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jonathan_lipkin
30-Nov-2010, 07:37
I've just bought a fairly inexpensive (due to a bit of Shneideritis) 90mm Schneider f/8 for my 45 camera and am wondering if it's sharp enough to make very large (40x50) prints. From much of what I've read, people here and other places seem to think that most modern lenses are pretty good, and again from what I've read that there is not an enormous amount of variation between manufacturers, or at least I've not found a place that does systematic comparisons of lenses, the way slrgear.com or dpreview.com do. Other people, however, have told me to get the best lens I can afford.

The lens seems a bit soft in one corner, but acceptably sharp throughout at f/22 and f/64, at least from my initial tests. However, there are so many variables at this point - scanner settings, photoshop sharpening, etc (I used an Imacon 848 and followed the sharpening regime described in Real World Sharpening by Frasier and Schewe) that it's hard to tease out where improvements can be made, other than getting drum scans made.

So my question is: would there be a point in investing in a more expensive lens? Again from what I've read, it seems a highly debatable point, and the next step up in lens price is pretty steep. (BTW, I don't necessarily need a faster lens)

I've looked through the forums and haven't really found anything too definitive about the qualities of lenses. Hope I'm not opening up too big a can of worms here.

Bob McCarthy
30-Nov-2010, 08:15
For the most part, large format lenses loaf through life. Unlike their 35mm cousins the enlargement ratio is small from 1 to 1 (contact print) to maybe 6 to one with 4x5 and 3 to one with 8x10. Very few prints exceed this threshold.

The 35mm cousins are typically at 10 to one for a small print, remember a 24x30 is a 24x enlargement (assuming you dont crop.

Perhaps far more important is character. OOF areas (boken), contrast etc.

But don't sweat the resolution charts, pretty much meaningless, only place a weak lens ever shows up is on the screen of photoshop at 100%, and rarely if ever on the print.

bob

BetterSense
30-Nov-2010, 08:24
Sharp enough depends on your standard of sharpness. I tend to use 400 speed film and if a lens resolves down to grain level I'm just tickled. If I don't get sharpness down to grain, it's usually because of focus, camera/subject motion, or film holder flatness/position. If I had a lens that wouldn't give me sharpness down to the level of 400 speed grain obscuring detail just as much as lens unsharpness, then I would consider it defective. Even cheap lenses will do that.

DuncanD
30-Nov-2010, 10:11
I have owned Schneider, Rodenstock, Niklkor, and Fujinon lenses from 72mm to 600mm. I shoot 4x5 and print nothing less than 30"x36", usually 38"x48" (full 4x5 image) and frequently over 60" on the long dimension.

On any of my images, from any of my lenses, you can walk and stick your nose against the print (i.e., viewing distance = 3cm) and see more detail rather than less.

In my limited experience, the most critical elements for sharpness have been

patience
ground glass at the correct film plane
8x or greater loupe for fine details


Given that I have taken care to buy lenses in good condition, my choice of which lens - e.g., Schnieder 210mm vs. Nikkor W 210mm vs. Nikkor AM-ED 210mm vs Fujinon A 240mm - seems almost the least important in my outcomes.

domaz
30-Nov-2010, 10:26
Your old Super Angulon will be fine. I have one of the earliest models that still came in the #00 shutter (i.e. really small shutter hard to use) and it outresolves my Epson 4990 Scanner.

Bob Salomon
30-Nov-2010, 10:45
Your lens is diffraction limited at f22. At 64 you are well in diffraction and that will degrade the image. Why are you at 64 in the first place? Will a newer lens outperform yours? Certainly! First they are multi coated so have substantially less flare resulting in better contrast and that will enhance sharpness. Then they will have better color correction and lower distortion. Lastly they reproduce a flatter field then the old versions. And yes, I represent Rodenstock. But that doesn't change facts.

However for you to see the difference a head to head comparison test will easily show the differences if you are shooting the same film, same subject with detail at infinity, same exposure, within the optimal aperture range of the lenses and processed the same.

GPS
30-Nov-2010, 12:23
I've just bought a fairly inexpensive (due to a bit of Shneideritis) 90mm Schneider f/8 for my 45 camera and am wondering if it's sharp enough to make very large (40x50) prints.

