smieglitz

Obtain a lens board and cut the hole so the lens just barely fits the hole. Most lenses have a slight collar just in front of where the flange would attach. If you abut this against the hole you can then take several screws or bolts/nuts distributed around the lens hole and use washers to overlap this collar slightly and hold the lens against the board by tightening down the screws/bolts. The pressure from several washers should hold the lens in place. It ain't pretty but it is a cheap way to get the job done and works for many lenses, at least with wooden boards. The aluminum boards might be challenging with this approach. Small machine bolts and nuts for making model airplanes might be useful wih the metal boards and can probably be found at a hobby shop.

 

You could also invest in a lens mounting iris diaphragm made specifically for this purpose though one small enough to fit a Graphic board might be extremely difficult to find and quite pricey as well.

The Vitax is a Petzval design and the knob shifts the rear element presumably like the Dallmeyer Patent Portrait lenses' twist mechanism. You can find info on these lenses by visiting the cameraeccentric.com website.

 

Being a Petzval, the Vitax should be very sharp in the center with a rapid transition to a zone of pronounced field curvature towards the edges. I wouldn't call it nor the Verito "soft-focus" lenses though. The Vitax is very centrally sharp and the Verito is diffused and dreamy with its chromatic abberation.

 

The Verito effect is hard to describe but it is definitely not soft. It strikes me more like the halation effect one gets from infrared film. The Verito may be a double meniscus lens IIRC. It is also convertible so the design and effect is quite unlike the Petzvals.

Jan Groover

Here ya go:

 

http://www.electricedge.com/greymatter/archives/00006060.htm

James,

 

As long as we are doing part B, I would suggest you make a viewfinder from a sheet of matboard with an 8x10 hole cut out of it. Holding that viewfinder 12 inches from your eye gives you the crop and perspective you will have on your film with the 12" lens you are using. Look through the card and move around to frame the subject as you want them to appear on the film, then position your camera so that the lens is at that exact spot. (You will also be able to gauge the relationship of foreground and background through the card and observe how this relationship will actually appear on the film.) Given your limitation of a single focal length, you now have the ideal position to take the photo that I spoke of in the previous thread. Focus with the rear standard. Make any bellows extension compensation needed to your exposure reading and take the photo.

 

See it first, move the camera there, focus with the rear standard, meter and shoot. SOP. Simple.

Your perspective is determined by your position in 3-dimensional space, either where your eyeball is or, in the case of a camera, where the lens is located in space. You move the lens and you change your perspective. If you want to keep the same perspective, focus with the rear standard. Should you not care about taking the photograph from the ideal physical position in space (with its requisite subject distance, magnification, image size, extension, etc.), then go ahead and focus with the front standard.

Consider that 11x14 is the first format where you can capture a full, life-sized, head-and-shoulders portrait image without enlarging. The subject actually fits and fills the sheet.

 

Also, I don't find enlarging fun at all and the absolute quality of a contact sheet can't be beat. From my point of view a better question might be: "Why choose a small format that causes you to invest in a lot of extraneous equipment in order to produce a degraded image in the larger size you desire?"

 

Joe

Another quick way to transfer the Packard between front mounting boards is to use 4 small eye hooks which are screwed next to the clipped corners of the Packard. Just tighten them down until they overlap and hold the shutter snug and turn them back 90 degrees to quickly release the shutter. I've purchased several B&J cameras with this arrangement internally and simply adapted the idea to front-mounted shutters.

Andrew,

 

One trick to control burning and dodging is to create a layer in PS that acts like a mask over your original image. Go to the Layers menu and create a new layer. When the dialog box pops up choose to use soft-light for the blending mode and check the box that says to fill the layer with 50% soft-light neutral color. Now, with this neutral layer over your original image, you can paint on it using the black and white tones (or grays I suppose if you wanted to be more subtle) and these will now burn & dodge areas underneath for you automatically. (This is something I originally picked up years ago during one of Dan Burkholder's seminars in Chicago. He has more tips online at his website although I think he is charging a small fee for access to them now.) Don't like the effect...just paint over it with the opposite tone to correct it until you have it the way you want. You can also adjust the opacity of the painting tools, use gradients or clone tones within the layer to give you a lot of control. Once completed, you can also adjust the contrast or brightness of the overall layer if you wanted by using the layer slider controls.

