View Camer Focusing vs Results

[RmFrase]

Being a newbe, I've found out a lot by trial and error as well as help from a friend of mine from a local camera club. However, I've come across something that i just can't quite find a solution.

When focusing, I use the Rodenstock Lupe, and focus it until the hatch lines on the fresnel are sharp. Once I've focused the Lupe, I then focus the on my object as normal.

The issue I've encountered is that I'm wondering if there is a distance gap, once I place the film into the camera (ie: PA-45) that is further enough to cause the object to now be Out-of-Focus?


I placed a small piece of printed paper with about an 8-10 size font into the center of this flower. I focused on that until the the print was sharp.

I then used the Camera's Tilt to bring the rest of the flower's petals into focus, rechecking the image on the fresnel from top to bottom, and ensuring I could see the fine details of the petals.

However, the scanned image appears blurred once enlarged. Could that gap between the film and where the fresnel was cause this distortion?

[memorris]

The design of the film holders puts the film at the same place as the ground glass. So, by design no but some holders are notorious for being off enough to create soft focus.

I was taught to use a lower power focus aid so you do not see the details of the fresnel and to focus the image sharply. In several books and from some who have been shooting for many years have warned about having too much magnification.

[Vaughn]

Not quite sure how your fresnel and GG is set up, but if you are focusing on the fresnel instead of the grounded side of the GG, that might be your problem.

Other possibilities -- the film and the GG may not be on the same plane. Your scanner might be the one off. Your fresnel is in the wrong place (relative to the GG).

Vaughn

[Ivan J. Eberle]

You don't mention the camera, but if the original design called for a groundglass only, and at some point the GG was replaced by a fresnel/GG sandwich (fresnel to the front) that effectively shims this GG depth out by the thickness of the fresnel, yes, then you could indeed have this very problem.

The standard depth for a filmholder is .197" for modern 4x5s, and the groundglass should be within .007" of that when measured with a dial indicator.

One solution is to put the GG to the inside (original location) and the fresnel to the back outside. Another is to cut the fresnel so that it is smaller and doesn't shim the GG from its original place if placed on the inside.

[RmFrase]

The Camera is the 4x5 Shen-Hao TZ45-IIB, and is all original. I'll also test to see if there might have been some ever-so-slight movement (that was not noticible visually,) in the subject that might have caused this as well.

The light was low, (natural light only) and I took several shots ranging from 1/2 - 2 seconds of various f-stops.

But, I'm temporarily out of film, until about Thursday of this week.

-R

[bobwysiwyg]

Did you lock down all movements after focusing, before tripping the shutter?

[photographs42]

There is a simple test for focus accuracy. I’m sure it’s documented somewhere but simply stated, you photograph a ruler (preferably a flat metal one) at an oblique angle. Focus on the 6” mark with film plane and lens plane parallel and aperture wide open. If the 6” mark is in focus on the developed film you’re good to go. If some other mark is focused sharper you need an adjustment.

Also, get the scanner out of the equation. Use your loupe on the film held to a light box or window.

Jerome

[Brian Ellis]

It's hard to tell without seeing the original but just looking at your image I wouldn't have guessed this flower was a candidate for gaining much by using tilt. It doesn't look all that deep and there are petals sticking way up in the air. At best it seems likely that some of the petals would have been above the plane of focus, so that not only would you need tilt, you'd also need to stop way down. You don't mention stopping down (or refocusing after applying tilt which also might have been necessary).

Did you by chance just apply tilt and think that alone would bring the entire flower into focus without stopping down to an aperture smaller than the one you used to compose and focus (presumably wide open)? Maybe it would have but it doesn't look like it from the picture. Or maybe you did that (and also refocused after the tilt if necessary) and just didn't mention it.

[RmFrase]

Here's my steps.

Opened the lens to 5.6 in order to see.
I then focused on the top (bottom of the fresnel,) then used tilt, and re-focused, and repeated this process from top-to-bottom on the fresnel until all appeared sharp.

took the readings from the Sekonic meter, and stopped down (various shots) from f/11 - f/25 adjusting for shutter speed.

this morning, I tested the Epson V700 Scanner by placing a different Test image from a book onto the platter, just as I have with the Fuji Instant Prints - and the scanner checked out ok as the resulting image was sharp.

Once I get new film in, I'll make sure I have better lighting so that I can Re-take the shots at a much higher shutter speed (just in case the flower actually moved during the 1/2 to 2 seconds initial expoures.)

[Peter Mounier]

It is hard to tell from the small image that you posted, but I have a couple of thoughts...

Did you also check the focus from side to side? At a wide open aperture, it may be the solution. Also, could it be that the neg needs post scan sharpening? All scans need some sharpening after scanning.

Peter