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Randy
22-Sep-2016, 12:53
I want to do some 1:1 or greater close ups with my 8X10 camera and I want as much depth of field as I can get (I want my 3D subjects to have as much in focus as I can get - I don't care about the background being in focus).

I have two lenses that I am considering, both have a minimum aperture of f/45 - a 150mm Konica Hexanon GRII and a Calter II-N 115mm. Both will cover, or almost cover 8X10 at infinity.

I guess my question is pretty basic - at 1:1 will the 115mm lens offer more depth of field than the 150mm lens when both are stopped down to f/45?

Leigh
22-Sep-2016, 13:01
Both will cover, or almost cover 8X10 at infinity.
Hi Randy,

The image circle at 1:1 reproduction ratio is twice the diameter of the ic when focused at infinity.
So either lens will more than cover 8x10 for your application.


I guess my question is pretty basic - at 1:1 will the 115mm lens offer more depth of field than the 150mm lens when both are stopped down to f/45?
Depth of field varies inversely with focal length.

The shorter the focal length the greater the depth of field at any given aperture.

HTH

- Leigh

Randy
22-Sep-2016, 13:09
Thanks Leigh, that's what I was unsure of - the depth of field.

Bob Salomon
22-Sep-2016, 13:14
Yes, but the shorter the lens the greater the foreshortening. This means that those parts of the subject closer to the lens will be much larger then those further from the lens. So, if you need to preserve the shape of the subject that shorter lens will not do that. In other words, a round object will reproduce more like a football.

Randy
22-Sep-2016, 13:38
I think I can live with that Bob. I guess I could try 1:1 with my 250mm lens - it stops down to f/45 also but that may not give me enough depth of field on that lens. I don't think I'll have enough bellows to shot 1:1 with a lens longer than 250mm. I have about 22" of rail length.

Jac@stafford.net
22-Sep-2016, 14:06
Perhaps some of our experts can suggest an enlarging lens that easily fits into a shutter.
In my outdated experience they are the only lenses that really work for macro with 8x10.

I look forward to their suggestions.

Best of luck,
Jac

Dan Fromm
22-Sep-2016, 14:27
At the same magnification and relative aperture and desired image quality (that's what the dread circle of confusion is about) all lenses give the same depth of field. At the same magnification, a longer lens requires more extension but gives greater working distance. That's all you have to play with, Randy.

Leigh's statements


Depth of field varies inversely with focal length.

The shorter the focal length the greater the depth of field at any given aperture.

are dead wrong. Leigh, before you vanished you and I sometimes breathed fire on each other. Please check what I posted and note that I quoted you exactly before breathing fire on me.

Randy, the longest lens that will give 1:1 at 22" extension is slightly shorter than 5.5". This because at 1:1 the film plane-to-subject distance is (4 * focal length) + the lens' internodal distance. For most of the lenses we use in LF, internodal distances are a small fraction of focal length so we usually ignore them when thinking about macro work, extension and all that.

The 150/9 Konica Hexanon GR II seems to be a symmetrical lens. I sold mine years ago so can't check. It was very good at all distances. But and however, as far as I know the cells aren't direct fits in any standard shutter. As I've pointed out, Randy, until you get more than 22" of extension it won't give you 1:1.

Randy
22-Sep-2016, 14:44
Thanks Dan - I wrestled with my question when making this post because I thought logically that, as you state -
At the same magnification and relative aperture and desired image quality...all lenses give the same depth of field. And I don't know why I thought that a bellows extension of double the F/L would give me 1:1. So it looks like if I want to get 1:1 I have to use the 115mm.

Jac, I don't have to have an enlarging lens mount in shutter as I have a Packard shutter mounted inside the front standard. I have a couple enlarging lenses but they all have a minimum aperture of f/32. I would guess I would need f/45 or f/64 to get the depth of field I want.

Dan Fromm
22-Sep-2016, 15:07
Randy, I had a mental lapse. And I'm not going to hide it by editing post #7 above.

You're right, at 1:1 extension is twice focal length. You have plenty of bellows to shoot at 1:1 with your 150/9 GRII. You still have to solve the shutter problem, though.

Randy
22-Sep-2016, 15:14
Thanks Dan - as for the shutter - Packard is already mounted.

Leigh
22-Sep-2016, 17:07
At the same magnification and relative aperture and desired image quality (that's what the dread circle of confusion is about) all lenses give the same depth of field. At the same magnification, a longer lens requires more extension but gives greater working distance. That's all you have to play with, Randy.

Leigh's statements

are dead wrong. Leigh, before you vanished you and I sometimes breathed fire on each other. Please check what I posted and note that I quoted you exactly before breathing fire on me.
Hi Dan,

No, the flame thrower is in the closet, disassembled. ;-)

We're talking about two different aspect of lens usage, and both statements are correct.

I'm talking about focal length. You're talking about magnification.

Short FL lenses have great depth of field.
That's why cell phone cameras don't have focusing mechanisms for their 5mm or whatever lenses.
Yet they resolve everything from the tip of your nose to the moon.

