- Joined
- Apr 3, 2017
- Messages
- 27
- Reaction score
- 15
- Age
- 61
- Location
- Baldwin City, KS
- Website
- blog.grumpysworld.com
So here are the results of my tests, after I briefly describe the procedure. Being in farm country, I flew above a frost-covered field of unharvested soybeans, which provided the ultimate in contrast and detail. I took off, climbed to an altitude in meters equal to the focal length in mm (i.e. 1000x the focal length, to approximate infinity), centered my landing pad in the viewfinder, then flew over the field and shot some photos at various apertures, keeping the overall exposure constant (by varying the shutter).
Results were not particularly informative, except in one case.
The 15mm showed uniform sharpness across the plane with soft corners (this was at f2.0), which seems about right.
The 25mm showed pretty much the same thing, but this was odd, because in looking at the 21 production photos I shot yesterday, about half of them had soft centers and the other half looked mostly okay. So what I'm saying is that the 25 appeared to work as expected this morning, and I could not detect any asymmetry in sharpness.
The 45, however, was a complete disaster. I have never liked this lens and rarely used it because everything I shot with it (even on the old X5S) was always soft. I just thought it was a crappy lens, and it may be. Well, the soybean field, even though I focused each shot in the center (AF) every time, was totally out-of-focus. Just horrible, really. So I'm still of the opinion that the Oly 45 is absolute trash, but it might just be my copy.
Regrettably, I do NOT have a m43 body to check these lenses on.
So maybe the conclusion is that my new X5S is probably okay, and the DJI 15 is okay, and the Oly 45 is junk, and my Oly 25 is sometimes okay and sometimes not, possibly because it took a nasty bump during a crash. I'm not sure I can conclude otherwise. Maybe I'll try some more tests this afternoon, perhaps using MF.
Results were not particularly informative, except in one case.
The 15mm showed uniform sharpness across the plane with soft corners (this was at f2.0), which seems about right.
The 25mm showed pretty much the same thing, but this was odd, because in looking at the 21 production photos I shot yesterday, about half of them had soft centers and the other half looked mostly okay. So what I'm saying is that the 25 appeared to work as expected this morning, and I could not detect any asymmetry in sharpness.
The 45, however, was a complete disaster. I have never liked this lens and rarely used it because everything I shot with it (even on the old X5S) was always soft. I just thought it was a crappy lens, and it may be. Well, the soybean field, even though I focused each shot in the center (AF) every time, was totally out-of-focus. Just horrible, really. So I'm still of the opinion that the Oly 45 is absolute trash, but it might just be my copy.
Regrettably, I do NOT have a m43 body to check these lenses on.
So maybe the conclusion is that my new X5S is probably okay, and the DJI 15 is okay, and the Oly 45 is junk, and my Oly 25 is sometimes okay and sometimes not, possibly because it took a nasty bump during a crash. I'm not sure I can conclude otherwise. Maybe I'll try some more tests this afternoon, perhaps using MF.