Focusing & DoF

There there

A
There there

  • 3
  • 0
  • 39
Camel Rock

A
Camel Rock

  • 7
  • 0
  • 152
Wattle Creek Station

A
Wattle Creek Station

  • 9
  • 2
  • 142

Forum statistics

Threads
198,959
Messages
2,783,796
Members
99,758
Latest member
Ryanearlek
Recent bookmarks
2
Joined
Jul 6, 2010
Messages
9
Location
Saudi Arabia
Format
Multi Format
Hello everyone,

I m still Learning the LF so please help me with this issue,

To set the correct (optimum) plain of focus, is it correct to focus on far, then focus on near, then bring the focus down to about the top third of the Ground Glass. I found that this theory is the same as the usual 35mm technique. Can this be true?

I have a Sinar F2 system.

Thanks.
 

JBrunner

Moderator
Moderator
Joined
Dec 14, 2005
Messages
7,429
Location
PNdub
Format
Medium Format
Since you have a view camera, you aren't limited to such simple things.. Focus the far, and tilt the near into focus on the front standard. If the far goes out, do it again. As long as you take it slow and easy you will find the tilt that gets you everything or near everything when stopped down. That is a basic way to establish a tilt, and the basic way to focus a view camera. You can use the rear standard as well, but it will change the perspective along with changing the focal plane.

Welcome to APUG BTW.
 
OP
OP
Joined
Jul 6, 2010
Messages
9
Location
Saudi Arabia
Format
Multi Format
Wow, I know you J since a year or so from your famous & funny video on the intro of LF on the you-tube...
I do use the the tilt but when I saw the final result I discovered that it is similar to the traditional "focus @ first third".
 

j_landecker

Member
Joined
Apr 18, 2004
Messages
170
Location
Vancouver, B
Format
Large Format
The 1/3 rule assumes that you're photographing a flat plane where the nearest and farthest things you want in focus are at the top and bottom edges of the ground glass, which is not always the case. What this rule is attempting to do is to give you a way to place the focus point at a distance half way between the near and far points you want in focus. One way to do this with view cameras is to observe the position of the standard on the camera rail when the camera is focused on the near and far points in the scene, and then move the standard to a position exactly half way between those two. Your Sinar camera may actually have a rotating dof scale on the focusing knob for doing this. There's an article on the LF home page that explains how to make such a scale as well as other articles on focusing and dof with the view camera. There is a Sinar user manual here that has a short explanation about the dof scale.

Jim
 

RalphLambrecht

Subscriber
Joined
Sep 19, 2003
Messages
14,656
Location
K,Germany
Format
Medium Format
Hello everyone,

I m still Learning the LF so please help me with this issue,

To set the correct (optimum) plain of focus, is it correct to focus on far, then focus on near, then bring the focus down to about the top third of the Ground Glass. I found that this theory is the same as the usual 35mm technique. Can this be true?

I have a Sinar F2 system.

Thanks.

Mohsen

Mark the near and far focus positions of the focusing standard, then move the focusing standard to the optimum focusing position, which is midway between the markings for near and far focus. This way, depth of field will be achieved between the near and far focal planes.
 

Steve Sherman

Subscriber
Joined
Sep 14, 2003
Messages
548
Location
Connecticut
Format
ULarge Format
Be very careful moving the front lens standard to control focus. The image circle of the lens will get used up considerably faster than when using the rear standard.

A simple formula that has served me well over the years, determine the 3 dimensional shape of your composition, if the shape resembles a cube then the only thing that will increase depth of field is F stops. If the shape resembles a rectangle in anyway, swing / tilt the rear lens standard AWAY from the longest plane of the rectangle or if you must use the lens standard then swing / tilt the lens TOWARDS the longest plane of the rectangle.