 

One thing I've found that helps is once I've lightened and darkened with the painting/gradient tools, I generally apply a guassian blur effect on the layer to make the transitions even smoother and eliminate the "tool marks" which are so apparent on your first example. I wouldn't attempt to burn/dodge without using this layer control and I've found it easier to do than making a standard PS "adjustment layer".

"...So if I need my image to be the same as my subject (ratio 1:1) as Joe Smigiel said then I move my subject or lens which ever you like to move and work with first. Move the subject till you get ratio of 1:1 or play around with your lens to get the ratio of 1:1 and then adjust with your rear standard to bring it in focus..."

 

 

 

Villiam,

 

Let me suggest that the easiest way to get 1:1 magnification is to set your lens extension to a total of twice the focal length as measured from the aperture position to the film plane. (Before someone points out this is not how an optical engineer would actually measure the focal length and the precise 1:1 magnification, I know that, but this method will be very close for most non-telephoto lenses. This is just a quick-and-dirty method to approximate doubling the actual focal length.)

 

Once the camera is extended in this fashion, move either the subject or the entire camera (move the tripod) without further adjustment of either standard to bring the subject into focus while maintaining 1:1 magnification. In this special case of 1:1 magnification, the placement of the subject (i.e., subject distance) should equal the focal length since the formula for determining image size gives:

 

Image size = (Focal length x Subject size)/ lens to subject Distance

 

or

 

I = (FxS)/D

 

and therefore

 

D = (FxS)/I

 

If S and I are equal as they would be at 1:1 magnification, D=F

"Perspective is determined by both the lens position and the film plane position."

 

Yes, in the sense that "perspective" also includes the relationships between objects imaged on the two-D surface. It is true that the shape relationships are controlled by both lens position and that of the film plane. I was speaking solely in the sense of perspective representing "viewpoint".

 

What is done to the back of the camera does affect the shape and image dimensions of the subject, but you will never be able to duplicate a certain viewpoint/look unless the lens ends up in the same point in space. Moving the back of the camera, whether to focus or alter the shapes, does not have the same effect as moving the lens position. You can duplicate the effect of front rise for example by utilyzing rear fall and raising the entire camera or duplicate front forward tilt by employing rear backward tilt and pivoting the entire camera forward , but the lens must end up in the same position or the viewpoint/perspective is altered.

 

Focusing with the front standard moves the lens and thus alters not only subject distance and the resultant critical plane of focus, but it also alters the size relationships and the perspective. Focusing with the rear standard brings different subject distances into sharp focus but does not change perspective in the sense of "viewpoint" and the best position to take the photograph. To say they are equivalent operations, as others have done above, is erroneous.

"Nonsense! The magnification is changed if you change the lens. The perspective is changed if you move the camera.

 

There is no difference in focusing with the front and or the back standard."

 

 

 

Sorry but no Tito. A simple example to clarify: take a 100mm lens and focus close so your lens extension is 200mm. You are now at 1:1 magnification (=image size/subject size). If you keep move the lens even closer to your subject, i.e., focus using the front standard, you increase the image size relative to the subject size and your magnification increases (as well as the overall extension, the extension exposure factor and back focus). Move the lens back and the magnification decreases. A 100mm lens at 300mm extension has a magnification of 3:1, while at 150mm extension the same lens has M= 1:2.

 

And only the position of the lens determines your perspective. Nothing else. As long as the lens stays in the same spot, your perspective will remain the same. You can change lens focal lengths and this will affect the angle of view, but your perspective will remain the same. A different focal length ("changing the lens") will also affect magnification, but not perspective as long as the lens position doesn't change.

 

Now, if you move the camera as you suggest, you move the position of the lens in space and this is what causes the perspective to change. As a result, moving the lens to focus using the front standard changes the perspective. It may be a slight change depending on your subject distance, but it is a perspective change nonetheless.

