Using grains focuser with or without paper on the easel

[RalphLambrecht]

Just as I expected that the depth of field would take care of it. I use it with paper underneath which may not be necessary, but I think is good practice.

paper under the grain focuser is s useful as an ashtray on a motorcycle and a good practice as wearing eyeglasses in th dark or closing your eyes in the darkroom just to be safe.

 

[faberryman]

paper under the grain focuser is s useful as an ashtray on a motorcycle and a good practice as wearing eyeglasses in th dark or closing your eyes in the darkroom just to be safe.

I close my eyes when I load film onto the developing reels. It helps me concentrate. I have been doing it for fifty years and have never forgotten to turn out the lights first. If you ever have one of those rolls of film that just won’t go on the reel, you might want to give it a try.

With respect to putting a sheet of paper under your grain focuser, a lot of people here say you don’t need to do it, but they are just making bald assertions. Matt said he actually did the math, and said it is covered by depth of field. I’ll accept that. My view is depth of field is a fancy word for approximate focus. When I focus my camera, I move the focusing ring back and forth until whatever I am focusing on snaps into focus and the microprism is clear. I guess I could just turn the focusing ring and say close enough it will be covered by depth of field. That’s what happens with a fixed lens or zone focus camera, or if you were doing street photos or whatever and had to make quick shots. But for the stuff I shoot, I have time to turn the focusing ring back and forth and get my subject in focus. Same way in the darkroom. I have time to slip some paper under the grain focuser and not have to rely on depth of field to get my prints sharp. Of course a lot of people use glassless negative carriers and don’t align their enlargers either. Maybe depth of field covers that too. It’s a slippery slope.

 

[Don_ih]

I close my eyes when I load film on my developing reels. It helps me concentrate. I have been doing it for fifty years and have never forgotten to turn out the lights first.

I close my eyes, too. For the same reason. Also, why keep your eyes open if it's dark? It wastes energy.

 

[AgX]

My view is depth of field is a fancy word for approximate focus. When I focus my camera, I move the focusing ring back and forth until whatever I am focusing on snaps into focus and the microprism is clear. I guess I could just turn the focusing ring and say close enough it will be covered by depth of field. That’s what happens with a fixed lens or zone focus camera, or if you were doing street photos or whatever and had to make quick shots. But for the stuff I shoot, I have time to turn the focusing ring back and forth and get my subject in focus.

Problem is, we hardly take photos of wall charts or tiled walls. For subjects else one typically needs DOF to make the intended photo.

 

[wiltw]

I close my eyes when I load film onto the developing reels. It helps me concentrate. I have been doing it for fifty years and have never forgotten to turn out the lights first. If you ever have one of those rolls of film that just won’t go on the reel, you might want to give it a try.

With respect to putting a sheet of paper under your grain focuser, a lot of people here say you don’t need to do it, but they are just making bald assertions. Matt said he actually did the math, and said it is covered by depth of field. I’ll accept that. My view is depth of field is a fancy word for approximate focus. When I focus my camera, I move the focusing ring back and forth until whatever I am focusing on snaps into focus and the microprism is clear. I guess I could just turn the focusing ring and say close enough it will be covered by depth of field. That’s what happens with a fixed lens or zone focus camera, or if you were doing street photos or whatever and had to make quick shots. But for the stuff I shoot, I have time to turn the focusing ring back and forth and get my subject in focus. Same way in the darkroom. I have time to slip some paper under the grain focuser and not have to rely on depth of field to get my prints sharp. Of course a lot of people use glassless negative carriers and don’t align their enlargers either. Maybe depth of field covers that too. It’s a slippery slope.

Well stated,
If, when shooting a photo of flat art, my subject is at exactly 10', I would not think it optimal to set focus at 9' with the knowlege that 'f/8 DOF covers it just fine'. So why apply that line of thought in the darkroom, if that previous sentiment (about focus accuracy on flat art) applies to your thinking while shooting?! That would seem to be inconsistent.