Enjoy the format
 
Joined
Dec 10, 2009
Messages
6,297
Format
Multi Format
Photo know how book

I have a Sinar F2 also. It's the field kit and I've been using it for over 20 years. I got this book published by Sinar by Carl Koch, the man that invented the Sinar system. This invaluable book is called "Photo Know How". Great explanation of how to get optimal focus on a Sinar. You have a great system for figuring out DOF and setting swings and tilts. If you could find a copy, I'd buy it.
 

Lee L

Member
Joined
Nov 17, 2004
Messages
3,281
Format
Multi Format

I believe Steve is talking about tilting/swinging the front standard as opposed to tilting/swinging the back. Excessive tilt and/or swing on the front standard will throw the image circle off the film. Tilting or swinging the back standard doesn't do that in the same way.

Lee
 

RalphLambrecht

Subscriber
Joined
Sep 19, 2003
Messages
14,656
Location
K,Germany
Format
Medium Format
I believe Steve is talking about tilting/swinging the front standard as opposed to tilting/swinging the back. Excessive tilt and/or swing on the front standard will throw the image circle off the film. Tilting or swinging the back standard doesn't do that in the same way.

Lee

That makes sense. As far as horizontal movement, there is no difference between front and rear standard.
 

Steve Sherman

Subscriber
Joined
Sep 14, 2003
Messages
548
Location
Connecticut
Format
ULarge Format
That makes sense. As far as horizontal movement, there is no difference between front and rear standard.

Certainly my thoughts refer more to tilt than to the swing movement, that said, when ever you move the rear standard away from the front standard the area of of film which needs to be covered actually decreases whereas whenever the lens standard is altered at all the covering power of the lens is diminished.

It really doesn't need to be as complicated as the Sinar people make it, at least in the landscape application.
 

RalphLambrecht

Subscriber
Joined
Sep 19, 2003
Messages
14,656
Location
K,Germany
Format
Medium Format
Well, he did say:


Rise, fall, and shift aren't really focusing movements.

I didn't make myself clear. Instead of 'horizontal' I should have said 'axial'. In other words, changing the distance between standards. That affects focus.
 

RalphLambrecht

Subscriber
Joined
Sep 19, 2003
Messages
14,656
Location
K,Germany
Format
Medium Format
... that said, when ever you move the rear standard away from the front standard the area of of film which needs to be covered actually decreases whereas whenever the lens standard is altered at all the covering power of the lens is diminished. ...

I'm still confused. When changing the distance between standards (not tilt, shift, turn... just straight axial distance), it does not matter which of the two are being moved. The effect is always the same.

This seems pretty obvious. What am I missing?
 

Q.G.

Member
Joined
Jul 23, 2007
Messages
5,535
Location
Netherlands
Format
Medium Format
Nothing, i'd say.

It's - quite frankly - nonsense. :D



Steve, how do Sinar make things complicated?
The F camera is as (un)complicated as any camera available, with the exception of teh P camera, which is the easiest and quickest to use by far.
 

Steve Sherman

Subscriber
Joined
Sep 14, 2003
Messages
548
Location
Connecticut
Format
ULarge Format
Nothing, i'd say.

It's - quite frankly - nonsense. :D



Steve, how do Sinar make things complicated?
The F camera is as (un)complicated as any camera available, with the exception of teh P camera, which is the easiest and quickest to use by far.

I believe Ralph and I have cleared things up via a PM where my terminology was taken in a different context than I had intended and vice versa.

Q.G.

When you cut your teeth on a camera which has an off axis rear standard and an on axis front standard your approach is different than focusing on the far and tilting for the close. It's apples and oranges, not a big deal.

I'd be more concerned with encouraging a beginner to make focus corrections with the lens standard rather than the rear standard with regard to lens covering capabilities as well as going away from the sweet spot of the image circle. This is especially true for lens which are less expensive and more likely to be used by newcomers to WOD (World Of the Darkcloth)

Cheers!
 

Q.G.

Member
Joined
Jul 23, 2007
Messages
5,535
Location
Netherlands
Format
Medium Format
I believe Ralph and I have cleared things up via a PM where my terminology was taken in a different context than I had intended and vice versa.

