Rodenstock Ronar 360mm f9 - 10x8 Coverage in the real world

[pixelda]

Regarding 10x8 coverage of the Ronar 360mm f9 in a Copal 3 shutter (not the barrel version)

I've seen a number of threads on this subject but apart from official figures, no one seemed to know what the real coverage is.
Having expanded from 5x4 into 10x8 also, I wanted a standard focal length lens but most of the options were very expensive, very heavy, or had enormous filter thread sizes (or all of these!)

One less-large option is the G-Claron 355mm but these are expensive and not widely available in the UK - I quickly found the Ronar 360mm f9 had availability here
I performed lens calculations from available figures, the results of which are close to the quoted numbers - i.e., the lens just covers 10x8

Out in the real world, I was finding that 5cm of front rise/fall was not cutting off the corners - strange given all documentation says it should
I performed a simple coverage test in the house as follows

• Mount lens on the camera
• Close room curtains around the camera so that the lens is pointing outside but the rear is in dimness
• Move bellows to less than 360mm for ease of test
• Remove camera back (ground glass)
• Move a white card back and forth to get infinity focus from the view outside
• Check corners are not darkened or cut off
• Mark a line on each side of the card (easier to put a line on one side beforehand)

The measured result is over 5cm of coverage from this test which bore out my real world use of the lens
For landscapes I never focus at infinity anyway - but on something nearer, increasing image circle

The barrel version of the lens may give a different result, but as a black and white shooter in 10x8 the lens is very well suited to my work

https://www.flickr.com/photos/pixelda/52213462688
https://www.flickr.com/photos/pixelda/52257362694
https://www.flickr.com/photos/pixelda/52213445856

[ridax]

Dialyte type lenses illuminate much more than they cover sharply. Their image circle is not limited by vignetting; it is limited by astigmatism rapidly growing after a certain angle limit.

[Drew Wiley]

That's why plasmats also exist. My own large coverage option for 8x10 is the Fuji 360 A in its petite no.1 shutter. Very high optical performance comparable to the best dialytes, but also a big big circle. I suspect the even bigger image circle of the comparably designed 355 GC is simply due to less mechanical vignetting of its bigger no. 3 shutter, which doesn't necessarily mean the spooky outer limits of its circle are equally good, but that's not important to the ULF shooters who use it with contact prints in mind.

My dialyte 360 is an Apo Nikkor f/9 - a superb optic with reasonable coverage for 8x10 field use provided wider apertures are not being used if serious front tilts are involved. But I've never gotten around to mounting it in a shutter since I have other options in that focal length already in shutter. But apples to apples, its effective coverage stopped down is about the same as my 14 inch Kern Dagor or my Zeiss 360 f/9 process tessar.

[MAubrey]

Ridax's comments about illumination and astigmatism are spot on.

And different lens manufacturers consider different amounts of astigmatism to be acceptable.

Example:
Rodenstock lists APO-Ronar 300mm f/9's dialyte coverage as 265mm.
Fujifilm lists its Fujinon C 300mm f/8.5 dialyte coverage as 380mm.

Of course, the glass types each manufacturer uses and the specific cell spacing is going to be different between them. But they still also represent different attitudes toward IQ acceptability in the outer frame.

[ridax]

My own large coverage option for 8x10 is the Fuji 360 A in its petite no.1 shutter. <...> I suspect the even bigger image circle of the comparably designed 355 GC is simply due to less mechanical vignetting of its bigger no. 3 shutter, which doesn't necessarily mean the spooky outer limits of its circle are equally good, but that's not important to the ULF shooters who use it with contact prints in mind.

I don't think the shutter vignettes anything in the lenses like these; it most probably depends on the glass elements size and the outer barrel design (though there were plasmat-type Horseman lenses that were not sharp at the edges so the optics itself matters, too).

My 355mm and 210mm plasmat-type G-Clarons were very sharp all their 78° through, and somewhat sharper than my Dagors in the middle of their field due to less astigmatism (but I actually prefer Dagors as they are unbeatable in their out of focus background rendition and may cover a little bit more).

[Drew Wiley]

Fujinon C's differ both by engineered design as general-purpose lenses to be somewhat wider coverage, and also by being infinity corrected. They aren't based on process repro applications like Apo-Ronars, and aren't as good really close up. Apo Ronars can be shimmed to work quite well at infinity too, but were basically a process lens tweak cross-marketed in an ordinary field shutter. And speaking of shutters, The 360 Apo R. is in a bulky no. 3, while the 300 and even 450 C's are in highly portable no. 1 shutter, hence "C" for "compact". Only the 600C is in a no.3. They're great field lenses unless you need near-macro.

