Xpan Dof in panorama mode?

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3js

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Hi all,

Ok, so the dof scale in xpan´s 45 is for 24x36, right? But in panorama mode the lens acts more like a 25? So how do you set the dof scale? I ´m trying to use it hyperfocal, but the scale don´t fit in in the panorama mode... Let´s say I shoot f11, so where does the dof begin?

Thanks!
 
sahe69 said:
The angle is wider of course in pano mode, but as the focal length of the lens does not change the DOF remains the same regardless of the format.
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I don´t think that´s quite true? I think that the relative picture size in the neg is more important. Dof remais the same only if the relative picture size is the same. Check out the nearest format, the 6x45. Ok, Coc is bigger, as is the negative, but so is the case in Xpan´s pano vs normal mode.
 
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Unfortunately the XPAN uses film, but if you can afford just one wide extra film frame for an experiment, just one, use the DOF scale and set the lens at the distance where infinity is just at the end of its aperture scale bracket. (hyperfocal distance) Then retake the pic (keep it on a tripod), now with distance set to infinity. [I assume here that you have a landscape in front of the lens.]

Compare the results and I predict that you will never again think about anything other than infinity setting for landscapes. Hyperfocal shots just look muddy at the horizon and bad. Good experimenting.
 
uhligfd said:
Unfortunately the XPAN uses film, but if you can afford just one wide extra film frame for an experiment, just one, use the DOF scale and set the lens at the distance where infinity is just at the end of its aperture scale bracket. (hyperfocal distance) Then retake the pic (keep it on a tripod), now with distance set to infinity. [I assume here that you have a landscape in front of the lens.]

Compare the results and I predict that you will never again think about anything other than infinity setting for landscapes. Hyperfocal shots just look muddy at the horizon and bad. Good experimenting.
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Yes I believe this as you put it, but I just hate to waste film🙂 And I don´t use Xpan for landscapes, but in streets. That´s why I need to set the hyperfocal distance, usually I don´t have time to focus...
 
uhligfd said:
...

Compare the results and I predict that you will never again think about anything other than infinity setting for landscapes. Hyperfocal shots just look muddy at the horizon and bad. Good experimenting.
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Not all "landscapes" are flat. IMHO, some of the best pictures are the ones with near, mid, and far planes.
 
And to answer the original question, AFAIK, the DoF doesn't change per se if you switch from 35mmm to pano format. Think about this. You take a picture @f8 and let say the DoF gives you acceptable focus between 5-8 feet out. Now cut the neg to smaller size (or a print 🙂 ). Does the DoF all of the sudden change? Of course now, but now the field of view changed. So it's the same thing if you are xpan-ing your film size.
 
didjiman said:
And to answer the original question, AFAIK, the DoF doesn't change per se if you switch from 35mmm to pano format. Think about this. You take a picture @f8 and let say the DoF gives you acceptable focus between 5-8 feet out. Now cut the neg to smaller size (or a print 🙂 ). Does the DoF all of the sudden change? Of course now, but now the field of view changed. So it's the same thing if you are xpan-ing your film size.
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That can not be true. If format changes, DoF will change too. A 45 lens has different DoF in different formats, if you don´t believe, check 6x9 vs 24x36. A 6x9 45 lens has alot more Dof than a 24x36. Or maybe we should say the results show more DoF...

In your example the only way you can get same DoF is to use 24x36 DoF. I´m not after that, I know the DoF for 24x36, it´s on the lens.🙂
 
3js said:
That can not be true. If format changes, DoF will change too. A 45 lens has different DoF in different formats, if you don´t believe, check 6x9 vs 24x36. A 6x9 45 lens has alot more Dof than a 24x36. Or maybe we should say the results show more DoF...

In your example the only way you can get same DoF is to use 24x36 DoF. I´m not after that, I know the DoF for 24x36, it´s on the lens.🙂
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Why don't you take a straight stick roughly 0.5-1 meter/yard long, put a mark on it every 10 cm or 4 inches, photograph the middle point mark of it at the closest focusing distance on both 24x36 and pano modes without touching any of the other camera settings in between, and verify with a loupe if there's a difference in DOF.

Where did you get the idea that the DOF markings on Xpan are for 24x36 only?
 
sahe69 said:
Why don't you take a straight stick roughly 0.5-1 meter/yard long, put a mark on it every 10 cm or 4 inches, photograph the middle point mark of it at the closest focusing distance on both 24x36 and pano modes without touching any of the other camera settings in between, and verify with a loupe if there's a difference in DOF.
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That would be a little difficult, now where can I found a stick that reaches infinity🙂

sahe69 said:
Where did you get the idea that the DOF markings on Xpan are for 24x36 only?
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Net is full off online DoF calculators. Most of them agree the markings on a Xpans lens. @F11 DoF starts from ~3 meters and goes to infinity, that is for 24x36. But I need to get closer... Are you saying that a format has nothing to do with DoF?
 
