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DoF will be dependant on subject distance which would be different with different lens focal lengths and film formats. So unless the OP starts quoting some actual figures for subject distance and focal lengths then I have no idea how anyone can answer the question.

I suspect its a lens problem. DoF means something should be sharp in the subject and if it isn't then it could be a dodgy lens.

you might consider one of these which takes the canham 6x17 back and can take a 72mm lens too. http://walkercameras.com/XL5x7.html

I wish Kodak would do us all a favour and hurry up and die instead of going through this long drawn out death scene with an announcement here and an announcement there. Why doesn't it just top itself and make a clean death of it.

The inner lock rleases the head for sliding up or down. The outer part is rotated for head height adjustment when inner part is in lock position. To lock head solidly, use locking knob under head. Its all in manual I gave you link to...

That's a downright lie. You went on an unprovoked attack and tried to discredit what I wrote in the previous topic and now you expect me not to argue about it. Do you know what hypocracy means. You said You said You said You said If that's not an unprovoked attack I don't know what is. And...

It's all anecdotal evidence where people find what they're looking for. e.g. I'm a photographer and know a photographer who died of parkinsons. It must have been the chemicals he was using. Fact is nobody really knows. I'm not suggesting these chemicals aren't bad for us if misused but if...

when it comes right down to it, most images on film are resolution limited by the film itself combined with the lighting contrast ratio on it. Result is that actually achieving 100 lp/mm on film is extremely difficult regardless of whether your film or lens are potentially capable of much higher...

but there is no depth of field at the negative. We're talking about the thickness of the emulsion layer on a negative of only .12mm thickness which is mostly the film base and not the emulsion. What is the thickness of the emulsion, 0.02mm maybe. And depth depth of filed outside of that just...

all lens WILL produce an airy disc. How much that is altered by other lens abberations and mis alignment we could argue about all year. But as I pointed our in original topic, I was quoting theoretical limits. Aim to get as close to those as possible and you maximise your potential. Aim futher...

Wrong. Depth of Field is at the Object(subject) and not the image(negative or print). An enlarger is a camera taking a picture of a negative. The resulting image is the print. Depth of focus is at the print when enlarging and Depth of Field is at the negative being photographed.

This disucssion is about Depth of Field at the negative. What is permissible as CoC is purely subjective. The real number of interest is the diffraction limit radius (or diameter). Anything bigger than that for acceptable CoC is a loss of print resolution whic is termed by ball park workers as...

you've just made that up clutching at straws.

you can tell me I know nothing all year if you like. But what you aren't capable of, is understanding that the figures I quoted are not mine but are those produced by the software written by an optics expert and not someone who has done a little reading. Once again, if you don't like the numbers...

resolution in print has nothing to do with CoC. Its all about diffraction limit at effective aperture. i.e. airy disc. CoC is for ball park good enough workers.

infact the figures I gave are based on the size of the airy disc at the effective aperture. i.e. virtually no margin for error without compromising print resolution (even if you think you couldn't see it). i.e. the COC = Airy Disc. Anything else is based on subjective choices.

exactly. But depending on how big you want to print, then with LF, magnification factor is often much smaller than with 35mm which I'm sure you're aware of. However, on film resolution of LF is usually less than can be obtained with 35mm so how much you can enlarge from LF is limited by that if...

And don't forget that if DoF is as great as you are suggesting, then AN glass grain would be in focus and show in the print which several people in previous topic say they have never seen.

yeah and? you've plucked 0.5mm out of the air becasue you don't know what the actual figure is. Why don't you calculate ist. A lens doesn't pluck its CoC out of the air. The CoC is variable depending on the lens and aperture and the figures I gave are calculated using that variability. The CoC...

Your 1mm DoF figure is plucked from thin air. Perhaps you should tell us how you intend to set your enlarger so that you get a 1mm DoF. Fact is a lens will give a CoC according to the aperture you set and its resulting affective aperture due to lens extension and that will also determine what...

I prefer to align my enlarger as accurately as possible. Parallel is parallel and not almost parallel is good enough in my book. And perpendicular is perpendicular and not almost perpendicular is good enough. I'd like to know how do you intend to measure within 1mm. i.e. not parrallel but almost...

and remeber that the CoC is the product of the effective aperture. Its not something you can set any other way. So the mere fact of using F5.6 with 6X enalrgement gives an effective CoC which is only 0.038mm. Anything bigger and you are you are throwing away print resolution. Even if you think...

depth of focus is usually way more than required. For the example above it would be + or - 1 mm using my figures and + or - 18mm using above 1mm Depth of Field example. The higher the resolution in the print the better it will look? The smoother is will look. The sharper it will look. Why would...

I really can't be arsed to argue the point. You use your own figures. I will trust the software and what it tells me is optimal and not marginal.

I understand that for digital backs on LF cameras that new lenses with smaller angle of view (AOV) also called image circle, have been designed since digital backs have smaller area than 4x5 for example. But for full frame 35mm cameras I can't see that there is anything special required for...

you are very confident that you know better than Dr Geoff Adams software predicts. I know who is spreading mis-information and whose work I trust. And a quick check in wikipedia says that for macro work that formula you have quoted is suspect becasue it depends very much on the lens design and...

The figures I gave in post #71 at earlier topic were calculated/taken from the software i gave link to. http://www.winlens.de/index.php?id=70 This software was written by Dr Geoff Adams and Rodenstock used to provide the software free at their website. I have no idea what his connection to...

The figures I gave in post #71 were calculated/taken from the software i gave link to. http://www.winlens.de/index.php?id=70 This software was written by Dr Geoff Adams and Rodenstock used to provide the software free at their website. I have no idea what his connection to Rodenstock was/is...

can anyone cite any cases where photographers have been conclusively proved to have suffered ill health from photo chemicals. Not hearsay or anecdotal examples but proven medical cases. Are there any stats on this anywhere.

goat or sheep or other mountain deer skin