Metering: incident, reflective or use an app?

An insident reading is taken with the light receptor pointing towards the camera with the white dome fitted, it is thus reading the light falling on the subject.

A reflective reading is taken with the light receptor point towards the subject without the white dome and measures the light reflected from the subject.

Paul
 
Lesson learned yesterday: if you rate your B&W film at half box speed, meter for the shadows then compensate with a 15% reduction in development time, you end up with...

...absolutely awful, muddy, low contrast negatives.

Damn.

As far as I can tell, it's nothing to do with the exposure and all to do with the under development. I think I've been getting mixed up with advice suitable for sheet film users.
 
You're correct. You've done everything exactly right for coping with a high contrast subject by reducing the contrast of the negatives. It works with any type of film - not just sheet film. It's easier with LF because you can develop each sheet differently, but you can do the same with any format so long as all the exposures/subject brightness ranges on the roll are the same. That's one reason why interchangeable backs are useful for roll film.
 
FujiLove said:
Lesson learned yesterday: if you rate your B&W film at half box speed, meter for the shadows then compensate with a 15% reduction in development time, you end up with...

...absolutely awful, muddy, low contrast negatives.

Damn.

As far as I can tell, it's nothing to do with the exposure and all to do with the under development. I think I've been getting mixed up with advice suitable for sheet film users.
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I usually don't reduce developer time. You'll probably find they scan well even if they need a big bump to get them looking right.
 
FujiLove said:
Lesson learned yesterday: if you rate your B&W film at half box speed, meter for the shadows then compensate with a 15% reduction in development time, you end up with...

...absolutely awful, muddy, low contrast negatives.
Click to expand...


I can't agree with that. My normal method with HP5 is to expose it at EI 200 and reduce development by 20%


Steve.
 
Terrywoodenpic said:
If the subject is distant but in the same light as you are just stand between the camera and subject and point towards the camera.
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Or just point it behind you.
For an incident reading all you need is for the light to hit the meter the same as it will hit the subject (the top of the dome represents the front (camera side) of the subject).
 
For incident light the subtle contour of the Weston Invercone was held to give more universally accurate readings than the simple half-globes of modern meters.
 
Steve Smith said:
I can't agree with that. My normal method with HP5 is to expose it at EI 200 and reduce development by 20%


Steve.
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They are Tri-X 400 developed with Ilfosol 3 (1+9 at 20 degrees). Honestly, the negatives are really muddy. They're not unusable (will post a few tomorrow), but they have very little punch. They have to be crunched into submission in Lightroom, and even then the lighter parts of the image have low contrast. Not my cup of tea, but like I said, a great lesson learned. I don't just mean that in a 'won't be doing that again' sort of way. I mean, I've discovered practically how to get low contrast images when I need to. A lot more fun than pulling sliders about in Photoshop.
 
FujiLove said:
They are Tri-X 400 developed with Ilfosol 3 (1+9 at 20 degrees). Honestly, the negatives are really muddy. They're not unusable (will post a few tomorrow), but they have very little punch.
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What were the lighting conditions like? The half the ISO/reduce the development works well in high brightness/high contrast conditions. In lower light, box speed and normal development is better and in very low light and low contrast, I would suggest reducing exposure further and extending development.

Basically, the amount of development is controlling the contrast. If you started off with a low contrast scene, reducing development isn't going to help.


Steve.
 
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Steve Smith said:
What were the lighting conditions like? The half the ISO/reduce the development works well in high brightness/high contrast conditions. In lower light, box speed and normal development is better and in very low light and low contrast, I would suggest reducing exposure further and extending development.

Basically, the amount of development is controlling the contrast. If you started off with a low contrast scene, reducing development isn't going to help.


Steve.
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There are different scenes with varying contrast. I've attached two images to show what I mean. These are both straight uncorrected scans out of Epson Scan. They were both shot in late morning in fairly bright sunlight, so I guess there is medium to high contrast in both?

The first one of the Red Lion is box speed Tri-X, incident metered in the sun and processed normally. The second is Tri-X rated at half box speed, incident metered for the shadows, with a reduction of 15% processing time. They were both processed using the same chemicals and temperature.

I concede that the second may contain more detail in the shadows etc. and it can be improved a lot with processing, but it just isn't to my taste at all. Also note how little contrast there is at the top right where the building meets the sky. That looks very compressed. I would expect to see much more of a difference in tone between the edge of the building and the sky. It does look way better after messing about in Lightroom and applying +100 contrast etc. but I'd rather not have to 'rescue' images and spend ages on the computer to get something vaguely pleasing.


View attachment 20565

View attachment 20566
 
Sorry to expand an already long topic to go slightly out of focus. How would you measure exposure for a sunset?
-with my Olympus OM1 which uses internal meter (reflective). If I meter for the sky I think I would be overexposed.
-with my Bronica which uses an external meter (incident). I don't think the reading are any relevant for sunset...

I'm used to digital were you can check you're exposure on a few test shoot and adjust accordingly to the result...
 
Lemaildetom said:
Sorry to expand an already long topic to go slightly out of focus. How would you measure exposure for a sunset?
-with my Olympus OM1 which uses internal meter (reflective). If I meter for the sky I think I would be overexposed.
-with my Bronica which uses an external meter (incident). I don't think the reading are any relevant for sunset...

