johnmikka

I'm sorry I didn't mean to direct it to you, I was just asking why "you that you can't measure a backlit curtain with an incident light meter". But I just got my answers in a different forum. thank you

I have revisited post #10 as you mentioned. if you see the video, I have measured using incidence meter both towards the window as well as pointing into the room, none of the reading is less than 3 stops over. Certainly the camera meter is measuring both reflective light off the curtain as well as see-through light from the window behind. But as I mentioned in the video I have measured with incidence to both direction. And I thought I cleared the question myself by saying, the incidence meter ignored the reflective reading as being a white curtain. hence the 2-3 stops difference. But then I was just plainly shoved with comments from you "You are just not supposed to". And I have explained myself that there is a reason why you are not supposed to use a screwdriver for the nails, requesting the similiar explanation for this metering situation. And you refused to answer me in this manner. Personally, I don't consider any object in real life situation "theoretical" or "remote", let alone shooting a curtain with an incidence meter. Art is made when rules are broken. I don;t know what "Real world photography" you are referring to, is it a place where students of the subject are not allowed to question how instrument works and why passing a certain point? As I said, spot meter or incidence meter they are both equipped with a light sensor, eventually measuring light falling onto the senors. ButI have yet received any explanation as to why by mounting a dome vs lens, will determine whether I could or could not meter a curtain against a window... But I no longer have any hope in getting answers here. Everyone can just let this post sink and die like any child's innocence....

Sometimes it's easier to just admit that you don't know... you are turning this whole thing into a gospel truth from the church... "You are not supposed to have sex untill you get married" Why? you are just not supposed to because that's what this manual said called holy bible!

1) Your previous post as quoted before said the reflective meter is affected by color, so I'm reasoning the meter in the camera is affected by the curtain being white, therefore F stops lower by 2/3 stops. why is this wrong? 2)Could you explain why my scenario is remote and well beyond 'theoretical'? Why is a backlit curtain is remote but a stained glass window is "close example" 3) When people tell me something is wrong or not supposed to used for that, I just couldn't take that as an answer. I have re-read every single post people has take the time to write, but here is my follow up questions still. They are basically asking the same thing. a)Why can't I used an incidence meter for backlit subject? b) What dictates a spot meter only measures reflected light, and an incidence measures lighting falling on the subject? c) They are both essentially a calculator with a light sensor, one is with a 1% 3% lens, one with a dome/ sphere But both are measuring light falling on the sensor... so how come when I point a spot meter at the backlit curtain it is ok, and when I point the incidence it is not? As a matter of fact, as mentioned Sekonic meters have accesories/adpaters to turn incidence meter into a spot. So could someone explain to me in fundamental terms, instead of the conclusive: What I'm after is why are you not supposed to "drive a nail into hardwood with a screwdriver.", because it will strip the wood, because the nail has no notches for the screwdriver? I'm here to learn, and that's all

I don't understand why I got so many criticism over a scenario that I'm observing in my bedroom: There is a white/ beige silk curtain backlit by the window, I have camera (pretending with no meter), I have an incidence meter --> how would I meter this curtain to get the right exposure.... is this so remote and "theoretical"??? Anyways, I just measured it, the Sekonic incidence gives consistently 2-2.5 stops under than the spot meter in my camera. And I attribute it to the reflective element of the curtain.

Yes, they are meant to work that way, but I'm making up a hypothetical scenario where my camera has no meter, and I'm shooting to expose the curtain correctly. I'm putting the dome closely against the curtain, is it not "close metered" as you mentioned?

Yes, I agree with AjG, I guess I worded it wrong. But that I meant, if a person is wearing a white shirt and a black shirt, it will be impossible to use a spot meter and get the "correct" exposure since it will average the two colors to compensate for a neutral grey, which translate to white is kind of grey and black is kind of grey.... am I correct this time?

I guess to answer my own question, is if "correct" means neutral grey... then yes, it's impossible.

But does this also mean if I'm filming a person wearing a white shirt and black pants, it will be almost impossible to get both piece of clothing in the "correct" exposure, (or similarly a really black person and a really white person)?

Yes. I just did some experiment myself. I guess I didn't think it would actually be THAT much of an exposure difference only due to the color itself . But apparently it does... valuable lesson learnt, again for free through the internet :D MEDIA REMOVED - Video is "private"

I think I figured out what went wrong here. If you see my 2nd video with the dome down pointing towards the window reads F2.8 My camera reads F5.6, I guess if I dial the dome to up position will get me half a stop over? And the rest can be explained by the white curtain factor affecting my matrix meter inside the camera? I will experiment more tomorrow when the sun comes up again :D

I'm sorry, but I'm so confused right now.. and it's not your fault, But I was told when you take an incidence reading (esp, in studio setting) you should point it towards the light source for a more regional reading.... but let's say there is a person standing near this curtain, wouldn't I point the incidence meter towards this same way as I did in the video I posted? facing to the window to get the amount of light projecting through the curtain?

I meant the real life situation where I want to control how much the curtain will be blown out (or not), how would I do that.. Not everyone shoot/meter around the human subject.

But if you see the video, I have pointed the incidence meter facing towards window, and got F-5.0 still 3 stops in difference.

Also, I noticed that in this scenario, the llight mainly comes from the window which is behind the curtain, there aren't much light shinning upon from the other side, so I'm not sure if the reflected light from the curtain being white will cause a F-11 vs F2.8 or a difference? help me to understand... i'm so confused... I tested the meter and camera spot meter again, under the sunlight over a surface, and both reading seems to match, so I think there is something I'm not understanding correctly here. My main concern is if this curtain situation were a real life scenario, and my camera didn't have the internal meter, how would I meter it with only an incidence one, am I supposed to think if it's a white curtain I have to +3/4 stops???