waileong Posted January 9, 2011 Share #21 Posted January 9, 2011 Advertisement (gone after registration) You misunderstand incident metering. It's NOT for slides per se. It just tells you what the exposure level is where you're metering. If you meter it in the highlights, it tells you what the correct exposure is to get correctly rendered highlights. Ditto the shadows. Hence the former is used when shooting slides, the latter is used when shooting shadows. Link to post Share on other sites More sharing options...
Advertisement Posted January 9, 2011 Posted January 9, 2011 Hi waileong, Take a look here Incident Light metering . I'm sure you'll find what you were looking for!
earleygallery Posted January 9, 2011 Share #22 Posted January 9, 2011 Interesting point. Not many of us shoot from ground-level to a nearby subject above us, but knock yourself out. The difference will be minimal. I stand by what I wrote. Just an illustration that the idea of pointing the meter towards the camera isn't entirely correct, it presupposes that the light source is behind or coming from the direction of the camera, which it will be in the majority of cases, but not every case. Reflected, spot and incident metering are all 'tools' to be used as most appropriate, together with an understanding of the light conditions, choice of medium and desired outcome. Link to post Share on other sites More sharing options...
tgray Posted January 9, 2011 Share #23 Posted January 9, 2011 Just an illustration that the idea of pointing the meter towards the camera isn't entirely correct, it presupposes that the light source is behind or coming from the direction of the camera, which it will be in the majority of cases, but not every case. If I'm taking a photo of someone facing the camera with the sun at their backs, you will get a perfectly acceptable exposure if you put the incident meter in front of them (in the same shadow that their face/body is in) and point it at the camera. I do agree with you. They are just tools and require some thought. And incident meters typically work quite well when you put them in the same light that your subject is in. It's essentially equivalent of sticking a gray card in a scene and doing a spot reading off of it. Link to post Share on other sites More sharing options...
geotrupede Posted January 9, 2011 Share #24 Posted January 9, 2011 When setting up a lighting scene in a studio, the reading are made towards the heads and not towards the camera. This is because the balance between the different lit areas is what matters. and the readings are made for all lights individually to fine tune power (f stops). Outdoor it is less of a problem unless the sunlight hits the subject from behind or sideways. Obviously a photographer should know what he is after and select the area of the image (and the light condition) that needs correct exposure and read there. Hope it helps G EDIT at a closer look the reading should be made using the normal of the surfaces. in studio it is always a face or a body, so effectively the normal is towards the light (unless our model is boxy ). But outdoor, for example taking the picture of a wall, I would suggest placing the meter directly on it (measuring vertical illuminance). This would account for the reduction in light due to the angle between the wall and the light source. Link to post Share on other sites More sharing options...
Stealth3kpl Posted January 9, 2011 Author Share #25 Posted January 9, 2011 You misunderstand incident metering. It's NOT for slides per se. It just tells you what the exposure level is where you're metering. If you meter it in the highlights, it tells you what the correct exposure is to get correctly rendered highlights. Ditto the shadows. Hence the former is used when shooting slides, the latter is used when shooting shadows. I think this is correct. An incident light meter measures light falling on its hemidirectional sensor. If you are taking a sidelit head you can aim the sensor more towards the major illuminating source to ensure highlights aren't burned out when using slide film. Using negative film one needs to expose for midtones so the meter's plane should parallel the subjects face. For accuracy one should be aware of the dynamic range of the film and adjust the exposure appropriately. Simply pointing the dome of the incident meter towards the sun isn't good enough but probably will do for slide film. It certainly isn't the point of the incident light meter. "Incident light" isn't just from the brightest light source (eg the Sun), it is incident via reflection from other surfaces (eg walls, the ground, moisture in the air etc). The incident light meter will still have some directionality (usually probably close to hemidirectional). The point of the incident light meter is to ensure the light reading isn't influenced by the colour and reflectance of the reflecting surfaces which could fool a reflectance meter. I think when literature states point the dome to the camera it is hoped that the meter is taking a good average (18%) reading of the incident illumination of the subject's face. Knowing how your film reacts to light and taking a reading from the highlights and shaddows and adjusting your exposure accordingly is the best method. Don't confuse this with reflectance metering. Pete Link to post Share on other sites More sharing options...
