Focal length: 300mm
Aperture: F 6.3
Min focus distance: 2.20m
Length (from flange): 93/95mm [+ 27mm for the adapter]
Weight: 350 gr.
A7 and the lens.
Sample pictures: You may click
on the sample image for full resolution. The
full resolution image opens in a new window, so you can keep it open
for comparison. Focus is on the
dish in the center of the photo.
Another one, focus on the solar panel.
Closest focus is at 2m, F 6.3. This photo was taken at
2.5m. Shallow DOF
makes it difficult to focus. Focus in the middle of the photo towards
the left border.
is a mirror lens, so it's relatively short, but there is only a fixed
aperture. This is one of the tiniest and lightest that have been made
for the market. It's only 95mm long and weighs 350gr (a 300mm
720gr). Even the diameter is small, 75mm. The standard mirror lenses
are 500mm, they are bigger and heavier and most of them are F8.
Seen the discussions on the web, I was positively surprised by this
lens. I my opinion contrast and sharpness are nearly o.k., but are in
no ways comparable to a glass lens. It's difficult to focus. It seems
as if the resolution of the camera is better than the resolution of the
tele lens, easy to carry in your bag.
was a trade name for Photo Porst. There was a silver coloured lens
traded as Hanimex which seems to be of a very similar build. Obviously
there were very few made. The Hanimex lenses seem to have shallow or no
coating, whereas my Weltblick has multicoating on both sides which
improves contrast. Maybe they made a second batch for Porst, but again
very few were made.
Apart from their major size/weight
advantage, mirror lenses have some flaws, a fixed aperture, a shallow
depth of field and lower contrast. Discussions on the web are mostly
not very helpful, it's a clash between mirror lens lovers and haters.
From what I have seen, stay away from cheap chinese ones, which are
traded under different names, but all look the same. In my opinion with
the Sony A7 and its focus assistance mirror lenses are an option.