Total: 11, showing: 1 – 11
On article What is equivalence and why should I care? (2341 comments in total)

wwick: Because the information on this site is always so excellent – and I assume my grasp of “equivalence” is pretty good – I was surprised to find myself confused. I don’t get how “total amount of light” on large versus small sensors is supposed to figure into the topic at hand. My guess is that it’s meant to be a non-technical way of introducing the concept of the inverse square law. If so, the graphic accompanying that discussion does not fully meet the criteria. It seems to me the relevant concept could be stated like this:

A Full Frame camera with an Equivalent FL set to an Equivalent DOF of a Micro Four Thirds camera would need 4 times more light than the smaller sensor. This would necessitate an increase in shutter speed, ISO, or the light level of the subject itself.

As to the consequences of increasing shutter speed or ISO with large versus small sensors, I’ll defer to you guys, but in terms of the basic optics, I think the article got a little more entangled than was necessary.

Regarding my "paradox" (above), I realize I'm reverting to a simple geometric equation again. My mistake.

Link | Posted on Nov 22, 2016 at 23:26 UTC
On article What is equivalence and why should I care? (2341 comments in total)

wwick: Because the information on this site is always so excellent – and I assume my grasp of “equivalence” is pretty good – I was surprised to find myself confused. I don’t get how “total amount of light” on large versus small sensors is supposed to figure into the topic at hand. My guess is that it’s meant to be a non-technical way of introducing the concept of the inverse square law. If so, the graphic accompanying that discussion does not fully meet the criteria. It seems to me the relevant concept could be stated like this:

A Full Frame camera with an Equivalent FL set to an Equivalent DOF of a Micro Four Thirds camera would need 4 times more light than the smaller sensor. This would necessitate an increase in shutter speed, ISO, or the light level of the subject itself.

As to the consequences of increasing shutter speed or ISO with large versus small sensors, I’ll defer to you guys, but in terms of the basic optics, I think the article got a little more entangled than was necessary.

With all the resampling going on, it's difficult for me to keep track of all the underpinnings effecting noise. I'll take you on your word that "total light" is the key indicator. I now see from your "noise" article, that whatever benefit a larger pixel can deliver, it's not neatly proportional to the inverse square law – it's light and electronics, not just geometry. I get that. But then it's not any clearer why total light works at the sensor level, so It sort of leaves me with nothing to hang on to. You have to admit, in the same-number-of-pixel scenario, if the larger sensor is even a little bit better than then smaller one, it's somewhat paradoxical that 4 1/4 size "inferior" pixels would out perform the larger sensor – until you consider that the 4x pixels are down sampled. Its confusing because there's so many moving targets. At now 2,300 comments, I suppose I'm not alone. All the more so I'm appreciative of your willingness to try to clarify what's going on. Thank you!

Link | Posted on Nov 22, 2016 at 23:20 UTC
On article What is equivalence and why should I care? (2341 comments in total)

wwick: Because the information on this site is always so excellent – and I assume my grasp of “equivalence” is pretty good – I was surprised to find myself confused. I don’t get how “total amount of light” on large versus small sensors is supposed to figure into the topic at hand. My guess is that it’s meant to be a non-technical way of introducing the concept of the inverse square law. If so, the graphic accompanying that discussion does not fully meet the criteria. It seems to me the relevant concept could be stated like this:

A Full Frame camera with an Equivalent FL set to an Equivalent DOF of a Micro Four Thirds camera would need 4 times more light than the smaller sensor. This would necessitate an increase in shutter speed, ISO, or the light level of the subject itself.

As to the consequences of increasing shutter speed or ISO with large versus small sensors, I’ll defer to you guys, but in terms of the basic optics, I think the article got a little more entangled than was necessary.

Richard,

I see where you're going, but let's slow this down a bit (as Widely Held Beliefs die hard).

In the same-number-of-pixels scenario, you say:

"If the larger sensor has the same number of pixels, then its image is cleaner. The light per unit area is the same and each pixel has a larger area."

So pixel size does make a difference.

But it's also true, that with a same-size-pixel scenario, 4x the amount of pixels per unit area on a full frame sensor is just as good - and maybe even better - than a single, larger pixel covering the same unit area.

And, that "total light" is all that's needed to estimate relative S/N values in both scenarios.