- Leigh

Eric Woodbury
22-Sep-2016, 17:56
Here's a DOF calculator. I set it for 100mm focused to 200mm and a 200mm focused to 400mm. Both 1:1 mag. Same depth of field at the same f-number. Focal length of the lens drops out of the equation. If your subjects are still, consider a pinhole. Rules are different without a lens, that is to say, the focus is the same everywhere, blurry. Or use less than 1:1 and enlarge the image from the negative. Or simulate an electron beam microscope with a slit light source and a scanner.

http://www.cambridgeincolour.com/tutorials/dof-calculator.htm

If you don't believe it, try it.

Leigh
22-Sep-2016, 19:50
I set it for 100mm focused to 200mm and a 200mm focused to 400mm.
You're making the same error as Dan, calculating DoF based on magnification.
That's certainly valid if you want to move the camera.

It's NOT valid if you change lenses while maintaining the same camera-to-subject distance, as is usually the case.
You normally change FL because you want to adjust the framing from the current camera position.

I calculated DoF using your calculator for 100mm and 200mm f/5.6 lenses both focused at 10 meters.

DoF for the 100mm lens is 24.02 meters, while that of the 200mm lens is 3.39 meters.

DoF is inversely proportional to lens focal length, as I said.

-Leigh

Dan Fromm
23-Sep-2016, 04:38
Leigh, you're a little confused. DoF is determined by magnification, relative aperture and desired image quality. Always and everywhere.

You went wrong by forgetting that at the same film plane-to-subject distance a short lens gives lower magnification than a long lens.

Leigh
23-Sep-2016, 05:04
You went wrong by forgetting that at the same film plane-to-subject distance a short lens gives lower magnification than a long lens.
No, Dan.

I did not go wrong in any respect.
My statements were absolutely correct, and supported by the online calculator supplied by others.

You're talking about changing lenses and moving the camera to maintain a particular magnification.
But people don't do that in the real world.

They change lenses while maintaining the camera-to-subject distance in order to change the framing.
That also changes the magnification.

I stated that quite clearly in my previous post. End of discussion.

- Leigh

Randy
23-Sep-2016, 05:30
OK, since I am having a difficult time with this, let me propose a situation:

With the two lenses I have, 150mm and 115mm, both at a distance from the subject to give a 1:1 magnification, both at minimum aperture of f/45, will one give greater depth of field than the other - if so, which one?

Leigh, I don't understand why I wouldn't have to move the camera closer or farther away to achieve the desired magnification when changing lenses. How could we assume that just changing the lens will give me the desired magnification without some modification of the camera to subject distance?

Leigh
23-Sep-2016, 05:35
Leigh, I don't understand why I wouldn't have to move the camera closer or farther away to achieve the desired magnification when changing lenses.
Yes, if you want 1:1 magnification you must move the camera when changing lenses.

But why would you do that?
At 1:1 you get the same Dof with any lens, so why change lenses in the first place?

- Leigh

Dan Fromm
23-Sep-2016, 05:41
Randy, @ f/x, x an arbitrary number, and 1:y, y another arbitrary number, all focal lengths give the same DoF.

By the way, @ 1:1 with the aperture set to f/45 the effective aperture is f/90. At f/90 the diffraction limit is on the order of 16 lp/mm at very low contrast centrally, less the farther off-axis you go. Y'r negs won't be enlargeable, may give unsatisfactory contact prints. Don't take my word for this, try a few shots and please me by telling me that for your purposes and standards I'm mistaken.

I have to catch a train, will reply more fully about part two of your question later today.

ic-racer
23-Sep-2016, 05:41
I guess my question is pretty basic - at 1:1 will the 115mm lens offer more depth of field than the 150mm lens when both are stopped down to f/45?
You need to already know the answer to your question to sift through the wrong answers with a question like that.

Randy
23-Sep-2016, 06:49
You need to already know the answer to your question to sift through the wrong answers with a question like that.?

Dan, I will be contact printing making 8X10'ish cyanotypes - no enlarging. I will set up the camera and do some experimenting today.
The reason I wanted to get an idea on what lens to use is because I suspect that at f/45 at 1:1, I will not be able to see the image on the ground-glass to determine if I am getting the depth of field I want.

DrTang
23-Sep-2016, 07:57
No, Dan.




and moving the camera
But people don't do that in the real world.



if one is shooting 1:1 - I'm guessing they are going to be moving the camera

Taija71A
23-Sep-2016, 11:34
I knew that this was going to happen... :rolleyes:


... I guess my question is pretty basic - at 1:1 will the 115mm lens offer more depth of field than the 150mm lens when both are stopped down to f/45?


At the same magnification and relative aperture and desired image quality (that's what the dread circle of confusion is about) all lenses give the same depth of field...

Since, the OP 'clearly' stated his Parameters to begin with (1:1 Magnification and f/45 Aperture)... Dan's answer was of course correct.