It may be true 'The eye will never know the difference', but in such a case we are knowingly accepting imperfect blur circles as a substitute for perfectly reproduced points of light. The print is inherently less sharp than it could be.
About striving for excellence (not 'perfection') in what we do in photography....

• Some folks obsess about not using filters when shooting because the photo is 'not as sharp as it could be'.
• Some folks obsess about AF calibration for their camera and each lens because the photo is 'not as sharp as it could be'.
• Some folks will not use a teleconvertor on a long lens because the photo is 'not as sharp as it could be'.
• Some folks always mount the camera on a tripod because the photo is otherwise 'not as sharp as it could be'.
• Many folks use the magnifier in the waist level finder of medium format cameras and most use magnifiers on the large format focusing screen, to improve upon their focus accuracy,
• Most folks use the focus aid in the center of the 135 SLR viewfinder rather than merely relying upon the ground glass area because the photo would be 'not as sharp as it could be'.
• When the exposure is somewhat long, most use mirror lockup, because otherwise the photo is 'not as sharp as it could be'

So why not use that same thinking in the darkroom? If you have a piece of photo paper in the easel to make it easier to frame the projection, one merely needs to put the grain focuser on top of the paper, and then remove both after verification of focus. No added effort because the paper is already there, it is merely a question of WHEN the paper is removed, so one does not need to be OCD about focus accuracy.
You already are using a grain focuser...why did you purchase one, if 'good enough' focus is all you want?! You could have saved yourself that expense, and the bother of using it to focus. And why care for it and not simply throw it around, if its accuracy is 'it does not really matter, I cannot see the difference'.
There is apparent inconsistency of thought seen in some of the responses...that, or there seem to be a lot of photographers who settle for 'good enough' in all their methods throughout photography?

It is not being 'dogmatic', it is merely consistency of approach.

 

[MattKing]

(you already are using a grain focuser...why did you purchase one, if 'good enough' focus is all you want?! You could have saved yourself that expense, and the bother of using it to focus. And why care for it and not simply throw it around, if its accuracy is 'it does not really matter, I cannot see the difference'.

Using a grain focuser is really important. It permits you to determine when the enlarger's focus is optimal.
But the math (and practical experience) indicates clearly that whether or not there is a piece of paper under the focuser doesn't affect the result you will get. As a result of the optics involved, as well as our visual acuity, it is not possible to differentiate between what we see with the paper there, and what we see with the paper removed - the two different images in the focuser will be identical. And it will not be possible to say that one is more or less in focus than the other.
Contrast that with what happens when we make even the slightest change to the enlarger's focus - that difference is relatively easily observed with the naked eye, and very easily observed in the grain focuser.

 

[Don_ih]

It is not being 'dogmatic', it is merely consistency of approach.

You're not being dogmatic - but others are. You offer reasons for your opinion, which makes it rational.

 

[Sirius Glass]

You miss the significance.
If the instrument you use to determine whether or not something is at a position of best focus is your sight, than if you cannot differentiate between the accuracy of two positions with that sight, then it doesn't matter which of the two positions you choose - each will be equally likely to be the best choice.
And your sight will not be capable of telling which of the two options will be best, because of how all of this particular optical system works.

Nor can I see if a beaker in the lab is clean before I use it, but I check it anyway. Your comment implies that my checking or taking extra care makes me a bad person.

 

[Sirius Glass]

paper under the grain focuser is s useful as an ashtray on a motorcycle and a good practice as wearing eyeglasses in th dark or closing your eyes in the darkroom just to be safe.

I close my eyes when I am loading film on a reel if I am having problems, it cuts distractions.

 

[Sirius Glass]

paper under the grain focuser is s useful as an ashtray on a motorcycle and a good practice as wearing eyeglasses in th dark or closing your eyes in the darkroom just to be safe.

So you are saying that I should not take off the lens cap before taking the photograph should not be done because it does not change the focus?