This does make sense, but I need to know if this is correct before I comment further.

Link | Posted on Nov 22, 2016 at 12:58 UTC
On article What is equivalence and why should I care? (2341 comments in total)

wwick: Because the information on this site is always so excellent – and I assume my grasp of “equivalence” is pretty good – I was surprised to find myself confused. I don’t get how “total amount of light” on large versus small sensors is supposed to figure into the topic at hand. My guess is that it’s meant to be a non-technical way of introducing the concept of the inverse square law. If so, the graphic accompanying that discussion does not fully meet the criteria. It seems to me the relevant concept could be stated like this:

A Full Frame camera with an Equivalent FL set to an Equivalent DOF of a Micro Four Thirds camera would need 4 times more light than the smaller sensor. This would necessitate an increase in shutter speed, ISO, or the light level of the subject itself.

As to the consequences of increasing shutter speed or ISO with large versus small sensors, I’ll defer to you guys, but in terms of the basic optics, I think the article got a little more entangled than was necessary.

I have to agree with Jerry R. On top of page 2, the graphic clearly illustrates how light intensity (per square mm) is the same for both sensors. But the graphic would have been more effectively utilized had the caption instead emphasized that while light intensity per mm across both sensors is indeed the same, light intensity on different size pixels is not. In trying to grasp the concept of the “total light” effect on different size sensors, I had reverted to a film analogy, and forgotten about effect pixel size has on noise. It didn't compute. The confusion continued when the concept of “same intensity per square millimeter” was reinforced later in the article.

The article need not be the last word on this topic. Should a future update be considered, I suggest jettisoning the "total light" concept.

Link | Posted on Nov 21, 2016 at 17:07 UTC
On article What is equivalence and why should I care? (2341 comments in total)

wwick: Because the information on this site is always so excellent – and I assume my grasp of “equivalence” is pretty good – I was surprised to find myself confused. I don’t get how “total amount of light” on large versus small sensors is supposed to figure into the topic at hand. My guess is that it’s meant to be a non-technical way of introducing the concept of the inverse square law. If so, the graphic accompanying that discussion does not fully meet the criteria. It seems to me the relevant concept could be stated like this:

A Full Frame camera with an Equivalent FL set to an Equivalent DOF of a Micro Four Thirds camera would need 4 times more light than the smaller sensor. This would necessitate an increase in shutter speed, ISO, or the light level of the subject itself.

As to the consequences of increasing shutter speed or ISO with large versus small sensors, I’ll defer to you guys, but in terms of the basic optics, I think the article got a little more entangled than was necessary.

OK, I appreciate you hanging in there. It's a new way of thinking for me because I'm so used to a higher degree of enlargement of smaller formats exacerbating deficiencies inherent in those systems. Some of that still may be in play, but not with respect to noise, total light levels being equal.

Link | Posted on Nov 18, 2016 at 21:24 UTC
On article What is equivalence and why should I care? (2341 comments in total)

wwick: Because the information on this site is always so excellent – and I assume my grasp of “equivalence” is pretty good – I was surprised to find myself confused. I don’t get how “total amount of light” on large versus small sensors is supposed to figure into the topic at hand. My guess is that it’s meant to be a non-technical way of introducing the concept of the inverse square law. If so, the graphic accompanying that discussion does not fully meet the criteria. It seems to me the relevant concept could be stated like this:

A Full Frame camera with an Equivalent FL set to an Equivalent DOF of a Micro Four Thirds camera would need 4 times more light than the smaller sensor. This would necessitate an increase in shutter speed, ISO, or the light level of the subject itself.

As to the consequences of increasing shutter speed or ISO with large versus small sensors, I’ll defer to you guys, but in terms of the basic optics, I think the article got a little more entangled than was necessary.

Ok, let's say FF and M4/3 are 20 both megapixel sensors. What you're saying, is the total light across the whole sensor is mitigating factor for noise, not sensor size (assuming comparable sensor quality among interchangeable lens type camera systems). With same pixel count, enlargement is not a factor.