[...]

I'd be more concerned with encouraging a beginner to make focus corrections with the lens standard rather than the rear standard with regard to lens covering capabilities as well as going away from the sweet spot of the image circle. [...]

Uhm...

Still that "different context"?
Could you then explain? Because i'll join Ralph in asking what it is that i am, we are missing.
 
Joined
Dec 30, 2005
Messages
7,175
Location
Milton, DE USA
Format
Analog
I think they're going with the KISS method. Sure, mess around with everyhting on the camera and learn its capabilities. But until you get into the water past your ankles (read: get into using the camera past inserting film and tripping shutter), best to learn things one step at a time. Do all of the work with one standard until you get to where it is not enough. More than likely that part will be down pat before needing to learn more and one has been making photographs all along.
 

2F/2F

Member
Joined
Apr 29, 2008
Messages
8,031
Location
Los Angeles,
Format
Multi Format
Hello everyone,

I m still Learning the LF so please help me with this issue,

To set the correct (optimum) plain of focus, is it correct to focus on far, then focus on near, then bring the focus down to about the top third of the Ground Glass. I found that this theory is the same as the usual 35mm technique. Can this be true?

I have a Sinar F2 system.

Thanks.

The first step in getting what you want to be sharp sharp is to orient your plane (not "plain") of focus so that it runs through the things shown in the image that are most important to have in critically sharp focus. You do this using front swings and tilts. (You can also do it with rear swings and tilts, or a combination of front and rear, but these two ways also distort the shapes of the things in your composition, which you may or may not want to do.)

Then you critically focus and worry about depth of field and diffraction.
 

2F/2F

Member
Joined
Apr 29, 2008
Messages
8,031
Location
Los Angeles,
Format
Multi Format
Be very careful moving the front lens standard to control focus. The image circle of the lens will get used up considerably faster than when using the rear standard.

A simple formula that has served me well over the years, determine the 3 dimensional shape of your composition, if the shape resembles a cube then the only thing that will increase depth of field is F stops. If the shape resembles a rectangle in anyway, swing / tilt the rear lens standard AWAY from the longest plane of the rectangle or if you must use the lens standard then swing / tilt the lens TOWARDS the longest plane of the rectangle.

Enjoy the format

I assume you mean using front swings and tilts in order to place/orient the plane of critical focus, not simply "moving the front lens standard to control focus." Obviously, whether you use the front or the rear to simply focus the image will have no effect on where the film sits within the image circle.

Assuming that this is true, I still do not see how your advice is practically applicable. If one does not wish to distort the shape of the image, then front swings and tilts are the only way to place/orient the place of focus, drawbacks be damned.

Additionally, it is an extremely rare occasion (i.e. never, in my experience) in which I have used front swing and/or tilt to such an extreme that the film reaches the edge of the image circle, using a lens that was designed to be tilted and swung. In what composition would you ever need that much tilt or swing? Most of the time I use under five degrees of them. It is rare that I would even need any more than the 15 degrees that my Speed Graphic or Technikas allow. Even in the rare cases in which I have tilted the front standard to approaching 45 degrees in order to get a horizontally-oriented plane of focus, I did not run out of image circle to use.

So, not only do the statements not make sense, but even if they did make sense, it would not be a practical concern - and certainly not a general concern - unless using lenses with small image circles for extreme movements...which only a blind Bozo would do anyhow, since you can see the image circle right on the ground glass!
 

Steve Sherman

Subscriber
Joined
Sep 14, 2003
Messages
548
Location
Connecticut
Format
ULarge Format
I assume you mean using front swings and tilts in order to place/orient the plane of critical focus, not simply "moving the front lens standard to control focus." Obviously, whether you use the front or the rear to simply focus the image will have no effect on where the film sits within the image circle.

Assuming that this is true, I still do not see how your advice is practically applicable. If one does not wish to distort the shape of the image, then front swings and tilts are the only way to place/orient the place of focus, drawbacks be damned.

