4x5 metering & Compensation [Archive] - Large Format Photography Forum

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Trevor_5267

6-Mar-2005, 15:00

Nigel Smith

6-Mar-2005, 16:10

Surprised no-one has replied... so here goes (I'm a newbie too)

1. Meter the subject, using whatever method you have and understand, spot meter, incident meter, sunny 16, another camera. I guess you could meter the ground glass if you calibrated and tested to do that but I've never read any reference to that but I'm guessing a std meter (maybe using a spot meter) reading off there won't be accurate.

2. Lengthing the bellows requires more exposure to compensate so in your example you'd open the lens from f11 to f8, or adjust shutter speed to accomodate the increased exposure.

Leonard Evens

6-Mar-2005, 16:22

1. Exposure meters for large format photography are used in basically the same way as for any other camera. The main difference is that you are unlikely to find one with a built-in exposure meter.

For outdoor use, taking pictures of landscapes or buildings, for example, you would use a reflective light meter which you would point at the subject to determine exposure and f-stop combinations. (Many old time photographers don't use any meter at all, judging exposure on the basis of experience and a few simple rules.) The position of the meter is not usually specially critical, but it would generally be near the camera. Many large format photographers use spotmeters, often in conjuction with Ansel Adams's Zone System. This way you can analyze the distribution of highlights, midtones and shadows and from that determine proper exposure. For portraiture and some commercial applications, it is sometimes more useful to use an incident light meter at the position of the subject. If you use flash, you might use a flash meter. Finally, there do exist a few special meters which can take readings directly off the ground glass, but few people use them.

2. When you have a significant bellows extension, you are reducing the light intensity at the film plane because the lens is further away, and the same light is spread over a wider area. That means you have to increase exposure, either by increasing the time appropriately or by opening the lens up by the appropriate number of f-stops or fractions of an f-stop. Smaller f-numbers correspond to larger apertures. So, in the example you gave, where f/11 was the appropriate f-stop when focused on a distant object, you would open up one stop by going from f/11 to f/8.

You might study one of the standard books about large format photography. Steve Simmons's Using the View Camera is a good introduction, and Stroebel's View Camera Technique is the most comprehensive reference.

Bruce Watson

6-Mar-2005, 16:50

http://search.barnesandnoble.com/booksearch/isbnInquiry.asp?userid=kr4VVt3BJE&isbn=0821221868&itm=6

Knowing where to point a meter is just the first part. The second part is knowing what to do with the information it returns. This leads directly to the Zone System. The above book explains it pretty well. The three Ansel Adams books are highly recommended.

Trevor_5267

6-Mar-2005, 17:56

Dear All....

Thank you SOOOOO much for your time and responses......

Will fly down to barns and nobles to search for that book.

=)

thank you once again.

Ron Marshall

6-Mar-2005, 18:13

Trevor, If you are doing B+W and processing yourself stick to one film and developer for a while and take a test roll to calibrate the ASA for your particular developing technique. Bruce Barnbaum covers this in his book, but I have seen it many places and it is a simple proceedure, you must waste one film.

steve simmons

6-Mar-2005, 20:42

Greetings to all...
i recently got hold of my late grand dad's calumet 4x5, and am terribly interested in 4x5 photography as a whole..

I'm however quite puzzled about the metering process and was wondering if anyone could provide me with any help with regards to metering.... or perhaps direct me to some resources.

1. Where do we meter from? off the subject? in front of the lense? or off the ground glass, and what is the difference?

Generally of of the subject from the camera's position

2. For the bellows compensation where we apply the formula, "For example: a 210mm or 8" lens with 11" of bellows requires a one stop exposure increase (the difference between f8 and f11)." Does this mean we increase the F stop from the original F8 (BEFORE THE CALCULATION)to the new F11, or from the original f11 to the New F8?

See the recent thread called View Camera Magazine. Do not let people snow you with math. My handy way of figuring this is in that thread.

If you are new to large format here is some suggested reading

User's Guide to the View Camera by Jim Stone

Large Format Nature Photography by Jack Dykinga

Using the View Camerathat I wrote.

all are books and should be available on Amazon.com

There are several free articles on our web site

www.viewcamera.com

steve simmons

steve simmons

7-Mar-2005, 07:23

Here is my easy formula

for every 25% you add to the infinity bellows extension you add 1/2 stop of exposure. For example if you have a 6"/150mmlens and you have 7.5 inches of extension then add 1/2 stop of expsure. Normallyyou can add the extra exposue with time or by opening up. However, if you are using strobe then adding time does not help and you must open up with your f-stops.

If you have a 6" lens and you have 9" of extension then add 1 stop. If you have 10.5" then add 1.5 stops an if you have 12" of extension then add 2 stops.

This formula works for any focal length lens.

Some people will snow you with math formulae but it is not necessary to know. My formula works everytme.

steve simmons

viewcamera.com

Rob Hale

8-Mar-2005, 15:45

Hi Trevor.

All the above is good stuff, but here are some suggestions which might help.

As a new comer to LF, with no light meter, I solved this problem by the following :-

My elderly Linhof monorail has a Graflok back so I can remove the ground glass assembly and use the slide clamps ( to hold roll backs etc ).

I made a cardboard plate from 6mm (1/4 inch) corrugated cardboard. This is 121mm (4 13/16 inches ) by 152 mm ( 6 inches). This fits in the recess that a roll back fits and can be held by the slide clamps.

I marked out the centre of this plate ( by corner to corner diagonals) and scribed a circle.

The circle is the same size as the lens mounting of an old Minolta xg1 I have. Any SLR camera with a self-lighting light meter read out will do the job. In my case I had dead lens so I removed the lens mounting ring, mounted the ring on the SLR body so I have a boss to fit snugly into the into the circle which I cut out carefully using a sharp razor blade.

How to use :-

I set up my shot. Clamp every thing down. Remove the ground glass back. Mount my card. Set the SLR ASA to the film speed ( later you will learn to read your negatives and may well find you get better results by being 1/3 or ½ a speed slower on your ASA setting than the film speed). Turn the SLR on.

Here is the trick bit. Holding the SLR to the card I refocus thro the SLR's view finder. Reason – The distance from the lens to the metering cell in the SLR needs to be allowed for due the mirror and prism, i.e. you will move the back stand towards the lens. Once focused, I have a light meter reading. There is a choice I can read just the time with the lens stopped or if the light levels are low I can open up the lens to the largest opening – read the time in the SLR and adjust the time to match my required stop down i.e. one time segment slower per f stop adjustment ( smaller opening ). Remove SLR, card and replace ground glass assembly and refocus. ( If the travel on rail is marked you can note the point you started from and can go back to that point then refocus)

I now have a wiz bang light meter but still carry my bit of card and old xg1 and will often use it to set a known datum point.

This system will compensate for bellows extension and with the old xg1 I get an all over grey card reading as if I were using an incident meter. It all so reduces the number of numbers – f-stops – times etc you need to think about while you are learning. If you take notes, which I highly recommend, you will very quickly find out which speeds on which shutters are too fast or too slow. I made up small charts for each lens with 1/3 or ½ stop adjustments listed for the various speeds of my elderly shutters( these go in the back of my note book ).

Have fun and enjoy your new past time.

Regards Rob Hale

Trevor_5267

9-Mar-2005, 21:25

To those that have contributed to this thread..

THANK YOU!!!!!!! i LOVE all your replies, have PRINTED them all out, and carry them in my Large Format Case whenever i go shoot now..

Once again, to all.. a big Thanks...

Largeformat Really has brought back the joy of photography to me.

=)
Trevor