 

To get the best picture, I repeat that there is a single best position in space for the lens. Put the lens there and focus using the rear standard. If the magnification or angle of view is not correct with that lens, then change to a different focal length until everything comes together. That is, after all, the reason why there are different focal lengths - so you can remain in the same prime spot and get the angle of view needed to include/exclude objects in the frame and retain your perspective.

 

One of the frustrating aspects of using a press camera for critical composition in close-up work is that by being forced to use front focus only, the magnification, perspective, and composition continually changes as you make the focus and subject distance adjustments back and forth. This problem is solved with even the simplest tailboard camera with fixed front standard and adjustable rear focus.

 

Joe

When you use the front standard to focus, you are changing both the magnification AND the perspective. There really is only one best position to take the picture so find it, put the lens there, and focus with the rear standard.

 

Joe

I said: "In ZS terms you might be giving perhaps N+2 development and rating the 400 film at EI 250"

"

Oops. That should read ...400 film at EI 640..." for an N+2 development change on that foggy day. You want to underexpose and overdevelop in that situation. Sorry for any confusion.

 

Joe

"Since I don't have a densitometer..."

 

Mac,

 

Purchase (for ~$9) a Stouffer 21-step density wedge (if that is not what you have already) and have the densities read by a local lab or ZS photographer. Record the density values for future use. This will give you a reference that you can visually compare your test films to and determine the densities achieved by different zones. The steps of the Stouffer wedge begin around a density of 0.04 for step 1 and increase by about 0.15 density per step (= one-half stop per step) all the way to around 3.0 for step 21. You might also invest in a Wratten #96 0.10 neutral density gel filter to use as a visual comparator for the zone I density target value. You'll be amazed how accurate your eye can be when comparing two film densities on a light table. Using two white index cards with a hole punched out of each and placing them over the respective film densities makes the comparison even more accurate.

"Does that 1/3 stop adjustment aim to keep middle values like zone V where they belong..."

 

Mac,

 

If you read "The New Zone System Manual" by White, Zakia, and Lorenz you will discover a discussion of technique where a middle zone stays fixed and the other zones fluctuate around it. They call this technique "Bi-Directional Contrast Control" IIRC. When I think of keeping a middle zone density constant like this, I think in terms of a seesaw with both ends rising and falling in opposition with changes of exposure and development. With different combinations of exposure and development, e.g., underexposure and overdevelopment vs. overexposure and underdevelopment, one can keep a constant density value for any single zone if desired. All the other zones will have widely different density values on the two films if compared.

 

OTOH, I envision the traditional Zone System practice as sort of "nailing down" the shadow end at Zone I and net density of 0.10 above fbf, and letting the mid and upper zones rise and fall in relation to this tethered shadow point as development is varied.

Mac,

 

A couple clarifying points perhaps:

 

1. You said: "Your film speed you select determines where you will have detail in the darkest areas of the scene. Zone III represents this threshold." Actually, the EI/film speed point is based on Zone I in the ZS, not Zone III. Technically, the exposure threshold (where the film first responds to exposure) actually is below the value for zone I on the characteristic curve. Most ZS users look for a net density of 0.10 above filmbase-fog to define the speed point. Adjustments to development will shift the position of this point on the characteristic curve as I've stated in my previous answer.

 

If you were to take your several stepwedge tests and plot the data as a series of curves on the same sheet of graph paper, you would see the curves rise a bit in the shadow areas with extended developments even though shot at the same ISO so that the 0.10 net density point shifts to the left with increased development and therefore occurs at smaller effective EIs.

 

Most workers are concerned with getting full shadow detail in zone III, but that is not the basis on which their EIs are determined. Most would use the position of the 0.10 net density value as the determinant of EI. If that EI is used, chances are very good that zone III will always have significant detail and full texture if the visualization of zone III and the metering has been done properly.

