Posted: Thu Jan 21, 2010 9:19 am Post subject: |
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kds315* wrote:
Well Sebastien, I am well aware of these rules, but was just curious to see how different that lens would perform, so I got it for testing (since it was also very affordable). It did turn out as I had suspected and wanted to share these results here, before it went back to its owner.
As you say, front lens is rather uncritical (but funny that most people seem to be so funny about that, maybe because it is so easy to see) and forget about the most important part closest to sensor/film, that is the rear element - often exposed mechanically since it protrudes the barrel (depending on lens design) and users sit lenses down to their back end most of the time making damage highly likely. Most wide angle retro designs suffer from that. Then there is the lens inside and fungus webs (often invisible to the unaided eye) [this example here looks crystal clear under normal viewing conditions and needs a strong back light against dark ground to make these fungus traces visible]
or other stuff on the lens surfaces such as fine grease mist condensation (lens kept in a hot place like a car back window) causes massive loss of contrast. The latter can often be professionally cleaned, if it is not "baked" to the lens surface. Lens element separation (of cemented lens elements, which looks like a rainbow developing) is also often seen as massive degradation of lens quality, but it is not in my experience and hardly noticeable in the results.
[faulty rear element with scratches from sitting lens down and debris inside baked on lens surface. Obviously it has been tried to open and clean the lens] _________________ Klaus - Admin
"S'il vient a point, me souviendra" [Thomas Bohier (1460-1523)]
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/uv_photos for UV Images and lens/filter info
https://www.flickr.com/photos/kds315/albums my albums using various lenses
http://photographyoftheinvisibleworld.blogspot.com/ my UV BLOG
http://www.travelmeetsfood.com/blog Food + Travel BLOG
https://galeriafotografia.com Architecture + Drone photography
Currently most FAV lens(es):
X80QF f3.2/80mm
Hypergon f11/26mm
ELCAN UV f5.6/52mm
Zeiss UV-Planar f4/60mm
Zeiss UV-Planar f2/62mm
Lomo Уфар-12 f2.5/41mm
Lomo Зуфар-2 f4.0/350mm
Lomo ZIKAR-1A f1.2/100mm
Nikon UV Nikkor f4.5/105mm
Zeiss UV-Sonnar f4.3/105mm
CERCO UV-VIS-NIR f1.8/45mm
CERCO UV-VIS-NIR f4.1/94mm
CERCO UV-VIS-NIR f2.8/100mm
Steinheil Quarzobjektiv f1.8/50mm
Pentax Quartz Takumar f3.5/85mm
Carl Zeiss Jena UV-Objektiv f4/60mm
NYE OPTICAL Lyman-Alpha II f1.1/90mm
NYE OPTICAL Lyman-Alpha I f2.8/200mm
COASTAL OPTICS f4/60mm UV-VIS-IR Apo
COASTAL OPTICS f4.5/105mm UV-Micro-Apo
Pentax Ultra-Achromatic Takumar f4.5/85mm
Pentax Ultra-Achromatic Takumar f5.6/300mm
Rodenstock UV-Rodagon f5.6/60mm + 105mm + 150mm
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