Dial Set Compur fires only one speed, Please Help

[lobitar]

How do you focus using the 4x5 cassette?

 

[DraganB]

How do you focus using the 4x5 cassette?

i am going to 3d print a frame with groundglas.

 

[Jonathan-sv]

I used this with some modifications to make adapters for two plate cameras, a Bergheil and what I think is an ICA. The 9x12 and 4x5 modern film holders are the same size so I use them with 4x5 film. Maybe you've already seen this.

International back for Voigtländer Avus 9x12 by ekech

There are lots of different folding cameras for 9x12 glass plates from the beginning of the 20th century.Popular examples are the Voigtländer Avus or Bergheil cameras as well as Ernemann, Zeiss ICA, Steinheil, but there are lots of different brands and builds which are quite similar.In rare...

www.thingiverse.com

Jonathan

 

[DraganB]

Finally found time to print the Groundglas Holder and make the Groundglas. Tomorrow first test.

 

[Romanko]

I can't wait to see the results. Good luck!

 

[DraganB]

I can't wait to see the results. Good luck!

So this is the first image, it's fine, the sharpness isn't really good at higher magnification. I need to check the lens elements and try another film like fp4+ or pan 50.


The shooting experience was very cool.

 

[DraganB]

Some Images from the location...

 

[JPD]

So this is the first image, it's fine, the sharpness isn't really good at higher magnification. I need to check the lens elements and try another film like fp4+ or pan 50.

It looks very good at that size. The 4,5/135 Tessars (and Skopars) I've tried were not as sharp as the 75mm ones on Rolleiflexes, but fine if you don't need very big enlargements with razor sharp details. The 6,3 Tessar is said to be sharper, but I haven't tried one yet. A good dialyte like the Eurynar or Dogmar would be sharper as well.

It's easy to scan a large format negative to a size equivalent to a huge print and look at the scans at 1:1 and be disappointed, but it could look great as a 30x40cm print.

 

[DraganB]

It looks very good at that size. The 4,5/135 Tessars (and Skopars) I've tried were not as sharp as the 75mm ones on Rolleiflexes, but fine if you don't need very big enlargements with razor sharp details. The 6,3 Tessar is said to be sharper, but I haven't tried one yet. A good dialyte like the Eurynar or Dogmar would be sharper as well.

It's easy to scan a large format negative to a size equivalent to a huge print and look at the scans at 1:1 and be disappointed, but it could look great as a 30x40cm print.

this one ?

i did not scan the right negative, i did two images one at f22 and one at f32, the one at f22 was better. but the negative i have used all the time for large format fomapan 100 is i think bad. will try ilford next time.

 

[JPD]

this one ?

Yes!

]i did not scan the right negative, i did two images one at f22 and one at f32, the one at f22 was better. but the negative i have used all the time for large format fomapan 100 is i think bad. will try ilford next time.

Perhaps too much diffraction at f/32. The sweet spot for a Tessar is around f/11.

 

[_T_]

You can use a diffraction limited aperture calculator to determine at what point you begin to lose detail for the size and resolving capabilities of the film you’re shooting.

Fomapan 100 has a pretty low resolution of 110 lines/mm listed on the spec sheet. So depending on what wavelength you choose you get a diffraction limited aperture of around f/14 on a 4x5 sheet of film.

So you’re definitely reducing resolution even at f/22 and it makes sense that f/32 looks worse. At f/32 your resolution is so low it’s something like 50 lines/mm or 20% of the possible resolution of each sheet.

These calculations are independent of the lens you choose and only require the relative aperture to give the size of airy disk produced regardless of lens design and specifications. That’s why all lenses will have the same diffraction limited aperture for a given size and resolution piece of film (or digital sensor for that matter)

 

[Romanko]

The shooting experience was very cool.

This is a great looking camera! I was afraid that the new back would dissonate with the rest of the camera but it doesn't.

I'm now looking at Gundlach Pictorial View Cameras that were produced in a 3.25 x 4.25 in format. They are less expensive than larger (4x5 and 8x10) models but have the same back design as your camera.

 

[DraganB]

Yes!



Perhaps too much diffraction at f/32. The sweet spot for a Tessar is around f/11.

looks like that was the problem, becuase i plan to enlarge in darkroom i need to test and see where the lens performs best.

 

[DraganB]

This is a great looking camera! I was afraid that the new back would dissonate with the rest of the camera but it doesn't.

I'm now looking at Gundlach Pictorial View Cameras that were produced in a 3.25 x 4.25 in format. They are less expensive than larger (4x5 and 8x10) models but have the same back design as your camera.

you could also make a 4x5 back for that camera, maybe the opening is big enough to cover 100%

 

[JPD]

looks like that was the problem, becuase i plan to enlarge in darkroom i need to test and see where the lens performs best.

Yes, I think that's probably a part of it. And we shouldn't forget the character of the lens, that razor sharpness isn't always the most important thing. I'm impressed by how sharp a 100+ year old Dogmar lens can be, but also by how smooth and nice a Heliar can be, even though it's less sharp.

 

[DraganB]

I built a digital camera adapter to test how sharp the lens is.

here is the result:

remember this is a portion of 23.5×15.6 mm from the 4x5 image!

I did not sharpen the image only resizing to 1000px.


f4.5, f5.6, f8

@ f/4.5:

@f/5.6:

@f/8

 

[MattKing]

I was confused by the similarity between the B&W images, but eventually figured it out - hope the f/ additions make sense.

 

[DraganB]

I was confused by the similarity between the B&W images, but eventually figured it out - hope the f/ additions make sense.

thank you king

 

[JPD]

Excellent test. It sharpens up nicely.