 

[eddie]

This debate is as ridiculous as arguing whether you must set your f stop before shutter speed, or vice versa.

 

[MattKing]

Nor can I see if a beaker in the lab is clean before I use it, but I check it anyway. Your comment implies that my checking or taking extra care makes me a bad person.

It isn't a case of lack of care. It is a case where the tools available are such that it is not possible to observe or measure any difference.
If the focus is first adjusted without the paper inserted, no one will be able to see anything change in that grain focuser which might reasonably cause them to adjust the focus after they insert the paper.
The tool for making measurements - our visual acuity plus the grain focuser - is not sufficiently precise to differentiate between the two alternatives (with paper or without).

 

[Sirius Glass]

It isn't a case of lack of care. It is a case where the tools available are such that it is not possible to observe or measure any difference.
If the focus is first adjusted without the paper inserted, no one will be able to see anything change in that grain focuser which might reasonably cause them to adjust the focus after they insert the paper.
The tool for making measurements - our visual acuity plus the grain focuser - is not sufficiently precise to differentiate between the two alternatives (with paper or without).

It may not make a difference but I will still do it.

 

[eddie]

So you are saying that I should not take off the lens cap before taking the photograph should not be done because it does not change the focus?

You do realize how absurd this statement is, don't you?

 

[wiltw]

Using a grain focuser is really important. It permits you to determine when the enlarger's focus is optimal.
But the math (and practical experience) indicates clearly that whether or not there is a piece of paper under the focuser doesn't affect the result you will get. As a result of the optics involved, as well as our visual acuity, it is not possible to differentiate between what we see with the paper there, and what we see with the paper removed - the two different images in the focuser will be identical. And it will not be possible to say that one is more or less in focus than the other.
Contrast that with what happens when we make even the slightest change to the enlarger's focus - that difference is relatively easily observed with the naked eye, and very easily observed in the grain focuser.

OK, Matt. Presumably if I agree to that line of thinking, I come back to my earlier statement...
" If you have a piece of photo paper in the easel to make it easier to frame the projection, one merely needs to put the grain focuser on top of the paper, and then remove both after verification of focus. No added effort because the paper is already there, it is merely a question of WHEN the paper is removed, so one does not need to be OCD about focus accuracy."

 

[Don_ih]

@MattKing is not saying anyone needs to stop using paper under a grain focuser.

There is a difference between saying there is no demonstrable reason to do something and saying that you should stop doing it.

Anyone here can demonstrate to him or herself whether or not paper/no-paper makes any difference.

 

[MattKing]

OK, Matt. Presumably if I agree to that line of thinking, I come back to my earlier statement...
" If you have a piece of photo paper in the easel to make it easier to frame the projection, one merely needs to put the grain focuser on top of the paper, and then remove both after verification of focus. No added effort because the paper is already there, it is merely a question of WHEN the paper is removed, so one does not need to be OCD about focus accuracy."

This is a very good and eminently sensible reason to have the paper there, and I don't disagree in any way with it. It is an approach that is useful with some of my easels, and not necessary with others.
For clarity, I really don't care whether people make a point of putting a sheet of paper under the focus finder - it won't make a difference either way to how well focused your print is.
But it interests (concerns?) me that people don't appreciate why it doesn't make a difference.
For me, it really helps to be able to understand how tools like grain focusers work - what can affect their successful use, and what either doesn't matter, or cannot be reliably controlled or observed.
I generally like to understand why I use the equipment and techniques I use, how sensitive to inaccuracy they might be, and how meaningful any such inaccuracy is.
I regularly see people really concerned with some things that have little affect on their results, while perhaps not paying nearly enough attention to other things that can have large affects on their results, and which can be reliably controlled.

 

[BrianShaw]

This debate is as ridiculous as arguing whether you must set your f stop before shutter speed, or vice versa.

PLEASE don’t get that discussion started!

