Do you loose a stop of light when using 35 mm lens adapted for the gh4?

stoneinapond said:
Are we confusing pixel size with sensor size? Yes, a larger pixel can absorb more light and a larger sensor has more real-estate to accommodate larger pixels. But the size of sensor itself does not influence the light gathering.
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Sure it does, given the same photosite design, larger sensor gathers more light.

20 1gallon buckets will collect about twice as much rain as 10 of them...


Also, it's worth noting that larger photosites may not actually mean better light gathering:

"Among the important measures of image quality are signal-to-noise ratio of the capture process, and resolution. It was shown that for fixed sensor format, the light collection efficiency per unit area is essentially independent of pixel size, over a huge range of pixel sizes from 2 microns to over 8 microns..." (https://theory.uchicago.edu/~ejm/pix/20d/tests/noise/noise-p3.html#pixelsize)
 
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nyvz said:
20 1gallon buckets will collect about twice as much rain as 10 of them...
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Invalid analogy. Buckets collect things in the vertical axis, whereas sensors work on a "horizontal" or flat plane (surface area) and do not retain the light they gather.
 
stoneinapond said:
Invalid analogy. Buckets collect things in the vertical axis, whereas sensors work on a "horizontal" or flat plane (surface area) and do not retain the light they gather.
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I'm not sure I follow what you mean by the vertical and horizontal part. The orientation doesnt matter, turn the sensor up toward the sky and it's not so different. I didn't mention the size of the bucket's opening which equates to the photosite size because my point was in response to you saying the sensor size doesnt matter in collection, but it does because one photosite or one bucket of a fixed size will only collect 1/20th as much water/light as an array of 20 photosites/buckets each of that same fixed size combined into one "sensor". Why would it matter if the raindrop or photon is retained as long as it is collected? Theoretically the bucket could have an mechanism that converts the raindrops' potential energy to voltage as well, but that's beside the point. The opening of the bucket has a surface area that directly correlates with how much rain it will gather, but how it is collected or read is not the point. Obviously it's an analogy intended to help illustrate a simple concept that may not hold true in every aspect, but it seems quite valid for the idea that given a fixed photosite size, more photosites put together to create a larger sensor will collect more light.

I suppose we are pretty far off topic now, but it seems the original poster never came back and clarified his question :(
 
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All else being equal, the number of pixels effects the resolution, while the size of the individual pixels effects sensitivity, & dynamic range.
 
In the end I say who cares? This topic is blown way out of proportion to what the OP asked. The simple answer to this very simple question is no. If you put a 25mm FF lens on a m43 camera or a 25mm m43 lens on a m43 camera and both are capable of f1.4 they will both look like f1.4. End of story. I see no misinterpretation here and only requires a simple answer.

I also feel as though FF is way over hyped. Sure it has a low light advantage but in the overall scope of quality and professional production environments that use good lighting it doesn't matter as much. Light can always be added. FF is not a video standard, super35mm is. We really need to stop thinking of FF when making films or shooting video. m43 may still be a bit smaller than Super35mm but it isn't that much smaller and the lenses tend to look sharper wider open with m43. I consider FF an abomination and has not been responsible for any of the best movies ever made in the last 100+ years. Anybody who thinks they need FF to make a great movie is only fooling themselves.

There is also the matter of how soft FF lenses are when wide open. It is a fact that many if not most FF lenses are very soft when opened up to f1.4, f2.0, f2.8 and sometimes even f4.0. native m43 lenses can sometimes be sharper when opened up to f1.8 or f2.0. Take for example the Olympus 75mm which is insanely sharp and high contrast even at f1.8. Of course FF at f2.0 will be brighter on a FF camera compared to m43 at f2.0 on a m43 camera but if one was trying to achieve a certain optical quality a lot of the FF low light advantage is tossed out the window. To achieve a similar optical look across the frame a FF camera may have to stop down a lens to f5.6 to match the same optical look across the frame of a m43 lens at f2.0. That is a 3 stop difference and a lot of extra light.
 
Bern Caughey said:
All else being equal, the number of pixels effects the resolution, while the size of the individual pixels effects sensitivity, & dynamic range.
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Yes I'm familiar with that conventional wisdom, but if you read that article I quoted/linked you'll see it may be more complicated than that.
 
Thomas Smet said:
In the end I say who cares? This topic is blown way out of proportion to what the OP asked. The simple answer to this very simple question is no. If you put a 25mm FF lens on a m43 camera or a 25mm m43 lens on a m43 camera and both are capable of f1.4 they will both look like f1.4. End of story. I see no misinterpretation here and only requires a simple answer.

