[JJ_SO]

Be it FF or µ 4/3, at base ISO I want to see the guy who is able to detect a difference for quite a range of output formats. Therefore I see the calculations with ISO extremely useless. Sensors are an ongoing development, today we see sensors we never thought about going eater that high in ISO or that low in noise or that high in DR - and each system has rather particular advantages.

 

And being able to shoot at f/2.8 instead of f/5.6 IS a speed advantage.

 

Trying to equivalence systems which are in no way scaled in the same proportions, on every single aspect which matters, will lead to meaningless results, simply because there are no mathematically perfectly scaled two systems. That's what I'm talking about when I say false assumptions. There are cameras around with small sensors which make bigger ones look pretty pale. There is post production of RAW. There are back and front lit sensors. Lenses cannot be scaled equally otherwise I already would have seen the same results. Production tolerances - you guys pretend these are also scaled, but the machines for the medium format lenses are the same like the ones for µ 4/3. There are so many factors in these theoretical assumptions that I can't believe you're not able to really that reality doesn't follow mathematical models, especially these kind of simple linear ones.

 

Try to scale down a Porsche to a 1/30 scale - the theoretical speed should be around 300/30 = 10 km/h (166.66 m/min) then? Now you also scale down the engine, the screws and the manufacturing tolerances. A nozzle in the engine of ø 1 mm with tolerance of ± 0.03 mm will become ø 0.0333 mm and a tolerance of 0.0001 mm - good luck in manufacturing that... And how do you scale down the petrol's energy to about 1/30 of it's power? How do you weld the sheet metal from 1.5 mm to 0.03 mm? And get the stability of it? Think your "scientific" equation until it's end and with all components, not just the selected ones you like to talk about.

 

Equivalence is not helping me in any way, so why bother? Like Wim says, most things can be done with µ 4/3, others better with FF, fine, what more do I need to know? Telling others "oh this 200/2.8 is pretty lame, on FF it's only 400/5.6" is soooo useless, that I just start with counting:

1. how many fast lenses for µ 4/3 are around to choose from? µ 4/3 owners will be pretty happy about, at least the ones with big enough pockets
   
2. how many really competing FF lenses 400/5.6 are around? Some old bottle bottoms and the rest is already 400/4 and not so easy to finance. That makes this comparison pointless.
   
3. I daresay a FF lens in this quality at 400/5.6 won't be much cheaper.
   
4. But might come with a more nervous bokeh.
   
5. but will have a much longer minimal distance
   
6. and need to bump up ISO by two stops, that can make the difference between a nice memory and a shot to sell
   
7. thxbb12, have you used a 400 mm on your FF camera, before you went mirrorless? It's a question to find out if equivalence in this case was helping you much
   

Very often when I read this kind of equivalence statements, it's simply not helping the people for who the lens is addressed to, often the lens choices are limited in mirrorless land. People who already started with µ 4/3 don't benefit - they read "400mm" think, oh that must be big - and when you mount a 400 on a FF it's pretty disappointing, because even with 600 mm the birds stays a small animal.


Be it FF or µ 4/3, at base ISO I want to see the guy who is able to detect a difference for quite a range of output formats. Therefore I see the calculations with ISO extremely useless. Sensors are an ongoing development, today we see sensors we never thought about going eater that high in ISO or that low in noise or that high in DR - and each system has rather particular advantages.

 

Trying to equivalence systems which are in no way scaled in the same proportions, on every single aspect which matters, will lead to meaningless results, simply because there are no mathematically perfectly scaled two systems. That's what I'm talking about when I say false assumptions. There are cameras around with small sensors which make bigger ones look pretty pale. There is post production of RAW. There are back and front sensors. Lenses cannot be scaled equally otherwise I already would have seen the same results. Production tolerances - you guys pretend these are also scaled, but the machines for the medium format lenses are the same like the ones for µ 4/3. There are so many factors in these theoretical assumptions that I can't believe you're not able to really that reality doesn't follow mathematical models, especially these kind of simple linear ones.

 

Try to scale down a Porsche to a 1/30 scale - the theoretical speed should be around 300/30 = 10 km/h (166.66 m/min) then? Now you also scale down the engine, the screws and the manufacturing tolerances. A nozzle in the engine of ø 1 mm with tolerance of ± 0.03 mm will become ø 0.0333 mm and a tolerance of 0.0001 mm - good luck in manufacturing that... And how do you scale down the petrol's energy to about 1/30 of it's power? How do you weld the sheet metal from 1.5 mm to 0.03 mm? And get the stability of it? Think your "scientific" equation until it's end and with all components, not just the selected ones you like to talk about.

 

Equivalence is not helping me in any way, so why bother? Like Wim says, most things can be done with µ 4/3, others better with FF, fine, what more do I need to know? Telling others "oh this 200/2.8 is pretty lame, on FF it's only 400/5.6" is soooo useless, that I just start with counting:

1. how many fast lenses for µ 4/3 are around to choose from? µ 4/3 owners will be pretty happy about, at least the ones with big enough pockets
   
2. how many really competing FF lenses 400/5.6 are around? Some old bottle bottoms and the rest is already 400/4 and not so easy to finance. That makes this comparison pointless.
   
3. I daresay a FF lens in this quality at 400/5.6 won't be much cheaper.
   
4. But might come with a more nervous bokeh.
   
5. but will have a much longer minimal distance
   
6. and need to bump up ISO by two stops, that can make the difference between a nice memory and a shot to sell
   
7. thxbb12, have you used a 400 mm on your FF camera, before you went mirrorless? It's a question to find out if equivalence in this case was helping you much
   

Very often when I read this kind of equivalence statements, it's simply not helping the people for who the lens is addressed to, often the lens choices are limited in mirrorless land. People who already started with µ 4/3 don't benefit - they read "400mm" think, oh that must be big - and when you mount a 400 on a FF it's pretty disappointing, because even with 600 mm the birds stays a small animal.