How to shoot long interiors with columns in foreground?

[macmx]

I am relatively new to LF, so I hope someone can help me.

I am going to do some interior shots (150mm and 90mm lenses) that feature long hallways, which means I will have to have sharp focus at approx. infinity). However, the interiors also feature some vertical columns in the foreground, which also need to be sharp. This means that I cannot use my tilt to create an increased DOF, since the top of the columns would then be out of focus.

How do I solve this? Is my only option to just use my shift and then stop down the lens a lot? Since there is only a little natural light, I am hesitant to do this since it would give me an exposure of several seconds - I would rather keep it at 1 sec or above.

If stopping down is my only option, where is to optimal point to set my focus before stopping down? On my Hasselblad, I would normally focus on the foreground and use the hyperfocal distance to set my aperture, but as large format lenses don't have these markings, this is not possible.

Any help would be much appreciated. Thanks!

Mc

 

[David A. Goldfarb]

Stop down a lot and focus around 1/3 into the frame, but try to check on the groundglass to see if everything is in focus at the working aperture. Put a flashlight in the scene for focusing purposes, and move it around as needed to check multiple locations, if you need to.

Long exposures are par for the course. Don't forget bellows factor for interiors.

 

[paul_c5x4]

If stopping down is my only option, where is to optimal point to set my focus before stopping down? On my Hasselblad, I would normally focus on the foreground and use the hyperfocal distance to set my aperture, but as large format lenses don't have these markings, this is not possible.

Large format lenses have a hyperfocal distance, as do all other lenses. You just need to draw up a little table for each lens and carry it around in your notebook - I used one of the online DoF calculators and did a table for each of my lenses.

Depending on how close the foreground columns are, you may well struggle to keep the exposure under one second. In which case don't forget to factor in reciprocity failure.

 

[polyglot]

You will get the greatest total DOF with no movements, i.e. with the lens centred and straight like it would be on a boring not-a-view-camera. At that point, it's just a matter of plugging numbers into a DOF calculator to figure out where to focus and how far you need to stop down.

Hyperfocus is a really easy approximation to use if you want to get infinity in focus and/or don't want to use complicated calculators and tables.

You can still use hyperfocal calculations etc without lens markings. You just need to measure, pace-out or just guess the location of a feature (one of your columns?) at the appropriate distance and then focus on that with the GG.

 

[darkosaric]

Don't forget bellows factor for interiors.

Hi David,

I don't use large format, but can you please explain to me what is this bellow factor for interior?

 

[ic-racer]

Check out the method of Paul Hansma for focusing the view camera.

Also, you can obtain The Ins and Outs of Focus by Merklinger free on the internet.

 

[Larry H-L]

Bellows Factor is the bellows extension, measured from front to rear standard, squared; divided by the focal length (in the same units of measure), squared. That will give you the factor. 1x = 0 stops, 2x = 1 stop, 4x = 2 stops, etc.

Example: your extension measures 10 inches. You are using a 5 inch lens. 100 / 25 = 4x, or 2 stops.

All of that said, bellows factor will be minimal in most interior scenes with a wide lens.

Reciprocity failure will usually be a bigger exposure adjustment in a dim interior when stopped way down.

 

[removed account4]

hi darko

here's a meaty thread for you that explains it all, in lots of different ways ...

this can be easy if you want it to be

if you got a 5.6 inch lens and you extend the bellows to 8 inches you need to add a stop
if you got a 5.6 inch lens and you extend the bellows to 11 inches you need to add 2 stops

if you got a 210mm lens and you extend 320mm you ain't gonna be far off if you add 1 stop
if you got a 210mm lens and you extend 450mm you ain't gonna be far off if you add 2 stops

see the pattern, forget about inverse square law this is quick and dirty and if you can be more accurate you have some super calibrated lenses and need to calm down

if you look under "fractional stops"
http://en.wikipedia.org/wiki/F-number
you will see all the f-stops which makes it easier if you have a strange FL lens that isn't
an exact fstop number

have fun !
john

 

[darkosaric]

"fractional stops"

Thanks John, it is clear now .

