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Lumix 20-60 difference between 47mm and 51mm

I was looking at 2 pictures, taken in a short time frame where I slightly recomposed. I never would have thought that just so little difference had quite an impact, compared to each other. Has it also to do with going from F8 to F5.3 ? Look at the wire, in the lower right corner. I had them in Lightroom and when going back and forth between the 2 pictures, it is very obvious. The F5.3 seems a bit more stretched. Both have camera corrections enabled... maybe Lightroom is applying different corrections at different F-Stops ? If I disable corrections on both, the difference get even bigger.


PANA0398.jpg
  • Panasonic - DC-S5M2
  • LUMIX S 20-60/F3.5-5.6
  • 47.0 mm
  • ƒ/8
  • 1/200 sec
  • Pattern
  • Manual exposure
  • ISO 1250
PANA0401.jpg
  • Panasonic - DC-S5M2
  • LUMIX S 20-60/F3.5-5.6
  • 51.0 mm
  • ƒ/5.3
  • 1/200 sec
  • Pattern
  • Manual exposure
  • ISO 500
 
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I took a look at the raws and cropped the one at 47mm to match the one at 51mm. Here they are side by side:

1710165843250.png

If you look at the windows of the house in reference to the hedge line, it's clear that the shot at 51mm is taken from a lower height which has changed the perspective on the ground features in particular. There is more foreground in view and any shapes in the ground have been elongated a little. I think this accounts for the differences.
 
So it comes down to different points of view / perspective.
Together with likely another focus point. Different aperture values. Totally different images as for comparison.

In cases you would like to compare 47mm versus 51mm in a more realistic way what it brings to optical differences.
Set camera on a tripod, use a manual "fixed" focus point. Use same aperture values.
Even than you can expect some differences, as 47mm do show more wide angle of view.
So what can be found at far corners at 51mm, is not at the far corners any-more within the image area by 47mm angle of view.
 
Yes, already was thinking in that area. But was not sure, because I kept the horizon hedge more or less the same.

But nevertheless, thanx you for your good explanation!

I do like the lens a lot. Which of the 2 do you like ?
 
So it comes down to different points of view / perspective.
Together with likely another focus point. Different aperture values. Totally different images as for comparison.

In cases you would like to compare 47mm versus 51mm in a more realistic way what it brings to optical differences.
Set camera on a tripod, use a manual "fixed" focus point. Use same aperture values.
Even than you can expect some differences, as 47mm do show more wide angle of view.
So what can be found at far corners at 51mm, is not at the far corners any-more within the image area by 47mm angle of view.
It was not intended to be compared. I had full screen and noticed it when I switched between them with the arrow key. If going back and forth between them the difference became very apparent as stretching. And I only had the aperature and mm difference in my head.

But there was also a slight change in perspective.

I do like the F8 (47mm) the most. Focal point changed hardly because by that time the pig already stopped walking towards me. The pigs head was my focal point.
 
F8 shall have more Depth of Field, so areas not in focus in front and behind the actual focus point shall be more sharp.
Besides 47mm is more wide angle, and shall have even a more wide Depth of Field than 51mm focal length.
So a "double" reason to have more general sharpness in foreground and background.

So as well the branches in foreground, as well "all" in background - trees and farm - made by 47mm F8
is more sharp, than the picture made using 51mm by F5.3

All what can be expected by common sense in how optical physics have their outcome to images. So no surprises.
-
 
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