PTLens looks interesting but I see some problem for shots at different focus
distance, like the Zuiko 18/3.5, it has very slight pincushion distortion
for distance object but high barrel distortion at close distance.
Distortion may not be very critical for 4/3 system. Most 4/3 lenses have
very low distortion. The cheap 40-150 has distortion as low as 0.08, 0.16
and 0.15% at 40, 100, 150mm respectively; the 18-180 super zoom has
distortion of 0.51, 0.2 and 0.18% at 18, 100, 180mm respectively and the
Leica 14-50/2.8-3.5 has distortion of 0.38, 0.02 and 0.04% at 14, 25, 50mm
respectively. I believe these distortions can be corrected with tools
built-in most photo editing software if necessary.
For my works, I use very little distortion correction tools, if needed it
will be PS Transform-Distort, a heavy correction for perspective. I also add
barrel distortion for group photos where wide angle lenses were used, this
correct the distorted heads on both sides.
I wonder if PTLens will accept the OM Zuiko wides, since sooner or later I
will get a 5D successor for my OM lenses ;-)
C.H.Ling
----- Original Message -----
From: "Moose" <olymoose@xxxxxxxxx>
> C.H.Ling wrote:
>> <big snip>
>> Distortion correction can be done by most photo editing software, as
>> mentioned above, I believe you will need one besides the RAW converter.
>>
> Again I seem to be a shill for PTLens, although I have no connection
> other than as a very happy user.
>
> All the RAW converters and editors that have a distortion correction
> function require you to do it by eye. Many contemporary WAs, especially
> zooms, have a complex form of distortion, not pure barrel.
>
> If you roll the mouse back and forth, you can clearly see the form of
> distortion on one lens.'Fraid I don't have any Olys to show. In any
> case, the correction was done using PTLens - in a second or two.
> <http://moosemystic.net/Gallery/MPhotos/Calif/Morro%20Bay/Oak01.htm>
>
> To correct this with PS, etc., would take some fussing and inevitably be
> a compromise. PTLens has a database of lenses with distortion info at
> various focal lengths. If it can read your image EXIF and the lens is in
> the database, it simply makes the correction. If not, you may choose
> from any camera/lens combo that's in the database.
>
> Any AF lens for a DSLR that isn't in the database he will add if you
> send sample shots fitting his criteria. Here are the lenses currently
> supported:
>
>
> 4/3 Lenses
>
> multiplier = 2.0
> Zuiko Digital 7-14mm f/4.0
> Zuiko Digital 11-22mm f/2.8-3.5
> Zuiko Digital 14-42mm f/3.5-5.6 ED
> Zuiko Digital 14-45mm f/3.5-5.6
> Leica D Vario-Elmarit 14-50mm f/2.8-3.5
> Zuiko Digital 14-54mm f/2.8-3.5
> Zuiko Digital 18-180mm f/3.5-6.3 ED
> Zuiko Digital 40-150mm f/4.0-5.6 ED
> Zuiko Digital 40-150mm f/3.5-4.5
> Zuiko Digital 50-200mm f/2.8-3.5
> Zuiko Digital 50mm f/2.0 Macro
>
> As $15 for lifetime use and upgrades for both stand-alone and plug-in
> versions, it's a steal. DXo does the same thing (as well as other
> things?) for fewer models and LOTs more money.
>
> Moose
>
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