 

[RobC]

Hi David,

I don't use large format, but can you please explain to me what is this bellow factor for interior?

The Aperture settings on all lenses relate only to focus at infinity. When you focus on anything closer than infinity then you have moved the lens further from the film plane. i.e. used a longer focal length distance to the film. You have not altered the physical size of the aperture. You have however altered the effective aperture value because aperture value is the ratio of its diameter to the focal length.

for example: Take 100mm lens @ F4 focussed on infinity. the aperture diamater is 100/4 = 25mm. Now focus closer so instead of the lens being 100mm from the film it is 125mm from the film. The 25mm diameter of the aperture hasn't changed. To find what the actual aperture value is now you use 125/25 = 5.
So by focussing closer in this case you have also from moved from F4 to an effective F5. That is what bellows factor is all about and you may need to recalculate exposure time to compensate for it.

When using through the lens metering it is taken care of automatically. It really only becomes siginficant when focussing at closer distances because that means you move the lens further from the film.

 

[Ian C]

The hallways might be long but the farthest visible point doesn’t extend to infinity.

I suggest reading post #77 here on page 8 for some ideas and a couple of examples.

(there was a url link here which no longer exists)

If you have or can estimate:

A = the nearest point (measured from the lens) where DOF must begin

B = the farthest point to which DOF must extend

f = the focal length of the lens

c = the circle of confusion diameter you choose for the format (4” x 5” usually uses 0.1mm)

With these we can calculate:

s = the optimal subject-to-lens distance (subject to first nodal point of the lens)

N = the aperture that gives us this field as defined by A, B, f, and c

If you don’t know the calculations, simply post A, B, f, and c and I can calculate s and N in a few seconds on my programmable calculator (which has the required program installed).

 

[RobC]

The real answer to your question is to use the right tool for the job. Use a MF or even 35mm camera with a very wide angle lens so that you get large DOF and, if possible, move as far back from the subject as you can so that you can get the columns and end of hall into focus at same time.

There is classic example of handling this in the Adams The Negative (approx page 170) where he has two pianists who both need to be in focus at different distances.

Your scenario may be more difficult. You gotta do the calculations. It ain't as simple as just turning up with a big camera.

 

[macmx]

Thanks for the replies everyone. That was the answers I was expecting. I was hoping that there was some easier way to use the hyperlocal distance method without the need for tables, but I think that I will be okay. I guess there must be a DOF calculator for iPhone that features 4x5.

Compensation for bellows is of course always a factor, but I think it will be minimal this case.

Thanks again!

 

[Doremus Scudder]

I am going to do some interior shots (150mm and 90mm lenses) that feature long hallways, which means I will have to have sharp focus at approx. infinity). However, the interiors also feature some vertical columns in the foreground, which also need to be sharp. This means that I cannot use my tilt to create an increased DOF, since the top of the columns would then be out of focus.

How do I solve this? Is my only option to just use my shift and then stop down the lens a lot? Since there is only a little natural light, I am hesitant to do this since it would give me an exposure of several seconds - I would rather keep it at 1 sec or above.

If stopping down is my only option, where is the optimal point to set my focus before stopping down? On my Hasselblad, I would normally focus on the foreground and use the hyperfocal distance to set my aperture, but as large format lenses don't have these markings, this is not possible.

Mc

Mac,

I've changed around the emphasis on your OP a bit. I'll address them one-at-a-time.

First, yes, in the situation you describe, tilts are pretty worthless. That said, if you have a longer expanse of floor before the vertical columns, a tiny bit of tilt may help somewhat in achieving a larger aperture and cutting down on exposure time. You'll have to check by tilting a bit, finding near and far focus points and checking focus spread. A smaller focus spread lets you use a wider aperture (see below).

