|
Re: Why no in-camera CA correction on Olympus bodies?
In reply to inasir1971,
4 months ago
|
inasir1971 wrote:
M43 is a very new standard and as such they have had the opportunity to include many things that others don't have but are relevant to digital photography and the high resolution sensors we have today.
Lenses for example, contain the distortion correction information and (for Panasonic lenses) lateral CA correction information. These are stored by the camera in raw files so there is no need for converters to have lens profiles or the like. They also have very accurate information for focal length being used for zooms and I guess for focus distance (IBIS uses both of these).
Even if you shoot raw, and you use an 'officially supported' converter like Lightroom, you will never see the image uncorrected for distortion. There is no way to turn off distortion correction for M43 cameras. The image presented to you by the camera in the rear display or EVF when shooting is already corrected for distortion. My suspicion is that there is also some correction for vignetting being applied as well.
Distortion corrections are hugely destructive for detail, particularly with the very high levels of distortion in M43 lenses.
That certainly depends on what you mean by "hugely destructive" and "very high levels". Pany and Oly have consciously decided to allow somewhat more distortion (up to about 5 % at the outset for WA primes and at the short end of WA zooms) than is the norm in the industry (about 2 % is usually considered tolerable for lenses using only optical correction) and correct it via software. The benefit of doing that is that they have more leeway to deal with other aberrations that are more difficult to correct with via software. A good idea in my opinion.
Correcting the 5 or so percent distortion that we are likely to see (at most) on MFT lenses takes its toll on resolution but only by a marginal amount. The corners are being enlarged/stretched by about five percent, which isn't a whole lot. And they may well be sharper after that operation than if they had been produced by a lens designed for optical correction only, which might well have encountered greater difficulties in rendering the corners sharp in the first place.
On other systems I don't use distortion corrections unless I need them for that image.
Lateral CA is something that there is no reason to leave in - apart from the more obvious fringing, it 'pollutes' color. It is just correcting something that the designers were not able to do.
To force distortion corrections which you may not want to use all the time but not enable lateral CA corrections which you would want to use all the time is bizarre.
| Post (hide subjects) | Posted by | When | |
|---|---|---|---|
| 4 months ago | 4 | ||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | 6 | ||
| 4 months ago | 2 | ||
| 4 months ago | |||
| 4 months ago | 1 | ||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | 1 | ||
| 4 months ago | 1 | ||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | 1 | ||
| 4 months ago | |||
| 4 months ago | 1 | ||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | 3 | ||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | 1 | ||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | |||
| 4 months ago | 2 | ||
| 4 months ago | |||
| 4 months ago |