Opticallimits
next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED - Printable Version

+- Opticallimits (https://forum.opticallimits.com)
+-- Forum: Forums (https://forum.opticallimits.com/forumdisplay.php?fid=4)
+--- Forum: Micro-Four-Thirds (https://forum.opticallimits.com/forumdisplay.php?fid=16)
+--- Thread: next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED (/showthread.php?tid=3090)

Pages: 1 2 3 4 5


next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED - Klaus - 07-09-2011

Not that great .... but then it's an extreme zoom lens:

[url="http://www.opticallimits.com/olympus--four-thirds-lens-tests/645-oly_m14150_456"]http://www.opticallimits.com/olympus--four-thirds-lens-tests/645-oly_m14150_456[/url]



by Sebbi (who is currently on vacation with the Pana 100-300)


next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED - Rainer - 07-09-2011

Thanks for the report ...



albeit u4/3 will likely not become my favourite system.



However, reading the report, there is something I'm wondering about:

If distortion is corrected in-camera or by most raw-converters ... why

do they do an "incomplete" correction ... leaving some amount of

barrel (or pincushion) distortion in the image. I know that distortion

at a given focal length is also depending on focusdistance ... nevertheless,

I think they could do better than they actually do. What is the gain in not

correcting any better?



Just a thought ... Rainer


next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED - Brightcolours - 07-09-2011

[quote name='Rainer' timestamp='1310210548' post='9857']

Thanks for the report ...



albeit u4/3 will likely not become my favourite system.



However, reading the report, there is something I'm wondering about:

If distortion is corrected in-camera or by most raw-converters ... why

do they do an "incomplete" correction ... leaving some amount of

barrel (or pincushion) distortion in the image. I know that distortion

at a given focal length is also depending on focusdistance ... nevertheless,

I think they could do better than they actually do. What is the gain in not

correcting any better?



Just a thought ... Rainer

[/quote]

Of course, the real idea(s) behind that can only come from the software teams who decide on the level of correction.



A few thoughts and interesting points on the subject though...



Is it the lens, or the camera, which contains the correction parameters for the lens in question? If it is the camera, the camera's firmware needs to be updated and expanded with every new lens release.

If it is the lens, which plays part in this, for the Panasonic cameras the situation gets a bit more complex, as there are 2 sensor sizes... the GH series has bigger sensors that allow 16:9, 4:3 and 3:2 formats, which all would need a different amount of correctiing.



On the correcting itself, lenses do not always have a smooth or uniform distortion. Look at this lens, for instance. The corrected result actually looks to have perfectly corrected corners, while there still is a bulge from the distortion further on. This means that correcting it more will need much more complex algorithms.



Also, the more you correct, the more resolution you lose. Both recorded resolution because pixels get spread/stretched over more than one corrected pixels, but also edges get cropped.



All in all, it is hard to get to a totally ideal situation.


next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED - Guest - 07-09-2011

I just tried to compare the Olympus M.Zuiko 14-150mm f/4-5.6 ED with the Leica D Vario-Elmar 14-150mm, but the very different scale makes it is hard to compare.

I prefered the old way with numbers shown in a schedule.



Regards


next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED - Klaus - 07-09-2011

[quote name='Bjoern' timestamp='1310213241' post='9859']

I just tried to compare the Olympus M.Zuiko 14-150mm f/4-5.6 ED with the Leica D Vario-Elmar 14-150mm, but the very different scale makes it is hard to compare.

I prefered the old way with numbers shown in a schedule.



Regards

[/quote]



The numbers are absolutely meaningless for comparisons between two systems.


next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED - popo - 07-09-2011

[quote name='Brightcolours' timestamp='1310212275' post='9858']

Is it the lens, or the camera, which contains the correction parameters for the lens in question? If it is the camera, the camera's firmware needs to be updated and expanded with every new lens release.

If it is the lens, which plays part in this, for the Panasonic cameras the situation gets a bit more complex, as there are 2 sensor sizes... the GH series has bigger sensors that allow 16:9, 4:3 and 3:2 formats, which all would need a different amount of correctiing.[/quote]

To me it would be most logical to put the correction data in the lens, exactly as you say if it was in the body you would constantly need to update the firmware every time a new lens came out. Well, each time you buy a newer lens at the least.



I don't see an issue with the varying aspect ratio sensors as the image circle is still the same. How you crop that image circle doesn't change the lens distortion and subsequent correction.


next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED - Tiz - 07-09-2011

Does distortion correction mean that the image is firstly cropped and then extrapolated to the original MP count of the sensor? In other words, is a distortion corrected 12 MP image not a true 12 MP image anymore but a bloated 10 MP image?


next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED - Brightcolours - 07-09-2011

[quote name='popo' timestamp='1310216031' post='9861']

To me it would be most logical to put the correction data in the lens, exactly as you say if it was in the body you would constantly need to update the firmware every time a new lens came out. Well, each time you buy a newer lens at the least.



I don't see an issue with the varying aspect ratio sensors as the image circle is still the same. How you crop that image circle doesn't change the lens distortion and subsequent correction.

[/quote]

A wider or higher image will need more correction, the correction in not on pixel level, but on the total image level. You see the same with the same lens on APS-C and on FF (but more extreme).


next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED - popo - 07-09-2011

[quote name='Tiz' timestamp='1310224039' post='9863']

Does distortion correction mean that the image is firstly cropped and then extrapolated to the original MP count of the sensor? In other words, is a distortion corrected 12 MP image not a true 12 MP image anymore but a bloated 10 MP image?

[/quote]



Near enough. Distortion correction will end up discarding some regions of image and therefore the information left must be less than before. How much so is harder to quantify.



[quote name='Brightcolours' timestamp='1310227901' post='9866']

A wider or higher image will need more correction, the correction in not on pixel level, but on the total image level. You see the same with the same lens on APS-C and on FF (but more extreme).

[/quote]

If you look at distortion as a single figure barrel/pincushion correction, that may be the case. They can do a bit more than that, by expressing the distortion as a function of distance from image centre that can correct for more complex distortion types also. I don't know if they actually do that or not though... I have to assume they thought of all this when defining the standard so they have adequate information to be close enough.


next PZ lens test report: Olympus M.Zuiko 14-150mm f/4-5.6 ED - Guest - 07-09-2011

What lenses do you use with the gh2 ? I'm seriously thinking about dumping my current system and getting a nex-5 or gh2. Maybe one of the new olympus with viewfinder is equal to the gh2 (question not statement) ?

-

I just find the current camera too large so i never take it with me; sometimes it is better to have something to travel. The nex-5 looks nice but not sure it is really any better than gh2/olympus and i definitely want a view finder.