Traditional 35mm film cameras use 36mm x 24mm sized film ("full frame", Nikon FX or Canon EF). Most DSLRs use smaller (roughly 24mm x 16mm) "cropped" image sensors (Nikon DX or Canon EF-S).
Cropped Lenses
Because the cropped DSLR image size is smaller, smaller and cheaper cropped lenses (smaller image size) have been made especially to suit them.
With the recent availability of relatively affordable full frame DSLRs, photographers are wondering if their cropped lenses can be used on full frame cameras.
Photographers who don't yet intend to get a full frame DSLR, will still have to decide whether to get a cropped or full frame lens for their cropped DSLR, in case they do upgrade to a full frame DSLR in the future.
Nikon DX Lenses on FX DSLRs
Nikon DX lenses will work on FX cameras.
The FX cameras are able to detect DX lenses and automatically switch to DX mode, using only the 24mm x 16mm center of the 36mm x 24mm image sensor. This effectively turns the FX camera into a DX camera.
Canon EF-S Lenses on EF DSLRs
Canon EF-S lenses will not physically fit on to an EF camera. A mechanical interlock prevents this.
Even if the EF-S lens was modified to fit, it could be damaged by the camera's reflex mirror. EF-S lenses are designed with the smaller EF-S reflex mirrors in mind. The mirror of an EF camera could hit the rear of the EF-S lens, damaging the lens and the mirror.
The Full Frame Question
The issue of using cropped lenses on full frame DSLRs arises because many photographers hope to upgrade to full frame DSLRs in the future.
With double the image sensor size, full frame cameras can
- Double the resolution (megapixels) while keeping the size of each pixel on the image sensor the same (same high ISO performance as a cropped DSLR).
- Have the same resolution as a cropped DSLR, with double the size of each pixel on the image sensor (double the high ISO performance of a cropped DSLR).
Or some combination of the above.
Full Frame Upgrade Paths
Strategies for upgrading to full frame
- One way for photographers to upgrade to a full frame DSLR is to simply save money until they can afford one.
- Another way is to wait for the price to fall. However, unlike with other IT products, this is unlikely. The prices of IT products have fallen mainly because the size of the computer chips (IC feature size) have been falling. The size of a full frame image sensor is fixed. It is unlikely that the price will fall by much in the long term.
- Buying a second-hand full frame DSLR is a viable option.
Full Frame Lenses on Cropped DSLRs?
Cropped DSLR users should not force themselves to buy full frame lenses, for a possible full frame future that might never materialize.
- It is not inevitable for a photographer to upgrade to full frame. Full frame DSLRs aren't always better, even for professionals.
- Cropped DSLRs work better with cropped lenses. Photographers should buy cropped lenses for cropped DSLRs, selling the lenses and buying full frame lenses when upgrading to a full frame DSLR.
Yuen Kit Mun - Kit Mun is a self-confessed information junkie, reading an average of a book a week over the past two decades. His growing Internet ...
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