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Tech/view camera and infinity

cyron123

Member
Hello,

i have a bloody question form an absolute beginner:

How could i focus to infinity on a tech. camera like the Linhof Techno or CS679 or Arca Swiss M-Line or Sinar something similar.

Thank you.
cyron
 

greygrad

Member
Either on the groundglass with your eyes and a loupe, or by marking the infinity point for each lens in (e.g.) pencil on the bed of the camera, or by fixing an infinity stop in place for each lens, or by using live view on an IQ/IQ2 DB, or by using an iterative shoot/review process with your DB (assuming the screen is good enough).
 

Jack

Sr. Administrator
Staff member
One other thing-- with ANY view camera, the total bed/bellows extension has to be longer than the lens focal length to hit infinity focus, OR you have to use a tele design lens. Obviously, you need even more extension to focus closer than infinity.

I mention the above, because many new shooters will put any old LF lens they've acquired on a cam with short extension like a tech cam, and the specific combo may not reach infinity.
 

cyron123

Member
Hi,
how is it possible to make markings on your rail, if you dont know if this is the infinity... I dont understand that. Sorry...
Is infinity to focus on very far away things and show on the groundglass if this is getting sharp??? Is this the workflow?
Thank you.
cyron
 

greygrad

Member
Choose a distant, high contrast subject (e.g. a telegraph pole or cell phone tower on a hill) and a nice, bright, sunny day, and you shouldn't have any problem focussing at infinity for a particular lens using the groundglass and loupe approach. Once you've established it, lock focus and then slide the infinity stop into position and fix it in place.
 

250swb

Member
I'm sure there must be more to it than the OP says because I can't think of why you would need to ask how to focus on infinity with a properly set up camera, you'd just do it. You point the camera at something at infinity and focus the camera on it.

It doesn't sound like the OP has a camera to try it with anyway, but thinking about it I'm not sure I have ever, in forty years of mostly landscape work, focused a LF camera on 'infinity'. True in the UK we don't have the vast landscapes of somewhere like China, or Australia, (OK you expected me to say America :D) but generally speaking for 'big landscapes' that include a point at infinity I've still always focused in the conventional way, on something one third into the frame and use small aperture DOF to make everything sharp front to back.

Steve
 

johnnygoesdigital

New member
True in the UK we don't have the vast landscapes of somewhere like China, or Australia, (OK you expected me to say America ) but generally speaking for 'big landscapes' that include a point at infinity I've still always focused in the conventional way, on something one third into the frame and use small aperture DOF to make everything sharp front to back. -250swb


What about the sweeping vistas of Northern Ireland or the stunning beauty of the coast of Scotland, known for its dramatic light and clouds? Actually, the UK is on my short list for photo destinations...again! The advantage of LF is that you don't have to use a camera in the conventional way. The use of front tilt will get both near and far objects sharp. Adding a small aperture will help, while knowing the diffraction limits. Mounting a 35-47mm lens on a 4x5 everything becomes a vast landscape!
 
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250swb

Member
What about the sweeping vistas of Northern Ireland or the stunning beauty of the coast of Scotland, known for its dramatic light and clouds? .......Mounting a 35-47mm lens on a 4x5 everything becomes a vast landscape!
Good point, and of course there are the tracts of wilderness in the Balti desert around Birmingham and the scrumpy swamps of Somerset. Put a 35-47mm lens on and you can make a landscape look like a sweeping vista from somewhere else in the world, but does it say more about the lens than the place?

Steve
 

RodK

Active member
Infinity is a non number. But for any formulas to work, a distance for infinity must be set.
Only aerial or satellite cameras may approach any distance we might believe is true infinity.
The infinity setting for each manufacturer is different. A good infinity distance is a stable detailed object such as a cell phone tower or Power pole scaffold, or a very detailed building at a distance of about 800-1000 meters or a 1/2 mile.
If you go longer you will find your near DOF for near objects, suffers and if shorter your far objects will, suffer as well.
Remember if you look at a scene in nature, objects at 1-15 miles are not as sharp as closer objects anyway.
Once you find your focus, and I would refocus several times until I consistently came to the same place on the bed or rail, before permanently marking it.
If your camera has rear focus, always use this feature. Front focus swells and shrinks the objects you are trying to focus as you move the knob. This causes optical confusion for your eye/brain and makes it more difficult to find sharp focus.
So that is also why I recommend several tries for consistency and accuracy.

While testing to find infinity you can also lay out a tape measure of 10-15Meters or 25-30 feet, from under your tripod, pointed at your infinity, and after finding sharp focus, make an image and study the image, either film negative/positive or digitally, to see what your near plane is for that lens at your shooting aperture.
A personal Hyperfocal for that lens!
Hope this helps,
Rod
 
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