 

2. You also asked: "Does that 1/3 stop adjustment aim to keep middle values like zone V where they belong, or does zone III actually move that much?" No is the answer to that question. The ISO shift aims to keep the value of zone I in place at a constant density value of 0.10 above fbf. The other zone values including zones III and V will drift both visually and with respect to their density values. However, the higher zones drift more than lower zones. In this respect, all the Zone System really is is a twist on the old adage "Expose for the shadows and develop for the highlights." Again if you plot the tests on the same sheet you will observe how the density range between any two zones increases at the same exposure level if you increase development. (For example at zone III exposure you will see a minor difference in density between the 5 minute curve and the 10 minute curve. But if you look at zone V, the density spread between the two curves is greater, and it is greater still at zone VI, and Zone IX, etc.)

 

3. One final point that is often overlooked in discussions of zone sytem and film testing: Just like you need to have some criterion for determining the effective EI (i.e., a net density of 0.10 above fbf at zone I vs. net density of 0.15 above fbf at zone I) you also need to define what the terms N+ or N- mean to you personally. Are you looking to raise zone V to the density of zone VI for N+1 development, or are you basing N+1 on the development shift from zone VII to Zone VIII? Those two cases will produce different development times and probably different EIs. The same holds true for contractions. Is N-2 from zone IX to VII or from Zone VIII to VI or VII to V? Each practitioner needs to define these criteria for themselves. That's why just following book recommendations often doesn't work and merely confuses.

 

The point of the zone system testing is to personalize film exposure and development methods for your own way of working. It is not to simply copy Adams, or White, or Schaeffer or Johnson or Bond or... It is however to get an individual eventually to the place where the technique becomes something almost entirely in the background and the concentration can be on the visual scene before them rather than on equipment or darkroom. A quick close read of Adams in "The Negative" reveals that he thought visualization was the key to the zone system and the most important thing to gain from it. He says so in the opening couple pages of "The Negative." All the other stuff is really secondary and has been taken and blown way out of proportion and overcomplicated. It really is just"expose for the shadows and develop for the highlights, and there are several ways to get there. The "systems" are just codified differently. Adams' Zone System is one, Davis' "Beyond the Zone System" another, and Kodak's (or Mortensen's) "ring-around" testing will all produce useful results.

Yes and Yes to your questions.

 

As you adjust your development to bring highlights into the proper zone, you will shift film speed slightly. In general, for each +1 stop increase in development, adjust your film speed higher by 1/3 stop before exposure. For example, expose TMAX 400 at EI 500 if you will give N+1 development. For N+2, rate the film at EI 640, etc. For contraction the same rule will generally hold. If N-1 development is to be given, rate the ISO 400 film at EI 320 and so on. Of course, one of the points of the film testing is to determine proper EI settings for various conditions and developments. You may find your personal results differ slightly from the recommendation I've given above as they are just generalities and not specific to your equipment and methods.

 

That leads into your second question. Because individual equipment, methods, and materials differ, you need to run the tests to determine your personal settings.

 

Having gone through all the testing several times I can also relate that one can approximate the results of ZS practice in general outdoor photography by simply noting the sky and shadow conditions and adjusting the EI and development accordingly. For example, on an overcast gray day with indistinct shadows, you may find yourself underexposing the film and overdeveloping it. In ZS terms you might be giving perhaps N+2 development and rating the 400 film at EI 250. On a bright sunny day with distinct hard-edged shadows you'll be overexposing (lowering EI) and underdeveloping (N- contraction development) to adjust contrast.

 

The big difference is the latter procedure does not take into account the subject values as ZS measurements would do. Also, they are just general guidelines for out-in-the-open situations and won't help if you are doing interiors or studio settings, photographing in deep woods or other low light conditions, etc. But, for a novice ZS worker the above may provide a quick reality check as to whether you are interpreting the scene correctly. For a hazy day, push (higher EI and increase development) and for a sunny day, pull(lower EI and decrease development).

Hi,

 

The following film holder specifications were recently pointed to on an earlier

thread in this forum:

 

http://home.earthlink.net/~eahoo/filmhold.html

 

I'm wondering if anyone has the specs for 7x17 holders? I'd like to attempt

making a 7x17 camera but would like it to match any applicable current

standard.