I also feel as though FF is way over hyped. Sure it has a low light advantage but in the overall scope of quality and professional production environments that use good lighting it doesn't matter as much. Light can always be added. FF is not a video standard, super35mm is. We really need to stop thinking of FF when making films or shooting video. m43 may still be a bit smaller than Super35mm but it isn't that much smaller and the lenses tend to look sharper wider open with m43. I consider FF an abomination and has not been responsible for any of the best movies ever made in the last 100+ years. Anybody who thinks they need FF to make a great movie is only fooling themselves.

There is also the matter of how soft FF lenses are when wide open. It is a fact that many if not most FF lenses are very soft when opened up to f1.4, f2.0, f2.8 and sometimes even f4.0. native m43 lenses can sometimes be sharper when opened up to f1.8 or f2.0. Take for example the Olympus 75mm which is insanely sharp and high contrast even at f1.8. Of course FF at f2.0 will be brighter on a FF camera compared to m43 at f2.0 on a m43 camera but if one was trying to achieve a certain optical quality a lot of the FF low light advantage is tossed out the window. To achieve a similar optical look across the frame a FF camera may have to stop down a lens to f5.6 to match the same optical look across the frame of a m43 lens at f2.0. That is a 3 stop difference and a lot of extra light.
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You clearly feel very strongly about ff35/vistavision, are you saying you believe it to be inferior or only slightly superior but overhyped?

You seem to be contradicting yourself at the end. First you say f2.0 is brighter on FF which if you mean more light reaches the sensor surface is true, but then you say f5.6 (actually f4 is a more accurate to match f2 on m43) is less light on FF than f2.0 on m43 but actually it's the same amount of light. That's the beauty of a larger sensor, an FF lens may perform badly at f2.0 but to match f2.0 on m43 you have to stop it down to f4 where it will likely perform better than the m43 lens at f2.0 and you still have the option of gaining 2stops by opening up which you couldn't do on the m43 camera.
 
nyvz said:
You clearly feel very strongly about ff35/vistavision, are you saying you believe it to be inferior or only slightly superior but overhyped?

You seem to be contradicting yourself at the end. First you say f2.0 is brighter on FF which if you mean more light reaches the sensor surface is true, but then you say f5.6 (actually f4 is a more accurate to match f2 on m43) is less light on FF than f2.0 on m43 but actually it's the same amount of light. That's the beauty of a larger sensor, an FF lens may perform badly at f2.0 but to match f2.0 on m43 you have to stop it down to f4 where it will likely perform better than the m43 lens at f2.0 and you still have the option of gaining 2stops by opening up which you couldn't do on the m43 camera.
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I'm not contradicting myself. Of course FF will always be brighter. My point was about optical quality. Yes FF has the ability to go even brighter but honestly most film makers shouldn't do that. There is an obsession with shooting with no lights either due to budget, fear or laziness and I consider this to be wrong. If one wants to achieve the best image their lens can resolve then the gap gets much smaller between FF and m43. It gets even smaller between super35mm and m43. s35mm tends to use FF lenses and therefore those lenses are subject to the same wide open limitations. Now many m43 users also use FF lenses which in that case throws out the entire argument because the lens still needs to be stopped down to f4 or f5.6 to look its best. I'm talking about pure native m43 lenses having a wide open advantage.

Really my whole point to all of this is that it really isn't as big of a deal as some make it out to be. If a production uses lights the right way then a lot of these arguments get tossed out the window. If you have to shoot FF at f2.0 you are seriously doing something wrong and need to rethink your productions and equipment. Don't invest $5,000.00 into a FF camera and lenses to shoot without lights. Instead use that money to buy some great lights that will last 10+ years. I will repeat this again. FF is not a film standard for making movies. Never has been. Are 1000's of Hollywood movies shot over the past 100+ years inferior in anyway because they were not shot with FF? I like S35mm because it is the format used by the best in the industry who likely work circles around the rest of us. We want to achieve what they can do and yet consider the sensor size they use as somehow inferior when we talk about it on forums. I cannot afford a S35mm camera and don't really like how Canon or Nikon handle video recording so m43 is the right fit for me. I will never claim that m43 is perfect but it is a perfectly capable format that in the right hands can create magic. I don't need FF to tell a story and make something beautiful. Anybody who thinks they can only use FF to create professional art is just plain wrong. That was really the whole point to the last part of my above post. That m43 is fully capable and a great system to work with.
 
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