Hi all,
I experimented a little with a tele conversion lens I have in my collection. It's a vintage Petri 1.5x teleconverter. If you don't know Petri, it was a Japanese camera manufacturer that produced very nice quality cameras and lenses up to the late 1970s. Their rangefinder cameras from the 1960s are very nice quality. This teleconverter was intended for a fixed lens rangefinder with 45mm focal length and f1.9 aperture. The converter has a simple 43mm thread. I attached it to the Ricoh GH-3 via a 49mm-43mm step down ring. Here is what it looks like on the camera (I think it looks kinda cool):
The converter vignettes bad if I leave it on the Ricoh GRII's 28mm setting, but the vignetting goes away 99% if I switch to the GRIIs 35mm setting. Now I have a 50mm equivalent with 10mp. Here are some samples (Please forgive the bad photos, they are just to show the image quality and have no artistic value). All photos in full res. on Flickr:
f2.8: Center is already bitingly sharp, but as expected falls off to the edges and corners.
f5.6: Center is fantastic and the edges start to clear up.
Here is a reference shot with the GRII's lens without the converter:
Now with the converter and a 50mm, 10mp equivalent:
Now with the converter and a 75mm, 5.6mp equivalent:
Close-ups work very well, too. Here the 75mm, 5.6mp equivalent:
50mm, 10mp equivalent:
So far, I'm really encouraged by the results. I think the image quality is very usable. What do you think?
Those Petri converters are not the most common items to find, but they do come up on Ebay from time to time if you are interested in one. They don't go for much, I bought mine two years ago for $15. Some even come as a kit with wide angle converter and external viewfinder.