In camera meter same as my incident? help

ddd

Your camera takes reflected light readings. If you are using the dome of your Sekonic, then you are taking an incident light reading. They are different. A reflected light reading is taken by measuring the light reflected off of a subject or object. An incident light reading is one in which the light is measured by the amount of light falling on the subject. For example: if you are taking pictures in a snowy place, an inceident light reading would be prefered as the reflection off of the snow would confuse the cameras reflected meter trying to render the relflected light off the white snow as 18% grey. When you use an incident reading, you are measuring the light that the subject is in, or the light falling on the subject. This would be more useful because there is not a high contrast reflection getting in the way. I don't know if I am helping or not.

Anyway depending on the Sekonic you have; if it is an old one like a L28c, you would take off the dome, and put your hand over the open reading area. Cover it up so m=no light gets in. Then take a reading. The EV value should be 0. If not, you need to calibrate it. There is usually a screw on the back to adjust up or down. Just repeat covering the light sensor until you get a reading of 0. It will then be calibrated. I hope this helps.

I confused you big time.. I totally understand what reflective metering is as opposed to incident.. What I was trying to convey is that I put my camera lens up to a gray card in AV mode (Partial meter mode) and set my aperture at F2.8 and got a shutter speed of 1/80th.

I then put my sekonic (incident) meter with the dome in front of the gray card but, had the dome facing the camera and got the same reading f2.8 with the shutter at 1/80th. Of course the ISO was set the same on the incident meter and the cameras meter.

Just to clarify once again, I took a reflective reading with my camera (obviously) and I did an incident (light falling on the subject) with my sekonic L358 comparing readings.

Of course I had the dome facing the camera lens with the back of my sekonic meter leaning up against the grey card..

I hope this clears things up and someone can confirm they get what I'm saying? My question is simply does that mean that I can trust the sekonic if the light falling on the subject is the same as the light reflecting off the gray card?

Thanks!

You are lucky to have two meters that match one another! It is very common for two different meters to NOT AGREE!
Keep in mind that the ISO standard for meter calibration is not a fixed equation...there is a Variable in the equation that the meter manufacturer gets to choose, and their selection might be different from another manufacturer! Meters are, after all, only a RECOMMENDATION. Camera shutters can be a bit fast or a bit slow from the rated speed; lens diaphrams could be a little wider or a little narrower from the rated f/stop; sensors could be a little more sensitive or a little less sensivitive than the ISO rating suggests! In view of the variables, meters can only offer a starting suggestion to you!

But yes, in view of the reflect light gray card agreeing with the incident light hemisphere reading, you can trust the incident meter to substitute. If anything, TRUST IT MORE because it cannot be fooled by subject brightness (white dress, black dog)

Wilt wrote in post #2820984
You are lucky to have two meters that match one another! It is very common for two different meters to NOT AGREE!
Keep in mind that the ISO standard for meter calibration is not a fixed equation...there is a Variable in the equation that the meter manufacturer gets to choose, and their selection might be different from another manufacturer! Meters are, after all, only a RECOMMENDATION. Camera shutters can be a bit fast or a bit slow from the rated speed; lens diaphrams could be a little wider or a little narrower from the rated f/stop; sensors could be a little more sensitive or a little less sensivitive than the ISO rating suggests! In view of the variables, meters can only offer a starting suggestion to you!

But yes, in view of the reflect light gray card agreeing with the incident light hemisphere reading, you can trust the incident meter to substitute. If anything, TRUST IT MORE because it cannot be fooled by subject brightness (white dress, black dog)

I'm glad to hear that I thought it was a good thing as well.. Thanks for your great info..

I have one more question regarding what you said about the "white dress, black dog thing?) Sometimes when I take an incident reading of a person in a white shirt the settings the meter gives me seems to blow out a bit of the details in the white shirt. Should I trust the zone system here and close down a stop from what the incident meter is telling me in situations like this?

globalbooks wrote in post #2821041
Sometimes when I take an incident reading of a person in a white shirt the settings the meter gives me seems to blow out a bit of the details in the white shirt. Should I trust the zone system here and close down a stop from what the incident meter is telling me in situations like this?

You confuse me by that statement!

A relected meter tries to take anything it sees (if it is filling the meter's FOV) and expose it to make it appear gray in tonality! So if you aimed at a white shirt and did not use EC, that white shirt should come out looking gray and you should have not issues of blown out highlights!

If you used an incident meter, it tries to take the light that falls on the scene and render the average scene brightness as 18% gray. So in that case, a white shirt with sunlight striking it could easily have highlights which exceed the ability of the sensor to capture a too-wide dynamic range.

Wilt wrote in post #2821136
You confuse me by that statement!

