I am a bit confused by the four thirds system. :scratch
It would appear that it has the effect of a 2x multiplication to standard focal length, is this correct? Can somebody explain why that is?
The sensor on DSLRs is smaller than those of a 35mm camera. Therefore less of the image from the 35mm lens lands on the sensor; This is known as cropping. In the four-thirds case, this crop factor is 2x -- that is, the image sensed by the camera covers a field of view equivelant to a lens which has twice the focal distance. So a 50mm lens mounted on a four-thirds system will create a final image as if it were shot using a 100mm lens. Clear as mud?
What I am wondering is besides telephoto and possible lens weight, what exactly the advantage here? Does it affect image noise? Is it more difficult to make a higher resolution sensor? Is it problematic to make an ultra-wide angle lens when you have to deal with a 2x multiplier?
I think the original idea about the 4/3 system was that the lenses and cameras would be smaller and lighter, and faster for a given effective focal length.
The problem is, as you suggested, no matter how good the sensor in a 4/3s system camera grows over time ( with continued engineering improvements) it is still only one half the size of a full frame camera which will have lower noise thresholds because the FF camera's pixel wells will be larger for the same number of pixels.
Michael Reichman has written several threads on the Luminous Landscape about this issue.
If we were only wanting to replace 35mm film, 4/3 is more than adequate ( and their are somethings I really like about Olympus - I used an OM-1 for years ) but the bar has been raised, so that we now expect Medium format film quality from a FF digital SLR.
We have several 4/3s Olypus shooters here, and the system is not the limiting factor. The camera is really only a minor part of making the image. The important part is between the ears of the shooter.
I frequently go out to shoot with a 20D, and leave 1 Series cameras behind, UNLESS I particularly need the capabilities of the 1DMKll for instance.
There is a 2x multiplier in regards to the same FL lens on a 35mm camera.
But since the Oly digital lenses are designed with the 4/3 sensor size in mind, they are in effect FF lenses as far as Oly is concerned.
True, however I was confused because Oly themselves advertises the focal length for their 4/3 lenses in 35mm. For example the 35-100mm f2, being a 4/3 lens they should have just called it the 70-200 that it is.
True, however I was confused because Oly themselves advertises the focal length for their 4/3 lenses in 35mm. For example the 35-100mm f2, being a 4/3 lens they should have just called it the 70-200 that it is.
They can't call it a 70-200, because it's not. A 35mm lens is a 35mm lens, regardless of the camera you mount it to. If 35mm film had never been invented, you wouldn't care that a 35-100 on a 4/3 was equivalent to a 70-200 on a full frame.
A company like Canon might be encouraged to publish their 35mm equivalent focal lengths because they want to raise awareness of their full frame sensors. But, Oly has no incentive to draw attention to full frame sensors when they're only backing their 4/3 horse.
They can't call it a 70-200, because it's not. A 35mm lens is a 35mm lens, regardless of the camera you mount it to. If 35mm film had never been invented, you wouldn't care that a 35-100 on a 4/3 was equivalent to a 70-200 on a full frame.
A company like Canon might be encouraged to publish their 35mm equivalent focal lengths because they want to raise awareness of their full frame sensors. But, Oly has no incentive to draw attention to full frame sensors when they're only backing their 4/3 horse.
Yep, like Ben says the actual focal lenght of the lens is 35-100. I argue, well try to discuss this at DPR in the Oly SLR forum, but get a lot of Oly fanboy crap.
So for the whole "4/3" size advantage is a moot point concerning Oly's fast lenses.
The 35-100 is half the focal length of a 70-200, one stop faster but it is much larger and heavier than any 70-200 with IS/VR.
The 90-250 is much larger than any comparable 35mm lenses such as the Sigma 120-300.
But the Oly devotees will tell you the lenses are "really" 70-200 F2.0 and 180-500 2.8 and there are no 35mm equivalents.
To me a rose is a rose is a rose. A lens is a lens is a lens. Focal lenght is focal length.
I think the original idea about the 4/3 system was that the lenses and cameras would be smaller and lighter, and faster for a given effective focal length.
That, and to have a standard lens mount so that you were not stuck to one manufacturer. I appluad that aim. Imagine if your stereo or video systems were proprietary, your Brand XXX CD player only attaching to a Brand XXX receiver...
What I have yet to understand is where the name "4/3" comes from. That is a mystery to me.