Additionally, it is an extremely rare occasion (i.e. never, in my experience) in which I have used front swing and/or tilt to such an extreme that the film reaches the edge of the image circle, using a lens that was designed to be tilted and swung. In what composition would you ever need that much tilt or swing? Most of the time I use under five degrees of them. It is rare that I would even need any more than the 15 degrees that my Speed Graphic or Technikas allow. Even in the rare cases in which I have tilted the front standard to approaching 45 degrees in order to get a horizontally-oriented plane of focus, I did not run out of image circle to use.

So, not only do the statements not make sense, but even if they did make sense, it would not be a practical concern - and certainly not a general concern - unless using lenses with small image circles for extreme movements...which only a blind Bozo would do anyhow, since you can see the image circle right on the ground glass!

It's been established that my context of "moving the rear standard" meant moving the film plane "off" parallel axis with the lens. I have cordially and without name calling cleared that issue up with Ralph thru PM's.

Further, my initial comments were not drop dead rules, rather a word of caution to a new comer to the LF world, one who might not have the incredible resources you must have to secure a lens with covering power @ 45 degrees front tilt while still staying within the given image circle.

Lastly, had you not used your time to amass 4000+ posts, your practical photographing experiences might have aided in a scenario where a 7x17 camera with no front movements in vertical orientation, only rear swing and tilt with camera approx. 2 feet off the ground and a tall building in the background could be in sharp focus @ nearly wide open while still preventing any vertical lines from converging in the slightest. But, I thought one couldn't move the rear standard and still preserve perspective, sorry, I did not know the rear standard was off limits

How??? by tipping the camera forward ( lens standard ) and then pulling the rear standard back to a vertical and parallel orientation to the building.

Looking back to my Blind Bozo days I might have reasoned that because I have only posted 10 % of 4000+ that I may have had 90 % more time to actually make photographs, however, that seems impractical to me given the wisdom of my years.

I really get a kick out of "forum photographers" who have to exert their absolute expertise with the written word rather than making and sharing photographs. So here again, the very best thing about these forums is also the worst, so much erroneous information is given out to the unsuspecting and uninformed new comer.
 

Q.G.

Member
Joined
Jul 23, 2007
Messages
5,535
Location
Netherlands
Format
Medium Format
You think it's about exerting expertise?
And not just about that when communicating with words, it does help when you're clear about which words to use and how to use them?

I agree that much erroneous info is given out.
But also much good info is not, turned into something that just adds to the general confusion, because it is hidden in unclear wording.
:wink:
 

epatsellis

Member
Joined
Jan 1, 2006
Messages
928
Format
Multi Format
As stated earlier, the Sinar F has a wonderful tilt/swing and DOF calculator built in.
Using the tilt/swing calculator, it takes literally seconds to determine movements, and if desired transfer them to the lens standard. It is only bested by the Sinar P series for ease of use.

The DOF calculator is rather optimistic, I allow at least one more stop than calculated for negatives destined for enlargement.
 

2F/2F

Member
Joined
Apr 29, 2008
Messages
8,031
Location
Los Angeles,
Format
Multi Format
It's been established that my context of "moving the rear standard" meant moving the film plane "off" parallel axis with the lens. I have cordially and without name calling cleared that issue up with Ralph thru PM's.

I called you no name. I said that your "warning" was unnecessary to anyone but the people who I called a name.

Further, my initial comments were not drop dead rules, rather a word of caution to a new comer to the LF world, one who might not have the incredible resources you must have to secure a lens with covering power @ 45 degrees front tilt while still staying within the given image circle.

I don't think I have incredible resources. I just have the experience that I shared, using lenses that are designed for movement, and that cover when approaching 45 degrees tilt. This was used as an extreme example, and this was clear in my post.