3js said:
That can not be true. If format changes, DoF will change too. A 45 lens has different DoF in different formats, if you don´t believe, check 6x9 vs 24x36. A 6x9 45 lens has alot more Dof than a 24x36. Or maybe we should say the results show more DoF...

In your example the only way you can get same DoF is to use 24x36 DoF. I´m not after that, I know the DoF for 24x36, it´s on the lens.🙂
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Firstly, what's your answer to my original proposition? Cut the film down to size, does the DoF all the sudden changes? Any reasoning you come up with, must be able to answer that question!

What you are referring to is that, to fill a frame with a "same size object," e.g. a head shot on a 35mm film vs. 6x7 vs. LF, the apparent DoF changes. Why? Because you change the subject to lens distance!!! Film size has nothing to do with it per se.
 
The asnwer is already there. The DOF doesn't change, when the distance to your subject doesn't change either. THe maginfication stays the same and the coc doesn't change.
You just get more on your picture that's it.

With MF your coc changes and your magnification changes for the same angle of view.
If you crop MF to 135 and keep the same angle of view your DOF will be the same too. BUt you have to walk back to get the same subject and therefore the distance to the subject will change.

Cheers,

Michiel Fokkema
 
Michiel Fokkema said:
The asnwer is already there. The DOF doesn't change, when the distance to your subject doesn't change either. THe maginfication stays the same and the coc doesn't change.
You just get more on your picture that's it.

With MF your coc changes and your magnification changes for the same angle of view.
If you crop MF to 135 and keep the same angle of view your DOF will be the same too. BUt you have to walk back to get the same subject and therefore the distance to the subject will change.

Cheers,

Michiel Fokkema
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First of all, I`m not gonna focus to anything. I use hyperfocal focusing. Second, I know that the 45 Dof scale is for 135. Third, most of you are thinking this in the wrong way, I´m not going to crop the pano mode. I just need the right DoF scale for pano mode.
 
didjiman said:
Firstly, what's your answer to my original proposition? Cut the film down to size, does the DoF all the sudden changes? Any reasoning you come up with, must be able to answer that question! .
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Ofcourse it don´t change, you have used the DoF scale of the lens, which is for 24x36... And as the pano formats DoF is greater, you have some margin there.

didjiman said:
What you are referring to is that, to fill a frame with a "same size object," e.g. a head shot on a 35mm film vs. 6x7 vs. LF, the apparent DoF changes. Why? Because you change the subject to lens distance!!! Film size has nothing to do with it per se.
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Would you please check out your lenses for different formats. Check out the Dof scales of a 6x45(mamiya have a 45 mm), the Xpan and a 6x9(Veriwide is quite close, a 47 mm) Are these DoF scales identical? No. So size does matter.
 
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In the case of the Xpan (or any other camera) it doesn't matter which format you choose DoF will be the same - If you took a 10x8 piece of plate film and placed it at the film plane you would get the same DoF - just your image would occupy a smaller part of the film. DoF depends on focal length and lens to film distance. Size doesn't matter!
Your DoF wont change if you just choose to use a different format - try telling your Xpan it is a plate camera, see if it takes any notice.
 
JonP said:
Your DoF wont change if you just choose to use a different format - try telling your Xpan it is a plate camera, see if it takes any notice.
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No, I just try to tell her she´s a panorama camera, not a 135🙂 I just hope she´ll get message.

DoF is also different because one of factor is CoC, which is based on how much you are going to enlarge the negative. Anyway, the basic CoC for 35 mm is around 0,032 mm. It´s from 1930´s😀 CoC is used in counting DoF scales in your lens.

Read this: http://www.normankoren.com/Tutorials/MTF6.html
And you will understand the question. Any way I´m not gonna write about this any longer, I´m gonna use Coc of 0,04, that´s pretty close, and enough for me as a street shooter. Over and out🙂
 
3js said:
DoF is also different because one of factor is CoC, which is based on how much you are going to enlarge the negative. Anyway, the basic CoC for 35 mm is around 0,032 mm. It´s from 1930´s😀 CoC is used in counting DoF scales in your lens.
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You know, I think we all have read something similar. That's exactly it, most people I know end up enlarging an Xpan pano about the same factor as the 35mm. but hey, you are the expert. The fact that Fuji/Hasselblad don't say anything could be a hint.

Me? I just go out and shoot pano 🙂
 
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