Yes, if you want 1:1 magnification you must move the camera when changing lenses. But why would you do that?
At 1:1 you get the same Dof with any lens, so why change lenses in the first place?

Why would you do that? Leigh, one very good reason for 'Changing' Lenses...
Was already stated by Bob in Post #4. Thank-you! -Tim.

"You can't teach an old dog new tricks."
~~ John Fitzherbert. ~~

Dan Fromm
23-Sep-2016, 15:56
Leigh, I don't understand why I wouldn't have to move the camera closer or farther away to achieve the desired magnification when changing lenses. How could we assume that just changing the lens will give me the desired magnification without some modification of the camera to subject distance?

Randy, I caught my train, went into town, ...

To answer your question, here's how I understand the relationship between focal length, magnification and film-to-subject distance:

First, the lens front node-to-subject distance is focal length * (magnification + 1)/magnification

Second, the lens rear node-to-subject distance is focal length * (magnification +1)

With LF lenses we usually treat the internodal distance as zero (0). For most of the lenses we use it is much smaller than focal length.

Substituting and ignoring internodal distance, film plane-to-subject distance is focal length *(magnification +1) * (1 + 1/magnification). If you want to be more precise than necessary, add internodal distance to the total.

Now do you see why changing focal length changes all the distances?

If you do a little fiddling, you'll see that when magnification = 1 film plane-to-subject distance is 4 focal lengths. Also that for every other film plane-to-subject distance there's a pair of magnifications that give the distance. For example 1:2 (magnification = 0.5) and 2:1 (magnification = 2) both give film plane-to-subject distance 4.5 focal lengths. This why standard practice to focus at near distances is to set the camera-lens distance to give the desired magnification and then focus by moving the camera/lens assembly as a unit. Focusing the usual way (by adjusting extension) risks finding focus at the wrong magnification.

If you're serious about learning closeup/macro photography, buy a copy of Lester Lefkowitz' book The Manual of Closeup Photography. Out of print, usually available used at reasonable prices from vendors on abebooks.com, alibris.com, amazon.com, ...

John Kasaian
23-Sep-2016, 16:23
I've had good luck at 1:1 with the 159mm Wollensak WA Yellow Dot.
Just throwin' it out there:cool:

Leigh
23-Sep-2016, 23:51
Second, the lens rear node-to-subject distance is focal length * (magnification +1)
i believe you meant the rear node-to-film distance.

- Leigh

Dan Fromm
24-Sep-2016, 05:55
i believe you meant the rear node-to-film distance.

- Leigh

Thanks for the correction.

Jac@stafford.net
24-Sep-2016, 08:17
I presume the OP is photographing a three-dimensional object.

Doesn't spherical aberration contribute to a sense of greater DOF?

Dan Fromm
24-Sep-2016, 09:11
I presume the OP is photographing a three-dimensional object.

Doesn't spherical aberration contribute to a sense of greater DOF?

Nice fantasy.

Its brother "curvature of field improves DoF when shooting 3D objects" is equally bad. Interesting idea, but finding a lens whose curvature of field gives a field that conforms to a specific 3D object isn't easy. Since the 3D objects we photograph aren't all alike, we'll need heaps of lenses ...

Joshua Dunn
24-Sep-2016, 20:09
Randy,

I know you are considering the 150mm Konica Hexanon GRII and the Calter II-N 115mm but have you considered shooting with a Nikkor AM ED 210mm? It is a macro lens and was designed to do exactly what you are trying to achieve, photograph at 1:1 on 8x10.

-Joshua

Leigh
24-Sep-2016, 20:28
have you considered shooting with a Nikkor AM ED 210mm?
It is a macro lens and was designed to do exactly what you are trying to achieve, photograph at 1:1 on 8x10.
That lens has a 400mm image circle at 1:1.

That's more than adequate for 8x10 (325mm diagonal) with significant movements.

- Leigh

Mark Sawyer
25-Sep-2016, 12:35
Randy,

I know you are considering the 150mm Konica Hexanon GRII and the Calter II-N 115mm but have you considered shooting with a Nikkor AM ED 210mm? It is a macro lens and was designed to do exactly what you are trying to achieve, photograph at 1:1 on 8x10.

-Joshua

Process lenses like the GRII are optimized for around 1:1. As Nikon says its Nikkor AM ED 210mm is also optimized for 1:1, I'm not sure what the advantage would be. Traditionally, macro lenses are for even greater magnifications. B&L, for example, touts their Micro Tessars as being capable of up to 50:1.

Randy
25-Sep-2016, 12:45
For my purposes, which are artistic rather than documentation, pretty much any lens that will offer sufficient coverage and close down enough to give me the depth of field I desire, will do. Oh - and the best lens for the project is one that I already have so I don't have to spend any $ that I don't have...

I did a little set-up test yesterday with the 150mm Konica Hexanon. Didn't expose any film but just gave it a try to see what it looked like on the GG. Worked fine with plenty of bellows left.

Thanks everyone for the tips.