would not give an accurate reading

 

[StephenM]

I see the point of a spot meter as being to measure a tone and then adjust the reading to place that tone where you want it. e.g. measure the deepest shadow in which you wish to retain detail and adjust the exposure it gives accordingly. If you then measure the brightest highlight you similarly want to retain detail, you then know the subject brightness range and can adjust the development time to keep that on the straight line portion of the film's characteristic curve.

Colour negative film is a world apart from black and white in that very few people print their own, and the high street labs will compensate like crazy.

As to absolute accuracy of exposure - remember how Kodak first set speed ratings?

Edit to add: you can take a reading of snow in shadow with a spot meter and get an accurate exposure provided that you know exactly what tonal value you want it to have in the print - how many stops away from mid gray, if you prefer it expressed that way.

 

[Steve Smith]

On accuracy and calibration etc., as far as I'm aware (and this agrees with my personal experience) you can produce an excellent print by the scan and digitally print route from a negative that would be unprintable in a darkroom.

My experience is the reverse. I once got some quite detailed prints from an under exposed negative which hardly had any density showing. If you looked at it quickly you would think it was a bank strip of film.


Steve.

 

[excalibur2]

I see the point of a spot meter as being to measure a tone and then adjust the reading to place that tone where you want it. e.g. measure the deepest shadow in which you wish to retain detail and adjust the exposure it gives accordingly. If you then measure the brightest highlight you similarly want to retain detail, you then know the subject brightness range and can adjust the development time to keep that on the straight line portion of the film's characteristic curve.

Colour negative film is a world apart from black and white in that very few people print their own, and the high street labs will compensate like crazy.

As to absolute accuracy of exposure - remember how Kodak first set speed ratings?

Edit to add: you can take a reading of snow in shadow with a spot meter and get an accurate exposure provided that you know exactly what tonal value you want it to have in the print - how many stops away from mid gray, if you prefer it expressed that way.

H'mm in the old days for B\W it was expose for the shadows and let the highlights take care of themselves, which at times caused problems (when enlarging) burning the highlights in esp if they were bright.

 

[steveo_mcg]

H'mm in the old days for B\W it was expose for the shadows and let the highlights take care of themselves, which at times caused problems (when enlarging) burning the highlights in esp if they were bright.

Not if you were a zone system type of person. You'd know exactly how your developer, film and paper responded and you'd do your best to put the highlights at the end of the zone spread, through your metering you'd know how much you'd need to adjust your development or sacrifice a little more shadow etc.

 

[excalibur2]

Not if you were a zone system type of person. You'd know exactly how your developer, film and paper responded and you'd do your best to put the highlights at the end of the zone spread, through your metering you'd know how much you'd need to adjust your development or sacrifice a little more shadow etc.

Well I did have a sorta zone system in burning in parts of the picture to my liking...
Remember someone here (maybe elsewhere) posted how one well known pro achieved perfection for his shot, on the print it was covered in ink circles and notes to burn in more (or less) parts of his picture.

 

[StephenM]

My experience is the reverse. I once got some quite detailed prints from an under exposed negative which hardly had any density showing. If you looked at it quickly you would think it was a bank strip of film.


Steve.

You're clearly a much, much better darkroom printer than I ever was. Faced with a very thin negative, all I could achieve was a grey, muddy print with no true blacks (and very little white either!). Given a piece of 5x4 film on which I couldn't see any image at all (not matter how carefully I looked) my scanner could give me an image; poor, yes, but far, far better than I could have achieved with a better negative in the darkroom.

Probably I lack the patience required to be a skilled printer.

 

[StephenM]

H'mm in the old days for B\W it was expose for the shadows and let the highlights take care of themselves, which at times caused problems (when enlarging) burning the highlights in esp if they were bright.

That's what the second half of the truncated quote guarded against: "expose for the shadows and develop for the highlights". Given that extra time in the developer builds up the highlights (and hence the contrast) and doesn't do much to the shadows, if the highlights were too bright, such that they'd need burning in, you'd just cut the development time. Too low a contrast, and you simply increase the development time to move the highlights up from light grey to white (or just off white).

 

[abdoujaparov]

The iPhones, especially the 5/6. have an excellent camera, with very good reputation for metering. The light-meter apps just relay that metering info to you, so it shouldn't be surprising that the the app can meter a scene as well as the iPhone camera can.

 

[Steve Smith]

You're clearly a much, much better darkroom printer than I ever was.

I doubt it!

Just in this case, I was very surprised at what I managed to get from the negative. Detail which didn't appear to be there on inspection.

However, if there is any detail there, it should be possible to find it either by darkroom technique or scanning if you are competent... or probably in my case, lucky!


Steve.