...

So my question is: would there be a point in investing in a more expensive lens?
...


How about going the easiest way - make a whatever picture 40x50 and see for yourself if "there would be a point in investing in a more expensive lens"? ;)

Bob McCarthy
30-Nov-2010, 12:24
Sharp enough depends on your standard of sharpness. I tend to use 400 speed film and if a lens resolves down to grain level I'm just tickled. If I don't get sharpness down to grain, it's usually because of focus, camera/subject motion, or film holder flatness/position. If I had a lens that wouldn't give me sharpness down to the level of 400 speed grain obscuring detail just as much as lens unsharpness, then I would consider it defective. Even cheap lenses will do that.

How does grain have anything to do with the sharpness of the taking lens. Scanner optics I totally agree, but taking lens, not to my way of thinking...

bob

rdenney
30-Nov-2010, 12:35
What Bob says is correct, but it may not reflect the reality of working in the field.

For example, he asks, why use f/64? Well, because we needed that much depth of field, even after adjusting the focus plane with tilts and swings. Yes, diffraction will be more noticeable at f/64 than at f/22, but it will be less noticeable than important things being out of apparent focus (and depth of field gets a pretty tight definition at 10x enlargement).

And being out of focus is a much bigger concern than lens resolution. Resolutions charts only tell you how a lens performs at the focus plane, not how it will perform elsewhere, even within the depth of field.

Of course, the downside of getting enormous depth of field with f/64 is that the shutter speed will be long, which will allow any wandering puff of breeze to ruin your shot.

Back when the 90/8 Super Angulon was the lens that guys like Bob were touting, people were making 40x50 prints from 4x5, and those prints still get hung in museums today. What makes a print worth hanging includes many characteristics, and sharpness is only one. And even within the sharpness category, the raw performance of the lens at the focus plane is a relatively subtle effect. Precise color accuracy, for example, is important for product photography, which gets a lot of attention from the manufacturers, but which is not particularly important to landscape photographers.

It will be difficult to get really good 10x enlargements from your 4x5 film without having it scanned by something beyond what most consumers can afford. Your 90/8 SA will outperform any scanner most of us can afford, so save the money for drum scans of your best few images. You'll get more for your money.

I have a 121/8 Super Angulon, and it definitely out resolves my Epson scanner. But Bob is right about another aspect of this lens, and that is flare. When I have strong backlighting, the lens will show a little glow around the bright bits, compared to the newer f/5.6 design with multicoatings. My 90 is of that newer type, and it is indeed a little contrastier than the older 121. But that is not necessarily the basis for it being "better". It depends on your requirements.

Before spending a nickel on a newer lens, however, make sure that your technique is getting the most out of the one you have. That means really using the tilts and swings to manage the focus plane, really making sure the breeze doesn't move your camera or subject, and using a really rigid tripod and head. Make sure the lens is shaded well (I use a compendium shade even with short lenses). And then make your evaluation on a real 40x50 print, not on what you see on your computer monitor.

Rick "whose chain has many weak links" Denney

Brian C. Miller
30-Nov-2010, 12:46
The lens seems a bit soft in one corner...

That sounds fishy.

What you should do is make yourself a step wedge and check that the focus is where you think it is. Just grab some cardboard, cut it up and make a step wedge. Glue some newspaper to each step. Focus on the middle wedge and make your photograph. The negative should the middle wedge in focus. Also, do that for the "soft" corner.

Jack Dahlgren
30-Nov-2010, 12:53
How about going the easiest way - make a whatever picture 40x50 and see for yourself if "there would be a point in investing in a more expensive lens"? ;)

You don't even need to print the whole thing, just a portion of it at the same scale.

jonathan_lipkin
30-Nov-2010, 13:43
You don't even need to print the whole thing, just a portion of it at the same scale.

Yes, that's what I've been doing. GPS, the only problem with testing side by side is that I'd have to acutally _have_ the more expensive lens. :->.

@Bob - I'm shooting at f/64 to maximize DOF, because of the subject matter and my insecurity about my ability to adjust movements of the camera to max effect.

@Rick - thanks for the pointers. I think I'm doing all you suggested to the best of my somewhat limited LF skills.

