|Posted: Tue Aug 02, 2016 4:55 pm Post subject:
|70-150/4 seems live up to its reputation. sharp wide open (almost as good as primes) and its has a very useful range
Almost? It's certainly better than the MD135/3.5 and pretty much on par with the MD85/2 (I'd expect it to be on par with the 4/4 135/2.8 too).
The MD75-150 has quite heavy focus breathing. I don't know where it's nodal points are so the only way to directly measure the focal length would be with two points at a large known distance (I'd also have to know the distance between the points),
that's doable (e.g. using the moon or two bright stars) but I don't think I'll go that far.
I've tried to make an educated guess of the actual focal range through field-of-view comparisons (INF vs MFD, "75mm" vs "150mm" and against a few other lenses), I would need one direct FL measurment to really get it right but this get's me pretty close...
At "75mm" and MFD, the focal length is 24.3% longer than at infinity.
At "150mm" and MFD, the focal length is 30.9% longer than at infinity.
At "150mm" and infinity, the focal length is 93.4% longer than at "75mm" (and infinity).
At "150mm" and MFD, the focal length is 103.7% longer than at "75mm" (and MFD).
I took my MD85/2 for comparison:
At 1.2m (the MD75-150's MFD), the MD85's focal length is 15.8% longer than at infinity.
At infinity, the MD85's focal length is 5% longer than the MD75-150 at "75mm" (and infinity).
At 1.2m, the MD85's focal length is 2.3% shorter than the MD75-150 at "75mm" (and 1.2m).
IF the MD85 is exactly 85mm at infinity, the MD75-150 should actually be 81.0-156.6mm at infinity and 100.7-205.0mm at MFD. (and the MD85 would be 98.4mm at 1.2m, probably a bit beyond 100mm at it's MFD).
Using a Fuji 18-55/2.8-4 at "55mm" as the reference (on an X-E1, accounting for the crop factor -as precisely as it's known - of course):
IF the 18-55 at "55" is exactly 55mm at infinity, the MD75-150 should be 79.2-153.2mm at infinity and 98.5-200.5mm at MFD.
So, I'd guess the MD75-150 is ~80-155mm at infinity and ~100-200mm at MFD. Good to know...
Sony: A7 | Samyang FE 35/2.8 | Sony FE 85/1.8
Pentax: K-5 | K28/3.5 | M50/1.7 | DA18-135/3.5-5.6 | F35-70/3.5-4.5
Minolta: X-500 | XD | MD35/2.8 | MC50/1.4 | MD200/4 | MD75-150/4
Canon: nFD24/2.8 | nFD35/2 | nFD50/1.4 | nFD300/5.6 | nFD35-105/3.5