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CFV100C on Technical Camera

TechTalk

Well-known member
No, the Rodenstock CFs are much better, they play in a different league.
With the Schneiders, the darkening is sprayed onto the glass.
Yes it is a "proper nightmare for interior, dusk and night photography".
The Rodenstocks are much more elaborately manufactured.
They consist of two glasses. The lenses are ground, curved on one side, one dark, the other clear and then joined together.
Unfortunately, these filters do not fit the SK lenses.
Although they can be mechanically adapted with step-up rings,
the compensating effect is not sufficient. However, I have not tested all combinations.
I had the 24XL, the 28 Super XL and the 35XL.
I struggled and fretted with work arounds for far too long before replacing all the wide angles with Rodenstocks.
From 72 mm upwards, however, I am a Schneider fan.
Just to add some additional information to what you said regarding Rodenstock's "Digital Center Filters", they were shown at Photokina in 2010. An announcement article discusses the "Reflection reduced Digital Center Filters" in some detail. If you click the PDF icon on Linhof Studio's webpage for the 86mm Digital Center Filter, you can download a detailed construction diagram.

B&H's description: Opposed to traditional application of an evaporated dark layer of density, this filter employs a secondary gray glass in order to produce the filter's density... A secondary gray glass is employed, versus a traditional vapor-deposited dark coating, in order to maintain image clarity, contrast, and color neutrality by reducing the likelihood of surface reflections and ghosting.... A dual cemented lens construction, incorporating one neutral gray planoconvex lens and one transparent planoconcave lens, helps to maintain the same refractive index, along with the same dispersion characteristics, as a normal, homogenous, planoparallel glass plate. However, since the neutral gray (density) lens features a convex shape, it is able to provide concentrically graduated density from the center of the filter, lessening towards the edges.

What's interesting is that Rodenstock was using this type of center filter construction over 100 years ago. Take a look at the description in this 1912 Rodenstock catalog of their Enixantos Compensator for the Pantogonal extreme wide-angle lens [page 21].

"For time exposures, when the full angle is used, it is advisable to use the Enixantos Compensator which is furnished with the lens. This consists of a plano-convex lens of yellowish green glass which absorbs very strongly blue and violet light, and a plano-concave lens of a colorless, very transparent material. The optical constants of both these lenses is exactly equal so that the cemented lenses act as a plane parallel plate which is dark in the center and transparent at the sides. The effect of this is that the marginal rays which pass through the lens at great angle undergo only a slight absorption, and therefore any marked decrease of light toward the edges of the plate is prevented. Thus the necessity of bunglesome and complicated appliances usually found on extreme angle lenses is obviated. With orthochromatic plates the Compensator has the added advantage of giving excellent color values."
 

4x5Australian

Well-known member
What's interesting is that Rodenstock was using this type of center filter construction over 100 years ago. Take a look at the description in this 1912 Rodenstock catalog of their Enixantos Compensator for the Pantogonal extreme wide-angle lens [page 21].
@TechTalk, that is a nice find.

And, on page 24, the catalogue describes the Mentor camera thus:
"The "Mentor" is provided with rising, falling and sliding front. This is a very desirable feature as it enables the photographing of tall buildings and other objects with absolute rectilinearity of lines. This should not be overlooked in the purchase of any camera."

We users of technical cameras should all give a cheer!

Rod
 
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vjbelle

Well-known member
Have you shot it on IQ4? What do you mean with smearing? Corner sharpness loss?

I always shift in landscape mode and was referring to correctable color cast.

With which sensor have you shot it and what was your max?

A lot of the bad rep comes from pre IQ4 posts, on BSI its not bad! I hope to find time to do some thorough testing, I literally picked it up this week and what I saw astounded me given how bad this lens was talked about in the past.
I have shot my 35XL on every Phase One DB since P25 and that includes the 4150. Don't you know what smearing is? The shifted edge starts to distort along with becoming very soft. I rarely shifted horizontally but always applied rise in Landscape position and could never go beyond 7mm on the 4150.

