Andrew O'Neill
Moderator
I do. And I teach my students to do it as well. Easier to see the image.
Ralph is right. Most of the time, I don't consider the height of the paper when I use my grain focuser. My enlarger lenses is normally used at f/8-11 at it's sharpest.as you suspected,the depth of focus eliminates this issue;there is absolutely no need for an extra piece of paper under the grain focuser;none!
nothing wrong with that.I've always got a scrap piece of photo paper on the easel, upside down, so I can view the image on the white paper instead of the yellow of my Saunders easels. So, I place my grain focuser on that to focus. And, why not be as accurate as possible, even if the difference is negligible?
Best,
Doremus
Noooooo... Save us. For recent discussions on the topic please see:
https://www.photrio.com/forum/threa...er-with-or-without-paper-on-the-easel.184886/
& https://www.photrio.com/forum/threads/grain-focusing-by-moving-enlarger-up-and-down.185678/
Oooops! Sorry. (Creeps away...)
Oh, dear. Didn't mean to come down like a ton of bricks. It was one of those threads that never ended, and even when it ended it didn't end.
At about the same time there was an interminable thread about the use of stop bath. It seems if folks can't find anything to talk about they talk about anything.
I'm a couple of years late to this thread, but the title caught my eye when I was bored. I'm one of those who does use a waste print underneath the focussing aid. Although I understand that in the DOF(ocus) of the enlarger lens should take care of any focussing inaccuracy, I'm not convinced that careful focussing is pointless. Almost everyone uses their focussing aid in the centre of the image (indeed cheap ones like mine will only work near the centre). For various reasons, corner focus (curvature of the focus plane, curvature of the negative, misalignment of the enlarger head relative to baseboard) may be slightly different from centre focus. If you make an error the wrong way at the centre, the corners may be better focussed as a result, or they may be pushed further out of focus. In the latter case, DOF may not cover the error. So as Doremus said above, why not be as accurate as possible? Then at least you know have control, rather than relying on a fudge.
the error introduced by the paper thickness it's too little to worry about. Nevertheless it's easy and fast to use a scrap piece of paper for ease of mind.When focusing, should I place the grain enlarger on a sacrificial piece of paper or directly on the easel? Essentially I’m wondering if they are calibrated to take into account the millimeter or so of paper thickness. I know some paper is thicker than others which is what got me wondering this. At the same time I’m thinking that the plane of focus may be deep enough to render this question moot.
Thanks,
Omid
the error introduced by the paper thickness it's too little to worry about. Nevertheless it's easy and fast to use a scrap piece of paper for ease of mind.
Noooooo... Save us. For recent discussions on the topic please see:
https://www.photrio.com/forum/threa...er-with-or-without-paper-on-the-easel.184886/
& https://www.photrio.com/forum/threads/grain-focusing-by-moving-enlarger-up-and-down.185678/
It's totally OK to put paper under the grain focuser to account for the thickness of paper because it is more accurate.I'm a couple of years late to this thread, but the title caught my eye when I was bored. I'm one of those who does use a waste print underneath the focussing aid.
Oh dear, what have I done, what have I done? ....
This is essentially a restatement of post #8.
Many enlarging papers are about 0.0115” or about 0.29 mm in thickness. This can vary somewhat depending on the particular paper.
Precisely
In theory, the thickness of a sheet of scrap paper of the same type as you're using under the grain magnifier will help you to perfect the focus. In practice, it makes no difference. For example, when making an 8” x 10” full-frame enlargement from a 35 mm negative with a 50 mm lens the required magnification is about 9.1X.
At that magnification, and with the aperture set at f/5.6, the depth of focus about the image plane is 29.9 mm using circle-of-confusion diameter 0.029 mm. About half of the depth of focus lies above, and half lies below the image plane. Whether the grain focuser is resting on a sheet of enlarging paper or not won’t make a discernable difference in the result.
The main benefit of using an upside-down scrap print in the easel is that it makes rough focusing easy due to the reflectance of the white paper. This makes it easier to see the projection. It also makes sizing and composing the image (adjusting the position of the easel) to fit the projection easy.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?