@Brian - I'll give that a try.

Again, thanks everyone

Bob Salomon
30-Nov-2010, 13:59
Yes, that's what I've been doing. GPS, the only problem with testing side by side is that I'd have to acutally _have_ the more expensive lens. :->.

@Bob - I'm shooting at f/64 to maximize DOF, because of the subject matter and my insecurity about my ability to adjust movements of the camera to max effect.


But you see the plane of focus as you tilt or swing on the gg and you can use a loupe to verify the sharpness distribution across the field. And what are you focusing on? Infinity, 1/3rd in? Somewhere else?

And you can always rent a lens for a day or two if you can't borrow one.

jonathan_lipkin
30-Nov-2010, 14:19
Good idea to rent lens. Do you know of a place in NYC that would do so? Fotocare? Lens and Repro?
For the tests, I'm just shooting a brick wall, so the plane of focus is flat. In the field, I'm usually shooting on a ladder at noon on a crowded beach, so things are a bit hectic. I've been following the focus far, tilt near procedure described by Q.-Tuan Luong on this site. What I'm unsure about is the dof on a tilted plane of focus. Still working with some of the math faculty here to work out the calculations...

BetterSense
30-Nov-2010, 14:28
How does grain have anything to do with the sharpness of the taking lens.

There is no point of the taking lens being sharper than the film. Since I use fairly grainy 400 speed film, all I care about is that the lens can resolve to the film. In other words, if there is a detail in the print that I cannot see, I could not see it with a better lens anyway, because of the film grain.

Bob McCarthy
30-Nov-2010, 14:32
There is no point of the taking lens being sharper than the film. Since I use fairly grainy 400 speed film, all I care about is that the lens can resolve to the film. In other words, if there is a detail in the print that I cannot see, I could not see it with a better lens anyway, because of the film grain.

I don't want to sound argumentative, but I don't think what you believe is possible. grain, or more precisely, grain clumps are pretty darn small and are far smaller than the 60 lpmm that the best of the best LF lenses are capable.

bob

Heroique
30-Nov-2010, 14:41
There is no point of the taking lens being sharper than the film. Since I use fairly grainy 400 speed film, all I care about is that the lens can resolve to the film. In other words, if there is a detail in the print that I cannot see, I could not see it with a better lens anyway, because of the film grain.

I think I understand you, but I’ve never thought of LF lenses this way.

Which lenses have less resolving power than ISO-400 grain, and which have more?

Plus I’m curious if, say, ISO-50 grain would change the answer.

Bob Salomon
30-Nov-2010, 14:56
Good idea to rent lens. Do you know of a place in NYC that would do so? Fotocare? Lens and Repro?
For the tests, I'm just shooting a brick wall, so the plane of focus is flat. In the field, I'm usually shooting on a ladder at noon on a crowded beach, so things are a bit hectic. I've been following the focus far, tilt near procedure described by Q.-Tuan Luong on this site. What I'm unsure about is the dof on a tilted plane of focus. Still working with some of the math faculty here to work out the calculations...

FotoCare and K&M both rent in NYC.

BetterSense
30-Nov-2010, 15:32
Here's an example crop, pardon the large size, which is kind of necessary:

http://www.chazmiller.com/images/bookwambig.jpg

I cannot read the book. However, I feel that the grain is just as much of a barrier to my seeing that detail as the lens is. Thus, the lens is sharp enough.

This is a scan of an 8x10 print, which if I printed the whole negative at this magnification, would be some 80 inches wide.

GPS
30-Nov-2010, 15:36
I've just bought a fairly inexpensive (due to a bit of Shneideritis) 90mm Schneider f/8 for my 45 camera and am wondering if it's sharp enough to make very large (40x50) prints.
...

So my question is: would there be a point in investing in a more expensive lens?

...


Yes, that's what I've been doing. GPS, the only problem with testing side by side is that I'd have to acutally _have_ the more expensive lens. :->.
...


Sorry, Jonathan, without wanting to dwell on the point - but in your OP you wanted to know if your lens is sharp enough to make the large print. Doing a side by side comparison of different lenses is a different question, isn't it...
You don't need to rent any stinking lens to see if your lens is good for your large print. No need to make the thing even more complicated... Kiss ;)

Heroique
30-Nov-2010, 17:19
...I feel that the grain is just as much of a barrier to my seeing that detail as the lens is...

