Large Format Camera - Focusing architecture (in a hangar)

[gigi75]

Hi People,
before I am going to photograph I am studying, knowing more or less the scene, where to focus to keep the whole image (reasonable) sharp. I am going to a hangar where the main subject (big pillars about six meters large and four meter height) are placed all around the perimetry wall. My idea is to stop down at f/32 using a 240mm lens. Now, to keep all sharp where I need to focus (keeping whole pillar in the image. Tilt cannot be used (the roof will be not sharp). Can I use the 1/3 rule or it is better to focus on the subject and stop down at f 32, knowing that I will be at 8 or 10 meters from the pillar?


Linhot camera IV ( 5x4 ) / lens 240mm Fujinon

Thank you

Luigi

[David Schaller]

Until someone more knowledgeable replies, I would say you should trust what you see on the ground glass. You might want to bring in a strong flashlight, if you are allowed, to help you get everything in focus. I would also take more than one lens, if you can’t move your camera position at will.

[Bob Salomon]

If you focus on the subject most of your DOF will be behind the subject. Is that what you want.

[Bernice Loui]

Why a 240mm lens on 5x4 ?

Greater the magnification aka longer focal length, more difficult to keep the entire image area in focus. In cases like this it might be better to back up, use a shorter focal length if possible before resorting to stopping down lots in an effort to maintain a large area of "perceived in focus".


Bernice



Hi People,
before I am going to photograph I am studying, knowing more or less the scene, where to focus to keep the whole image (reasonable) sharp. I am going to a hangar where the main subject (big pillars about six meters large and four meter height) are placed all around the perimetry wall. My idea is to stop down at f/32 using a 240mm lens. Now, to keep all sharp where I need to focus (keeping whole pillar in the image. Tilt cannot be used (the roof will be not sharp). Can I use the 1/3 rule or it is better to focus on the subject and stop down at f 32, knowing that I will be at 8 or 10 meters from the pillar?


Linhot camera IV ( 5x4 ) / lens 240mm Fujinon

Thank you

Luigi

[Michael Kadillak]

Why a 240mm lens on 5x4 ?

Greater the magnification aka longer focal length, more difficult to keep the entire image area in focus. In cases like this it might be better to back up, use a shorter focal length if possible before resorting to stopping down lots in an effort to maintain a large area of "perceived in focus".


Bernice

Agree. I would think that a wide angle lens around 90mm on 4x5 would be a much better option as it relates to critical focus and coverage.

[LabRat]

Also look up hyper focal distance tables for your FL... Then set a light towards the lens using a tape measure the distance on your table... Then just watch the edges to frame it...

The prior suggestions of using a WA lens gives you more focus breathing room...

Steve K

[Doremus Scudder]

Since you're studying, you should definitely study the article on the LF home page about selecting the right f-stop: https://www.largeformatphotography.info/fstop.html . The article on focusing on the same page is good too.

I've been using this method for years with total success.

Keep in mind that if you want to keep vertical parallel lines parallel in your final print, you need the camera back to be oriented parallel to those lines. If anything in the foreground is nearer you than the highest near object, you can use a bit of front tilt to put the near foreground object and the nearest tall object on the same focus plane. That will help a bit with getting everything sharp. Otherwise, it's "focus near, focus far, split the difference and choose your optimum f-stop based on the focus spread." It's all in the article linked to above.

Best,

Doremus