Small Lens Very Useful
Like the 140 degree format. Only fixed f/8 but works great in good light. Even have goo night images from it when I can shoot a slow shutter speed. A sleeper lens. I keep it on my PM2 or PL/7 when I want to pocket the camera for a long walk or a hike. I carry the 17 f/2.8 or 14-42 in pocket, add the 40-150 if I take a vest and have everything I need. Such a small package with this lens. Fisheye images are so much fun! Image quality is better than expected and center is very sharp. Not cheap for a little fixed f/8 body cap lens but still only $100 and worth it for the fun you can have with it. I have a 7.5mm fish eye - a full 180 degree f/3.5-f/16 lens but its much bigger and heavier. I take it with me when I have a case but for light duty walking around this 9mm fisheye is great!
Exceptional value Fisheye
An economical may to get a fisheye lens. It compliments my 12-40 F2.8 PRO that I use as my primary lens. The F8 aperture is not an issue as the lens would would have been stopped down for depth of field if I were using a super wide zoom. There is only minimal barrel distortion, less than I expected at the cost of the lens.
I did not find the opening mechanism a problem as there is an indent that allows almost infinite depth of field
The camera and lens are now compact enough to fit in a pocket. It will be perfect for street shooting in travel situations where it is unwise to advertise an expensive camera and still get better than point and shoot quality.
Adding Metadata in Lightroom
This is a fun little lens. The only downside to the 9mm body cap lens is that photos taken with it will not have any lens metadata in them, as there’s no electronics in the lens and therefore the camera doesn’t know what lens is attached. Fortunately, it’s possible to add lens information, which can be useful when sorting or searching photos. There are a few ways to do this. I tried using exiftool and the LensTagger plugin, but couldn’t get either to work.
What worked was to create a XMP file for each photo, save it in the same location as the photos, and then import them into Lightroom. The lens information is saved in Lightroom’s database, and in a sidecar XMP file if you have that option enabled in Lightroom or use the “Save Metadata to File” command. The advantage of this approach is that the metadata is not written into the original RAW file, avoiding the potential of corrupting the file.
The XMP file that I created contains the following:
<?xml version="1.0" encoding="UTF-8"?>
<rdf:Description rdf:about="" xmlns:exif="http://ns.adobe.com/exif/1.0/">
<rdf:Description rdf:about="" xmlns:aux="http://ns.adobe.com/exif/1.0/aux/">
<aux:Lens>OLYMPUS 9mm F8.0</aux:Lens>
Note that the ApertureValue of 6 converts to an F-stop of 8.0. There is a similar MaxApertureValue field, but I could not get Lightroom to read the information correctly, so I didn’t include it in the XMP file (Lightroom will record the maximum aperture value as 0/256 in the XMP file and display it as an F-stop of 1.0). As for the name of the lens, I used the same format that Olympus uses for their other Micro 4/3 lenses, but I left out the “M.” as it’s not an M.Zuiko lens.
The XMP file must be saved as a plain text file with the same name as the photo, and the extension XMP. Creating multiple versions of the same file is relatively easy in Mac OS X (I have no idea about Windows). I press Command-D to duplicate the file, and keep pressing it until I have as many XMP files as I need, then I bulk rename them to match the RAW file names (which are usually in sequence).
A cute little lens
Easily opened in error in your bag and completely manual but, for little money, size and weight, it's a fun lens to have.
Cute cap lens
The fisheye cap lens is a cute little addition. It's not a real micro 4/3 lens in the sense that it does not connect to the camera's electronics. It's simply a cap with a non-trivial but manually-operated lens. The switch to open and close the lens is a little primitive, and can be easily bumped open if you have you're storing your camera loosely in a bag. But I find the lens quite useful in many fun situations where one may not want or need a very sophisticated lens, like say, chasing my boy around at the beach.