For example the 35-100mm f2, being a 4/3 lens they should have just called it the 70-200 that it is.
Incorrect. The lens is still a 35-100mm lens, which is why it is called a 35-100mm lens. The focal length of a lens is dependant entirely upon the lens itself and has absolutely nothing to do with the film or sensor size of the camera it is attached to.
What I have yet to understand is where the name "4/3" comes from. That is a mystery to me.
Incorrect. The lens is still a 35-100mm lens, which is why it is called a 35-100mm lens. The focal length of a lens is dependant entirely upon the lens itself and has absolutely nothing to do with the film or sensor size of the camera it is attached to.
Good point, hence my trying to figure out the multiplier. I think the 4/3 comes from it being a 4/3 inch sensor.
"The standard defines things like sensor size and aspect ratio (18x13.5mm and 4:3), lens mount size and distance from sensor and lens-camera comunication protocol."
The sensor size given above is indeed a 4-to-3 aspect ratio, and with a long-side of 18mm is half the size of 35mm film (which is 36x24mm), and would be a 2X crop factor.
OK, I still have no idea why 4/3 is named as such, but thinking about the 2x multiplier, I think they might be on to something. Fast telephoto glass is a very real physical challenge, but quality wide angle on a cropped sensor has already been proven, take the Canon 10-22 for example.
OK, I still have no idea why 4/3 is named as such, but thinking about the 2x multiplier, I think they might be on to something. Fast telephoto glass is a very real physical challenge, but quality wide angle on a cropped sensor has already been proven, take the Canon 10-22 for example.
I've seen a lot of professional sports photographers cuss at crop factor cameras, even the 1D Mark II's paltry 1.3 factor. They prefer full-frame, and from what I can gather the reason is primarily 1) noise, and 2) shallower depth of field. Those guys will spend the money for big, long f/2.8 glass and are willing to heave it around. A 2X crop factor will have a noticeable increase in depth of field. Most vocal seem to be the Nikon people who at best have a 1.5 crop, and on the high-speed-crop models its 2X.
I really like the idea of the 4/3's system on multiple fronts. Primarily being a standard lens mount. I have to wonder how many Nikon sports shooters would dump their 2X bodies for a 1.3X Canon if it did not require buying new lenses (Canon and Nikon both, of course, realize this "problem"). I do not know why professional photographers have put up with proprietary lens systems for so long, but it may explain why so many I have talked to don't likewise see a problem with proprietary RAW file formats.
Imagine if your stereo or video systems were proprietary and you had to buy a Pioneer DVD player to attach to your Pioneer plasma television...
Good point, I figured noise would be an issue, but I did not realize the dof would be affected as well.
Sensor size (or film size, for that matter) definitely affects depth of field. Medium format cameras, with their large negative, can get incredibly shallow depths of field. I can just image what an 8x10 camera could do.
The small sensor used in small point-and-shoot cameras gives them lots of depth of field. I think this has a benefit that the auto-focus system does not need to be very accurate or sophisticated. Nearly everything is in-focus on any given shot anyway.
Thanks, that is good to know. Now I'm thinking it would be the best of both worlds to have a 5D for wide and shallow dof stuff, but a 4/3 body as a backup for extreme telephoto. What is the possibility of putting a Canon lens on a 4/3 body? I saw an adapter for Nikon, but have not found one for canon yet. Perhaps I'm crazy, but wouldn't that make a normal 70-200 f2.8 a 140-400 f2.8 on a 4/3 body if it is possible?
You said it. I'm thinking it won't happen for Canon lenses because they have no physical aperture control on the lens and depend on the camera body to set it. :cry
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Moderator of the Technique Forum and Finishing School on Dgrin
It sure is, but what got me was the 35-100 f2, sounded great until I realized that it would be a 70-200.
What I am wondering is besides telephoto and possible lens weight, what exactly the advantage here? Does it affect image noise? Is it more difficult to make a higher resolution sensor? Is it problematic to make an ultra-wide angle lens when you have to deal with a 2x multiplier?
The problem is, as you suggested, no matter how good the sensor in a 4/3s system camera grows over time ( with continued engineering improvements) it is still only one half the size of a full frame camera which will have lower noise thresholds because the FF camera's pixel wells will be larger for the same number of pixels.
Michael Reichman has written several threads on the Luminous Landscape about this issue.
