6x7cm film format, lenses, and quality

[Robert J Pellegrino]

I have several specific questions, regarding large format lenses used with 6x7cm film format. I am interested in purchasing a large format lens in the 120mm-15 0mm focal length range, but I have a couple of issues to work out first. I reall y want to achieve the highest overall image quality possible from the relatively small 6x7 film size. I'm aware that the maximum resolution available on many large format lenses, is considerably less than that available on medium format l enses. Therefore when using a large format lens for the 6x7cm film format, the resulting image may not equal the overall image quality obtained by using a trad itional medium format camera and lens combination. For this reason I believe th at I should start out with a very high-resolution large format lens. I've been told that usi ng a lens with a very large image circle, for a given film size will reduce the overall contrast of the image. Most manufactures offer at least two lenses for a given focal length, usually one is said to be an improved " in some form " ver sion of a basic model. When I look at the specifications for these upper end len s, more often than not, the image circle is larger on these improved versions. C an you folks provide some insight regarding these issues. At this point this is all academic to me, because I have no personal experi ence with any of this. What I really need is some sound advice on purchasing a h igh quality large format lens in the 120-150mm focal length range to use on my A rca-Swiss 6x9 F-line camera. Do you think that it's possible while using the Arca 6x9 with a 6x7 film back to equal the image quality of a traditional medium format 6x6 image croppe d down to 6x4.5? One more important question, do you think I would be better off using the full 6x9 format and then cropping to 6x8 rather than using the 6x7 format? I prefer the traditional aspe ct ratio of 1:1.25 i.e. 4x5, 8x10, etc. If you could make brand and model specific lens recommendations that would be very helpful. Thanks a lot.

Bob Pellegrino

[John Lehman]

IMHO, if one is hung up on resolution however measured, the major difference between large format and medium format is not the lenses but the precision of the camera/film/lens. As an example, I have a Rolleiflex F2.8 with a Zeiss 80mm f/2.8 Planar lens and I also have the same lens mounted on a 6x9 Crown Graphics. The former with Ilford panF in PMK will resolve 90 lpm; the latter only 60 lpm at f/8. Even my so-so 1950's vintage lenses (e.g. a Wollensak 65mm WA Optar) have aerial resolutions of close to 100 lpm measured with a microscope at the film plane. They have nowhere near that in practice, because the precision of the cameras is marginal compared with a non-bellows precision metal MF camera. This will be true of any large format camera.

Personally I doubt if in practical use you will be able to tell the difference between LF lenses of reasonable quality -- those who have spent large amounts of money for lens X vs lens Y will probably disagree :-)

[shaman]

I had the same question as you and finally decided to simply try it myself. I bought an ARCA 6x9 with Horseman film holder and the Schneider 110 XL (despite it's huge image circle) and 2 Rodenstock lenses. The quality is VERY high and rivals my Hassleblad's! I would be very surprised if you find the quality of 6x7 shot with a large format lenses inferior to the quality obtainable with 6x4.5 traditional medium format camera - to some extent of course this will depend on your application. If you find use for increasing DOF by tilting the lens stage then the view camera will win hands down. If you use your view camera mostly without tilts, then the comparison will be much closer.

In Summary: I was pleasantly surprised by the image sharpness obtainable. However I am also surprised how different photography is using view camera as opposed to medium format camera and I wouldn't want to say that one is inherently "better" than the "other". They are simply different - very different!

[Trevor Crone]

Bob if I may try and answer some of your questions from some of my experiences. For many years I used a Pentax 6x7 with a range of lenses from fish-eye to telep hoto and got what I thought was good results but it wasn't until I purchased a v ery basic 6x9 wood field camera with the now discontinued 100mm Nikkor-W and Sch neider's older version of the 47mm/5.6 Super Angulon that I realised what I was missing out on. My prints (and I'm only speaking as a b/w worker here) took on a n almost 3D quality with beautiful fluid tones. It wasn't so much an increase in sharpness but an increase in gradation esp. the middle/high values. And I was u sing the same enlarger and lens. One could of course say that the Pentax lenses etc. are nowhere near as good as say Hasselblad, I don't know. So the comparison could be flawed. However I've al ways felt that the format wars is not about sharpness (and I've seen some incred ibly sharp images from 35mm) but about the smoothness of gradation, the richness of tones that the larger the format the finer this becomes. So providing you focus correctly and with todays computer designed lenses you kn ow its going to be sharp whatever the format. With regard to a lens in 120-150 bracket I would recomend the 135 Apo-Sironar it s small, light and versatile, takes 40.5mm screw filters and it certainly delive rs sharp results whatever format you use it on. Hope this is of some help, Trevor.