 

[wiltw]

This is a very good and eminently sensible reason to have the paper there, and I don't disagree in any way with it. It is an approach that is useful with some of my easels, and not necessary with others.
For clarity, I really don't care whether people make a point of putting a sheet of paper under the focus finder - it won't make a difference either way to how well focused your print is.
But it interests (concerns?) me that people don't appreciate why it doesn't make a difference.
For me, it really helps to be able to understand how tools like grain focusers work - what can affect their successful use, and what either doesn't matter, or cannot be reliably controlled or observed.
I generally like to understand why I use the equipment and techniques I use, how sensitive to inaccuracy they might be, and how meaningful any such inaccuracy is.
I regularly see people really concerned with some things that have little affect on their results, while perhaps not paying nearly enough attention to other things that can have large affects on their results, and which can be reliably controlled.

Matt,
Many of us understand, "It does not make a difference in focus accuracy, to have paper there vs. not."

• If it does not matter, why are so many defending the removal of paper before focus? Is that not as dogmatic as "You must have enlarging paper to focus properly"?!
• And if the paper is already there, why not leave it in place?
• Why are we so careful about focusing on flat art to be photographed, if the focus care is not echoed in enlarging?
• If we are aware of error in the process, is it not best to reduce error (focus to a point in the middle between 'out of focus' limits) when we can, rather that leaving an opportunity for greater error to be introduced? It it analogous to focusing on the tips of the ears rather than focus on the eyes for a portrait, "DOF will take care of it and no one can tell the difference at f/8"...inconsistency of thought.

 

[reddesert]

I did the math back in post #26: [URL="https://www.photrio.com/forum/threads/using-grains-focuser-with-or-without-paper-on-the-easel.184886/page-2#post-2433900"]Using grains focuser with or without paper on the easel[/URL] The amount of blur caused by the extra thickness of the paper is negligible. This is another way of saying that the depth of field is much larger than the paper thickness. People who don't want to hear this should test it for themselves, of course.

 

[wiltw]

I did the math back in post #26: Using grains focuser with or without paper on the easel The amount of blur caused by the extra thickness of the paper is negligible. This is another way of saying that the depth of field is much larger than the paper thickness. People who don't want to hear this should test it for themselves, of course.

Then why not focus on the tips of the ears rather than on the eyes, if DOF at the shooting aperture takes care of it? the math proves that, too.

 

[Doremus Scudder]

Heck, if you don't want to put a piece of paper in your easel to focus on, just glue a small piece onto the bottom of your grain focuser and be done with it forever; and be as precise as you possibly can be.

Doremus

 

[Don_ih]

Then why not focus on the tips of the ears rather than on the eyes, if DOF at the shooting aperture takes care of it? the math proves that, too.

Because focusing on the tips of the ears may not get the tip of the nose in focus.

 

[MattKing]

Why are we so careful about focusing on flat art to be photographed, if the focus care is not echoed in enlarging?

It is echoed in enlarging - that is why we use the grain focuser.
But depth of focus when using an enlarger manifests itself in a significantly different way than depth of field when using a camera.
With an enlarger and a small or medium format enlarging lens at f/8 (assuming an aligned and flat baseboard) you won't be able to detect the effects of a 1 mm displacement of the focus aid or paper, because those effects are too small to see with the eye or in the paper (which is the final product).
With a camera, the effects of that 1 mm displacement are magnified through the chain, so they may very well become visible later.
I would point out, however, that with a 1 mm displacement of your flat art, unless you have really high supplementary magnification on the camera, you probably cannot see enough change at the camera stage in order to be able to adjust the focus to take that displacement into account.

 

[cliveh]

Then why not focus on the tips of the ears rather than on the eyes, if DOF at the shooting aperture takes care of it? the math proves that, too.

There is a hell of a difference between the shooting focus between ear tips and eyes at whatever aperture, compared to the enlarger focus difference between paper thickness and easel even at full enlarger aperture.