Secondly, (as an aside) I assume you mention shift for a good reason. We use rise to keep verticals from converging and can use shift to do basically the same horizontally. This, however, places the optical center of the image to one side, affecting the perspective from side to side differently. That's great if that's what you want (I do this all the time on purpose, a la Canaletto et al.), but if you're after symmetry, then placing the camera well in the center of the scene is what you want to do. Stopping down in situations like you describe to get the needed depth-of-field is often the only option.

As for longer exposures: If you have to stop down to get depth of field and you can't use faster film (an option sometimes!), then you're stuck with long exposures. Get the reciprocity tables for the film you're using and simply apply the correction needed for longer exposures; it's easy. A one-second exposure and a 30 second exposure both need the subject to be relatively still.

On to the crucial point: how to choose the optimum focus point. Hyperfocal charts and DoF tables are nice, but I prefer to use the focus-spread method. This simply requires that you measure the difference on the camera bed or rail between standards when focused on the the nearest and farthest objects you want to render sharp. This is your focus spread. You then set the focus exactly halfway between the extremes and choose an aperture based on the total focus spread.

The method is explained in detail here: http://www.largeformatphotography.info/fstop.html

However, my chart for 4x5 may help you. In the following D(mm) = the distance of total focus spread in millimeters. F is the f-stop expressed as a decimal. It is more accurate than needed; just extrapolate to the nearest 1/3 stop or whatever, erring on the side of smaller aperture.

D(mm) -- F
1 ----- 16.6
2 ----- 22.6
3 ----- 32.2
4 ----- 32.6
5 ----- 32.9
6 ----- 45.2
7 ----- 45.4
8 ----- 45.6
9 ----- 45.8
10 ---- 45.9
11 ---- 64

This optimizes DoF and diffraction. The largest print you can make depends on the original focus spread (smaller = more resolution), your tolerance for blurriness in the print and viewing distance.

Hope this helps.

Doremus

 

[macmx]

Hi Rob,

I need large format for the camera movements. I think large format is a pretty well proven tool for architectural photography.

 

[macmx]

Doremus,

Thank very much. That was a very helpful reply. I will definitely use that.

You are correct: I meant to say rise, not shift. I need the rise to keep the columns vertical.

 

[RobC]

Methinks you you need to provide some distances and heights for anyone to give you any thing reasonably accurate. You will certainly need to use you 90 lens unless you are quite a way back from the columns.

 

[removed account4]

Thanks John, it is clear now .

my pleasure darko !
have fun
john

 

[David A. Goldfarb]

Thanks for the replies everyone. That was the answers I was expecting. I was hoping that there was some easier way to use the hyperlocal distance method without the need for tables, but I think that I will be okay. I guess there must be a DOF calculator for iPhone that features 4x5.

Compensation for bellows is of course always a factor, but I think it will be minimal this case.

Thanks again!

If you're shooting an interior, you probably don't need to focus at infinity (unless you're also looking out a window and want the outdoor scene to be in focus), so hyperfocal distance isn't the best use of your limited DOF.

An iPhone app that I like for this is pCAM, which is expensive for an app, but designed for cinematographers and does many useful calculations that can be used with any still or motion picture format, including your own custom formats. The DOF calculation screen also gives you a diagram that shows how far in front and how far behind the focal plane will be in the DOF zone that makes it easy to visualize. It also has a focus target, so you can put your phone into the scene with the target displayed and check it with a loupe on the groundglass.

 

[M Carter]

When I shot a fair amount of 4x5, I'd usually bring a 6" 750 or 1k fresnel. I'd keep it near the camera and aim it at focus points to triple check focus if the location was fairly dark. Really made a big difference. I didn't use it for exposure, but just as a focusing light. Small enough to be simple to use, but a lot of kick compared to nothing.

A polaroid back was also really handy back then… sadly 4x5 polaroid is a memory...

 

[norm123]

Swing is maybe an option. Focus on near point. Swing until far is good enough. Repeat until everything looks sharp.

Here an example of this method.

https://www.flickr.com/photos/norm1thestorm/16295063983/in/dateposted-public/

Regards