Lastly, had you not used your time to amass 4000+ posts, your practical photographing experiences might have aided in a scenario where a 7x17 camera with no front movements in vertical orientation, only rear swing and tilt with camera approx. 2 feet off the ground and a tall building in the background could be in sharp focus @ nearly wide open while still preventing any vertical lines from converging in the slightest. But, I thought one couldn't move the rear standard and still preserve perspective, sorry, I did not know the rear standard was off limits

How??? by tipping the camera forward ( lens standard ) and then pulling the rear standard back to a vertical and parallel orientation to the building.

I think you were hoping for your technique to be some mind-blowing and clever revelation to me that would zingingly prove me wrong. However, this is the oldest trick in the book (and a great - I would say "essential" one) for squeezing the effects of front movements from a camera that does not have them. I have even explained it before on this Website for those with limited cameras. I do it often with my Kodak No. 2 5x7, which, like your big camera, has no front tilt or swing, but has rear tilts and swings. The net effect is not one of rear tilt, but one of front tilt. There is no way to have net rear tilt or swing without changing the shape of the image.

It is not rear tilt/swing just because you physically tilt/swing the rear of the camera. It is front tilt/swing you have when using this trick. It is the effect on the image that matters. You are arriving at front tilt/swing by using a tilting tripod head combined with a subsequent leveling of the rear of the camera. The rear moves, but it the manipulation employed is front tilt. Just look at the camera when it is set up this way, and imagine the rail or bed is not there (because the bed or rail doesn't matter when describing net camera movements anyhow; only the relation of the lens standard to the film standard, the latter of which is the point of reference). The rear is level, and the front is tilted. The rear of the camera is physically tilted, but this is front tilt, not rear.

It is worth mentioning that if you use this trick to get front tilt from a camera without a physically-tilting front, and then raise or lower the front in order to get the composition back to what you intended (which is what you must do if you intend to end up with the original composition you envisioned after using this trick), you end up being just as close to the edge of the image circle as you would have been when using a camera with a tilting front. The only thing that matters as far as clipping the composition with the edge of the image circle is where the lens is in relation to where the film is.

So, what does this mean for your original suggestion to the OP? It means that your suggestion that rear tilts and swings are a preferable alternative to front ones is only applicable in pictures in which changing the shape of objects in the image is acceptable. Hardly a general-enough situation to give this as general advice when working with large format.

Looking back to my Blind Bozo days I might have reasoned that because I have only posted 10 % of 4000+ that I may have had 90 % more time to actually make photographs, however, that seems impractical to me given the wisdom of my years.

I really get a kick out of "forum photographers" who have to exert their absolute expertise with the written word rather than making and sharing photographs. So here again, the very best thing about these forums is also the worst, so much erroneous information is given out to the unsuspecting and uninformed new comer.

Being correct or incorrect has nothing to do with number of posts made or number of photographs digitized for sharing on the Web (something I am definitely not into doing, and with good reasons). Yet someone who is incorrect will almost always point to these things as if they matter.

You are also incorrect in calling me a "forum photographer" (a name directed pointedly at me, and meant to be disparaging, unlike my comment, which was directed at no one in particular and meant to be lighthearted). The facts of my life prove that I am not. Just because forum activity is a fun time for me does not mean that I do not photograph (and a lot, at that!), and it does not mean that the forum is my life. I lightheartedly called the people who would actually need your warning that name, not you. I.e. people who can't see that they have gone over the edge of the image circle when composing on the G.G. Additionally, "blind Bozos" is a rather mild and goofy term, meaning someone who makes an obvious and silly mistake, and makes a Bozo out of them self by doing so. It was my attempt to jokingly say "WYSIWYG." However, I guess it touched a nerve with you, having been misunderstood by you.
 
Last edited by a moderator:
Photrio.com contains affiliate links to products. We may receive a commission for purchases made through these links.
To read our full affiliate disclosure statement please click Here.

PHOTRIO PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Ilford ADOX Freestyle Photographic Stearman Press Weldon Color Lab Blue Moon Camera & Machine
Top Bottom