A relected meter tries to take anything it sees (if it is filling the meter's FOV) and expose it to make it appear gray in tonality! So if you aimed at a white shirt and did not use EC, that white shirt should come out looking gray and you should have not issues of blown out highlights!

If you used an incident meter, it tries to take the light that falls on the scene and render the average scene brightness as 18% gray. So in that case, a white shirt with sunlight striking it could easily have highlights which exceed the ability of the sensor to capture a too-wide dynamic range.

First let me say thanks wilt for helping.. I didnt mean to confuse you, what I was trying to convey was when I take an incident reading measuring the light that falls on the subject sometimes the whites are blown a bit. I know how to take an incident reading properly I Normally will have my camera on a tripod and I face the dome at my lens... Would you suggest taking the incident reading and stopping down a stop if there is white clothing in the scene? Of course all of this considered with me using a 20D

globalbooks wrote in post #2819949
I'm pretty new to photography and I have a question if you would be so kind to answer?

I'm trying to find out if my sekonic incident meter is callibrated properly.
I set my 20D to partial and metered an 18% gray card last night and got the same reading with my sekonic using the white dome. Of course the sekonic was in front of the gray card toword the camera. The exposure was exactly the same on the sekonic as it was in the camera meter.
I was careful to make sure the meter was in the same light location as the gray card. I took the reflective reading with my camera in AV mode (right up on the gray card) and did the incident with my sekonic facing me up against the gray card. (in case there is confusion)

Does this mean that I should trust the sekonic if the readings are identical?

Thanks so much

Just to let you know that your first post (copied here) was well written and you definitely seem to understand the subject involved.

You are correct that the Sekonic meter's calibration appears to match that of the camera's meter fairly well.

It is possible that both meters are off by a little bit, though. At least once you figure out whether you generally need to add or subtract up to a half-stop, you can be sure of doing the same thing with either meter - at least in roughly the same light levels as your experiment. You might find differences between the meters in significantly different light levels.

globalbooks wrote in post #2821896
First let me say thanks wilt for helping.. I didnt mean to confuse you, what I was trying to convey was when I take an incident reading measuring the light that falls on the subject sometimes the whites are blown a bit. I know how to take an incident reading properly I Normally will have my camera on a tripod and I face the dome at my lens... Would you suggest taking the incident reading and stopping down a stop if there is white clothing in the scene? Of course all of this considered with me using a 20D

An incident meter reads the fundamental lighting and provides the exposure that causes a camera to record the inherent brightness. 18% gray reproduces at 18% gray. If the scene has whites at +3EV from the inherent brightness, it will just go into clipping, perhaps. And it is possible for a scene to have even brighter highlights and darker shadow areas (which is why B &W film could record 7EV of dynamic range). So in that scene, it would not be at all unusual for there to be large areas of blown highlight detail. If one tried to 'shoot to the right' you could capture the highligth details, but at the expense of losing shadow detail! That is why 'blind adherence' to the 'shoot to the right rule' is NOT necessarily the best practice in all scenes! What is important to YOU in the scene, as the photographer, should determine what 'proper exposure' is for the scene! If you WANT deep shadow details in a dark cave to show up, what does it matter if some bright white details in an area does not get reproduced?...it doesn't matter! That is part of the judgement call that you make as the photographer, regardless of the type of meter in use. And that is also the reason why master photographers choose the type of meter best suited to the job they need to do!

Now, having rattled on about the metering philosophy, my anwer to you is to 'adjust the exposure if you think it is most important to capture all of the detail in the bridal gown, at the sacrifice of the detail in the groom's black tux'. But if the most important detail is the black dog in the shadows who belongs to the person who hired you to shoot photos of the dog, to heck with the girlfriend's white outfit, don't adjust the exposure for the white outfit, but maybe even bias it toward maximizing shadow detail!

Thanks skip for the words of wisdom.. Also, wilt, wow that was lots and lots of info and I appreciate it.. I think I have a pretty good understanding when it comes to exposure it's just the whole incident metering thing that I'm trying to work out thats all. I totally get what you are saying about knowing whats important to preserve in a photograph that makes perfect sense. Of course shooting a brides gown next to a black tux we all know that the tux doesnt exist right ??

globalbooks wrote in post #2825428
Thanks skip for the words of wisdom.. Also, wilt, wow that was lots and lots of info and I appreciate it.. I think I have a pretty good understanding when it comes to exposure it's just the whole incident metering thing that I'm trying to work out thats all. I totally get what you are saying about knowing whats important to preserve in a photograph that makes perfect sense. Of course shooting a brides gown next to a black tux we all know that the tux doesnt exist right ??

"What...was the groom in that photo?!?!?!"