[Doug Paramore]

Bob, Trevor is giving you some good advice. I agree that gradation, smoothness and sharpness of a 6x7 neg is the main reason to go into the larger format. I would like to address a couple of the specific questions you posed. There is absolutly so advantage to be gained by shooting 6x9 and cropping to 6x8 or 6x9. The only advantage is to Kodak, Ilford, etc., if you make an 8x10 prints. You use more film for the same number of shots. As to problems with image circle, the image can be degraded due to the light from the lens hitting the bellows and causing internal reflections. This is easily avoided by using a proper lens shade. In practical terms, about any good lens made for large format will work well in the 6x7 format. If you are planning to shoot test charts instead of scenics, buildings and folks, you may want to do extensive testing. If you are planning to make good pictures, quit worrying about resolution and just get a good lens made by a major manufacturer and enjoy your camera. Resolution, as long as it is adequate, is not a factor in LF photography.

[Glenn Kroeger]

Bob: Last fall I ran some tests of 6x9 vs 4x5 with matched lenses and DOF equivalent apertures. For example a 180 Apo-Symmar on 4x5 and a 120 Apo-Symmar on 6x9. Same film, Velvia. Scanned both on a Tango scanner and printed at Res12 on a LightJet5000 printer. The difference in sharpness is nearly invisible in sizes smaller than 20x24 (20x30). There is some additional grain in the 6x9 at 20x24 which makes the 4x5 looks somewhat smoother with slightly better tonality. Remember though, at 20x24 these differences are just BARELY noticible to someone who is looking for them. So if you are happy with prints smaller than 20x30, you won't be unhappy with rollfilm.

This assumes good holders (Horseman, Toyo, or Sinar) and the best in modern Apo lenses.

It is also very important is to limit your aperture when using rollfilm. In 4x5 I use f/22-f/32 alot. When you go down to 6x7 or 6x9, diffraction is a more pressing issue and you should try to use f/11-f/16, and f/22 only if absolutely required. Since you are only using the "sweet" center part of the lens coverage, using f/11, if it gives you enough DOF, will also improve sharpness.

[paul owen]

Robert, I agree with Trevor (above), the fluidity of a LF neg is far superior to anything in a smaller format. IMHO and from experience, my MF negs "appear" sharper than my LF negs when viewed through a loupe on the lightbox. This apparent sharpness is especially evident in the background of many of the landscapes that I have photographed. But on enlarging the negs to about 12x16 inches there is NO comparison. The LF prints win hands down. There is a quality that is simply not attainable with a smaller neg. The tonality of the print is quite beautiful and the image bitingly sharp. My MF prints are very sharp, but on enlarging are clearly inferior to those made from LF negs, and do not exhibit the same "luminosity" as the LF. This is probably due to the amount of enlarging required to achieve the print size being far less than that for the MF negative. I use Schneider 47mm (non-XL) for MF on 6x9, and Schneider 110mm XL for LF. I hope this is of some help!!! Regards Paul.

[Robert J Pellegrino]

Thank you for taking the time to reply to my questions. I look forward to performing my own exploration into the view camera world. I am slowly putting together my outfit as finances allow. I have ordered my first components I'm awaiting their arrival. I plan to research each item, before I buy. That has not always been the case in the past. So I'll be asking a lot more questions in the future. The foundation of my new system is an Arca-Swiss 6x9 F-Line Metric, That I've ordered new from Robert White UK. I first heard of Robert White UK on this forum, that advise alone has saved me a substaintial amount of money. Thank you.