The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

New Cambo Actus for Digital Backs

Steve Hendrix

Well-known member
Cambo is showing an Actus modified to accept a digital back. As you can see from the attached photo, the front and rear base are enhanced (reinforced and height is added for clearance of the digital back).


Steve Hendrix
Capture Integration
 

Paul2660

Well-known member
I guess they really had to consider the effect it would have on future tech camera sales (WRS). If you are just starting out, with out lenses, this is a perfect solution.

You get movements, shift and swing/tilt. You can still mount the Schneider and Rodenstock lenses, but in a much less expensive mount, i.e Copol 0. No more need to spend the extra dollars for the Cambo T/S mount.
Knobs all look much larger also.

Your lenses actually hold more value, since you can sell them to anyone (all they need to do is add the mount for their camera, and not remove a Cambo mount)

Digital issues such as crosstalk will be the same dependent on the back/tech lens selected. But the cost of entry is I am assuming much less.

Smart move.

Paul
 

alajuela

Active member
So it should be easy to really see just how future proof the Otus lens really is - for those of us that need a push :angel:

What will be cool is when somebody puts an Otus with an 250, 260 , or 280 back and measures the resolution in the center of the frame.

That would be intersesting and then compare it to the Sigma, Canon, and Nikon lenses. Maybe even Schneider and Rodenstock.

Phil
 

jagsiva

Active member
So it should be easy to really see just how future proof the Otus lens really is - for those of us that need a push :angel:

What will be cool is when somebody puts an Otus with an 250, 260 , or 280 back and measures the resolution in the center of the frame.

That would be intersesting and then compare it to the Sigma, Canon, and Nikon lenes.

Phil
Exactly, I'd love to see that, along with the actual size of the IC.
 

Guy Mancuso

Administrator, Instructor
I guess they really had to consider the effect it would have on future tech camera sales (WRS). If you are just starting out, with out lenses, this is a perfect solution.

You get movements, shift and swing/tilt. You can still mount the Schneider and Rodenstock lenses, but in a much less expensive mount, i.e Copol 0. No more need to spend the extra dollars for the Cambo T/S mount.
Knobs all look much larger also.

Your lenses actually hold more value, since you can sell them to anyone (all they need to do is add the mount for their camera, and not remove a Cambo mount)

Digital issues such as crosstalk will be the same dependent on the back/tech lens selected. But the cost of entry is I am assuming much less.

Smart move.

Paul
Paul you hit it on the head. Now this could possibly take any lens you throw at it. The biggy is you save 1200 to 1500 per lens in the Cambo mount not buying the tilt feature mounts. The cam has it. Given image circle you maybe able to bolt anything on it like a Sony A7 series
 

yatlee

Member
But only for the newer CMOS back with true live view? I guess you can use ground glass, but it will be quite clumsy changing the back in and out.
 
Last edited:

Paul2660

Well-known member
Paul you hit it on the head. Now this could possibly take any lens you throw at it. The biggy is you save 1200 to 1500 per lens in the Cambo mount not buying the tilt feature mounts. The cam has it. Given image circle you maybe able to bolt anything on it like a Sony A7 series
I can see one headed your way. :)

Paul
 

jagsiva

Active member
Paul you hit it on the head. Now this could possibly take any lens you throw at it. The biggy is you save 1200 to 1500 per lens in the Cambo mount not buying the tilt feature mounts. The cam has it. Given image circle you maybe able to bolt anything on it like a Sony A7 series
Guy, leaving cost aside, it also means that your lens is not tied down to one tech cam system. You stick it on a board an use it in any 6x9 or 4x5 as well. If LV focussing does come to be the norm, then hopefully, lenses can all have a standard mount, the way they originally intended - at least in the view camera world.
 

Shashin

Well-known member
It is really neat that folks are rethinking the monorail camera. Great platform, but it seemed to fall out of favor. I think the real key is reducing the size--the Linhof CS679 was a great idea, but large and heavy. This looks really neat.

If I were Guy, I don't know how I could resist. ;) :D
 

torger

Active member
What usually is the criticism of these type of cameras (it's quite similar to Linhof Techno) is that it's not rigid and precise enough, that you get parallelism issues. The other criticism is ground glass focusing, but with live view coming up there are alternatives.

For a "low" cost entry to MF tech digital make sure to look at the CFV-50c which just now gets live view directly in the back through a firmware upgrade. At $15k is much cheaper than the Leaf and Phase One backs.

