Anyone keen to photograph some candles, for scientific experiment?

[tris_d]

As a part of scientific experiment I'd appreciate if someone could take two photos of a candle. First photo should have a candle at distance one meter away, and on the second photo the candle should be two meters away from the camera. The exposure time and aperture size should be the same for both photos. It is important photo should not be over-exposed, that is the image should not contain any pixel with brightness higher than 99 (where 100 is max brightness).

The purpose is to prove whether this illustration is wrong, or not:

Cosmology | Stephen's Website

 

[Bitter Jeweler]

It's wrong.


What do I win?

 

[Helen B]

You win another like. You need them.

 

[fjrabon]

The problem you're going to have is that in order to expose a photo such that a picture of a DIRECT FLAME isn't blown out, the picture will be so underexposed that noise will totally destroy any hope of precision accuracy.

Scientists have proven your photo is wrong. If you don't trust that, why would you trust us?

 

[Helen B]

Have you never seen a picture of a room full of candles? They are all the same brightness. The reason is that the inverse square law is exactly offset by the change in the area of the image of the candle flame*, so the image brightness stays the same. If you really want a careful example, I might do it later tonight if no-one else has beaten me to it.

*Excepting for a digital camera when an anti-aliasing filter enlarges the image of the flame significantly, thus spreading it over too many sensels, or when the image is appraoching the sensel size and spacing.

 

[Bitter Jeweler]

You win another like. You need them.

I DO!
4000 BABY!
YEAH!​

 

[tris_d]

The problem you're going to have is that in order to expose a photo such that a picture of a DIRECT FLAME isn't blown out, the picture will be so underexposed that noise will totally destroy any hope of precision accuracy.

Scientists have proven your photo is wrong. If you don't trust that, why would you trust us?

If that guy could take a photo of a light bulb with only slight over-exposure then surely it can be done with a candle even better. And I don't care about the noise, if both flames are going to have the same brightness, then the second photo should not get four times dimmer just because of the noise.

That's not my photo. That's how they calculate the distance to the stars. If the brightness does not vary with the square of the distance as Wikipedia says, then how in the world do you think they can measure any distance? All the physics text books say is that intensity falls off with the square of the distance - photons get spread out radially and so the amount of photons (intensity) decreases with the square of the distance. That's all they say, there is no relation in those equations to apparent size what so ever. There is no article on the internet that mentions anything about any apparent size in relation to inverse square law, it is not part of the equation.

You don't get it, I have no agenda here, it's all the same to me. Please stop arguing when there is no any argument. I didn't even get to the point to make any claims. We got stuck when I was trying to establish the basics, it is all the same to me. By the way, do you think there is any chance we could get moderators to re-open that thread? I don't want to bring that discussion here.

 

[tris_d]

Have you never seen a picture of a room full of candles? They are all the same brightness. The reason is that the inverse square law is exactly offset by the change in the area of the image of the candle flame*, so the image brightness stays the same. If you really want a careful example, I might do it later tonight if no-one else has beaten me to it.

*Excepting for a digital camera when an anti-aliasing filter enlarges the image of the flame significantly, thus spreading it over too many sensels, or when the image is appraoching the sensel size and spacing.

Please do. At this point, after wasting so much time blabbering about it, I'm ready to pay for it even.

 

[fjrabon]

The problem you're going to have is that in order to expose a photo such that a picture of a DIRECT FLAME isn't blown out, the picture will be so underexposed that noise will totally destroy any hope of precision accuracy.

Scientists have proven your photo is wrong. If you don't trust that, why would you trust us?

If that guy could take a photo of a light bulb with only slight over-exposure then surely it can be done with a candle even better. And I don't care about the noise, if both flames are going to have the same brightness, then the second photo should not get four times dimmer just because of the noise.

That's not my photo. That's how they calculate the distance to the stars. If the brightness does not vary with the square of the distance as Wikipedia says, then how in the world do you think they can measure any distance? All the physics text books say is that intensity falls off with the square of the distance - photons get spread out radially and so the amount of photons (intensity) decreases with the square of the distance. That's all they say, there is no relation in those equations to apparent size what so ever. There is no article on the internet that mentions anything about any apparent size in relation to inverse square law, it is not part of the equation.

You don't get it, I have no agenda here, it's all the same to me. Please stop arguing when there is no any argument. I didn't even get to the point to make any claims. We got stuck when I was trying to establish the basics, it is all the same to me. By the way, do you think there is any chance we could get moderators to re-open that thread? I don't want to bring that discussion here.

That's because you can't measure the apparent size of stars because they are REALLY FREAKING FAR AWAY. After the get to the point of being so small that our eyes or any precision instrument can't resolve a difference in size, then apparent brightness takes over.

Here you go:

http://thornscompose.files.wordpress.com/2010/04/prayer-candles.jpg

 

[480sparky40 39]

If the brightness does not vary with the square of the distance as Wikipedia says, then how in the world do you think they can measure any distance? ........

Red shift, for one. Parallax, for another. Quasars. Cepheid variables. SuperNovae. GRBs.

 

[unpopular]

this has been discussed already:

http://www.thephotoforum.com/forum/...ns/289251-really-stupid-physics-question.html

 

[cool09]

I'm not interested in candles or light bulbs but I would like to take a picture of Edison. Edison, NJ that is.

Or maybe as a science experiment since the Holidays are near you can take photos of colored light bulbs.

I know a lot of people in Colorado are lighting up right now.


Seriously, I do know a Physics teacher in another forum that can answer any question you have. At audiokarma.org (tybrad), amazing guy.

 

[tris_d]

That's because you can't measure the apparent size of stars because they are REALLY FREAKING FAR AWAY.

Why do you do that? Pulling stuff out of your hat and making assertions as it was a fact. There is apparent size, it's called Angular diameter. There is also radius, but none of them are part of the equation in regards to brightness, distance and inverse square law.

Angular diameter - Wikipedia, the free encyclopedia

After the get to the point of being so small that our eyes or any precision instrument can't resolve a difference in size, then apparent brightness takes over.

And how do you know that, pulled it out of your hat? Why no one else knows about it? Why it is not mentioned anywhere? Please provide the reference that can confirm your statement, otherwise you just spreading misinformation, for some strange reason.

Here you go:

http://thornscompose.files.wordpress.com/2010/04/prayer-candles.jpg

What is your agenda? Please let me be and mind your own business if you don't care about this. You know that photo is over-exposed, otherwise there would be noise, as you previously said.

 

[480sparky40 39]

......... There is apparent size, it's called Angular diameter. There is also radius, but none of them are part of the equation in regards to brightness, distance and inverse square law.
...........

Perhaps you would care to provide a list of how many stars (besides our own Sol) have had their angular diameter actually imaged? Last I heard, the total was 1.

 

[tris_d]

this has been discussed already:

http://www.thephotoforum.com/forum/...ns/289251-really-stupid-physics-question.html

Thank you.