[Bernice Loui]

The Rodenstock APO ronar brochure.
https://www.kennethleegallery.com/pdf/Apo-Ronar.pdf

https://www.pacificrimcamera.com/rl/00817/00817.pdf

Rodenstock notes the image circle of 308mm @ f11, 318mm @ f22 infinity focus, why?
This has more to do with Rodenstock's standards and point of reference for optical performance, not illumination circle of a given lens.

In the case of many sheet film foto images, the optical performance criteria might not be the same as the optical designers at Rodenstock. Or simply put, what is acceptable to the image maker is not the same as what is acceptable to the optical designers of the given lens... and this happens quite often as image circle size coupled to a small size lens IS highly desirable for many view camera users today.. in the same way as the current popularity of lightweight field folder view cameras and carbon fiber tripods... This is much about current view camera market fashion and what the current user/market base expects/demands.


Bernice

Ridax's comments about illumination and astigmatism are spot on.

And different lens manufacturers consider different amounts of astigmatism to be acceptable.

Example:
Rodenstock lists APO-Ronar 300mm f/9's dialyte coverage as 265mm.
Fujifilm lists its Fujinon C 300mm f/8.5 dialyte coverage as 380mm.

Of course, the glass types each manufacturer uses and the specific cell spacing is going to be different between them. But they still also represent different attitudes toward IQ acceptability in the outer frame.

[Bernice Loui]

Out of focus rendition is often not highly considered or part of the lens personality desirability features list.. IMO, this is partly due to the f64 ideology of everything in the image "sharp" style of image making.

Being a Dagor user for nearly four decades to date, the Dagor does have a unique image personality in many good ways. This coupled with their small size for their image circle persist in making them one of the classic view camera lenses and why this design/formula has been in production for so many decades and remains one of the more desirable view camera lenses. The other being the Dialyte design/formula which is a Dagor variant, trading off smaller image circle for improved correction of optical issues.

These two lens designs, Dagor and Dialyte along with the Tessar has remained the foundational three normal to longer than normal focal length lenses used for decades..

Yet, there is a shift to largest possible view camera lens apertures from those venturing into this view camera stuff that have their roots and history in digital/roll film cameras using the large les full aperture image making style.


Bernice

My 355mm and 210mm plasmat-type G-Clarons were very sharp all their 78° through, and somewhat sharper than my Dagors in the middle of their field due to less astigmatism (but I actually prefer Dagors as they are unbeatable in their out of focus background rendition and may cover a little bit more).

[Tin Can]

So you deny the value of portrait lenses over the last 140 years?

Out of focus rendition is often not highly considered or part of the lens personality desirability features list.. IMO, this is partly due to the f64 ideology of everything in the image "sharp" style of image making.

Being a Dagor user for nearly four decades to date, the Dagor does have a unique image personality in many good ways. This coupled with their small size for their image circle persist in making them one of the classic view camera lenses and why this design/formula has been in production for so many decades and remains one of the more desirable view camera lenses. The other being the Dialyte design/formula which is a Dagor variant, trading off smaller image circle for improved correction of optical issues.

These two lens designs, Dagor and Dialyte along with the Tessar has remained the foundational three normal to longer than normal focal length lenses used for decades..

Yet, there is a shift to largest possible view camera lens apertures from those venturing into this view camera stuff that have their roots and history in digital/roll film cameras using the large les full aperture image making style.


Bernice

[Drew Wiley]

I don't think the Dagor has a pleasing out of focus effect at all, certainly not in comparison to my Zeiss process tessar. Neither do dialytes. The Dagor does render a certain interesting edge look of its own, along with extreme contrast and microtonality due to its only 4 air-glass interfaces. All of the above, in my own case, plus my 360 Fuji A, are hard-sharp. Probably nothing back in the classic but brief f/64 episode was comparable. Enlarge any of that old work much and it starts getting mushy fast. They did have the option of actual soft-focus "pictorial" and "portrait" lenses, but the current concept of bokeh seems to be a relatively recent thing, and is now deliberately designed into certain 35mm lenses; my own Nikkor 84/1.4 Ais would be a notable early example. Where is Jim Galli when we need him?