giordano Posted January 9, 2011 Share #26 Posted January 9, 2011 I'm going to summarise Dunn & Wakefield's recommendations in The Exposure Manual (4th edn, 1981) because they worked it all out from scratch with lots of experimentation, including designing incident light receptors. They identify four lighting scenarios that have to be taken into account: (A) Highly diffused lighting from a very large source - e.g. the sky when the sun is obscured by a cloud; a completely over- cast sky; light from the sky only (when the subject is completely in the shade); or fully diffused (i.e. non-directional) artificial lighting, ( frontal lighting due to one or more localised sources behind or near to the camera - e.g. the clear sun or one photoflood lamp (or more if grouped together) within about 45° of the camera direction line, © side lighting from one or more localised sources at one side of, and/or above or below, the subject - e.g. the clear sun or lamps between about 45° and 90° from the camera direction line, and (D) back lighting from one or more localised sources more or less behind the subject plane - e.g. the clear sun or lamps at more than about 90° from the camera direction line. They also consider three types of incident light reflector: flat (now only used by specialists, so I'll say no more about it) three-dimensional (e.g. the hemispherical ones fitted to virtually all current incident light meters) 'back-light-compensating' (e.g. the big Invercone that came with the later Weston meters). For hemispherical receptors, their recommendations (for everything except still monochrome negative film) boil down to: (A,B,C): Point the meter at the camera. (D): If the main light source is less than about 130 degrees from the camera direction line, point the meter at the camera. The shape of the receptor compensates for the changing lightin. Beyond about 130 degrees, in extreme backlighting, you'll need to think. Pointing the incident light meter half way between the camera and the main light source may give a good compromise, or using the average of the incident light reading pointed at the camera and an averaging reflected light reading. For still, monochrome, negative film, they recommend using a reflected light (including spot) meter to expose for the shadows. The book pre-dates digital photography but I think that for monochrome digital they'd have recommended using an incident-light meter (in order to peg diffuse highlights at a safe level). With the big Invercone (partly designed by Dunn), which accepts light from almost directly behind the meter, you can get good results even with the light beyond 130 degrees, as shown in the pictures below. Dunn & Wakefield also experimented with a meter that automatically combined incident and reflected readings; this never made it into production, I guess because people who cared that much about exposure were buying spot meters and everyone else just wanted in-camera metering. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! (Dunn & Wakefield, 4th edn, Plate 11, using a precursor to the big Invercone.) Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! (Dunn & Wakefield, 4th edn, Plate 11, using a precursor to the big Invercone.) ' data-webShareUrl='https://www.l-camera-forum.com/topic/141105-incident-light-metering/?do=findComment&comment=1552791'>More sharing options...
tgray Posted January 9, 2011 Share #27 Posted January 9, 2011 Advertisement (gone after registration) Good points. Thanks for taking more time and effort than I did and fully explaining it. Incident meters require you to think and use them properly in more complex lighting scenarios, just like other types of meters do. As long as you know how they work, you can interpret the results correctly. Link to post Share on other sites More sharing options...
leicameter Posted January 10, 2011 Share #28 Posted January 10, 2011 This may helps. Accurate Exposure with Your Meter Link to post Share on other sites More sharing options...
geotrupede Posted January 10, 2011 Share #29 Posted January 10, 2011 I think in general the idea of pointing the meter to the camera is fine, but as I mentioned before when you are in a studio things are slightly different. The following text is about the basic principles of studio lighting: how to setup a scene and balance the different components measuring the various flashes. You will see that the aiming direction for the meter is not always the same. In a studio, what matters is the object and the direction of the spotlights. I think the same approach could be used outside of a studio. Perhaps most of the time this translates in aiming the reading towards the camera, but not always: the important step is to fully understand how the reading works and which is the right direction to use for the specific task. Have fun with your M, G Anyway here is the extract: "Build up the lighting Start with your Key light (this can be any lightshaper depending on whether you want hard or soft lighting). Choose where you want to place it (which side of the camera axis for Broad or Short lighting, normally higher than eye level) and then meter it (pointing light meter towards Key light) and transfer the F-stop you get from the Key light to your lens/camera. Switch on Fill light & switch off Key light. Fill light – all this does is to lighten the shadows made by the Key light – it’s your choice how light or dark you want the shadows to be. Meter Fill light (meter pointing towards Fill light) to know how many F-stops difference there is between the Fill and Key lights. Switch on the Key light and meter both lights together (light meter now pointing towards camera), depending on the power/distance of the fill light the F-stop from the Key light ‘may’ increase, if this does then adjust the F-stop on the lens/camera. Add Effect light (hair/halo) – a light from side or rear of subject to help separate subject from background. Meter towards Effect light. Rule of thumb – this light needs to be brighter than F-stop on lens generally by 1 or 2 stops. ...." etc. Link to post Share on other sites More sharing options...
geotrupede Posted January 10, 2011 Share #30 Posted January 10, 2011 ...and here a couple of pictures where the idea of light measurement and balance between reading is illustrated. For example the halo cannot be measured by pointing the reading to the camera, and same for the background... Anyway pictures are not great but the idea is to illustrate the principles described in the post above. G Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/141105-incident-light-metering/?do=findComment&comment=1554362'>More sharing options...
gyoung Posted January 11, 2011 Share #31 Posted January 11, 2011 Just an illustration that the idea of pointing the meter towards the camera isn't entirely correct, it presupposes that the light source is behind or coming from the direction of the camera, which it will be in the majority of cases, but not every case. Reflected, spot and incident metering are all 'tools' to be used as most appropriate, together with an understanding of the light conditions, choice of medium and desired outcome. Sorry, I think you are incorrect, its a way of measuring the light falling on the subject that the camera sees, disregarding the reflectance of the subject. So the meter should be pointed at the camera position. How you interpret and apply the results is, as always, where the art comes in! I used an incident light meter for donkeys years mainly for strudio work, usually the Weston which has much the best 'sphere' for this purpose. Most if not all of the others have a simple dome. Gerry Link to post Share on other sites More sharing options...