Very interesting, yet your scan raises another question:

What do you see when viewing the film directly w/ a loupe?

Would your ISO-400 grain (or “grain clumps”) be “finer” than any lens can resolve, as Bob claims?

Bob McCarthy
30-Nov-2010, 18:32
I may be spoiled with tmy-2' but how can one read a resolution chart if grain were larger than the evaluation lines pairs.

And at optimum f-stop almost any 4x5 lens does 40+ lpmm which represents roughly an 8X enlargement.

Bob

BetterSense
30-Nov-2010, 18:54
What do you see when viewing the film directly w/ a loupe?
I can't see that well with any loupe that I have. I would need to use a 20x grain magnifier or a microscope.

jonathan_lipkin
1-Dec-2010, 07:35
Sorry, Jonathan, without wanting to dwell on the point - but in your OP you wanted to know if your lens is sharp enough to make the large print. Doing a side by side comparison of different lenses is a different question, isn't it...
You don't need to rent any stinking lens to see if your lens is good for your large print. No need to make the thing even more complicated... Kiss ;)

GPS - I am an academic. It is my job to take simple things and make them more complicated ;->

And you are correct - my initial question was logically inconsistent. A more accurate question would have been along the lines of how much image quality improvement would I see if I were to purchase a more modern, expensive lens.

I've been busy notching my film holders and testing them for light leaks. Now it's off to making test prints from the 90mm.

Thanks

Cor
1-Dec-2010, 08:14
What I'm unsure about is the dof on a tilted plane of focus.


Jonathan, there are loads of links and literature on that subject, simplified it means that DOF at the start of the tilted is minimal/zero, and it expands above and under the tilted plane the further you get from the lens.

Allow me to show you a recent photograph of mine: I tilted the plane of focus of my 120mm Angulon (4*5 film, FP4+) so the big rock in front and the middle of the building were sharp, stopped down to f22..

In this 8*10 test print I judge the building as completely sharp, the rock too but some of the smaller stones/pebbles in the front not, since DOF was at it's shallowest there.

Hope this helps,

Best,

Cor

rdenney
1-Dec-2010, 08:58
What I'm unsure about is the dof on a tilted plane of focus. Still working with some of the math faculty here to work out the calculations...

Depth of field is calculated as the distance in front of and behind the plane of sharp focus that appears to be in focus according to whatever standard you apply. For a given focal length and aperture, those distances will be smaller for closer subjects and longer for more distant subjects. When the focus plane is tilted, some subject elements along the focal plane are near and some far. The depth of field distances around the near subjects are less than they are around the more distant subjects, just as you'd expect if you left the lens parallel to the film refocused at each of those subject elements.

You end up with a wedge-shaped depth-of-field zone surrounding the tilted focus plane, with the narrow end of the wedge surrounding the part of the focus plane that is closest to the camera.

In this photo, the 121mm Super Angulon is heavily swung to the right to angle the focus plane so that it runs along the surface of the window opening and through the distant tower. The silhouette of the left side of the window opening, however, is clearly out of focus. The depth of field at the window opening is narrow--as one would expect with any camera focused on an object that close. I still had to use f/45 to extend the depth of field as much as I did. The three points I kept checking on the ground glass were the lower right portion of the window opening, the tower at lower left, and the cross on the top of the tower. Three points, of course, define a plane, and I kept swinging, tilting, and refocusing until they were all sharply focused wide open. The resulting tilt/swing was rather extreme, but that lens has a lot of coverage on 4x5. That put a zone of sharp focus through my most important subject material. Then I stopped down.


http://www.rickdenney.com/images/ConcepcionSTwr032793-9_lores.jpg
Mission Concepción South Tower, 1993
121/8 Super Angulon, 1s. f/45
FP4 in HC110B

This image is made with a lens of the same design and vintage as your 90, and it's plenty sharp.

Rick "who likes near-far relationships" Denney

jonathan_lipkin
3-Dec-2010, 07:13
Thanks, all. Off do to some additional testing of the lens. Just spent the day yesterday reading on diffraction.