medium format vs large format lensesgreenspun.com : LUSENET : Large format photography : One Thread
I have had my 4x5 camera for a few months now and have shot quite a few pictures with it. I have always thought that I should be seeing more out of it though in terms of sharpness. I have some pictures of the same subjects I took with my medium format (mamiya) camera and they are significantly sharper. I focus my 4x5 carefully and check every area of the gg. But even when focusing on a specific single object the mamiya is sharper. I use tmax in both and develop both in the same developer. I print the medium format with a new Rodenstock lens and the 4x5 with a new Schneider comp s. I have used a readyload and the toyo film holder in the 4x5 with the same results. My lenses are a Nikon 90sw 5.6 and a new Rodenstock 180mm sironar s. Does any one have any thoughts? It seems to me it is probably a lens difference. Looking at a print from the medium format side by side with one from the 4x5... well, the 4x5 in really unacceptable.
-- mike hardaway (email@example.com), August 07, 2001
Assuming you are in the U.S. and have one of our Rodenstock lenses with the lifetime warranty we would like to see the lens and a print and a negative.
Call us at 800 735 4373 if it is one of our lenses to set up a test by our service center.
-- Bob Salomon (firstname.lastname@example.org), August 07, 2001.
Mike, Could it be that you are not stoping the lens down far enough? I have found that with the majority of my landscapes I use f22 as the absolute minimum and often use f32 as my "norm". IMHO I understand that on the whole MF lenses are sharper than LF, and 35mm are even sharper than MF! But the benefit of using LF is in the tonality I can get from my larger negs when compared to a MF one. To get anywhere near the quality of 5x4 negs I need to use a much slower film and enlarge to a lesser degree. The lenses you are using are amongst the best in their class, I would be VERY surprised if you had 2 duds! I always assumed that my LF negs would show ultimate sharpness, they don't ,however they are still "better" than anything smaller. Give them another try, maybe a shot of a building facade so you won't need any movements. Stop the lens well down and then compare the results. Let us know how you get on and good luck! regards Paul
-- paul owen (email@example.com), August 07, 2001.
Good job Bob!!
-- Jorge Gasteazoro (firstname.lastname@example.org), August 07, 2001.
There is a possibility that the Mamiya optics display greater acutance while the LF lenses display greater resolution which may be deceiving until print size really starts to increase.
However, you don't mention which LF camera it is that you have had for a few months or whether it was purchased new or second-hand. Given that the Toyo and Readyload holders are performing equally yet producing an inferior image sharpness than the Mamiya I would venture to suggest that the positioning of your ground glass in the ground glass frame may be the culprit. If there is a discepency between the Ground Glass Plane during viewing/focussing and the Film Plane during exposure no lens will be performing at its optimum with the error more noticeable the shorter the focal length.
Other threads on this forum have dealt with ground glass / film plane allignment and this is an area that may warrant some consideration in your case.
Good luck ... Walter
-- Walter Glover (email@example.com), August 07, 2001.
I've noticed the same thing with my 6x9 view cameras but assumed that because they don't have the advantage of a larger piece of film, this is a byproduct of their larger image circle and to be expected.
That said, have you confirmed that your camera's back is locating the film plane in the same plane as the ground-glass? It's also possible the fresnel (assuming your camera has one) is positioned incorrectly, which can cause the plane of focus to shift far enough that the Depth of Focus can't cover for it.
If you're not able to address these issues yourself, then it might be worth paying a good technician to check them out for you. Although I can't claim them as mine, I've seen some _very_ sharp 4x5 prints over the years so I know that it's possible.
-- Jeffrey Goggin (firstname.lastname@example.org), August 07, 2001.
One reason for disappointment with optics on view cameras can be traced to alignment errors in the ground glass. You can have the sharpest, most contrasty lens in the world and if your ground glass/film plane coincidence is out of whack, you'll never get a sharp negative. I've seen this numerous times. A good friend and I went on a trip to test out his newly acquired Meridian folding metal field camera. The previous owner thought it might be a good idea to install a Fresnel brigtening screen under the ground glass. It made the view brighter, but it also made it impossible to ever get a sharp image. Contact prints from his negatives were as big an image he could live with. I removed the Fresnel, replaced the grungy gg with a new one and did a test with film to confirm proper alignment. It passed with flying colors and continues to yield excellent images. With hand cameras, it is almost a certainty that what appears sharp in the viewfinder will be just as sharp on film (assuming the camera hasn't been damaged), but with view cameras there are many more variables. Tell us what camera you are using and whether you purchased new or used. Does it have an aftermarket viewing screen installed? You may simply need to have the gg adjusted. This should be done by an experienced professional and should be film tested to prove the adjustment was successful. I authored an article on how to build your own gg alignment test target. See if you can get your hands on the Nov./Dec. 1996 issue of ViewCamaera magazine and check it out. Don't get rid of that lens or abandon LF until you've investigated this. Good luck.
