Slightly out of focus?

[mealers]

I'm having alot of trouble with all my 5x4 negatives being slightly out of focus, even printing on 10x8 you can see that each print is not quite as sharp as it should be.
I've pretty much ruled out errors made when enlarging. I always focus on the grain (with HP5) and I have also checked my negatives under a loupe and I can see they are OOF.
I did a test today where leveled the camera, set both standards so they were parallel, stopped down to f/32 and took an image of a brick wall. The result was the same as all my other negs, slightly OOF.

I have read that it is sometimes possible for the film plane to not be in the exact position as the GG?
How would I check this and rectify it?
I'm using Fidelity Elite, Astra and Toyo film holders.

I'm using a Shen Hao with 90mm SA and a 150mm Schneider Kreuznach

Has anyone got any ideas of what I'm doing wrong or how to fix the problem?

Many thanks
Mike

[Ian Grant]

Check the the film plane is the same as the Screen. Sometimes a screen etc is set for a plain screen, adding a fresnel shifts the plane of focus.

Ian

[mealers]

Thanks Ian
I dont have a fresnel on it, just the standard Shen Hao GG.

Mike

[jnanian]

are your lens elements screwed in tight ?

[mealers]

are your lens elements screwed in tight ?

Just checked them, they seem tight, I wouldnt want to do them any tighter.

I realise their are so many variables with this and I appreciate any input anyone has got.

[Jon Shiu]

Also make sure your enlarging grain focuser, if you are using one, is set correctly for your eyesight. That is, adjust the eyepiece so that the line is in focus.

Jon

[Curt]

I would suspect the Shen Hao back, If you make three exposures, one focused as you normally do, two focus as you normally would then focus slightly forward, very, very little, three do the same as two except focus and move backward. You will be defocussing forward and backward, if the ground glass is off, placed off the plane of focus then it will be obvious when you see them through the loupe.

I learned this at Brooks Institute of Photography in a seminar on focus for non removable focus screens in roll film cameras. You could use a dial indicator and measure the back without the ground glass in of course. My Mamiya 645 was off for years, just a little, until I learned how to test it, the results are stunning.

When I enlarge I put a piece of enlarging paper, the same brand as I'm using, under the magnifier.

Curt

[Bob-D659]

Note, with the negative really out of focus. Also some/most grain magnifiers have two dark lines, you should be able to see the light line between the two dark ones. Young eyes are really adaptive in seeing the set lines and the image in a grain magnifier as both being in focus at the same time, when they are not.

[Jon Butler]

Mike,
If the unsharp negs are from different holders it may be the camera!?
What about movement - camera shake?
I'm sorry I sent you that print now.

Regards JON.

[mealers]

John Shui/Bob
Yep Ive checked the focus finder, I used it to print a 6x6 neg which was way sharper than my 4x5.

Curt
I think I'II try your idea tomorrow but if the film plane is too far forward or back then wouldnt that mean another part of the image should be tack sharp? The whole of the negative area is slightly OOF, not just the part that I focused on.

JON
Yep its all your fault, I was quite happy making crap prints until you sent me one of yours
My test shots today were taken on a good tripod/head and in no wind, ideal conditions really.