Pinhole – macro

I am thinking of doing some pinhole macro work.

Looking the internet up I found some interesting thoughts

If you draw a ray diagram you may see a problem if you bring it very close to your subject, and your film sensitivity curve isn’t narrow.

For one thing the material in which the hole is made would need to be very thin, or you’ll get some odd vignetting.

But also remember that pinhole does a very poor job of focusing different wavelengths to the same plane. As the subject gets closer to the pinhole, that issue should get more noticeable: rays containing all the colours will need to approach the pinhole from more extreme angles.

Hence my suggestion to use a film with a narrow sensitivity curve… it’d be best if it were sensitive to a single wavelength

Seems I will have to do some tests myself

Camera – Cameradactyl

Finally a free afternoon. I went out with the (black) Cameradactyl 4×5 to try a few shots with the cheaply aquired, cleaned and mounted 127 lens.

https://www.cameradactyl.com/

Of course as soon as I arrived with my bicycle the weather went to light rain.

The tripod mount I glued in is not stable (looking for an idea to get it right) and while composing the camera was rather wobbly on the tripod.

Fuji X-ray film (Fuji AD-M 18×24 100 Bl. mammography film, one side emulsion), Rodinal 1:100, 20 Celsius, about 10min under red light with visual control.

The pic shows part of the eremitage, a long forgotten place where some monks once lived in solitude near the Nahe valley, Bad Kreuznach.

x-ray – eremitage

RSS 6×17 Pinhole Camera

A very nice ultrawide pinhole camera from James Guerin at aupremierplan.

Here is his description the loading of this camera:

Curved film plane?

bmp-Model

The film plane is curved to ensure even exposure across the negative, not possible with a flat film plane with such an extreme wide angle view (141° angle view of equates to a focal length of 6.4mm in 35mm terms). T

A side-effect of the curved film plane is that it results in a curved horizon in your photos unless the photo is taken with the camera level.  This is why a precise bubble level features on the top plate of the camera.

Camera features

  • CNC machined body
  • Curved film plane with a radius of 70mm (focal length).
  • Large 6x17cm (57x170mm) negative giving 4 shots per roll of film (120 roll film).
  • Angle of view: 141 degrees horizontal, 44 degrees vertical.
  • Laser drilled 300 micron (0.3mm) pinholes (f/233). Pinhole material thickness = 50 microns (.002″).
  • Magnetic shutter
  • Dual pinhole allows horizon to be placed on upper or lower third (camera level)
  • Accurate aiming lines for composition.
  • Precise bubble level.
  • Standard 1/4-20 tripod mount socket
  • Rubber feet
  • Film spool tensioner at take up spool

Scheimpflug

Tilting the front or back plane with a large format camera is a important feature.

The Scheimpflug rules explain the effect.

It states that the film-, sharpness- and lens plane meet themselves at some point.

In a usual small format camera they meet in infinity, therefor the planes are strictly parallel : III

As soon as you tilt, the planes meet and you can play with depth of field:

This is a picture of a view camera with lines drawn through the film plane, the lens plane and also showing the subject plane.  All three planes cross at the Scheimpflug Line.
Merklinger, http://www.trenholm.org/hmmerk/
http://www.trenholm.org/hmmerk/VCGM.gif
The Hinge rule
Diagram showing how depth of field works for view cameras.
Photograph of Lisa holding a surveyor's rod that indicated the position of the plane of sharpest focus for a view camera.  Copyright C. Reardon & H. Merklinger 1995.

Front plane tilting needs a larger image circle of the lens and puts the film to the edges of the image circle, out of the optimal sharpness region of the lens.

Back plane tilting avoids this problems.

Usually the tilt is just a few degrees, much less I expected at first.

Pinhole pictures

2019, Sicily, „at the beach“, Foma 100, D96, RSS 6×6

2019, Sicily, „sunscreens“, Foma 100 D96 RSS 6×6
2019, December, „pinhole in action“ – look at the left backpack side….
2019, July, „home toen“, Bad Kreuznach, Oranienpark
Foma 100, 8sec, Ondu 6×9, Rodinal 1:100 1h semistand


2019, November, Gensingen, „old truck“, RSS 6×9
The year 2020 keeps me limited pinholing on my way to and from work, due to the Covid Pandemie.
I usually travel by bicycle. I was late, it was already dark and the RSS was mounted on my bike.
RSS 6×9, expired Ilford PAN 100, Rodinal 1:100 stand.

2019, Spain, Madrid. RSS 6×9, wxpired Ilford PAN 100, Rodinal 1:100 semistand.
2020, June, „my way home“, expired Delta 100, Rodinal 1:100 semistand, RSS 6×6
2020, August, „my way home“, expired Ilford PAN 100, 510-pyro 1:200 8min, RSS 6×6
2020, July, „nightshift“ , RSS 6×9, very old Agfa Ortho 25, Rodinal 1:100 semistand.


2020, March, „nightshift“,RSS 6×9, expired Ilford PAN 100, Rodinal 1:100 semistand

Cameras – Agfa Isolette

The Agfa Isolette (I)

https://www.youtube.com/watch?v=hZVx9psFESI

https://www.youtube.com/watch?v=5klXMZcX_Zk

https://www.youtube.com/watch?v=AIMiCsTkcMw

And more :

https://de.wikipedia.org/wiki/Agfa_Isolette

http://www.optiksammlung.de/Agfa/IsoletteI.html



Loading the film :

https://youtu.be/EbvFVDC7j9A


I got a nice old camera, but the shutter was not working and the focus ring would not turn.


The wonderful page here explains a lot about this camera.


The repair :

First I unscrewed the focussing ring (3 small screws to loosen).

Than a serrated focus ring has to be unscrewed anticlockwise after turning the „half a screw“ out of the way.

Now you can unscrew the front and the second lens anticlockwise.

 Next the aperture ring goes of.
From the back of the camera I now unscrewed the third, back lens, than a screw, than the bellow can be loosened from the shutter assembly from behind.
A few small paper rings ( focus adjustment ) have to be carefully stored.
From the front now i succeeded unscrewing the first and second lens en bloc, the grip I got with pieces of old bike tires.
The shutter now free I used Isopropanol and a ultrasound cleaner for about 30 minutes, works like a charm now, than I used a little Silikon Spray on a toothpick to lubricate a few suspicious screws.

I still had trouble to separate the first/second lens element (they should allow to focus), heated them in the oven to 60 degrees Celsius, ultrasounded them, lubricated them, and soaked them in oil.
Soaking in acetone finally loosened them enought.

Now they are seperated and the hardened green glue is completely removed.

 And – finally – the camera is ready.
But – adjusting the focus comes first. I taped a piece of transparent paper at the back ( where the film would usually be ). Than I put the camera on a tripod and turned the front lens until a skyscaper in about 800 m distance was sharp. Now I put the focus ring in infinity position on and screwed it tight. 
Done.

This morning I loaded a film and will take a few shots after work.

By the way :

Another victim of bellow – lightleaks  told me to repair the bellows with
McNett Aquasure, it seems to be a good glue and much cheaper than a new bellow…

Another tip is to oil the bellows with Ballistol, a well known weapon oil.


And last not least – a rather funny hack :
https://www.flickr.com/photos/9192444@N06/3954217278/

Sometimes, like here with very old Technical Pan (in 510-pyro) the old Isolette can deliver something unexpected sharp and detailed:

CyberViewX v5.16.75 Model Code=66 F/W Version=1.37

Cameras – repair & manuals

Here are some links to manual pages for our old cameras :


http://www.butkus.org/chinon/index.html

http://mikec62.tripod.com/

http://thecameracollection.blogspot.de/p/manuals.html

http://www.antiquecameras.net/

http://pdf.textfiles.com/manuals/CAMERAS/VINTAGE/




Not so much manuals 😉 :

http://tazmpictures.com/site/?page_id=1577

http://www.collectorsweekly.com/cameras/overview

http://camera-wiki.org/wiki/Main_Page

http://learncamerarepair.com/

http://rick_oleson.tripod.com/index-27.html

http://pheugo.com/cameras/index.php?page=default

http://www.rolandandcaroline.co.uk/repair.html

Cameras – pinhole construction

Interesting results are easy to get – use a pinhole….
I had gotten my hands on lots of old x-ray film. Expired since the nineties, but in lightsealed boxes.
The format is 18×24 cm, so the cassettes fit in 8×10 large format cameras.


The 8×10 inch (20×30 cm) and the german 18×24 cm cassettes I got are very different, I had to mark them to load the matching film format.



If you construct a pinhole

a.

the optimal pinhole size =  0,037 * SQR(Distance film to pinhole) 

Aperture =  film-pinhole distance / pinhole size

The projected circle of light from the pinhole =  pinhole-film distance  * 3,84 
(using an 125 degree angle)

Exposure time =  (exposure time aperture x) * (aperture pinhole / aperture x)2
(But I find usually I have to go with try and error, so take more cassettes than you think you will need or (like I do) load the cassettes on the road. I never know how much the Schwarzschild effect will kick in because I´m using old expired film. If you use documented film there will be a table in the documentation)



b.

The following equation can be used to calculate the pinhole size:

Pinhole formula No. 1

where d is the pinhole diameter, c is a constant (usually Lord Rayleigh’s constant, which is 1.9), f is the focal length (i.e. the distance between the pinhole and the light sensitive material) and l is the light wavelength. The wavelength used here is yellow/green, which is 0.00055mm.


c.
If you are not all that fond of doing the math youself, here is a table of a number of focal lengths, where you can find the number closest to your camera size and use as a guide when making the pinhole.

Focal length
(mm)
Optimal pinhole size (mm) * Focal length cont’d.
(mm)
Optimal pinhole size cont’d. (mm)
150.171100.47
200.201150.48
250.221200.49
300.241250.50
350.261300.51
400.281350.52
450.301400.53
500.321450.54
550.331500.55
600.351550.55
650.361600.56
700.371650.57
750.391700.58
800.401750.59
850.411800.60
900.421850.61
1000.451900.61
1050,462000.63

More Infos 

pinhole.se

http://www.die-lochkamera.de/

(a german site), you get all the infos you need.

http://www.pinhole.cz/en/pinholecameras/exposure_01.html

is in english.

If you need absolute precision (I don´t) :

https://www.thorlabs.de/NewGroupPage9.cfm?ObjectGroup_ID=1400


 The camera


and a picture, old x-ray film, expired 2001, developed in x-ray development machine (paper developer gives better results).

The screen photo doesn´t show the fascination of the original film, that you have to see for yourself.