08-31-2016, 11:09 AM
I will look tonight if I still have one of those pictures made with the 18-35 on FF, but I'm afraid to have them deleted. I recall the distance between each DX-corner and FF corner was less than 50% dark, but I can't say much about IQ of this zone. I know, it's a very exotic camera and for sure not the smallest mirrorless, I also know if the Fuji makes me happy for most purposes, the wish to get a new Sigma toy will decrease as I only would use it for maybe 1/10 of my pictures. The lack of a good, quick enough converter becomes a big deal as well.
Anyway, the APS-H version so far is only announced. These are neither available nor with a known price.
The reason for the 80 MP quick and dirty panorama was less the Sigma, than how much of the newly added 12 GB more RAM will be used to stitch this 12 TIFF pictures.
Thanks this time for your critical and correct observation. I will try to make a better version, just to be able to handle it better next time with a nice panorama situation. I know now I have to deal with the shadow noise before stitching.
Edit:
![[Image: vignetting.gif]](http://www.sigma-global.com/en/lenses/cas/product/art/a_18_35_18/data/vignetting.gif)
I was looking a bit more into the differences. The vignetting charts from Sigma appear to be really concerning, from 100% down to 35% at the diagonal edge of Sigma's APS-C (diagonal roughly 28 mm). However, the APS-H (26.7×17.9 mm) diagonal is only 2 mm/radius more (32 mm).
So, the 20/1.4 appears to be a much better choice in terms of vignetting:
![[Image: vignetting.gif]](http://www.sigma-global.com/en/lenses/cas/product/art/a_20_14/data/vignetting.gif)
But practically: Who makes reproductions at 18 mm wide open? If I use this lens at the sd quattro, it's for sure not for available light photography primarily, but because at normal apertures its' behaving like a very good prime, with the bonus of occassionally going artsy-fartsy and be able to focus in dark situations.
Comparatively: A Zeiss Batis 18/2.8 wide open has at 14 mm radius 60% vignetting, the 18-35 (at f/4!) 85% and the 20/1.4 (at f/2.8) more than 90%.
And I'm not sure what the infrared filter between mount and sensor will also eat up from this theoretical vignetting values.
Anyway, the APS-H version so far is only announced. These are neither available nor with a known price.
The reason for the 80 MP quick and dirty panorama was less the Sigma, than how much of the newly added 12 GB more RAM will be used to stitch this 12 TIFF pictures.
Thanks this time for your critical and correct observation. I will try to make a better version, just to be able to handle it better next time with a nice panorama situation. I know now I have to deal with the shadow noise before stitching.
Edit:
I was looking a bit more into the differences. The vignetting charts from Sigma appear to be really concerning, from 100% down to 35% at the diagonal edge of Sigma's APS-C (diagonal roughly 28 mm). However, the APS-H (26.7×17.9 mm) diagonal is only 2 mm/radius more (32 mm).
So, the 20/1.4 appears to be a much better choice in terms of vignetting:
But practically: Who makes reproductions at 18 mm wide open? If I use this lens at the sd quattro, it's for sure not for available light photography primarily, but because at normal apertures its' behaving like a very good prime, with the bonus of occassionally going artsy-fartsy and be able to focus in dark situations.
Comparatively: A Zeiss Batis 18/2.8 wide open has at 14 mm radius 60% vignetting, the 18-35 (at f/4!) 85% and the 20/1.4 (at f/2.8) more than 90%.
And I'm not sure what the infrared filter between mount and sensor will also eat up from this theoretical vignetting values.