Home Made Lens Success !!!

Discussion in 'Large Format Cameras and Accessories' started by SteveH, Aug 14, 2006.

  1. SteveH

    SteveH Member

    Jan 3, 2006
    4x5 Format
    Yesterday, I took out my rigged up lens for a test - just to be sure it gave me the look I wanted on film before I committed the cutter to brass. So I took my cardboard f/stops and went down to a local wildlife/land preserve on the Brandywine River.
    Being a nice evening, I enticed my girlfriend to come along; with the promise of a relaxing evening bbq/picnic. Unknown to her at the time, I was also looking for my first portrait :D .
    After the BBQ and some idle chitchat, I retrieved the camera. It was about an hour before sundown, and the sun was touching the trees. I needed this sort of light, because my 'Galli' shutter isn't honed yet :D . So with 25asa film (I don't have any 77mm ND filters, which would be *just* too small anyway), I was able to get close to repeatable accuracy.
    I wanted to shoot a variety of textures, as these old lenses seem to display different characteristics when shooting different patterns. So I found some woodland scenes with a lot of foliage, some shots of just trees in a row, and a sneak portrait of my girlfriend relaxing.
    Upon developing the negs today, I am VERY pleased. The shots that have the canopy in them give a sunburst effect, with a center sharpness that can be adjusted via f/stop. Wide open (f/3.3 or so), the focused area is nice and soft, slowly sunbursting out. At about f/5.6 the center starts to sharpen up, and stand out of the background. By f/11, individual textures on blades of grass can be seen, but yet the OOF area swirls away. At f/22 (the smallest one I made), nearly most of the neg is sharp, with a slow softness at the edges.
    It doesn't give the concentric distortion in the background that a petzval gives, but rather a 'warp speed' sort of look. This seems to come and go dependant on the subject, and the area of focus...Im beginning to think that the burst-like look is dependant upon bellow extension. At infinity, etc there is more glass used to make the image on the neg, so the light refracts off of the curved surfaces more. Whereas when the bellows are extended to focus on something closer than infinity, these abbreviations are cast to either side (into the bellows), and only the center portion of the image is projected on the neg. It isn't like the look when a lens doesn't cover the format - its different (plus, at infinity, I have like...2.5" of coverage still !). It would be interesting to test this theory on an 8x10.
    The portrait is what impressed me the most. Its smooth and sharp without being too sharp. There isn't any of that sunburst distortion either. We'll see what it prints like, but judging by the negative, this is turning out to be a worth-while project !!!
    As I said earlier, my Galli shutter isn't honed, so I have shots that are mostly over exposed by a stop or so. There is one photo that is exposed well, and it shows some real nice contrast - MUCH better than the old Helostar I was messing with earlier.
    Hopefully I can cut the barrel this weekend. I still don't have a packard to mess with, but at least I have the electronics figured out. So slowly but surely Im getting there...

    I'll try to get some scans later this evening.