Ad
Ad
Ad
Pages: « 1 [2] 3 »   Bottom of Page
Print
Author Topic: Alpa TC21 and Phase MF back?  (Read 12906 times)
ericstaud
Sr. Member
****
Offline Offline

Posts: 384


WWW
« Reply #20 on: October 08, 2006, 06:34:20 PM »
ReplyReply

"(with tongue firmly planted in cheek): can you correct the leaf centerfold problem as easily?"

Yes the color in those samples is corrected using the LCC in C1 Pro.  It is just as easy to correct the centerfold line (in my experience).  The concept is functionally identical from the users standpoint.  Shoot a white plexi card and let the software correct out the color casts and centerfold.  One main difference is that Leaf uses a stand alone application and C1 Pro has the utility built in.  Another difference is that the Leaf utility allows for removal or Lens falloff (which I ussually leave intact).  With C1 pro I would correct files later, in photoshop.

-Eric
Logged
pixpop
Newbie
*
Offline Offline

Posts: 37


« Reply #21 on: October 08, 2006, 08:21:18 PM »
ReplyReply

Quote
"(with tongue firmly planted in cheek): can you correct the leaf centerfold problem as easily?"

Yes the color in those samples is corrected using the LCC in C1 Pro.  It is just as easy to correct the centerfold line (in my experience).  The concept is functionally identical from the users standpoint.  Shoot a white plexi card and let the software correct out the color casts and centerfold.  One main difference is that Leaf uses a stand alone application and C1 Pro has the utility built in.  Another difference is that the Leaf utility allows for removal or Lens falloff (which I ussually leave intact).  With C1 pro I would correct files later, in photoshop.

-Eric
[a href=\"index.php?act=findpost&pid=79596\"][{POST_SNAPBACK}][/a]


yes. i'm quite aware of the lcc facility in c1 pro. oh. . . .so let me get this straight: the lcc situation for phase one (if there really is a "situation" for some) can be handled very easily. i'm not a leaf owner, but if i were confronted with the centerfold problem i would have a very sick feeling in the pit of my stomach because i don't think it's easily handled as in a lcc situation because there is a very clear demarcation - a line - whereas with lc, it's a gradation which lends itself much more readily to a recalibration using software. understandably, leaf are not saying publically that this is the official way to handle centerfold issues.

an aside point which i think is worth mentioning to potential digital back buyers is that phase one in addition to having phone and email support, has a support forum where all their "dirty laundry" are aired in the open for everyone to view and evaluate.

pp
« Last Edit: October 08, 2006, 08:22:57 PM by pixpop » Logged
eronald
Sr. Member
****
Offline Offline

Posts: 4118



« Reply #22 on: October 08, 2006, 08:44:03 PM »
ReplyReply

Quote
an aside point which i think is worth mentioning to potential digital back buyers is that phase one in addition to having phone and email support, has a support forum where all their "dirty laundry" are aired in the open for everyone to view and evaluate.

pp
[a href=\"index.php?act=findpost&pid=79609\"][{POST_SNAPBACK}][/a]

Yes, the public Phase forum is a good idea. Confidence building.

Edmund
Logged
ericstaud
Sr. Member
****
Offline Offline

Posts: 384


WWW
« Reply #23 on: October 08, 2006, 10:42:35 PM »
ReplyReply

"i don't think it's easily handled as in a lcc situation because there is a very clear demarcation - a line"

In my experience, the line is very easy to deal with.  The line occurs at an exact location.  So the picture of your subject and the picture of the Plexi card have the line in EXACTLY the same place.  The utility is called the Custom Gain Adjuster.  It uses the Plexi shot as sort of a mask which equalizes the sensor reaction to light coming from that particular lens at the settings you used to make your innitial image.  It is a gain adjustment, and as such, can also remove lens fall-off if chosen by the user.
Logged
pixpop
Newbie
*
Offline Offline

Posts: 37


« Reply #24 on: October 08, 2006, 11:54:21 PM »
ReplyReply

Quote
"i don't think it's easily handled as in a lcc situation because there is a very clear demarcation - a line"

In my experience, the line is very easy to deal with.  The line occurs at an exact location.  So the picture of your subject and the picture of the Plexi card have the line in EXACTLY the same place.  The utility is called the Custom Gain Adjuster.  It uses the Plexi shot as sort of a mask which equalizes the sensor reaction to light coming from that particular lens at the settings you used to make your innitial image.  It is a gain adjustment, and as such, can also remove lens fall-off if chosen by the user.
[a href=\"index.php?act=findpost&pid=79619\"][{POST_SNAPBACK}][/a]

hmmmm. . . .since this line is very easily dealt with, all the leaf owners who experience this centerfold problem should quit complaining. . . .at least until leaf replace the defective sensors
« Last Edit: October 08, 2006, 11:58:16 PM by pixpop » Logged
ericstaud
Sr. Member
****
Offline Offline

Posts: 384


WWW
« Reply #25 on: October 09, 2006, 01:44:06 AM »
ReplyReply

"hmmmm. . . .since this line is very easily dealt with, all the leaf owners who experience this centerfold problem should quit complaining. . . .at least until leaf replace the defective sensors"

Except that one of the main selling points of the Leaf back was not having to shoot a plastic card with every shot.  For me personally it adds another 30-60 minutes to every shoot day to shoot the extra images and then apply those corrections back at the computer.