-- Robert A. Zeichner (email@example.com), August 07, 2001.
Your right Mike. I used to have a mamiya 6 but I've traded for cambo wide with 47mm XL. I recently compared the B+W negs of the 47 XL and 50 mm of the mamiya 6 (same image ie a japanese bridge at night) the mamiya was heaps sharper wide open (F4) vs F11 of the 47 XL even whe I crop the 4X5 to the image size of the mamiya. I'm not going to even bother taking an image with F5.6 with the XL and compare it with F4 of the mamiya.
Obviously the 4X5 image is heaps bigger than the mamiya and the coverage of the 47 XL is unbelievable. Which is the reason why I traded in my mamiya! It would have been nice if the lens is as sharp.
I will buy the 150mm apo symmar soon for my cambo wide. Any comment on this lens guys? Regards, Renee
-- dangal (firstname.lastname@example.org), August 07, 2001.
It would probably be a good idea to test the back and rear standard of your view camera. It could be that the film holders and readyload holder are not in the sharpest plane of focus for your back.
Somewhere on the www, I've read a technique for determining how to check the holder alignment with the camera back. I can't remember who had this on their site. Anyone remember???
A non-scientific way would be to take multiple shots with each shot at some slightly different focusing point in relation to what you deem the sharpest focus on the ground glass. I hope someone else can explain this better, but I'll try again.
1.) Take a shot with what you deem the sharpest focus achieved at the ground glass.
2.) Next, move the back slightly (very slightly) out of focus (forward of where you'd normally have the sharpest image on the ground glass) and take a shot.
3.) Next, focus the ground glass so the image is sharpest again and then move the back backward so it's just slightly out of focus. Take this third shot.
Make note of each shot. I'd put something into the actual scene to indicate which shot is which so you can later differentiate the three easily on the light table. Maybe a small white card with something different written on it for each shot.
Make sure your technique is exactly the same for all three shots (i.e. lighting, letting the camera stabilize after inserting the holder, letting the tripod stabilize, etc.). Use the same lens for all three shots, same aperture and shutter speed, same shutter release technique, etc. Minimize as many variables as possible, so you can determine the actual cause of unsharpness.
Try the same exact technique for both of your lenses to see if one lens exhibits the problem more than another. Next, if you want to pursue this further, repeat this test at different subject distances (i.e. close-up subject for one trial, then a distant subject focused at infinity for another trial).
I hope this helps. Let us know how it works out.
-- S Ratzlaff (email@example.com), August 07, 2001.
While there are many valid points above (gg alignment etc...) your enlager lenses are different. Try removing that variable by conducting a similar test using a fine grained transparency film such as Provia in both cameras. Inspection of both trannies with a good loupe should give you a better idea of the discrepancy.
-- Dominique Labrosse (firstname.lastname@example.org), August 07, 2001.
Mike: Here's the third vote (fourth?) for checking that the ground glass is where it is supposed to be. Stick a line of objects on a fence, focus on one you'll recognize on the negative, and shoot one sheet with the lens wide open. If the glass is out of register, you'll know it. Are the objects you are comparing for sharpness the same absolute size in the negatives?
-- Kevin Crisp (KRCrisp@aol.com), August 07, 2001.
This is a process of eliminating variables to find the culprit.
Check the negative itself, not the print. Is it sharp? (Using transparencies as suggested is also an option). If the negative is sharp, then the fault lies in the enlarging process, not the camera nor camera lens. Problems can be ... well, you probably know what can cause an unsharp enlargement. Post again, if you don't.
-- Charlie Strack (email@example.com), August 07, 2001.
Thanks everyone for the quick and thoughtful responses. And thanks also to Bob for the great customer service. My camera is a new Toyo field camera. I have done no modifications on it. I find myself shooting anywhere from f16 to f32 usually. I went and looked at my trasperancies as suggested (thanks) to eliminate the enlarger. The change from 4x5 to medium fmt is the same in the slides. It seems to occur in both the 90mm and the 180mm equally. It does seem unlikely that they would both be off and by the same amount (appx). So, it would seem more likely that my gg to holder position is off. The suggestion of lining up objects then shooting one with the lens open seems like a good idea. Any others? And if that is the case, how do I fix it?
-- mike hardaway (firstname.lastname@example.org), August 07, 2001.
A couple of thoughts...
The Toyo is designed to have its fresnel in front of the groundglass (iow inside the camera); disagreements about proper fresnel position aside, the absence of a fresnel lens or perhaps it being put on the back of the groundglass could cause a problem. If the camera's brand-new, that's most likely not the problem.
Considering the groundglass itself, it's pretty dark, which can make focusing difficult with the wide lens. Even so, you _should_ be able to focus accurately enough.
Be sure you're using enough magnification in a loupe, but not too much; around 4x-5x is best. Too little won't give enough magnification to clearly see focus, while too much will magnify the groundglass graininess and fresnel rings so much that it'll also make focusing difficult. Worst is the common cheap 8x Agfa (and other) plastic loupes. If you don't have a decent loupe, just try viewing the groundglass through a reversed 35mm to 50mm lens off a 35mm camera; that makes a great high-quality loupe.
-- John Hicks (email@example.com), August 08, 2001.
Mike, I would add the following points....
1. If your using a new Toyo Field and Toyo holders, I would not look there for the problem. Toyo puts every camera thruogh a laser test to assure gg / film alignment. If it is off, MAM usa will correct this and check it if you beleive its a problem, assuming you are in the USA. If it's happening with both lense, it obviously is not the lenses...the chances of two bad new lenses is nill. You are shooting the LF lenses at the desired f stops, so thats not an issue.
2. Maybe your expectations are too high? I shoot with the Toyo AII and also the Mamiya7. In general MF lenses using modern glass will clearly produce sharper chromes of EQUAL size. However, the limitation of resolution to film is limited more so by the film, not the lenses. So although MF lenses will deliver sharper chromes, and higher contrast images to film, the difference is not significant enough to make up the 2x larger 4x5 film. MF lenses would have to deliver 2x the resolution "to film" to overcome the 4x5 2x size advantage, this is impossible. The limitations of any camera system is limited to the total system, as described in a formula in the back for the Fuji handbook ...bottom line, even the best glass in the world can not improve on-film resolution by more than 25% , i.e. better than your LF lenses. This is also evidenced by C Perez tests results of LF and MF glass.
3. I know this may sound obvious, but it was not addressed above. A fair comparison would be to look at each image using an adjustable loupe. Inspect each chrome at the same final size. This would equate to a 4x loupe setting on the 4x5 chrome and a 8x loupe setting on the MF chrome. Now you are looking apples to apples at the final print size with the same loupe. If doing this experiment, the MF looks sharper, its time to have your gg / film alignment checked. If you were looking at both images at the same magnification, than nothing is wrong! My M7 chromes blow away any LF chromes I shoot, even with my Schneider SS XL's.
I think the best LF glass is inferior to the best MF glass. LF lens designers probably felt there was no need to match the sharpness since the film size more than overcame the small difference in sharpness. But after reading a few threads on this board, it seems this is changing as the new digital LF lenses seem to have MF sharpness that can be used on LF film.. I think the image circles are big enough for 4x5... maybe someone can comment on these lenses for Mike. If not, you can re check the threads for the posts I am referring to. Hope this is helpful!
-- Bill Glickman (firstname.lastname@example.org), August 08, 2001.
I think the physics of the situation works against LF with respect to smaller focal lengths, in general. Consider what a lens does: It bends finite points of light and brings them into "focus" with some degree of accuracy, the higher the accuracy the sharper the image. It stands to reason, then, that the greater the distance between the refractive surfaces and the film plane the more lens aberation will be magnified. Sure, there are abundant examples of fuzzy short lenses and sharp long lenses. It's just more difficult to make sharp long lenses.
I recall reading, some time ago, when those little Kokak disc cameras were popular, that the lenses in them resolved 80 lpm. They were made of plastic and were very short.
The lenses used in aerial recon, by the military, also resolve 80 lpm. and they are long....but extremely expensive.
In the end it is market forces that determine how sharp a lens is. How sharp do you have to have it? How much are you willing to pay?
-- Bruce Wehman (email@example.com), August 08, 2001.
I think it has to be the back, I have a TK45 and a hasselblad, when I compare the negatives the ones from the TK45 are much sharper than those from the hassie, even though the ones from the hassie have more contrast, the reason I think they "appear" sharper. So beleive me, the 4x5 should be sharper, even with cheap lenses, I sometiems use a Nikkor 210 w, and although the contrast is horrible the negs from this lens come out sharp as ever....good luck.
-- Jorge Gasteazoro (firstname.lastname@example.org), August 08, 2001.
Since we haven't nailed it yet, look for the obvious.
1. Using a tripod with the 4x5? Is it heavy enough to stabilize the camera?
2. Any chance of camera motion?
3. Any chance of subject motion? (You didn't say what the subject was.)
4. Using a cable release?
4. Do the lenses project a sharp image? Try this at night: open the shutter, and focus the image of a bright light source (street light, moon, porch light, whatever)on a matt sheet of paper--can you get the image in focus?
Do you have an experienced LF friend close by who could look at your equipment & technique?
While MF lenses are better than LF, no way should any LF negative have unacceptable sharpness when things are aligned & used right. My simple 4x5 portraits just bowl me over compared to MF & 35mm. In fact, I think LF has generally been underappreciated in portraiture. Suberb tonality and detail. Sorry you're not seeing it yet.
If, by chance, you're in the SF Bay area, & you can't figure it out, I offer to meet you to help see what's going on.
-- Charlie Strack (email@example.com), August 08, 2001.
Thanks Charlie for your kind offer. I really do wish I could take you up on it, I could use some help in large format technique. However, I am in Virginia. I have never used, seen one used or even known anyone who had a large format camera until I bought mine. But over the past months I have read most of the recommended books on the subject and surfed the net nightly in my studies. Through trial and much error I am getting better. As far as the lens issue goes, my tripod, etc is very stable. I ran a couple of tests and looked at the results. I also went back over some of my prints looking for clues. The first test I did that was suggested here to me was photographing one object in a row of objects with the lens wide open. I did this with both my Rodenstock and Nikon. I put a few cases of Corona (left over from my wedding) in a row on my deck rail and the one I focused on was the one that came out sharpest with both lenses. I used these cases because I would not only be able to see the edges but also the writing on the boxes for comparison. (I could also drink one as it was about 96 outside) I used tmax in a readyload and my regular Toyo holder for this. Both looked the same under a loupe. The thing i did notice though, is that the Rodenstock is a sharper lens. But even more noticeably it has better contrast and much more "local" contrast. This makes the Nikon lens look a bit soft in comparison. I then went back and looked at my prints and saw that show up in those too. My next test was suggested to me by Jeff at Badger Graphics. He suggested that one reason my images are not as sharp as I want them might be because I am not stopping down enough. I took a water ski I have with crisp, bold writing on it and stood it up agains a brick wall. I then took some pictures with my Nikon each at a different stop to f45. I then examined them under a loupe. Under a loupe and to a lesser extent with my naked eye I can see the images getting sharper to f22, then about the same at f32 then falling off a bit at f45. Chances are I do need to stop down more than I thought. But really the lens is still not as sharp as I would like it and more importantly it does not have as much contrast as I would like to seperate the details. I did however find some portraits I did with the Rodenstock that are fantastic, both in sharpness and contrast. So obviously my technique in certain situations is more than suspect and needs improvement. So, I will keep working at it until I have more sucesses than failures- then I will work harder. Because as most of you I have never enjoyed photography as much as when I am using my large format camera. And with such a great instrument it would be a shame for me not to use it to its potential.
-- mike hardaway (firstname.lastname@example.org), August 09, 2001.
Your tests are interesting, but let me suggest another interpretation. Starting with the waterski test (and assuming you were trying to focus on the ski): this may actually suggest that there is a problem w/ your GG alignment. Increasing sharpness as you stop down is likely an indication that the ski was not actually in the plane of focus (since stopping down increases depth of field but doesn't change focus on the exact plane of focus. Note, however that stopping down could result in some increase in sharpness on the plane of focus because it also can eliminate some lens aberrations.)
The beer case test may not be sensitive enough to pick up the GG misalignment. (The case you focused on could have been the closest to the plane of focus although not on it.) You might try it again by lining up the bottles, closely spaced, and see whether the one you focus on is in the best focus on the negative. (I'm assuming you haven't drunk them all by now.) Good luck.
-- Chris Patti (email@example.com), August 09, 2001.
I strongly urge you to read my article in the Nov/Dec 1996 issue of ViewCamera. The test set up I describe is specifically designed to take contrast into account. It actually makes use of perceived contrast to help in determining whether or not your camera passes the test! It is designed to test gg alignment under the most unforgiving conditions. The actual (and optimum) performance of most view camera lenses are usually obtained when stopped down. The depth of field needed for most photographs is exactly what you don't want when testing ground glass alignment. Beer bottles, water skis and newspaper print don't begin to do the job of a good test target.
-- Robert A. Zeichner (firstname.lastname@example.org), August 09, 2001.
I agree with Chris above.... I have run these tests also, to check gg and film alignment... if take a paper with small print, (you need to experiment with the size based on the fl lens you are using) and have 60 lines of print... like, 11111 on the first line, 222222 on the second line etc. Then you take that paper and put it on a slant board, so that with the lens wide open, you only have one line in focus and all other lines out of focus ( you need to experiment with the slant angle) Note which line is in focus...take a shot wide open and see if the same line is in focus on the film. This is good indication of gg / film alignment, not as good as lasers, but a good first test...
-- Bill Glickman (email@example.com), August 09, 2001.
A low contrast Nikkor??? rare bird. The fact that the Nikon 90 is not as sharp as the Rodenstock 180mm indicates to me that there is still case answerable for film plane / GG plane alignment.
The error does not have to be very great for it to have a devastating effect on the image quality so what I suggest is that you remove the Ground Glass frame as you would to place a Graflok holder in place and then check the metal surface surrounding the ground glass for burrs, dirt hair etc. and then check the surface upon which it seats. Maybe there is a ridge of light trap material or some other particle.
While you're at it, check your film holders.
-- Walter Glover (firstname.lastname@example.org), August 10, 2001.
There is a chance you have bad lenses. They don't all come out perfect! Take Bob Solomon up on his offer to check your lens out.
(Having 2 bad lenses, each from a different supplier seems unlikely, but it is possible.)
-- Charlie Strack (email@example.com), August 10, 2001.
Mike: Forget about all the dissertations about lenses! With MF the film plane is determined from birth, and the only deviation will be the result of the paper and film buckling. With LF cameras the film plane position is determined by the camera construction, the way the GG is installed and by the film holders. Additionally, one hopes that the GG is also at the same position. One photographer that does workshops always starts its students by calibrating cameras, which invariably are off calibration. Holders also can vary significantly. I have one Linhof holder that has perfectly flat septums on both sides, even though there is a slight difference in the film plane from one side to the other. I have measured many other holders from several other brands, none measure up to this one Linhof holder. Friends, when talking about film sharpness it's time to give up 35mm and MF thinking habits and realize that the mechanics are totally different. Forget about differences in optics for the start and start with the basics. The needed measurements require a depth micrometer and a perforated (for the micrometer probe) "flat" aluminum plate. Not much to it except for patience and attention to detail. Re-check your work and do statistics to avoid errors. With a little thought you can figure out what has to be done. Check your GG, then your holders and don't be surprised at the discrepancies. Finally, do not skimp on holders. The cheapest plastic can ruin the images from your space age glass. Remember when saving $20 on holders how much you paid for the glass and how much it cost you to get there. I can think of no photo expense that is cheaper than film holders. With Linhof later model technikas the GG position can be adjusted to within 0.001" by turning tiny screws. If you are lucky, your camera also provides for adjustments. I personally would not buy any LF camera that can't be adjusted.
-- Julio Fernandez (firstname.lastname@example.org), August 11, 2001.
Mike, sorry for this basic question, but I have seen this happen a few times: Is your tripod really strong enough to hold your view camera steady as a rock and absorb the shutter shake and the vibrations due to wind and cable release operation?
But even if it's the case, your Mamiya lenses will beat the LF lenses by far. Check Chris Perez lens test pages (http://www.hevanet.com/cperez). Some Mamiya lenses produce as much as 95 l/mm when an excellent LF lens at it's best opening hardly passes 67l/mm. Film flatness is also an issue with LF. Check also what apertures produce the best results. Usually 16-22. At f32, a LF lens is considerably softened.
-- Paul Schilliger (email@example.com), August 11, 2001.