Victor B.
 

Ben730

Active member
Strange patterns most likey due to Phase Detect AF points (property of the 100c sensor). It has been reported in some reviews of the BSI back.
Does this mean that these patterns also appear on the new Hasselblad back?
That would be a massive reason to stay with Phase One.
You can't take this picture without patterns with a GFX 100, for example. Even the new T/S lens doesn't help here.
Ben.jpg
 

Ben730

Active member
I have shot my 35XL on every Phase One DB since P25 and that includes the 4150. Don't you know what smearing is? The shifted edge starts to distort along with becoming very soft. I rarely shifted horizontally but always applied rise in Landscape position and could never go beyond 7mm on the 4150.

Victor B.
Same here on every back until IQ3100. With 3 different examples of the 35XL.
 

FloatingLens

Well-known member
Does this mean that these patterns also appear on the new Hasselblad back?
That would be a massive reason to stay with Phase One.
You can't take this picture without patterns with a GFX 100, for example. Even the new T/S lens doesn't help here.
View attachment 210441
Could be (I only repeat what I saw in reviews). I think the Northrup 100c review made explicit mention when shooting into the sun.
 

rdeloe

Well-known member
I'm blind. I can't see any patterns. ☹
I'm not sure what I'm supposed to see either.

Is this a small crop from a large, slightly out of focus image? Is the softness the issue? There's flare and ghosting everywhere. There may be something weird happening in the sky above the houses, but it could also be a cloud pattern.
 

Ben730

Active member
I'm not sure what I'm supposed to see either.

Is this a small crop from a large, slightly out of focus image? Is the softness the issue? There's flare and ghosting everywhere. There may be something weird happening in the sky above the houses, but it could also be a cloud pattern.
Sorry, I did not make myself clear. The posted image does not contain this error.
It is photographed with IQ1 50. I meant to say that this picture would have the pattern if I had wanted to take it with a Fuji GFX.
Unfortunately I don't have my Fujis to hand for the next few days, otherwise I would post an example. I don't have any pictures with these patterns in the archive. I delete such pictures.
 

diggles

Well-known member
This is good to know for sure. It looks like the phenomenon happens in very specific situations and the article does go on to say how to avoid it.
 

Ben730

Active member
This is good to know for sure. It looks like the phenomenon happens in very specific situations and the article does go on to say how to avoid it.
But they do not write down the simplest method to avoid it: Use a P1 back. :ROFLMAO:
 
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MGrayson

Subscriber and Workshop Member
I have found an example.
It's not from a GFX, but the example looks the same.
The color pattern does not occur with Phase One Backs.
Looks like diffraction grating reflections. Pixel pitch is too large - pixels are 3-4 microns and visible light is about half a micron in wavelength, but it wouldn't take much structure inside the pixel well for there to be patterns at the sub-micron level.

Wild unfounded speculation on my part.
 

TechTalk

Well-known member
I have found an example.
It's not from a GFX, but the example looks the same.
The color pattern does not occur with Phase One Backs.
The article you linked contains this notice: "UPDATE: this turned out to be an issue with all mirrorless cameras that have a short flange distance. Please read this post to understand the issue in detail."

The article to which the update links says: "Basically, this has largely to do with the reflective nature of the sensor surface. As light rays enter the lens, they get squeezed into a very small aperture. At this point, each internal reflection in the form of flare is already part of the image. The light rays reach the sensor and immediately bounce back to the rear element of the lens. In essence, each pixel on the sensor that gets hit with the bright source of light reflects some of the light back to the rear element – that’s what creates the grid pattern."

It's a potential issue with any sensor and lens when the rear element of the lens is very close to the surface of the sensor. Bring a lens element close enough to a digital back (or mirrorless camera) of any make in a specific lighting situation and you could encounter this.
 

Whisp3r

Active member
I have found an example.
It's not from a GFX, but the example looks the same.
The color pattern does not occur with Phase One Backs.

