Pana is rumored to plan CFF (compact full frame) for post M43

Started Mar 19, 2013 | Discussions thread
ultimitsu
Veteran MemberPosts: 5,576
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Re: FF should be taken seriously
In reply to Mike Fewster, Mar 22, 2013

Mike Fewster wrote:

This is clearly the wrong way to look at it. 2 x 2 = 4 is the most simple math so I am not sure what can make one get that wrong. You are on the wrong side of both theory and measured data.

If you look at a print made with ff v (say) mft, (all other factors such as lens choice and iso being equal) you will see better sharpness dr and color gamut for the ff, but is it 4x better?

That is like saying, if you were driving a Veyron and a Corolla on a 50kph road, is the veryon 4 times faster? Can you not see the fallacy in such comparison?

Where light is plenty and DOF is wide and the print is small, you cannot even tell the difference between a goo P&S to a FF. but we are not buying good cameras for these shots only are we? we buy them for photos taken in less ideal lighting, or where we need narrower DOF, or where we print big. Just like Veyron is not made for 50kph roads even thought it can drive on it just the same.

Those factors have nothing to do with the senor size.

They have everything to do with sensor size. it is called physics.

Try the following where this issue is being discussed to see what I am trying to say.

http://theonlinephotographer.typepad.com/the_online_photographer/2011/09/mikes-position-on-sensor-sizes.html

This is where you are completely wrong:

"Each successively larger film size had either no advantage or only a subtle advantage over the next smaller format up until the print size reaches a certain rough threshold."

You take the assumption that all images, in comparison tests and in real life, are done with plenty of lighting thus with maximum IQ, I already told you that that is not how it works in real life. where light is not plenty, difference in IQ becomes obvious.

Compare the area of a Nex sensor to that of an mft. If what you are contending (and what many Nex owners incorrectly contend, and I'm a Nex user) was right, there would be a very clear IQ advantage to a Nex. There isn't. The advantage (from the larger sensor) is marginal and mathematically is closer to the linear difference (diagonal actually) rather than the area. Of course, picture IQ is composed of many elements so we are in the "all other aspects being equal" field of discussion. Different lenses effect IQ and while the nft lenses are good and many are arguable better than those on the Nex, they aren't that much better to overcome the IQ advantage your figures would suggest for Nex.

I think you do not quite understand just what is the advantage of larger sensors and when do they kick in. so I will explain them in a bit more detail for you.

1, shallower DOF. when standing at the same distance to the subject, using lenses of equivalent FOV and similar aperture ratio, larger sensor gives you shallower DOF, useful in portrait shooting. for example a FF with 85 F1.8 (a moderately priced lens), will give you much shallower DOF than m43 + 45mm F1.8, to get the same look as the FF, m43 need a F0.9.

2, better lens shapness. flowing from the previous advantage. portrait images are often sharper with FF because the F ratio does not have to be so large to get the desired isolated look. for example many people use 50mm lens at F2.8 for portrait, all seven 50mm lenses from canikon are bleeding sharp at F2.8, to get the same look one would need to use a 25 F1.4 on m43 at F1.4, it is a lot softer. this is not even taking into account the inherent extra resolution in FF.

3, lower cost for shallow DOF. also flowing from advantage number 1 is cost, like I said 85 F1.8 is a moderest cost lens, canikon both offer it at around 500 usd, a 45mm F0.9, if exists, would cost no less than 2000 USD. both canikon also offer a 50 F1.8 at about 100 USD, nikon offers a superior model at 220 USD, the m43 25mm F1.4 cost 499.

4, more resolution in good light. this needs no further explanation. As you have commented, the advantage is not apparent on smaller prints. One thing worth mentioning is that people tend to over-estimate the miximum size where you cannot see the difference. Because all lenses are imperfect, some resolution is eaten up by that imperfection. 7-14, 25 f1.4, 45 F1.8 can be considered top end lenses for M43, right? Even with the 16mp GH2, none was able to achieve more than 10mp . So basically, with m43,, the biggest you can print at 300 DPI is about A4.

5, Better IQ low light. This is the big one. if you are an average joe who shoots a bit of everything then majority of your shooting will not be done under ideal lighting. most indoor flashless shots, even on a good day would exceed iso100. quality of image is determined by amount of light hitting the sensor and that in turn is determined by sensor size. I will repeat the data I give you before - the maximum iso that one can maintain SNR of 30dB, DR of 9 EVs and a color depth of 18bits is only 618 on G5, 826 on OM-D, on the FF side of the battle we have D800 with 2853 and D3s with 3253.

6, Lower cost for lens resololution. Similar to point number 3, it is cheaper to buy lenses that would give you X resolution with FF. As I have told you in point number 4 that those three top quality m43 lenses cannot giev you more than 10 mp, about half of their money, you can buy Canon 17-40, 50 F1.8, 85 F1.8, they will produce more than 10mp of resolution on any current FF body.

7, 8, More dynamic range and better colour depth. The jury is still out as to why FF do better in these two areas. But measured data indicate that bigger sensor is indeed better. OMD uses the same sony technology as D800 but has less colur depth and drynamic range. os if these two things are on your priority list, you go FF.

To answer your question as to why NEX is not better than M43 - Firstly NEX's IQ is better than M43, high iso IQ is better and dynamic range is better. Secondly NEX does suffer from a design mistake - its flange back distance is too short for good corner IQ, this is why to date there is no good NEX lenses with acceptable IQ around the corners. This significantly impact the overall image quality in landscape and architecture photos.

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