LCC with PhaseOne backs

[Esben]

We are considering to purchase a PhaseOne back and would like to know how many users deal with some kind of lens color cast or other lens errors. Can they all be handled with LCC, and with which lenses and with which PhaseOne back do you see the errors ?

Did your dealer swop you back to new one or did you accept the work-arounds ?

Best,
Esben

[Ron Steinberg]

We are considering to purchase a PhaseOne back and would like to know how many users deal with some kind of lens color cast or other lens errors. Can they all be handled with LCC, and with which lenses and with which PhaseOne back do you see the errors ?

Did your dealer swop you back to new one or did you accept the work-arounds ?

Best,
Esben
[a href=\"index.php?act=findpost&pid=109301\"][{POST_SNAPBACK}][/a]

Lens cast is not an error, it is a function of the design of wide angle non retrofocal lenses on digital chips. The LCC tool in Capture One handles the issue perfectly. As to which lenses you might experience this with, in general it is the wider lenses on view cameras or something like a Cambo WideDS, or if you make significant shifts with normal lenses on a view camera (although that situation may or may not create lens cast, it varies by situation). There is no reason to swap out the back as it will not solve the issue.

What other errors are you concerned about?

[Esben]

Hi Ron

I'm trying to get an impression of what I can expect from a PhaseOne digital back.
I know for a fact that each chip is acting different, even if its placed in the same model of digital back. One back can show LCC errors and another back will not. Since the design is the same, I will consider this to be an error to that specific back and not to the function of the design.
The error can appear with the Hasselblad V 250mm. APO or with wide-angle lenses used with or with-out tilt and shift.

If possible, I would like to keep this topic only for PhaseOne owners who actually have had LCC issues.
Please list which lens, camera, and back you use.
Especially interesting would be to hear from Hasselblad H and Mamiya owners.

Best,
Esben

[Lester]

Esben,
You hit the nail right on the head. I think the same way about lens cast. I had a P25 that has so much lens cast that the LCC does not correct it all. When I upgrade it to a P45, I was surprise that I only have lenses cast on about 10% of the images the other 90% I could not see it. This is using the same lenses and same camera but the difference is only the back. This is on a Mamiya system. It also seems that it really does not matter, if the lens is wide angle or normal or tele. About 6 months ago, there was a poster on Rob Galbralth that bitch about the lenses cast on his P45, which is on a Hass V system. I did email him and he told me that he got lenses cast on everyone of his lenses and that Phase One did replace the back 3 times and he still have the same problem.
The best thing to do is test the back and it is good enough, get it. Us old timer can remember the DCS 14n, which is the 1st time I see lens cast, that is one reason Kodak is not making cameras anymore. Their DCS 660 and DCS 760 was on top of the hill, nobody could touch those cameras at that time.

Hi Ron

I'm trying to get an impression of what I can expect from a PhaseOne digital back.
I know for a fact that each chip is acting different, even if its placed in the same model of digital back. One back can show LCC errors and another back will not. Since the design is the same, I will consider this to be an error to that specific back and not to the function of the design.
The error can appear with the Hasselblad V 250mm. APO or with wide-angle lenses used with or with-out tilt and shift.

If possible, I would like to keep this topic only for PhaseOne owners who actually have had LCC issues.
Please list which lens, camera, and back you use.
Especially interesting would be to hear from Hasselblad H and Mamiya owners.

Best,
Esben
[a href=\"index.php?act=findpost&pid=109449\"][{POST_SNAPBACK}][/a]

[DavidP]

I use a P25 with both a V system hasselblad and view camera with phase one sliding back. I have had no problems at all with Lens cast with any of my Hasselblad lenses From 40CFE to 120 makro.
Where I have to use it is with very wide NOT retro focus view lenses, I have a 35 mm Rodenstock Digital lens. I have to use the lens cast tool with it 100 percent of the time.
My understanding was that it had something to do with the light being at too much of an angle to the recepters or what ever you call them. Hence the wide non retrofocus lenses being worse.
The 35 is very close to the chip.
I have also wondered if the P 45 would be worse with the smaller size of the receptors.
I have been reading reports from some people on the phase one user forum having to do lens cast on normal Hasselblad lenses and It makes me wonder if there are variations with the backs.
I would find it unacceptable to have to use the Lens cast tool with my normal hasselblad lenses. I think before I upgraded I would have to make that very clear with the dealer I am not sure what their policy is on that sort of thing.