I rummaged through my discard pile hoping to find some examples, not sure if this is what you're looking for, I'll let the experts decide :)

0002-DSCF9679.jpg
Gear: Fuji GFX 100II, Fujinon 30mm T/S @ f/11

0004-DSCF6175.jpg
Gear: Fuji GFX 100II, Fujinon 30mm T/S @ f/9.0

It doesn't always occur though, here are two similar photos, no strange phenomenon as far as I can see:
0003-DSCF3437.jpg
Gear: Fuji GFX 100II, Canon TS-E 50mm @ f/9.0

0001-_DSF6096.jpg
Gear: Fuji GFX 100II, Fujinon 32-64mm @ 32mm, f/4.0

Maybe it's important mentioning another useful piece of information: the first two images, where the issue occurs, are HDR DNG exports, whereas the last two are plain exports from the original .RAF files (inclusing tweaks but no HDR-shenanigans).

Hope this is useful!
 

P. Chong

Well-known member
Maybe I am stupid, but I quite like the look…😅😆. I find it quite artistic, like cinematographers like the anamorphic glare.



I rummaged through my discard pile hoping to find some examples, not sure if this is what you're looking for, I'll let the experts decide :)

View attachment 210451
Gear: Fuji GFX 100II, Fujinon 30mm T/S @ f/

Maybe it's important mentioning another useful piece of information: the first two images, where the issue occurs, are HDR DNG exports, whereas the last two are plain exports from the original .RAF files (inclusing tweaks but no HDR-shenanigans).

Hope this is useful!
 

Alkibiades

Well-known member
So on the 28 XL in portrait mode with a 54mm sensor I get the following with CF:

View attachment 210420

That's 5, 10, 15mm rise in portrait.

C1 cleans up:

View attachment 210421

All except 15mm rise in portrait are cleaned up. At 15mm there remains noise in the topmost section and you can see some faint remaining tiling. At 10mm it also is there very, very faintly, but it gets cleaned up to my eyes fully.

If you use frame averaging and carefully expose you should be able to get somewhere between 10mm and 15mm rise out of the 28 XL in portrait mode on the IQ4.

It looks to me that you shifted around 15mm with a 54mm chip (judging the pattern in the sample you posted) which is beyond the limits of this lens and outside the IC as the borders of the chip are beyond the circle already. At 15mm the top left and right parts should hit the ICs end and be very dark. The post work could have been avoided by stepping a bit back and keeping it at slightly above 10mm in portrait.

If you work within 12.5mm in portrait or just 10 that's still very wide and should work without problems.

You can make presets in C1 and then its a one-click fix after ingesting as long you always rise by the same amount.

By extension it means you have significant headroom already with the 28XL on the new Hassy chip. The long ends of both chips differ by 10mm! Which means you could go for 22.5mm (even more if you take into account that the chip is also shorter on the short side) in theory at 28mm ... which is also significantly more than the TSE30 on a like for like basis if you crop to crop MF – while being fully rectilinear.

I will do some testing with blue sky, etc. once I have time, but I think 10-12.5mm should be fine ... which is a lot on a 54mm sensor, which is 10mm longer than the Fuji sensor ...

Once you go beyond the intended product specs while shooting you get tiling and LCC can't fix that and then you basically end up in PS and need a lot of retouch.

I looks to me that within spec this lens is great on BSI, especially on Hassy backs you will be able, if you can manage LCC, to work these SK lenses in a good way.

I mean 20mm or a tad more of rise on a CFV100c with 28mm is exceptional.
my reason to get the 100c is the use of the 28 xl with bigger movements and at difficult light also.
I use the 28xl sometimes on phase one IQ 250, but try to avoid bigger movements and diffucult light. When CC removal meets stronger lightning of dark parts the file will be to grainly at these parts. For me 28xl is schneiders best wide lens they ever made, the only one with thease lens design. I also hope to get bigger stiching wit 43 xl as I can do now, this should allow the BSI sensor.
 
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