Camera ID help/shutter question

[elrint]

I recently bought a camera and the seller knew nothing about it. I've researched what I can about it, but with no labels or limited resources online of what I can search, it's making it hard. It's a 5x7 folding tailboard camera (no labels) with the numbers '28' on the lens board and a brass lens with '18491 C. Berthiot Fabricant Opticien Paris No. 3' engraved. I'm having difficulty trying to find anything about the model/maker since there is nothing on the camera itself, and tried researching the lens to get an idea but can't find much about that specific model sadly.

I went to test out the camera and wanted some advice on the shutter. You wind the gear once and the curtain/blind that covers the aperture gets wound up on a drum off to the side and exposes an opening in the cloth (no slits..a wide opening) where you can focus the image on the ground glass. You wind the gear again and that portion gets wound up also and the aperture gets covered up by another section of curtain....basically a horizontal guillotine shutter. The only problem is when I go to fire the shutter and expose film, instead of a regular guillotine shutter movement, it will go from the curtain to the opened/exposed view and stay there. I then have to lift the lever again and this releases the shutter tension again and it completes the movement and releases so the original curtain now covers the aperture.

Does anyone know why this happens instead of completing the whole wiping motion in one release? I thought perhaps something was warped or got stuck but there is nothing abnormal that interferes when the tension is released. There is a raised area that 'locks' the gear in place for both the opened section and 2nd cloth, my problem is when I go to release the shutter, it gets caught or stops at the first 'lock', which is when the aperture is fully open. When I lift the lever again the shutter releases again to the first cloth. Just want to know why it's doing this since I'll set the shutter speed, but it clearly doesn't make a difference if it stops when the aperture is fully exposed and I have to manually release the tension again.

Thanks for any and all help. Sorry if explaining the shutter problem was confusing...I'll try to take a video but I posted photos below for now...feel free to follow up with questions and I'll answer best I can.

[Steven Tribe]

This is a Nice travel camera of size 13x18cm - not 5x7”!
The thornton-pickard type shutter is designed to Provide both instantaneous AND time Alternatives. Check for Simple adjustment at the release sIte on the side.
The “28” is a wooden part matching guide - many of these cameras were without maker providence. I hope you have some plate holders as these are not standard!

[Dan Fromm]

Berthiot was a major French lens maker.

Per P-H Pont's chronology the serial number is from not that long before 1900.

In that era, according to Pont & Princelle's Berthiot pamphlet there were two #3 lenses in straight barrelsm, ordinary/rapid Aplanats and Extra Rapid Aplanats. The first line's #3's focal length is 22 cm, its front element's diameter is 34 mm and it covers 13x18 wide open. The second line's #3's focal length is 18 cm, its front element's diameter is also 34 mm and it covers 9x12 wide open. They say nothing about maximum apertures. Both were sold with Waterhouse stops.

OP, you're apparently a new arrival here so probably are not aware of this site's resources. You may want to visit the LF Home Page (button at the upper left of the screen) to read the FAQs and articles. Also click on the link in the first post in this https://www.largeformatphotography.i...mainly)-lenses discussion to get to "the list," a set of links to sites etc. of interest to LF photographers. One of the things it points to is my article on Berthiot's anastigmats. That's not what you have, but my references will take you to sites with information on Berthiot's older lenses.

[elrint]

This is a Nice travel camera of size 13x18cm - not 5x7”!
The thornton-pickard type shutter is designed to Provide both instantaneous AND time Alternatives. Check for Simple adjustment at the release sIte on the side.
The “28” is a wooden part matching guide - many of these cameras were without maker providence. I hope you have some plate holders as these are not standard!

yes i have 2 holders, decent condition

[elrint]

Berthiot was a major French lens maker.

Per P-H Pont's chronology the serial number is from not that long before 1900.

In that era, according to Pont & Princelle's Berthiot pamphlet there were two #3 lenses in straight barrelsm, ordinary/rapid Aplanats and Extra Rapid Aplanats. The first line's #3's focal length is 22 cm, its front element's diameter is 34 mm and it covers 13x18 wide open. The second line's #3's focal length is 18 cm, its front element's diameter is also 34 mm and it covers 9x12 wide open. They say nothing about maximum apertures. Both were sold with Waterhouse stops.

OP, you're apparently a new arrival here so probably are not aware of this site's resources. You may want to visit the LF Home Page (button at the upper left of the screen) to read the FAQs and articles. Also click on the link in the first post in this https://www.largeformatphotography.i...mainly)-lenses discussion to get to "the list," a set of links to sites etc. of interest to LF photographers. One of the things it points to is my article on Berthiot's anastigmats. That's not what you have, but my references will take you to sites with information on Berthiot's older lenses.

Thanks I'll definitely research those sites to help narrow it down. Based on what I researched before I estimated the lens between 1895-1897, and this lens came with one Waterhouse stop also. Hopefully one of those sites has some more info