It is over a third quarter cenchury since the VPK were made. There are very few samples which could be able to take fine picture. It is common here in Japan that there are the way of using the meniscus lens of VPK by current 35mm SLR cameras in order to taste a smooth soft image of its lens flare.
|VPK lens Ass'y on cap|
Lens from Borownie folder
The K mount Pentax 35mm SLR is the best for this purpose because it is easy to get a "Herikod Extention Tube K" and a plastic body cap.
Attaching lens is easy that you first get a 20mm of diameter in the center of a body cap. You have only to set the VPK's shutter assembly(lens inside) tightly. Now your are ready to shoot.
It is possible to get the focus of 0.3 meters close to infinity without any adjustment. It has about 72mm focal length and able to move an element about 8mm front to rear insde of shutter assembly, if you need more focus.
Taking a picture
You should set shutter lever to T(Time) to keep the shutter brades open when you've got a shoot.
These lenses have a Hood which is to controll the aperture, in order not to open more than F11. You should also take this Hood off from flont or make the hole larger with a reamar, which is, I made, like on the photo.
If we call the green aperture positions on the left hand photo in normal VPK lens, the A is about F=6.8 at the full open aperture position. The B is just a center between 1 and A, it makes F=8, a C must be the center between 1 and B, it makes F=9.
The aperture position 1 is F=11, 2 is F=16, 3 is F=22 and 4 goes F=32.
It would normally be in good soft image result when an A might be used at the close focus, the B might be for middle length and the C for the long distance shooting.
Why VPK Meniscus?
It have been almost 20 years for me since I started enjoying VPK's soft effective. There were few soft lenses in the market at that moment. As the VPK was about 20$ from US camera vender, thanks to say, I could enjoyed a real soft image in very cheap price.
Meanwhile, Kiyohara Optics made a VK70Ri70mmF5.0jwhich was modeled on the meniscus lens of VPK. Although this new lens was farster and well coated, it still had a traditional two element single group configration. The soft description of this lens is realy similar to the VPK's except giving a high contrast image. After that, Kiyohara made a VK50R(50mmF4.5) for wide angle and a VK105L(105mmF4.0) for midium format cameras.
The VPK was a long seller camera for 15 years around 1920s. The earlier model seems to give more better soft image than the later one.
It was no way to use at all when I tried to shoot in daylight time by VPK body itself with 127 film. I needed a very high speed shutter anyway because it required a wide open aperture for a soft description. So the best way is to use with recent SLR. (T.Kubo)