Peter, thanks, that looks like just what I need - looks sturdy and it does from 18mm on up to larger than I will need. I think I'll order one.Originally Posted by pjd
Peter, thanks, that looks like just what I need - looks sturdy and it does from 18mm on up to larger than I will need. I think I'll order one.
Back to "not perfectly round apertures", but perhaps close depending on your hand/eye. Fold the paper three or four times around a center point and cut off the point. The result is a faceted round-ish opening when unfolded. A bit hard to precisely control hole-size though.
Meniscus lenses are cool and fun to work with.
Understand and makes perfect sense.
Newly made large format dry plates available! Look:
https://www.pictoriographica.com
I cut mine using an old drafting compass. I replaced the pencil lead with a small nail of about the same diameter. I cut the nail to length, then filed an edge on it, and lastly sharpened it with a sharpening stone. It works pretty well, though not being a hardened steel, I do have to resharpen it frequently. But I don't use it that often, so it's not a big deal to me. Plus, since it's not tempered, it doesn't take long to put a sharp point on it. If I used it more frequently, it might be worth my time to temper the steel. But it's one of those things you only use once or twice a year.
The more I think about this, the more I wonder why you don't just go with a stiffer material and use drills. Lot's of sizes available, including adjustable hole drills. Something like thin, stiff, flexible plastic/nylon would be able to be cut with scissors and drilled as well (especially if you held it between two pieces of something). The resulting aperture sheets would be more robust, easy to store in an envelope or file book and easy to use and reuse.
Best,
Doremus
I tried making some stops out of rigid plastic with an adjustable hole cutter, for a very similar sounding project to what Randy mentioned - I have a couple of Imagons in barrel, one of which has no discs, and I don't like the weird highlights with the outer holes in the discs used anyway. Getting nice specular highlights is the same reason I wanted to try for the roundest aperture I could get, too. In absence of aperture blades in Imagon barrels I wanted to make a series of stops for more subtle changes than are possible with just a set of Imagon discs. I also made some bigger waterhouse stops for a big diy barrel lens I made out of PVC pipe.
Cutting rigid plastic was labour intensive, fussy, messy and time consuming for me at least (just what Randy said he wanted to avoid) - but the paper cutter was really easy to use. The blades get blunt after a while, but are replaceable. The card apertures I cut are strong enough, specially when stacked together when stored. If one gets messed up, it'll just take a few minutes to cut another. Black card is cheap, easy to get hold of and easy to work with. I rather fancy that a thin material is preferable for an aperture, too?
If you wanted to cut holes in plastic, probably the best way to do it is to clamp it between two pieces of wood and drill a hole through all of them. That should keep the plastic from flexing, warping, or tearing. Of course, that's dependent on you not being too picky about your aperture sizes, or being able to find the drill bits in the sizes you need. Those screw tap bits come in in-between sizes, so you're not always limited to what comes with your typical drill bit set. You could also do the same thing with thin sheet metal. That's how I made some waterhouse stops for my Petzval out of aluminum.
Indeed, I have to agree with you. With a drill and a set of fine files you can make a hole of whatever diameter you trace on a piece of thin aluminum sheet.
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