tgray Posted January 11, 2011 Share #32 Posted January 11, 2011 Sorry, I think you are incorrect, its a way of measuring the light falling on the subject that the camera sees, disregarding the reflectance of the subject. So the meter should be pointed at the camera position. I'd have to disagree. When working with lighting setups, its very convenient to modify which way you aim the meter to get a help set your lighting ratios. Link to post Share on other sites More sharing options...
gyoung Posted January 11, 2011 Share #33 Posted January 11, 2011 I'd have to disagree. When working with lighting setups, its very convenient to modify which way you aim the meter to get a help set your lighting ratios. Yes, but that is not working out the camera exposure. Link to post Share on other sites More sharing options...
tgray Posted January 11, 2011 Share #34 Posted January 11, 2011 Yes, but that is not working out the camera exposure. It's not really worth getting in an argument, but it is working out the camera exposure. If I want my fill light to be two stops under my key, I meter the key light, set my camera to that exposure, then meter the fill light and reduce it's intensity so it's two stops below the camera setting. It's just a tool. You can use it multiple ways and interpret the information it gives you in multiple manners. For typical outside use, I often just point it at the camera (and not at the sun) because I know how to interpret the meter's readings. For more complicated lighting scenarios, that's not always the best way to use the meter... Link to post Share on other sites More sharing options...
pico Posted January 11, 2011 Share #35 Posted January 11, 2011 Yes, but that is not working out the camera exposure. It is for studio work. There is a reason many incident meters also provide a flat disc or a retractable disc - for measuring ratios. It's pointed at the light from the subject. If you don't have one, then pointing towards the light is the way to go. Link to post Share on other sites More sharing options...
holmes Posted January 11, 2011 Share #36 Posted January 11, 2011 The topic of this message caught my eye having familiarity with incident reading light meters. The list of professionals who use a handheld meter is about endless. For my own experience owning and using two different of the top brands I can tell you all meters are calibrated the same. I place my tripod with camera attached. I need to stand in the bright sun. I stand by my camera and point the dome directly at my lens. I measure the exposure and set my camera accordingly. Or I'm in an old adobe building with few if any windows. Out comes the meter. I have my tripod set were I want it. I walk out from my camera and take an incident reading. Maybe two and average them. I can recall doing some landscapes in the Sangre de Cristo mountains next door to Santa Fe NM. My focus was a midpoint between where I stood and Albuquerque about 100 miles south. I did not want to depend on reflective metering. I set the tripod/camera near the edge, but not to close to the edge of the cliff. I set the distance at slightly less than infinity. I walked close to the edge and pointed the meter's dome at my camera. I go back to my camera and read the digital results. I have several meters, all either Sekonic or Gossen. Link to post Share on other sites More sharing options...
gyoung Posted January 12, 2011 Share #37 Posted January 12, 2011 It's not really worth getting in an argument, but it is working out the camera exposure. If I want my fill light to be two stops under my key, I meter the key light, set my camera to that exposure, then meter the fill light and reduce it's intensity so it's two stops below the camera setting. It's just a tool. You can use it multiple ways and interpret the information it gives you in multiple manners. For typical outside use, I often just point it at the camera (and not at the sun) because I know how to interpret the meter's readings. For more complicated lighting scenarios, that's not always the best way to use the meter... On reflection, it was really far to hasty a comment of mine, you're right of course, in situations where you have complete control of the light sources, incident light measurement is at its best and your methods dsescribed are in the main as I did it. The Weston is particularly useful for that because it has its dials marked up for different lighting ratios (at least in my IV it has, I seem to remember that they changed that on the V or Euromaster). I've been 'retired' (from paid photography) for a while and haven't done any studio stuff for quite a while, I was probably thinking more of the more simplistic outdoor uses I use now for landscape/architecture etc. although even here its not as simple as just pointing the meter at the camera position from the subject, especially if the subject is inaccessible (eg across a river ) Gerry Link to post Share on other sites More sharing options...
Xmas Posted January 12, 2011 Share #38 Posted January 12, 2011 Hi To summarise The light meter is just a light meter The calculator that comes with the meter only 'does exposures' for average subjects The calculator for non average subjects is 4 inches behing your nose Noel P.S. for Gerry the Weston III to V all have the x2, /2, U and O marks on their calculators. Link to post Share on other sites More sharing options...
pico Posted January 12, 2011 Share #39 Posted January 12, 2011 For my own experience owning and using two different of the top brands I can tell you all meters are calibrated the same. I would not mention this, but someone has mentioned Weston meters. If one is lucky enough to have an old one, then compare it to a more recent one. They are definitely calibrated differently. They changed after model III. Link to post Share on other sites More sharing options...
nikau Posted January 12, 2011 Share #40 Posted January 12, 2011 Gosh, I've been using incident metering for decades. Would never have started if I realised it was so HARD! Link to post Share on other sites More sharing options...
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