Anyway back to the camera; indeed a rigid pancake camera design can be more precise, but you get expensive mounts and generally more limited movements. For practical image making with f/11 and smaller apertures there's also a limit to how precise you need the camera to be. If you shoot infinity-focused grand views at f/8 or less I'd choose a pancake camera, but if you shoot with f/11 there's no need to go overkill - a lightweight camera rich in movements will do fine and give you more compositional flexibility. Learn to love some diffraction blur, it smoothes out aliasing artifacts :)

This Cambo Actus with digital back is really interesting. The main question to me is -- what wide angle lenses are you going to use with your CFV-50c / Credo 50 / IQ250? From say 50mm and up - Schneider Digitar and Rodenstocks will be fine, but below crosstalk will really become an issue if you want to be able to use the movements.
 

Paul2660

Well-known member
Don't forget the IQ150 :)

I feel the whole issue of crosstalk is being conveniently overlooked by dealers. It's a real issue and if you buy the Actus or the Univeralis, from Arca, movements IMO would be a real key. On the smaller Sony 36MP sensor, the effect of crosstalk, (loss of color saturation) is pretty significant by 12mm of shift.

Each person has to see it and it's effects to understand just how important a factor it is.

I guess if you choose to use the 35mm lenses, or other 645 lenses, that the Cambo can support, this issue won't be as big a deal since the lens will much further away from the sensor (as the lenses were designed for a mirror box).

Similar results (very good) that Gerald has been getting with the Canon TS-E lenses on the Hcam and the IQ250.

Edit, I am assuming only the Nikon PC-E will work, as they have a manual aperture ring, the Canon's need a Hcam type setup to stop down the aperture ring.
Paul
 
Last edited:

torger

Active member
Yes Canon lenses need a smart mount with electronics, and if you have a digital back also a focal plane shutter unit, which counts for Nikon lenses too.

I'm guessing that there will be no focal plane shutter unit for this one either, so you need leaf shutter lenses, or go with the DSLR/135 mirrorless version.
 

jlm

Workshop Member
why would you need the camera movements if you are using the canon TS lenses? just to add the other axes?
 

torger

Active member
why would you need the camera movements if you are using the canon TS lenses? just to add the other axes?
You don't. But they're one of few alternatives to go really wide without getting hurt with crosstalk on current CMOS sensors. With this type of camera it's likely one is interested to shoot wider than 50mm, but it's unclear which lenses to use then. In that context the product seems ahead of time.
 

Steve Hendrix

Well-known member
Don't forget the IQ150 :)

I feel the whole issue of crosstalk is being conveniently overlook by both by dealers. It's a real issue and if you buy the Actus or the Univeralis, from Arca, movements IMO would be a real key. On the smaller Sony 36MP sensor, the effect of crosstalk, (loss of color saturation) is pretty significant by 12mm of shift.

Each person has to see it and it's effects to understand just how important a factor it is.

I guess if you choose to use the 35mm lenses, or other 645 lenses, that the Cambo can support, this issue won't be as big a deal since the lens will much further away from the sensor (as the lenses were designed for a mirror box).

Similar results (very good) that Gerald has been getting with the Canon TS-E lenses on the Hcam and the IQ250.

Edit, I am assuming only the Nikon PC-E will work, as they have a manual aperture ring, the Canon's need a Hcam type setup to stop down the aperture ring.
Paul

That is a pretty insulting thing to say Paul. It goes past implication, and actually infers that dealers have been withholding information on "crosstalk" issues when we sell a lens for use with a movement-based/technical camera. You're saying we're not addressing this with our clients? Paul, we don't sell a technical lens without discussing the limitations with our clients.

I have emails from 3 years ago discussing this with you.

I feel like the phenomenon of "Crosstalk" is slightly overblown. Creating a catchy name to an existing issue. And it is an issue - but just because a lens interacting with a CCD or CMOS sensor experiences "crosstalk" doesn't mean that combination is useless. It's certainly less useful than most would like, because it limits the amount of shift you can employ. And it's more extensive with the latest CMOS sensors compared to the previous and current CCD sensors.

This is not new. It now has a catchy name. And it is something that Capture Integration discusses with every client who is purchasing tech camera/lenses. In detail.

As a company that takes a LOT of pride in our integrity, I'm offended by your statement Paul.


Steve Hendrix
Capture Integration
 

torger

Active member
Offended or not, it's pretty obvious that there's been a huge disconnect between lens designers, sensor designers, digital back designers and dealers.

The SK28 is a mystery from a lens design perspective. Designed just a few years ago it only works with Kodak sensors, and even there it pushes it more to the limit. Clearly the lens designers did not even check how digital sensors work, or hoped for some new technology to arrive in the future sooner than it has.

