Micro Four Thirds Focal Reducer Shootout

Started Feb 20, 2014 | Discussions thread
Anders W Forum Pro • Posts: 21,468
Re: Micro Four Thirds Focal Reducer Shootout

Klarno wrote:

MichailK wrote:

So, I want to ask everyone using these adapters if in real life use the results of the second test (Hotspotting) are a deal breaker - we are talking about solid white back illuminating frame and solid black center rectangle which is an extreme case - isn't it? In a "normal" lit scene it should be no real fuss unless nitpicking I suppose but what do you guys using such adapters say?

I've actually observed hot spotting in entire lenses. When I had the Super Takumar 50mm f/1.4, used with a simple adapter (this was on a DSLR and before focal reducers were a thing), upon stopping down it would develop a spot of blue flare in the dead center of the image. This was under normal daylight conditions with subjects of average contrast levels. The more stopped down, the smaller, better-defined and brighter the blue flare was. I felt this problem made the lens unusable for color photography. From what I can see from samples, the blue spot flare on focal reducers that exhibit this problem seems just as bad, if not worse.

I don't think it's that unusual for legacy lenses to display this problem, the reason presumably being that the antireflective coatings on the rear side of the lens elements where never designed to handle a shiny digital sensor. Here's another example with a 50/1.4:


I also want to ask Mr. Brian Caldwell what exposure settings were set up in the Hotspotting test and verify that they were kept exactly the same between shots (I am sure that a serious guy would never make such a mistake as leaving the camera in auto exposure but I would prefer to ask just in case - hope I am not insulting!). Looking at the jpeg it seems that the white part around the black square is exposed to 100% so less exposure could push the hotspot well into the shadows to be any problem in real life shooting for the parts exhibiting such a fantom image.

Any flare you get is proportional to the exposure. If you have a darker exposure for a given flare condition, you do have darker flare, but you still have just as much flare relative to everything else, so you really don't have any less flare.

-- hide signature --
 Anders W's gear list:Anders W's gear list
Panasonic Lumix DMC-G1 Olympus OM-D E-M5 Olympus E-M1 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Panasonic Lumix G Vario 7-14mm F4 ASPH +28 more
Post (hide subjects) Posted by
(unknown member)
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow