mark_stevenson
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Posts posted by mark_stevenson
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I just finished building a 2nd 20x24 with a 30" Goerz Artar. Total
cost for the camera about $40 and total weight with the lens is 25
lbs. It's easy to backpack, just affixed my old backpack to it via
threaded inserts. About a week to build during a family reunion.
Fixed on infinity everything is in focus at f64 for distance or f128
for "closeups" (8'-300'). As far as I'm concerned this is the only
way to go. No focusing. Set up time is about the same as 35mm and
everything is always in focus. No movements needed for landscape.
Framing is basically right on every time. A Stanley Workmate works
perfect for a tripod or even the roof of the car. It's a no brainer.
Did the same thing in 4x5 with a 100mm WFE. Now that's my point and
shoot.
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Bill...What you've said makes perfect sense. However, I have been
shooting 4x5 and comparing my 20x24 contact prints with a 19x24
enlargement from my 4x5 is roughly equal to comparing an 11x14
enlargement from 4x5 to an 11x14 enlargement from 35mm as a general
observation, basically no comparison. But that's my own opinion.
People who veiw the 20x24 contact prints are fascinated by the detail,
it really feels like you are there. Those viewing the 19x24 and 16x20
enlargements from 4x5 really like the prints but little mention is
made of the detail. Hence my efforts to make a new 20x24 camera which
would be more mobile and DOF friendly at the near end.
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Bill...I've been using a cc of .75 on the existing camera and my depth
of field calcs have seemed to be right on. At f128 I get a HFD of
20'. There seems to be no degredation that I can see at these high
f-stops. I have one photo taken at f64 which contains a 1 foot sign
with six lines of small lettering about 50' away. I can't read the
small lettering of the sign on the contact print with my naked eye.
With a 6x loupe the lettering is very clear. I believe this lens is
from the 1920's or even before. It's certainly not a red dot or
anything. I saw somewhere to use a cc of .75 but this was assigned to
the format. They also said to use .3 for 8x10 and .15 for 4x5. Say
it is .75 for 20x24 with my 30" lens at 30" from the film plane. If I
move the lens out to 34" what would my cc change to? I know I'm
simplifying here because some of this stuff can't be measured.
Anyways, it will cost about $15 plus a days labor to make this new
camera so I guess I'll give it a shot
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I'm using HP5 20x24 inch sheets. It's available in boxes of 25 sheets
for about $350. Then I contact print. I created a spreadsheet which
does all the calcs for HFD, NFD, FFD, DOF, and lens to film plane
distance. The following data is pluged in: focal length, circle of
confusion, object distance, and f-stop. The formula I'm using for lens
to film plane distance is from Ansel Adams' The Camera and is 1/focal
lenght minus 1/circle of confusion = lens to film plane distance. I
would like to post a photo of the camera I've been using but I'm not
sure how to do it. It's just a simple box made of 1/2 inch birch
plywood. The whole top comes off so that I can place the film inside.
No moving parts except for the aperature. I show that without the
lens tilt and the lens to film plane at 34 inches my near focus
distance is 11 feet and far distance is 378 feet. I'm guestimating
that with a lens tilt of 10 degrees that the near focus distance will
come down to about 6 feet. Am I guessing right?
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I currently use a 20x24 box type camera fixed at infinity focus with a Goerz 30" Artar which I love but the near focus distance is 20' at f128 so I've been limited to shots off bridges or overlooks etc. I wish to build a second box camera using this lens which will give me a focus range of say 6' to 300'. I've attempted to run the calculations and figure if I move the lens out 4" to a total 34" from the film plane and tilt it downward 10 degrees i.e. the Scheimpflug Effect, that this will give me the desired DOF. Can anyone confirm these calcs or steer me in the right direction?
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I bought a 20x24 contact printing frame for doing this size
negative from the formulary for $65 which uses standard window glass
and I've yet to notice a newton ring or any other problem except for
minor dust, which can easily be remedied, in any of the many prints
I've done. Mark
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I picked up a 1954 Zeiss Ikonta 2x3 folder with a Novar 105mm lens for
$125. This is truly a great camera. No problem with the lens. It
folds flat and is a joy to carry. Less bulk than my Contax SLR,
although more than my Rollei 35. Perfect for 11x14 prints. 16x20 and
up I prefer the 4x5.
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I picked up a green party light at the hardware store for about $2.
This is all I use for development by inspection with 4x5 and 20x24.
DBI is the only way to go but I dreaded the thought of sheet film when
roll film seemed so easy. I've tried many films and developers with
DBI in trays. I go with emulsion side up and when areas of the neg.
start turning jet black I pull the film and put in the next tray.
Doing multiple sheets in trays using DBI is easy, just flash the light
to view each sheet separately. You don't have to worry about
exposure in the field, chemical temps, watching the clock, and you can
reuse the film developer by leaving the film in longer. I just put on
my Bible study tapes from
http://www2.oneplace.com/Ministries/Radio_Liberty/Archives.asp
and away I go.
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The camera is just a box with a lens. Here it is. It's at the end of
the bench with the two brass handles. Refrigerater is behind with
part of a contact print from the camera visible.
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I wish to take close-ups of small flowers, say 3 inches in diameter, with a 20x24 camera with a Goerz 762mm lens and have this image cover the film. I built the halfsize of a refrigerator camera and figure I could build another much longer camera. What would my depth of field be with 20 feet of bellows at f64. Is this just to rediculous to consider. I love this camera and the results. I also love my Rollei 35, Contax with Zeiss 1.4, Rollieflex, Zeiss Ikonta, and homemade 4x5 with 100mm Wide Field Ektar, but nothing compares to the 20x24. Any suggestions?
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Yes I have contacted them and spoke with a gentlemen who had seen a
single one of these lenses in 3 decades although not of this
particular focal length. I understand there are many Hypergons but
only a few with huge coverage and these few are very rare.
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Looking for the 200mm Hypergon fan lens for 20x24 camera. This lens is extremely rare, about the diameter of a salad plate, and gives 24x28 coverage. Would allow me to use the camera at tripod height without DOF issues of 30" Goerz Artar. Are there available specs on this lens for an attempt at remanufacture thru Edmund Scientific etc? Or is this an impossible wish.
Contact print frame - borderless
in Large Format
Posted