frank_doering

<p>As for testing, the easiest thing would be to go into open terrain with a detail-rich foreground (say, a corn field at his time of year), focus at the most distant object and shoot wide open. If there is significant lack of parallelism, one should be able to discern an asymmetric pattern of sharp focus (not just a the kind of symmetric falloff towards the edges that would be expected at a large f-stop). In particular, there would be foreground stuff equidistant from the camera that's significantly sharper on one side than on the other. A line of leafless trees on the horizon should also give a good indication of any left-right slant in the plane of focus.</p>

<p>Thanks, Richard. This is very helpful and reassuring. If your camera were out of whack anywhere near as much as the one in the official pictures appears to be, your measurements would have shown it because there we are talking about millimeters, not micrometers.</p>

<p>Measurements in Photoshop confirm that the front and back of the camera body in the picture are parallel to within at least 0.1 degrees, while the lens standard is slanted by 1.2 degrees. Perspective foreshortening cannot explain the 1.2 degree slant (unless the camera body is thicker on the left than on the right, which is unlikely). The slant would introduce significant and obvious fosusing errors. If focus is set at 5m, the plane of sharp focus for a 6x7" frame would slant from 3.23m on the left to 11.31m on the right; for focus at 2m, it would slant from 1.67m on the left to 2.57m on the right; at infinity focus and anything but the smallest apertures, the distant horizon would be out of focus on both sides. This sort of thing should be obvious in the images. <br /> <br /> The evidence from flickr is inconclusive. I found only very few images in which I can discern with some confidence the orientation of the plane of sharp focus. Where it appears slanted, it goes in the opposite of the predicted direction (warning: large files):<br /> <br /> <a href=" 1</a> : the large background tree is sharpest by far in the top left corner; so the POSF slants away in that direction.<br /> <br /> <a href=" 2</a> : the plane of sharp focus as traced through the leaves on the ground is closer on the right than on the left)<br /> <br /> <a href=" 3</a> : the curb to my eye tracks the plane of sharp focus, which would imply good parallelism)<br /> <br /> This may be a case where the absence of evidence turns out, on closer analysis, to be evidence of absence. I have the feeling that if the camera showed on average anything like a 1.2 degree deviation from parallelism, then this would show up in lots of scans on the web. <br /> <br /> Enough speculation. Could some owners of the camera chime in, preferably with careful measurements of the camera as well as comments? Does the lens click into place and perhaps failed to do so in the promo picture?</p>

<p>Color rendition is another consideration. Under certain conditions, negative film clearly trumps digital. Take a look at exhibit 1 <a href="http://www.doeringphoto.com/projects/powerplant/info2.html">here</a> .</p>

<p>Thomas, I had the same experience with that Fuji. I sold it cheaply and bought (after some test shooting) a Rolleiflex 6003. The acutance of the negatives is of a different order. I wouldn't accept the excuse that the Fuji has a larger image circle. I have plenty of 4x5" negatives that show considerably more resolution and acutance than my two binders full of Fuji negatives. I wonder what that new Fuji folding camera will be like. The question will not just be lens quality but parallelism. On the photos at the German Bessa website, it looks as if the lens standard is not parallel to the film--but that might be a perspective effect.</p>

Got the get the html spelling right:

 

<a href="http://doeringphoto.com/venice/venice.html">Venice Gallery</a>

Here is a <a ref="http://doeringphoto.com/venice/venice.html">gallery of Venice images</a> taken with the M6 TTL on

Delta 100 and TP.

75mm. Beware: the advertisement says the camera takes standard film holders. It doesn't. It only takes polaroid backs. Standard holders slip out of the clamps.

Half of <a href="http://doeringphoto.com/berlin/berlin.html">this</a> is Leica stuff, the other half is 4x5.

The issue is depth of field. Given identical camera position and identical final print (or projection) size, depth of field depends upon NOTHING BUT THE PHYSICAL SIZE OF THE APERTURE. Your maximum opening on your 50mm lens is 50/1.4 = 35.7mm. Your maximum opening on a 35mm lens is 35/1.4 = 25mm. To get a 25mm opening on your 50mm lens, you stop down to f/2. Ergo, the look you get with the 35mm f/1.4 lens fully open equals the look of the 50mm lens at f/2, as far as DoF is concerned. This is what causes a headache at the wide end. In order to get the angular coverage of, say, a 28mm lens attached to an M7, I need a 20mm lens on an M8. But the wider lens will be at least one stop slower, and in addition I will incur the effect of stopping down one stop due to the conversion factor. So the digital "look" I get amounts to a depth-of-field increase by TWO f-stops (and this is the best case scenario for the fastest lenses around). This is unacceptable if you like shallow depth of field in a wide angle image.

