11-20-2017, 06:57 AM
Quote:Yes, it offers an insane max. aperture at this focal length but at least technically you won't find greatness at f/1.8. the corners are soft. Whether this matters at this aperture is a different question. Astrophotographers may have hoped for more (at least at 50mp) whereas it's a not an issue in shallow depth-of-field scenarios really.
Did you do a resolution test at ∞ ? Otherwise I just ask how do you rate the lens for astrophotography? And a very sharp center very wide open is just not great enough? I don't want to talk away the soft borders, but I'd like to discuss ultra wide shots, available lights and the importance of sharp corners ^_^
The stair house shot could not have benefitted of better corners - due to DoF the corners already are soft.
Emphasiszing something in the corners and a lot of blurred background? Don't know, so far I didn't feel my composition sucks because of weak corners.
However, I don't agree with the weak corners at ∞ and I know, you guys usually test at 25-50 × f which in that case would be 50 × 14mm = 700 mm distance between test chart and sensor. That's a bit bold to conclude from this distance to it's behaviour at distances suitable for astro.
![[Image: i-MnSdccX-L.jpg]](https://photos.smugmug.com/photos/i-MnSdccX/0/e0c91813/L/i-MnSdccX-L.jpg)
Here's the full res.
Typically, I use the lens mostly for this kind of subjects
![[Image: i-N7gWzBv-L.jpg]](https://photos.smugmug.com/photos/i-N7gWzBv/0/a5ec77d2/L/i-N7gWzBv-L.jpg)
or that one
![[Image: i-VXNSRTn-L.jpg]](https://photos.smugmug.com/photos/i-VXNSRTn/0/288a9d1b/L/i-VXNSRTn-L.jpg)
Soft corners? I don't care much, I'm not using this lens for reproductions of flat objects wide open

Of course I understand you're using the standards of PZ or OL for your tests and for all lenses, but there's were trouble starts: Not all lenses are needed/bought for the same purposes. Sharp corners are very interesting for a couple of subjects - just not for all and if it comes to wide angle lenses tested not even close to infinity, I scratch my head about the testing method.
What if the field curvatures radius approaches ∞ at ∞? You haven't tested that, otherwise you would have told us.
And the Laowa 15/2 is only made for Sony E mount...