[Boghb]

Lens cast is not an error, it is a function of the design of wide angle non retrofocal lenses on digital chips. The LCC tool in Capture One handles the issue perfectly. As to which lenses you might experience this with, in general it is the wider lenses on view cameras or something like a Cambo WideDS, or if you make significant shifts with normal lenses on a view camera (although that situation may or may not create lens cast, it varies by situation). There is no reason to swap out the back as it will not solve the issue.

What other errors are you concerned about?
[a href=\"index.php?act=findpost&pid=109378\"][{POST_SNAPBACK}][/a]

Lens cast is a defect that has plagued all of the Phase backs I have owned (I have owned more than 5 P25s and P45s).  The defect was much worse on my P45s.  Some like the post above like to call it a "function of design" or some other term that makes it seem like a fact of life.  But it is just a design defect that corrupts most Phase files.

Lens cast is not entirely corrected by the LCC tool.  But in most cases the correction is enough to make the file usable.

I have used Phase backs (P25 and P45) with the Hassy V and H systems.  The V lenses prduced much more cast than the H lenses.  

In my experience, the amount of cast that one experiences has more to do with the lenses than the backs of the same model; all my P45s produced the same amount with the same lenses.  Stay away from the P45/CF lens combination.

There is no truth to the assertion that lens cast only occurs with wide lenses; my CFE40 produced far less than my 120 Makro and 250SA.

The plus series of Phase backs are supposed to address this defect.

[Lester]

Boghb, where are you located? I have a Hass to my Mamiya converter and I could do a test with your lenses and I will have less Lens cast. You probably got all your P45 about the same time, so you probably have the same batch of CCD on those P45. You are right by saying that the lens cast is not entirely corrected by the LCC tool, I could never get full correction on my P25. I am one happy camper, because I do not get a noticeable lens cast, on any lens I put in front my P45. If you have a P back and want to see if you get lens cast or not, just shoot a black top road or the blue sky, with the sun behind you.

Lens cast is a defect that has plagued all of the Phase backs I have owned (I have owned more than 5 P25s and P45s).  The defect was much worse on my P45s.  Some like the post above like to call it a "function of design" or some other term that makes it seem like a fact of life.  But it is just a design defect that corrupts most Phase files.

Lens cast is not entirely corrected by the LCC tool.  But in most cases the correction is enough to make the file usable.

I have used Phase backs (P25 and P45) with the Hassy V and H systems.  The V lenses prduced much more cast than the H lenses. 

In my experience, the amount of cast that one experiences has more to do with the lenses than the backs of the same model; all my P45s produced the same amount with the same lenses.  Stay away from the P45/CF lens combination.

There is no truth to the assertion that lens cast only occurs with wide lenses; my CFE40 produced far less than my 120 Makro and 250SA.

The plus series of Phase backs are supposed to address this defect.
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[jklotz]

I use a P25 on a Cambo Wide DS. LCC is just part of my workflow. The shots are simply not usable without. It's no big deal really, just sometyhing else to remember. The 35mm Schnider is particulary bad. What I have found is that the LCC works fine as long as you don't use too much shift. 10mm shift is about the max with that lens. One recomendation - If you go that route, test it before you take it on a job. My tests showed that as the LCC is the first problem encountered when reaching the limits of the shift. In other words, don't shift until you see a hard vinette, then back off a little, thinking you actually have that ammount of shift. When in doubt, shoot the LCC card and apply it to the image to make sure it works properly. Shooting teathered to a laptop is pretty necessary if you plan to use extreem movements, as I do shooting architecture.

That bieng said, I have shot with most of the lenses available for my Contax 645 with the same P25 and have almost never seen any LCC problems whatsoever. I still shoot the LCC card with it just in case, but find that it is almost never necessary.

Hope this helps.

James