01-07-2011, 01:01 AM
[quote name='ecle' timestamp='1294313951' post='5367']
I just wanted to say that the 12-60 has really good resolution.[/quote]
Can't remember using that lens but I'm sure it is very good for what it is because I've heard many talk about it. I'd expect it to be good when it's equivalent to a 24-120 f/5.6-8.
[quote name='ecle' timestamp='1294313951' post='5367']
The best lenses of Olympus are easily on the level of Canon and Nikons best. For example the 150mm F2 or 300 2,8. I don't think that the Canon 600mm F4 is better compare to 300mm 2,8.[/quote]
I've used the 150 f/2, 90-250 2.8 and 300 2.8, all on the E3 and also on the E-30... the only lens that impressed me was the 150 f/2 and that was mainly because the other two were very unimpressive. They're all heavy and slow to focus (no SWD). The 150 f/2 is such an expensive and a troublesome way to get a 300 f/4 effect. With the 90-250 and 300 you definitely need a monopod or a tripod at all times because the viewfinder isn't stabilised and the lenses are very heavy to handhold. Their max apertures being small doesn't help.
I haven't used the out-going Canon 600 f/4 IS but once you get past the extra weight, a stabilised viewfinder and USM is so much more nicer to use and will help you in getting better shots. You need to stop it down to f/5.6 to make things comparable to the ZD 300 2.8 anyway.
5D2 + 600 f/4 IS:
http://www.flickr.com/photos/43799161@N04/4485824092/sizes/o/in/photostream/
[quote name='ecle' timestamp='1294313951' post='5367']
Ok you have 1 stop less noise on a 12Megapixel FF[/quote]
Actually the difference is roughly 2 stops because the area of a FT sensor is 17.3x13=224.9 and the area of a FF sensor is 36x24=864. So 864/224.9 = 3.84 ~= 2 stops.
[quote name='ecle' timestamp='1294313951' post='5367']
but I guess you can build better lenses on smaller sensors. FT needs only half the diameter for the same angle of view so there is room for better optics or even better F stops.[/quote]
No... not really:
You need higher resolution lenses on smaller sensors to achieve the same resolutions you can get on a larger sensor and its lenses. I explained this in the lp/mm explanation earlier. This is no benefit... this is a problem. As the lenses get faster (under f/2), it gets very difficult to make them sharp. That's why FT lenses are always slower than FF equivalents. For example, the 24-120 equivalent lens on FT (the 12-60) is a f/5.6-8 equivalent lens when 24-120/24-105 type FF lenses are constant f/4.
Just like with resolution, faster f-stops are required on smaller sensors because the sensors have a smaller light gathering area. Larger sensors require slower shutter speeds because they gather light over a larger area. This is not a benefit for small sensors... it's a requirement:
http://en.wikipedia.org/wiki/Image_noise#Effects_of_sensor_size
E.g. A 70-200 2.8 lens on a FF is like a 35-100 f/1.4 on FT but there's no such thing on FT. As another example, the Leica D-Summilux 25mm f/1.4 for FT is like a 50mm f/1.4 FF lens stopped down to f/2.8. A 50 2.8 on FF would be sharper and be smaller and cheaper too.
So at the end of the day FT (and small sensors in general) need faster lenses and higher resolution sensors than FF cameras to match them. Making a lens fast and high in resolution are very conflicting objectives.
In comparison, just making an image circle bigger is not that difficult. For example the [url="http://www.bhphotovideo.com/c/product/36862-GREY/Nikon_1309_105mm_f_5_6_Nikkor_W_Lens.html"]Nikor-W 105 f/5.6 lens[/url] has an image circle that is 31x the area of a FT image circle but it's still a f/5.6. It weighs only 185g and costs $350... but on its native format (6x9) it only needs to resolve 22 lp/mm to match that 12-60's 12MP resolution. And it does that while giving the DOF of 42mm f/2.2 lens on FF.
GTW
I just wanted to say that the 12-60 has really good resolution.[/quote]
Can't remember using that lens but I'm sure it is very good for what it is because I've heard many talk about it. I'd expect it to be good when it's equivalent to a 24-120 f/5.6-8.
[quote name='ecle' timestamp='1294313951' post='5367']
The best lenses of Olympus are easily on the level of Canon and Nikons best. For example the 150mm F2 or 300 2,8. I don't think that the Canon 600mm F4 is better compare to 300mm 2,8.[/quote]
I've used the 150 f/2, 90-250 2.8 and 300 2.8, all on the E3 and also on the E-30... the only lens that impressed me was the 150 f/2 and that was mainly because the other two were very unimpressive. They're all heavy and slow to focus (no SWD). The 150 f/2 is such an expensive and a troublesome way to get a 300 f/4 effect. With the 90-250 and 300 you definitely need a monopod or a tripod at all times because the viewfinder isn't stabilised and the lenses are very heavy to handhold. Their max apertures being small doesn't help.
I haven't used the out-going Canon 600 f/4 IS but once you get past the extra weight, a stabilised viewfinder and USM is so much more nicer to use and will help you in getting better shots. You need to stop it down to f/5.6 to make things comparable to the ZD 300 2.8 anyway.
5D2 + 600 f/4 IS:
http://www.flickr.com/photos/43799161@N04/4485824092/sizes/o/in/photostream/
[quote name='ecle' timestamp='1294313951' post='5367']
Ok you have 1 stop less noise on a 12Megapixel FF[/quote]
Actually the difference is roughly 2 stops because the area of a FT sensor is 17.3x13=224.9 and the area of a FF sensor is 36x24=864. So 864/224.9 = 3.84 ~= 2 stops.
[quote name='ecle' timestamp='1294313951' post='5367']
but I guess you can build better lenses on smaller sensors. FT needs only half the diameter for the same angle of view so there is room for better optics or even better F stops.[/quote]
No... not really:
You need higher resolution lenses on smaller sensors to achieve the same resolutions you can get on a larger sensor and its lenses. I explained this in the lp/mm explanation earlier. This is no benefit... this is a problem. As the lenses get faster (under f/2), it gets very difficult to make them sharp. That's why FT lenses are always slower than FF equivalents. For example, the 24-120 equivalent lens on FT (the 12-60) is a f/5.6-8 equivalent lens when 24-120/24-105 type FF lenses are constant f/4.
Just like with resolution, faster f-stops are required on smaller sensors because the sensors have a smaller light gathering area. Larger sensors require slower shutter speeds because they gather light over a larger area. This is not a benefit for small sensors... it's a requirement:
http://en.wikipedia.org/wiki/Image_noise#Effects_of_sensor_size
E.g. A 70-200 2.8 lens on a FF is like a 35-100 f/1.4 on FT but there's no such thing on FT. As another example, the Leica D-Summilux 25mm f/1.4 for FT is like a 50mm f/1.4 FF lens stopped down to f/2.8. A 50 2.8 on FF would be sharper and be smaller and cheaper too.
So at the end of the day FT (and small sensors in general) need faster lenses and higher resolution sensors than FF cameras to match them. Making a lens fast and high in resolution are very conflicting objectives.
In comparison, just making an image circle bigger is not that difficult. For example the [url="http://www.bhphotovideo.com/c/product/36862-GREY/Nikon_1309_105mm_f_5_6_Nikkor_W_Lens.html"]Nikor-W 105 f/5.6 lens[/url] has an image circle that is 31x the area of a FT image circle but it's still a f/5.6. It weighs only 185g and costs $350... but on its native format (6x9) it only needs to resolve 22 lp/mm to match that 12-60's 12MP resolution. And it does that while giving the DOF of 42mm f/2.2 lens on FF.
GTW