Link | Posted on Nov 18, 2016 at 20:38 UTC
On article What is equivalence and why should I care? (2341 comments in total)

wwick: Because the information on this site is always so excellent – and I assume my grasp of “equivalence” is pretty good – I was surprised to find myself confused. I don’t get how “total amount of light” on large versus small sensors is supposed to figure into the topic at hand. My guess is that it’s meant to be a non-technical way of introducing the concept of the inverse square law. If so, the graphic accompanying that discussion does not fully meet the criteria. It seems to me the relevant concept could be stated like this:

A Full Frame camera with an Equivalent FL set to an Equivalent DOF of a Micro Four Thirds camera would need 4 times more light than the smaller sensor. This would necessitate an increase in shutter speed, ISO, or the light level of the subject itself.

As to the consequences of increasing shutter speed or ISO with large versus small sensors, I’ll defer to you guys, but in terms of the basic optics, I think the article got a little more entangled than was necessary.

Thanks for the reply, and sorry for the continued confusion. We are both saying that full frame set to both equiv. FL and DOF requires a 4x boost in time or ISO. I also understand that the 4x area of FF "cancels out the difference" in total amount of light. I'm just wondering why that information is important. We still have to boost time or speed parameter. Is it that the negative effect of a 4x ISO boost is canceled because of the larger surface area of the FF sensor? I.e. because we don't have to enlarge the FF as much as the 4/3 to get the same size image?

Link | Posted on Nov 18, 2016 at 19:56 UTC
On article What is equivalence and why should I care? (2341 comments in total)

Because the information on this site is always so excellent – and I assume my grasp of “equivalence” is pretty good – I was surprised to find myself confused. I don’t get how “total amount of light” on large versus small sensors is supposed to figure into the topic at hand. My guess is that it’s meant to be a non-technical way of introducing the concept of the inverse square law. If so, the graphic accompanying that discussion does not fully meet the criteria. It seems to me the relevant concept could be stated like this:

A Full Frame camera with an Equivalent FL set to an Equivalent DOF of a Micro Four Thirds camera would need 4 times more light than the smaller sensor. This would necessitate an increase in shutter speed, ISO, or the light level of the subject itself.

As to the consequences of increasing shutter speed or ISO with large versus small sensors, I’ll defer to you guys, but in terms of the basic optics, I think the article got a little more entangled than was necessary.

Link | Posted on Nov 18, 2016 at 18:10 UTC as 57th comment | 16 replies

I like the setting and the community spirit, but the overly suspenseful tone is unwarranted given the nature of the project. Also, as this apparently was not shot with a 24 square meter camera, it's not a true contact print. I do love how the process recorded the participants hand prints, providing both scale and tangible evidence of community participation – points the film could have made, but sacrificed for the sake of drama.

Link | Posted on Jul 25, 2016 at 20:27 UTC as 10th comment | 1 reply
On article Welcome to our studio test scene (270 comments in total)

Well done. As one who's complained about the last couple of iterations of the test target, I think you finally have it right. I particularly like the tungsten light option. It was a good choice to use a household bulb on one side to create the fall off. It's just the the kind real-life condition we need to evaluate. I also like having a medium format reference shot. Might you consider including Hasseblad multishot (200 megapixel) back as well? I've often thought it would be useful to have the current resolution champ (whatever that may be) as a reference that could be automatically down sampled to any camera in the data base, but that may be too much to ask for. : )

Link | Posted on Sep 18, 2013 at 20:16 UTC as 76th comment
On article A sneak peek at our forthcoming camera test scene (320 comments in total)

rich889: the point of the comparison scene is to COMPARE between cameras across the board, OLD AND NEW. The most logical way to do that is to expand the current scene rather than delete it and start with a clean slate.

My comments when the previous test target was introduced in 2009:

"it's unfortunate that you didn't take this opportunity to make a clean break with the past and start and over with an attractive, coherent arrangement of objects that would not only be pleasing to look at in detail, but would put far greater demands on cameras."

"I think your new set should have been wider and shallower so that aperture was not a big factor. You should also have consulted an experienced prop stylist, still life photographer, or set designer so we would have something attractive to look at and you would have something less dreary with which to do your painstaking tests".

Three years later you have adopted all but the suggestion of making the scene more coherent and attractive. The flat lighting is unfortunate too. Two steps forward, one giant step back.

Link | Posted on Oct 11, 2012 at 21:19 UTC
 Total: 11, showing: 1 – 11