If your lens is in a Compur or Copal #1 shutter, the front thread is M40x0.75mm. Although 40mm is not a common filter size, it is now easy to buy a filter step up ring like 40 to 46mm or 40 to 49mm...
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If your lens is in a Compur or Copal #1 shutter, the front thread is M40x0.75mm. Although 40mm is not a common filter size, it is now easy to buy a filter step up ring like 40 to 46mm or 40 to 49mm...
You need a 4" square board for the Graphic View. A 96x99mm board sounds like a Linhof Technika board. In addition to not being the right size, it probably won't have the right shape of rebates...
Some of the scales are marked for which lens, like one starts "Tess 4.5 ..." and another starts "47cm VL 9.5 ..." which might be a Protar, or a single cell of a Protar. Protars are convertible....
It does not matter. The main issue is to make sure that when fully open, the shutter does not vignette your lens.
First, the amount of time that the shutter is opening and closing is a small...
There are tripods with a leg that's a detachable monopod. One could use that as a hiking pole while strapping the rest of the tripod on one's back. I think that detachable-leg tripods are mostly...
I'm impressed by building a custom wood frame. I hope this isn't taken as critical:
- A foam insert with dividers would likely be protective enough. However, many non-hiking backpacks do not have...
Interesting - I'm not familiar with the Toyo 57G. Was that an interchangeable back with the same fitting as the usual Toyo-Sakai 4-3/4 x 6-1/2, or a uniquely 5x7 version of it?
There's a few...
The Toyo / Sakai metal field 4-3/4 x 6-1/2 does have swing in the front. It unlocks with a chrome lever at photographer's right, bottom of the front standard. No front shift, no rear swing (and no...
Because the maximum aperture of a lens is limited by the lens design, not necessarily by the mechanical opening of the shutter's aperture. The shutter's aperture lever may have travel beyond what the...
It sounds like you need to understand how to mount an LF lens to a lensboard. The lensboard needs to have a hole that accepts the mount diameter (outer thread) on the rear of the shutter, and then...
Yes, but there are many other cameras (some not made by Linhof) that take Technika-IV-style boards but don't have the exact same front standard as a Technika, so it's possible that somebody modified...
A Technika III board is a little taller and narrower than a Technika IV board, and the light trap on the back is different.
I would guess a Technika III board that someone added notches to so that...
Yes, but sometimes the M sync delay mechanism is sticky. It's a little weird that it manages to move but so slowly as to take a 1/4 second. I have had lenses where it was just stuck, so the shutter...
I used 600 grit silicon carbide. I got a pound of it from a local tool shop that also caters to jewelry and rock-hounds (lapidary, rock-polishing). A pound of SiC grit cost $8 a few years ago and is...
I also read the article and was skeptical about the arrangement described. I think it's likely that Hank O'Neal's recollection was incorrect and that there was a single camera obscura / projection...
Doremus, in your second paragraph you wrote "Diffusion is always present ..." but obviously meant to write "Diffraction is always present ..." - just for clarity.
"Confusion" in imaging can refer...
I've always seen "circle of confusion." That is mostly a photography term, not an optical science term. Generally (in English) diffusion refers to a different type of physical process, a multiple...
It's a filled circle. I don't think that is the confusing part for most people.
Other terms that could be used include "disk" (commonly used for the Airy disk as someone mentioned), and "spot...
The spot meter attachment from the old Luna Pros does not fit on the Digital F, which is smaller. The Digital F is still available new as the "Sixtomat F2" (Gossen always had different model names in...
I also have a Fujinon 210mm in the Seiko #1 shutter that is like a Copal #1 shutter but slightly larger. I've posted about it here before to assist people. It mounts in a 48mm hole versus the 42mm...
Something is wrong with this (simulated 35mm overlaid on 4x5) image. The image of the sun is improperly scaled for focal length. You can tell because the image of the sun should be 10x linearly...
Sorry, I didn't see this in time. The disk of the sun is about half a degree diameter, so about 1/110 radian. This means that to get any appreciable extended image of the sun, you need a very long...
Nice photos! Were you there at a time or day that the Colosseum was closed? It looks quite early or late in the day from the shadows. I was there in spring of this year and the whole plaza was...
Unfortunately as seasonal employees the Park bears are extremely vulnerable to layoffs during shutdowns, so it's a good thing this has been averted.
I wouldn't interpret the Schneider cautions about precision to mean that lens cells must never be touched. There isn't any mechanical degree of freedom to adjust when a lens cell stops as you screw...
There's a review of the Wisner plasmat set by Jean-David Beyer on the LFphoto main page, dated Oct 1997: https://www.largeformatphotography.info/plasmats.html
I think he used to post to the...
Several years ago I assembled an inexpensive mini storage oscilloscope from a kit (a JYE Tech DSO150) for about US$20-30. I did a writeup of it on a guitar pedals forum, you can find it at the...
The shutter speed app is very useful even in the free audio version and Fritz is very kind to make it free. Although it's not as correct as a real 2-point focal plane shutter tester, it can tell you...
It's a phototransistor and a resistor. You can find details if you look around. I made one myself, and the homemade one works fine although you have to interpret the waveform that comes from it (it...
I don't think one goes to expensive art school to be a famous artist. I mean, maybe that is one's ambition, but most graduates aren't going to become famous artists, just like most football players...
E. E. Barnard, among many other things, made a number of celestial photographs with a large lens he refers to as the "Willard lens," a lens he describes as 31" focal length and 6" clear aperture,...
It's not just Simmons who says that the position of the back determines perspective. Writers of books on the view camera such as Strobel and others have been saying this long before 2015. If one is...
People are having fewer children, and that's what gives them the disposable income to go on vacation to Yosemite. It may be a special madhouse this summer, but the way to deal with that is to go...
I think that is a 62mm long extension for a telescope focuser for 2" diameter (50.8mm) eyepieces. Not what the OP wants.
Spacing only the front cell of a lens away from the shutter and rear cell...
This is a good one too: Scratched Front Element, https://www.lensrentals.com/blog/2008/10/front-element-scratches/
(typically, rear element damage has worse effects than front element damage).
Put a few drops of windex-type glass cleaner or lens cleaning or alcohol on a microfiber cloth, wipe gently, and dry. You shouldn't need to do anything more. Using anything that seems remotely...
There is an interesting DIY air filter called a Corsi-Rosenthal Box that was designed during the height of the Covid pandemic but would also be useful for this moment of wildfire smoke, and general...
There is a kernel of truth to the serendipitous origin story of optical coatings, although it's not about a photographer, cigarette smoke, or resolution; but respectively Lord Rayleigh, tarnish, and...
Now that is pretty cool!
Do you have any videos showing the shutter in operation?
Roosinov's patent is US2516724A, https://patents.google.com/patent/US2516724A/en?oq=us2516724 You have to download the PDF as the OCR'ed text is very poor.
He uses "aberrational vignetting" to...