...scanned at 4000 dpi on a Microtek 120tf

80mm EL Planar with Pentax Achromat, Delta 100<div></div>

The only way for me to get pictures that are sharp in the corners with the 58 XL is to shoot

at f/16 or smaller, use a mirror device to align the camera standards, and focus near the

center of the ground glass. ALL view cameras are depressingly imprecise as regards

parallelism. The central focusing point is crucial if your Fresnel lens is mounted in front of

the ground glass (as e.g. in Arca Swiss). I find a slight quality falloff, but nothing dramatic.

 

frank@doeringphoto.com

At Champion. 514.937.3918.

If it is a notch up from the 1800f, then it's still a number of notches down from even a

high end flatbed scanner. I have the 1800f, and 4x5" aren't nearly as sharp as ones from a

shop in Montreal done on some flatbed device. Still quite good for reasonable print sizes.

Thanks everyone for your suggestions, and apologies for the late acknowledgement: I have

been on the road.

Can anyone recommend a printer who is good to work with and can make a superb

archival 3 x 2.5 ft silver-gelatin FB print from an (unsharply masked) Delta 100 4x5"

negative? The print size is beyond what I can do in my darkroom. I live in the sticks, so

location doesn't matter (as long as it's in the US); quality does. I am looking for someone

with whom I can cooperate in the long run. Thanks for your input.

 

Frank

Get two first surface mirrors. Have a hole drilled in the center of one (I use a round one) and place it on a spare lensboard, facing inside the camera. Place the other on a spare film holder (slide removed). Peek through hole and align camera so that the receding mirror pattern is centered. It`s the only way I am able to shoot 58mm, regardless of camera make.

Gary, for what it's worth, check out the thread in the 6x9 lens

department on 55 and 58mm lenses.

Michael`s point about exposure is well taken. But it doesn`t explain the mushiness. Nor does flare explain the mushiness. Camera shake is certainly a worry. As is focusing. But don`t you think that people who make extremely heavy weather about precision and sharpness would control these matters in a test? Shall we ask ALPA or Schneider?

Can anyone explain what is going on in the shootout between Schneider

and Rodenstock posted on the ALPA "No Comments" page below? The

difference would seem to be astonishing.

 

http://www.alpa.ch/digital/index1.html

 

Frank

Thanks for your suggestions. (Note: my Newton rings came from

between the glass and the film, not from between film and

paper.) I'll try one of the older frame designs.

I am having problems with 8x10 contact prints. Because of

Newton rings, I replaced the glass on a Paterson contact printer

with ANR glass. This is slighly thicker than the original glass and

thus receives higher pressure from the foam bed below. As a

result, the glass bends, creating a gap between paper and

negative right in the middle of the print, which results in

noticeable loss of sharpness compared to the edges. Question:

What is a good contact printing frame for someone haunted by

Newton rings? (I seem to have read something at some point

about a frame with an inflateable bubble under the glass.)

Thanks for your help.

Sorry for not getting on the thread any earlier; I'm having

connectivity problems. Thanks for all the suggestions.

 

<p>

 

I think I have found the cause of the problem. The fabric that's

used as a lighttrap on the camera back seems to be a little in the

way. It is fully compressed by the groundglass frame, so that the

frame sits flush with the back. But it isn't fully compressed by the

film holder (which has a wider rim than the groundglass frame

and therefore, I presume, exerts less pressure per square in on

the fabric). As a result, the film holder comes to sit a little further

back than it should. One can actually see a small gap, which can

be closed by pressing on the back from behind.

 

<p>

 

Frank

I am having film registration problems with a Linhof

Technikardan 45S that I suspect will be widely shared.

Calculations based on careful test shots, as well as

measurements with a homemade rig, concur in the conclusion

that sheet film in Fidelity holders comes to sit about 0.5 mm

behind the plane of the groundglass. The discrepancy is too

large to be chalked up to measurement error. The camera back

was inspected by HP in NJ and Linhof in Munich and found to

meet their specifications. So I suspect there is a mismatch

between Linhof specifications and Fidelity dimensions. Btw, no

such discrepancy exists in my Linhof Kardan GT 810. Any

suggestions as how to get this fixed?