I'm used to digital were you can check you're exposure on a few test shoot and adjust accordingly to the result...
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IIRC meter for the sky above the sun.........For this shot I just let the Canon T70 do the work which probably metered to include the seas as well.:-




For this shot was fed up waiting for a red sunset and decided to leave and just took a shot with a Canon AV1 (semi auto) and it came out quite nice
 
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Lemaildetom said:
Thanks for the examples. Is that the internal metering built in camera you are talking about?

Any way of metering such thing with an incident light meter?
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It was the camera meter and have never tried incident light readings, but check out metering the sky just above the sun as I'm sure a guy mentioned how he did his VG shots....anyway you can always take a few shots with different apertures but I'm surprised how good a camera meter can handle the situation.

Nikon EM on auto:-


Canon T70 on semi auto
 
Lemaildetom said:
Sorry to expand an already long topic to go slightly out of focus. How would you measure exposure for a sunset?
-with my Olympus OM1 which uses internal meter (reflective). If I meter for the sky I think I would be overexposed.
-with my Bronica which uses an external meter (incident). I don't think the reading are any relevant for sunset...

QUOTE]
if you meter direct from the sun ,( its going to be a reflective reading ) then the foreground will be a silhouette , but if you meter from the sky near to the sun ,you will get some detail in the foreground ( as Brian says )
and just in case it confuses anyone ,all meters in camera are going to be giving a reflective reading ,,,but not all external meters are going to give an incident reading ,some are reflective only and some are reflective and incident .( the way its written above seems to imply that an external meter is an incident meter and an internal is a reflective ,although im sure thats not what is meant )
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Thanks sorry to be confusing. I think, I get it with the OM10 and it's built in lightmeter.

I was more confused to do with camera which have no lightmeter and you need to use a handheld incident light meter. I can try pointing it to the sky without the dome on to see what came out. I only shot in this conditions ones with the Bronica and I did totally guess the exposure which came out pretty good actually but didn't feel me with confidence!
 
i dont know ,,but i would think that most ( all ?) handheld light meters can be used to take reflective readings as well normaly by taking the dome off ,as you did anyway
 
Sorry, I'm a bit of a slow thinker, and this has been rolling around inside my head for a while. Two thoughts: many folk recommend incident metering, which seems fine if the subject is within easy reach, like a portrait, a product shot, etc. But a landscape is far away, so surely incident metering can't really work? And the reflective metering is measuring the light actually reaching the camera, which sounds better than measuring the light somewhere else. The problem seems to be turning that into the correct exposure for scenes that aren't typical 18% grey?

Second thought: in a couple of threads about exposing for colour negative and for transparency (or rather, about scanning those films), it's become clear that I don't have nearly a good enough understanding of the variations of light within a shot. Wouldn't I be better off with a proper spot meter (like one of those Pentax ones), and working the zone system? At least that way I'd be forced to confront the light variations within the scene...

Only trouble is, last time I looked they were about £300!
 
For incident light, just have the meter in the same light as the subject. Unless you're under a cloud, the light will be the same as on the distant hills. Reflected light isn't so much measutring the light that reaches the camera per se, but measuring the light reflected from the subject. If you meter from a single square of a chess board, you'll get a different answer depending on whether the square is black or white, and you have to choose the exposure that will give the correct result. If yuo measure the light from the whole board, it may average out (depending on the relative brightnesses of the two colours). The problem here is just the same one you've mentioned - how to relate what the meter tells you to what the exposure should be.

Let's step back a moment and consider this. You can photograph a white card and make the print show any shade of grey from pure white to pure black by adjusting the exposure. And you can do exactly the same thing with a matt black card. Exposure controls how bright an object will be; and you decide how bright you want it. Exposure depends more on the effect you want than anything else - the meter only guides you.

If you use a spot meter, you'd better realise that estimating which part of a scene to measure as a mid grey is a matter of experience. What you can see (at a glance) if you meaure the brightest part where you want detail and the darkest part ditto is see if the range will fit within the range of your film. If it fits exactly, fine (but you have zero latitude on the exposure, as more or less will give blown highlights or blocked shadows. If it fits comfortably (say with 2 stop to spare) then you have 2 stops to play with in terms of over or under before it goes wrong. If the range is greater, then (if black and white film) simply give more exposure and less development to increase the range of the film.
 
Well I'm not dis-agreeing with Stephan and other posts but unless it's a tricky shot where you want the shadows as well as highlights or just shadows and so on, it all seems complicated for 90% of general shots e.g. a shot of grey mountains and green grass? why bother with incident light readings as the scene (not with misty haze) is close to Kodak grey. If your subject is in the same light then a sun tanned hand, blue sky, green grass, grey pavement, light green shrubs and maybe very light reds and so on or all near to Kodak grey.
About 40 years ago I bought a Kodak grey card and compared subjects they are very near to it (i.e. for exposure) and use them and I rarely have negs with incorrect exposure, well maybe the really tricky ones but then it's my own fault for not bracketing :eek: e.g Portraiture with very white or very black skin.
 
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To be honest I'm not sure how valid example scans of neg images are for judging how accurate the metering was. We know a ridiculous amount can be recovered from a poorly exposed frame on neg film and we have no idea how much processing has been used to arrive at these results when the examples were scanned. E6 examples would probably be pretty accurate, I'm just not sure about examples from negative film.

Just a random point. :)
 
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