 

If there is no standard, I'm hoping someone might be able to supply actual

measurements (width, length, distance to light baffle tab, distance to exposure

field, T-depth, etc.) from an existing holder they may possess. Thanks.

At 1:1 magnification you have extended the lens twice its focal length and the

extension exposure factor is 4x or 2 stops. At an extension of 1.4 times the

focal length you have an exposure factor of 2x or 1 stop.

 

The extension relationship works like the f/stop sequence so that every time

you increase the extension by 1.4 times the focal length, the film will require

an additional stop of exposure compensation. (This works with any focal

length BTW.) At 2.8 times the focal length your extension factor will be 8x or 3

stops and so on.

 

The most frequent compensation adjustments typically will occur between

infinity and 1:1 magnification. Based on the above relationship and knowing

these two limits, it becomes easy to estimate an exposure compensation

factor by just eyeballing the extension of the lens.

 

For example, a 10" lens extended out 14" requires an additional stop. By 20"

it requires two stops, so at 16" I'd give it about +1 1/3 stops. At 12" I'd guess

about +1/2 stop would be appropriate. This matches pretty well with the

extension factor dial in the Kodak Pro Photoguide.

"The others' suggestions of placing the trunks against a white background is also good"

 

Excuse me. That should read "The others' suggestions of placing the trunks against a dark background is also good." Sorry for any confusion.

Ryan,

 

Your last comment perhaps gives some insight into at least part of the problem. By overexposing you reduce contrast and coupling that with underdevelopment you get even less contrast. In addition, an overcast day has lower contrast as well so you are doing 3 things that lower the contrast of the scene. Generally, an overcast day or other low contrast lighting situation calls for slight underexposure coupled with overdevelopment. You've done just the opposite. However, in this situation my guess is that you simply need to meter carefully and expose and develop normally, or perhaps slightly overdevelop the film although I seriously doubt the latter will be needed.

 

I'd meter the shadowed snow area and go with that exposure in a bright sunny scene. This will put the shadowed snow value at middle gray (Zone V) and the aspens and bright snow will probably fall on zones 7 and 7 1/2 or so. Check out the value of the shadowed snow in Riddell's photo to see the effect of such placement. Again, I suspect that normal development will be in order.

 

You might also try using a polarizer to knock down reflections on the snow and thus deepen the apparent snow value a bit without affecting the relative brightness of the tree trunks.

 

The others' suggestions of placing the trunks against a white background is also good.

http://www.hubphoto.com/packard-shutters.htm

 

(Note that you can also purchase synched Packards.)

 

Packard Shutters are available in many large sizes. I've front-mounted one with a 5 inch diameter hole to my 18 inch Verito lens and another smaller one to an 8 3/4 inch Verito. To mount them behind a large lens requires a very large lensboard. (In the case of the 5 inch diameter Packard, the lensboard needs to be 9 inches square.) Front mounting is more adaptable although perhaps not as convenient in the long run.

 

Here's a couple helpful links on front-mounting Packards or building a lensboard box for them:

 

http://mysite.verizon.net/fowler/photo/packard1.htm

 

http://mysite.verizon.net/fowler/photo/packard2.htm

Plan B: Buy some Kodak Hypo Clearing Agent then mix and use according to the package directions (dilute 1+4 for use from the mixed stock solution). The stuff is mainly sodium sulfite and will work fine for clearing Polaroid p/n films.

If you are metric impaired buy a pound of sodium sulfite and it will be equal to 454 grams. Measure the contents into another container using a tablespoon and divide 454 by the number of spoonfuls it takes to empty the package. That will give you the number of grams per tablespoon.

 

A liter of water is equal to just about one quart and the liter of water will weigh 1000 grams. To get close to an 18% solution you would need 180 grams of sulfite in a quart of solution and you could determine the amount of tablespoons needed from the measurement done previously.

 

Or, you would need ~720 grams sodium sulfite per gallon (@180gm/qt X 4 qt/gal). Therefore, if I've done my math right, a pound of sulfite will make up about 80 ounces of an 18% solution sulfite solution. Mix the pound package into a half gallon of water and add additional water to bring the solution up to 80 ounces. That will be very close to the recommended solution.