Stikkord: Petri 7s

Experimenting with depth of field

Playing with the Christmas decorations is not an activity reserved for cats. When I tested the Petri 7s for the first time in the beginning of December, I noticed how good the lens seemed to be. Even though my test then showed that the camera had seen better days, the f1,8 lens turned out to give very nice, details and I decided to shoot some frames to test it out. I decided to go with the Christmas, or actually Advent, decorations. I lit a candle in a glass candle holder, and let that work as a foreground, and I placed the rest of the decoration approximately 80cm away from the lens, which would be the closest focus length for this camera.

My setup. Petri 7s on a black glass plate with the decorations. I have taped the camera because the back has a tendency to «pop open» at any point.

I went with shots at f1,8, f4 and f16 to see how much difference there would be in sharpness and how they would turn out. I did not change the lighting conditions, but I adjusted my shutter speeds to compensate for the smaller aperture. for the f16 image, that was two and ha half minutes with compensation for the Schwarzschild effect.

Petri 7s – Ilford FP4 plus Xtol Stock. f1,8 1/8 seconds – f16 180 seconds – f4 1/2 seconds

All in all I think the lens gave me the results I anticipated. The f1,8 gives me a very nice bokeh, but the focus is a little bit off, so maybe the focus ring isn’t as accurate as I would hope for. The f4 image gives more sharpness and retains the nice bokeh feel, and the f16 gives a very sharp image.

The mood changes a lot between the images, and I am not sure which one is my favorite. You can make a judgement yourself, and I hope the images are to your liking.

Playing around with a Petri 7s

If you have followed this blog for a while, or read some of my posts, you may know that I have a Petri Racer that I really love shooting. I find the little Petri to be very reliable, accurate, light and handy as well as giving the images some character. I can’t really put my finger on why I like that particular camera so much, it is just a camera I enjoy shooting. A few weeks ago, I came across a Petri 7s on an auction online, and I won it on a very low bid.

The reason I was interested in this particular 7s was that it had the f1,8 lens, which some sources claim to be a six element lens with an interesting bokeh-pattern. Whether it is six element or four, as the f2,8 version, does not necessarily mean that much to me, but I do love nice bokeh and sharpness. For the very low price that I payed, it was worth the gamble at any rate.

The Petri 7s f1,8 Rangefinder camera w. amber coated lens

A gamble it surely was as this camera has a few personality traits that is very specific to this particular one. First of all. The Rewind-knob is loose, and you cannot turn the camera on its head without risking the film to lose tension as the rewind knob disengages. Another interesting «asset» this camera has, is a dodgy lock on the back. This means you will get the luxury of using electrical tape to secure it from opening mid-roll. In addition to this, the camera invites to a creative approach to focussing, with a rangefinder (although rather dim and dodgy) that jumps in and out of «sanity» a few times pr shot. I ended up guesstimating my focus because I trusted my own eyes more than the rangefinder unit.

Reklamer

These faults aside though, the aperture settings and shutter speeds are fairly accurate. When I took it to Lillehammer to try it out on the newly fallen snow, I got very good negatives. My test was done with half a roll of Fomapan 200, which I because of the lighting conditions shot at 100. I shaved 20% off the development time compared to box-speed, and ended up at 6 minutes with Xtol Stock.

Petri 7s f1,8 – Fomapan 200@100 Xtol 1-0 6 minutes.

As you can see, in some of my images, my lens fogged over. However, this is not lens-haze, but rather an issue of a swift temperature change and a forgetful photographer who didn’t remember to wipe the lens before shooting against the sun.