TaylorHobson
Active member
- Messages
- 52
- Reaction score
- 0
DSLR sensor mania, Just the facts. What I am posting here is everything I learned on DPreview. You can check the facts yourself by doing appropriate seaches. Only Fact 7 is made up and represents only my personal opinion and preference with no claim to being superior in any particular photo imaging aspect.
The longest threads here are those involving the defense of APS-c and 4/3 sensor sizes versus full frame. Here are some plain facts.
Fact 1 Size.
FF is 2 times larger (area wise) than APS-c. APS-c is 2 times larger than 4/3. So FF is 4 times larger than 4/3.
For PS (point and shoots) people who are confused, PS cameras are compact because FF is 22 times larger than sensor chip used in G9. FF is 36 times larger than sensors used in typical pocket Powershot PS types.
Fact 2 light sensitivity
Since all manufacturers try to keep up with the megapixel race so for same 12 mp sensor constant for each format, a 2x larger pixel in FF sensor will gather 2x the light of APS-c and 4x light of 4/3. So if 4/3 has max iso of 1600, then APS-c will be 3200 and FF will be 6400 at same noise level using same sensor technology. This is exactly what you see in today’s crop of cameras
Fact 3 viewfinder size.
FF with larger mirror will always be larger and brighter than APS-c and so forth with 4/3 always having the smallest view using same priced optics, mirror or prism arrangements.
Fact 4
The lensmount of the FF and APS-c are same size and 4/3 is probably in middle, smaller than EOS but larger than Nikon F. Ultimate camera size is determined by lens mount size so all current dslr formats will have similar size bodies. Right now FF is much larger but remember as technology improves, budget consumer FF will come down in size. Canon’s last budget film FF the rebel Ti is same size as current Oly E430 claimed to be the smallest dlsr.
Fact 5. Why APS-c was introduced
APS-c came about only due to the very high sensor prices in the infancy of dslrs. A FF sensor was priced many times higher than an APS-c or 4/3. When sensor prices fall as they inevitably will, FF cameras may cost maybe only 10% more than similar megapixel APS or 4/3. Higher pixel count regardless of sensor size will add to cost because faster chips have to be used throughout to keep fps from slowing.
Fact 6 lens ability, size and cost
People think cropped sensors allow you to use smaller lenses for same focal length equivalent. If you make pixel size same which means that larger sensors will have more pixels, the same lens will produce the same detail so no detail is gained by the smaller sensor. In any case, the lens sizes of all three sensor sizes are similar. A typical 50mm f1.4 FF prime is same size or smaller than an equivalent 35mm f1.4 APS-c prime or a 25mm f1.4 4/3 prime. The cost of lenses in any sensor size in equivalent focal length are all in same range.
Fact 7 New category of cameras will come soon as true alternative to FF dslrs.
There will be an interchangeable lens 16:9 hi-resolution (svga 800x600) evf cropped sensor (16mm x 9mm no more than 12 mp) with choice of 3:2 and 4:3 with new standard lens mount. Since these cameras have no mirror box, lens can be optimized for thinner bodies and closer position to sensor. These new cameras will be logical move up for current PS crowd desiring better quality images and more flexibility like interchangeable lenses and HD movie taking capability. No mirror box, smaller sensor than current 4/3, these cameras will live up to truly more compact and lighter tourist travel cameras. Canon can make this the G11 with availability of pancake wide angle prime. Or how about Panasonic TZ9. The current TZ5 already has a true 16:9 with choice of 3:2 and 4:3. Note the TZ5 uses a lens circle optimized for 16:9 and 3:2 .16:9 (3712x2088) is wider than 3:2 (3552x2368). Both canon and pano should switch to body based IS like sony, pentax and oly to keep lens cost down and more rugged.
The longest threads here are those involving the defense of APS-c and 4/3 sensor sizes versus full frame. Here are some plain facts.
Fact 1 Size.
FF is 2 times larger (area wise) than APS-c. APS-c is 2 times larger than 4/3. So FF is 4 times larger than 4/3.
For PS (point and shoots) people who are confused, PS cameras are compact because FF is 22 times larger than sensor chip used in G9. FF is 36 times larger than sensors used in typical pocket Powershot PS types.
Fact 2 light sensitivity
Since all manufacturers try to keep up with the megapixel race so for same 12 mp sensor constant for each format, a 2x larger pixel in FF sensor will gather 2x the light of APS-c and 4x light of 4/3. So if 4/3 has max iso of 1600, then APS-c will be 3200 and FF will be 6400 at same noise level using same sensor technology. This is exactly what you see in today’s crop of cameras
Fact 3 viewfinder size.
FF with larger mirror will always be larger and brighter than APS-c and so forth with 4/3 always having the smallest view using same priced optics, mirror or prism arrangements.
Fact 4
The lensmount of the FF and APS-c are same size and 4/3 is probably in middle, smaller than EOS but larger than Nikon F. Ultimate camera size is determined by lens mount size so all current dslr formats will have similar size bodies. Right now FF is much larger but remember as technology improves, budget consumer FF will come down in size. Canon’s last budget film FF the rebel Ti is same size as current Oly E430 claimed to be the smallest dlsr.
Fact 5. Why APS-c was introduced
APS-c came about only due to the very high sensor prices in the infancy of dslrs. A FF sensor was priced many times higher than an APS-c or 4/3. When sensor prices fall as they inevitably will, FF cameras may cost maybe only 10% more than similar megapixel APS or 4/3. Higher pixel count regardless of sensor size will add to cost because faster chips have to be used throughout to keep fps from slowing.
Fact 6 lens ability, size and cost
People think cropped sensors allow you to use smaller lenses for same focal length equivalent. If you make pixel size same which means that larger sensors will have more pixels, the same lens will produce the same detail so no detail is gained by the smaller sensor. In any case, the lens sizes of all three sensor sizes are similar. A typical 50mm f1.4 FF prime is same size or smaller than an equivalent 35mm f1.4 APS-c prime or a 25mm f1.4 4/3 prime. The cost of lenses in any sensor size in equivalent focal length are all in same range.
Fact 7 New category of cameras will come soon as true alternative to FF dslrs.
There will be an interchangeable lens 16:9 hi-resolution (svga 800x600) evf cropped sensor (16mm x 9mm no more than 12 mp) with choice of 3:2 and 4:3 with new standard lens mount. Since these cameras have no mirror box, lens can be optimized for thinner bodies and closer position to sensor. These new cameras will be logical move up for current PS crowd desiring better quality images and more flexibility like interchangeable lenses and HD movie taking capability. No mirror box, smaller sensor than current 4/3, these cameras will live up to truly more compact and lighter tourist travel cameras. Canon can make this the G11 with availability of pancake wide angle prime. Or how about Panasonic TZ9. The current TZ5 already has a true 16:9 with choice of 3:2 and 4:3. Note the TZ5 uses a lens circle optimized for 16:9 and 3:2 .16:9 (3712x2088) is wider than 3:2 (3552x2368). Both canon and pano should switch to body based IS like sony, pentax and oly to keep lens cost down and more rugged.