Then there's been myths of what color cast is at all. I've heard things like because MF sensors are so incredibly sensitive they record the color of the coatings from the lenses. For a layman it may not sound too unlikely, the magenta color of the coatings kind of look like what you see on the LCC shot. I don't really know from where the myth comes originally but I can imagine an ill-informed dealer tried to answer a customer question.

Such myths would never appear if there's been connection between lens designers, sensor designers, back manufacturers and dealers. But instead it seems like everyone has half-hearted tried to figure it out on their own with limited success.

Crosstalk is not just a catchy name, it's the correct technical term of what is happening, and the problem is has become worse for each new sensor generation, and is now peaking with the Sony CMOS sensors. Crosstalk differs from regular color cast (which is afaik caused by pixel vignetting variations due to unevenness of the pixels) in that it cannot be restored with the normal LCC process, therefore it's very important.

Before 2014 I have not ever seen a dealer mention crosstalk a single time. Then the IQ250 was released and tech cam tests showed real odd LCC failures, so I started reading technical papers on sensor design and found out the crosstalk metric and then all fell in place, these strange LCC failures were of course crosstalk. Learning more about the particular sensor designs and looking at microscope images of the sensors it became obvious this was a large problem. I even designed a crosstalk cancellation algorithm that could reverse crosstalk in some cases, but unfortunately not in as huge amounts as we see on the CMOS sensors.

It's also obvious to me that Phase One have never informed the dealers about what crosstalk is and why it cannot be corrected with LCC, and which problems that lead to. You have to excuse me but I don't believe that dealers "have known all along", nothing in all I've read and heard indicate that, and if they did know they have not been honest in the information to the customers. That people know about crosstalk now is through the information campaign I've had on this forum and LuLa.

These systems are not $500 cameras, it's $50k systems. I think customers can expect that designers, manufacturers and dealers are fully aware of technical limitations of this kind. This has not been the case, things have just been slapped together and hoping for the best. Then I think the least you can expect is to get criticism.

For similar reasons like the SK28 this Cambo Actus is partially a design mystery. It's clearly designed for CMOS sensors, but there are no good wide angle solutions available. Sure you could use it for 50mm and up, and not shift the wides. But the attraction of such a small compact camera is of course to use it outdoors and shoot landscape and architecture, and what is that without wide angle lenses? My assumption is that just like lens designers at Schneider Kreuznach that made the Digitar 28, the designers at Cambo designed this camera without fully understanding the crosstalk issue.
 
Last edited:

torger

Active member
If crosstalk is overblown or not is a matter of taste. If I'd claim that you must have zero percent crosstalk for the lens/sensor combination to work alright then I'd exaggerate, unless I was talking about reproduction photography. 10% crosstalk usually have no visible effect on a picture. But with these CMOS sensors it's not these kind of levels were talking about, it can be 50+% even with normal amounts of shift, and vary depending on orientation of the sensor and other effects that may not seem logical.

Thus rather than do 1 or 2 casual tests without really knowing what's happening, what should be done is to contact lens designers and sensor designers, get the proper data and figure out how large image circle is when you can guarantee say no more than 10% crosstalk regardless of sensor orientation, so you can get guaranteed image performance. This is what I think a pro customer buying gear at this level could demand.

If find it a bit offending that dealers market the exactness of color and fine tonality of these backs, but think that crosstalk that severely degrades this performance metric shouldn't be taken more seriously than it is.

It seems like dealers hope for that the customer won't notice the degradation in color reproduction, and many perhaps will not -- you can be a great photographer while not having great color vision. If you buy a system at this level marketed for having supreme color and tonality then I think you should be allowed to expect that dealers take that seriously, even for wide angle lenses.

To be very clear -- if I had been designer at Cambo I would not release the Cambo Actus at this point, and if I hade been an MF dealer I would not market the product. Without proper wide angle support, which I don't see that it has, I think the use of it is too limited concerning that it is designed as a portable camera otherwise particularly suitable for wide angle shooting. I as a MF dealer would understand that customers interested in this camera would very likely want to shoot wide angle landscape and architecture with this, and then I would have to disappoint them, and therefore I'd say "this product is not market ready, we need new CMOS technology or new lenses before it's ready".

I don't mind that Cambo designers and MF dealers think otherwise, but I find it problematic that when criticism and questions concerning wide angle support and this "catchy" name crosstalk comes up over and over again causes irritation. You should have seen that coming with this design.
 
Top