If we were only wanting to replace 35mm film, 4/3 is more than adequate ( and their are somethings I really like about Olympus - I used an OM-1 for years ) but the bar has been raised, so that we now expect Medium format film quality from a FF digital SLR.
We have several 4/3s Olypus shooters here, and the system is not the limiting factor. The camera is really only a minor part of making the image. The important part is between the ears of the shooter.
I frequently go out to shoot with a 20D, and leave 1 Series cameras behind, UNLESS I particularly need the capabilities of the 1DMKll for instance.
Moderator of the Technique Forum and Finishing School on Dgrin
There is a 2x multiplier in regards to the same FL lens on a 35mm camera.
But since the Oly digital lenses are designed with the 4/3 sensor size in mind, they are in effect FF lenses as far as Oly is concerned.
You don't go around saying the the Panny FZ30 has an 8X "crop" factor do you?
Same thing with the Oly. Lenses are designed for that particular size sensor that happens to be about 1/2 the size of a frame of 35mm film.
Gene
True, however I was confused because Oly themselves advertises the focal length for their 4/3 lenses in 35mm. For example the 35-100mm f2, being a 4/3 lens they should have just called it the 70-200 that it is.
A company like Canon might be encouraged to publish their 35mm equivalent focal lengths because they want to raise awareness of their full frame sensors. But, Oly has no incentive to draw attention to full frame sensors when they're only backing their 4/3 horse.
www.ackersphotography.com
Yep, like Ben says the actual focal lenght of the lens is 35-100. I argue, well try to discuss this at DPR in the Oly SLR forum, but get a lot of Oly fanboy crap.
So for the whole "4/3" size advantage is a moot point concerning Oly's fast lenses.
The 35-100 is half the focal length of a 70-200, one stop faster but it is much larger and heavier than any 70-200 with IS/VR.
The 90-250 is much larger than any comparable 35mm lenses such as the Sigma 120-300.
But the Oly devotees will tell you the lenses are "really" 70-200 F2.0 and 180-500 2.8 and there are no 35mm equivalents.
To me a rose is a rose is a rose. A lens is a lens is a lens. Focal lenght is focal length.
Gene
What I have yet to understand is where the name "4/3" comes from. That is a mystery to me.
Incorrect. The lens is still a 35-100mm lens, which is why it is called a 35-100mm lens. The focal length of a lens is dependant entirely upon the lens itself and has absolutely nothing to do with the film or sensor size of the camera it is attached to.
A former sports shooter
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Good point, hence my trying to figure out the multiplier. I think the 4/3 comes from it being a 4/3 inch sensor.
That is definitely not the case. 4/3 of an inch is roughly 33 or 34mm, which is very close in size to 35mm film.
I did find this however at:
http://www.4-3system.com/modules/smartfaq/category.php?categoryid=3
"The standard defines things like sensor size and aspect ratio (18x13.5mm and 4:3), lens mount size and distance from sensor and lens-camera comunication protocol."
The sensor size given above is indeed a 4-to-3 aspect ratio, and with a long-side of 18mm is half the size of 35mm film (which is 36x24mm), and would be a 2X crop factor.
A former sports shooter
Follow me at: https://www.flickr.com/photos/bjurasz/
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Moderator of the Technique Forum and Finishing School on Dgrin
I really like the idea of the 4/3's system on multiple fronts. Primarily being a standard lens mount. I have to wonder how many Nikon sports shooters would dump their 2X bodies for a 1.3X Canon if it did not require buying new lenses (Canon and Nikon both, of course, realize this "problem"). I do not know why professional photographers have put up with proprietary lens systems for so long, but it may explain why so many I have talked to don't likewise see a problem with proprietary RAW file formats.
Imagine if your stereo or video systems were proprietary and you had to buy a Pioneer DVD player to attach to your Pioneer plasma television...
A former sports shooter
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The small sensor used in small point-and-shoot cameras gives them lots of depth of field. I think this has a benefit that the auto-focus system does not need to be very accurate or sophisticated. Nearly everything is in-focus on any given shot anyway.
A former sports shooter
Follow me at: https://www.flickr.com/photos/bjurasz/
My Etsy store: https://www.etsy.com/shop/mercphoto?ref=hdr_shop_menu
A former sports shooter
Follow me at: https://www.flickr.com/photos/bjurasz/
My Etsy store: https://www.etsy.com/shop/mercphoto?ref=hdr_shop_menu