I shot an annual report with a P25 earlier this year mostly untethered.  It took alot of time to create an LCC for each setup and apply that to all the images from that setup at the end of the day.  If I wanted to try an alternate composition by shifting up 3mm, I would have to shoot another LCC shot for that bracket.  I have used a few Phase backs and have always seen the LCC issue with these lenses (sometimes it may only be a corner of a white room going 2 points magenta).  It is a known and accepted part of using the Kodak sensor.  Like dealing with reciprocity from the film days it is just something that Phase One users accept as part of the workflow.

The primary reason I now own an Aptus 75 is to avoid the Plastic card.  I was willing to sacrafice the superior workflow of C1 pro, and the ability to shoot long exposures so that I could just walk out my door with my Alpa and Aptus 75 around my neck and shoot pictures knowing that the files would not need a LCC or gain adjustment.

Of course I have to appologize to narikin for officially hijacking this thread.  I just felt that if Leaf does solve this problem, then the Aptus 75 will be a back that is better suited to a handheld camera like the Alpa 12TC with the wide digitars and HR's than the P45.  Put the Alpa on a tripod and it may be a different story.

Also Narakin,  There is a universal shoe that Alpa sells...

http://www.alpa.ch/en/products/pictures/_l...tive0-25-25.jpg

This would allow you to use viewfinders from other cameras like a Cambo Wide, Horseman, Leica, Blah, Blah, Blah.  You may find something more suitable for the normal to long lenses.  Jeff at Fotocare is my Alpa dealer and he has been very helpful with questions like this.  I'm sure Jeff at Badger is very good too.
Logged
pixpop
Newbie
*
Offline Offline

Posts: 37


« Reply #26 on: October 09, 2006, 11:30:14 AM »
ReplyReply

Quote
"hmmmm. . . .since this line is very easily dealt with, all the leaf owners who experience this centerfold problem should quit complaining. . . .at least until leaf replace the defective sensors"

Except that one of the main selling points of the Leaf back was not having to shoot a plastic card with every shot.  For me personally it adds another 30-60 minutes to every shoot day to shoot the extra images and then apply those corrections back at the computer.

I shot an annual report with a P25 earlier this year mostly untethered.  It took alot of time to create an LCC for each setup and apply that to all the images from that setup at the end of the day.  If I wanted to try an alternate composition by shifting up 3mm, I would have to shoot another LCC shot for that bracket.  I have used a few Phase backs and have always seen the LCC issue with these lenses (sometimes it may only be a corner of a white room going 2 points magenta).  It is a known and accepted part of using the Kodak sensor.  Like dealing with reciprocity from the film days it is just something that Phase One users accept as part of the workflow.

The primary reason I now own an Aptus 75 is to avoid the Plastic card.  I was willing to sacrafice the superior workflow of C1 pro, and the ability to shoot long exposures so that I could just walk out my door with my Alpa and Aptus 75 around my neck and shoot pictures knowing that the files would not need a LCC or gain adjustment.

Of course I have to appologize to narikin for officially hijacking this thread.  I just felt that if Leaf does solve this problem, then the Aptus 75 will be a back that is better suited to a handheld camera like the Alpa 12TC with the wide digitars and HR's than the P45.  Put the Alpa on a tripod and it may be a different story.

Also Narakin,  There is a universal shoe that Alpa sells...

http://www.alpa.ch/en/products/pictures/_l...tive0-25-25.jpg

This would allow you to use viewfinders from other cameras like a Cambo Wide, Horseman, Leica, Blah, Blah, Blah.  You may find something more suitable for the normal to long lenses.  Jeff at Fotocare is my Alpa dealer and he has been very helpful with questions like this.  I'm sure Jeff at Badger is very good too.
[a href=\"index.php?act=findpost&pid=79626\"][{POST_SNAPBACK}][/a]


after taking over 50,000 images with my phase backs, i've never had to use the calibration card with my phase digital backs in the studio on a neutral gray background or out of the studio. i've never had a color cast issue - ever. Never with my alpa or h2.

pp
« Last Edit: October 09, 2006, 12:30:17 PM by pixpop » Logged
andrewparker
Newbie
*
Offline Offline

Posts: 17


« Reply #27 on: October 10, 2006, 04:43:57 AM »
ReplyReply

Quote
my 2 cents: I use alpa and phase one backs with a few of alpa's wide angle lenses

Since Alpa don't make lenses, as far as I know, can we assume that you are using Schneider or Rodenstock non-retrofocus wide angles on an Alpa view camera,
and not having any colour cast problems with Phase backs?

I am curious because this is such a well-known technical isssue that even Phase dealers are open about in person, and you seem to be saying that you haven't had it yourself.

I may be missing something- can you clarify?

Andrew Parker
Logged
vgogolak
Sr. Member
****
Offline Offline

Posts: 337


WWW
« Reply #28 on: October 10, 2006, 09:17:30 PM »
ReplyReply

Quote
I was told this is normal performance for the Phase One backs regarding LCC with the super wide lenses....  the 2nd one is corrected (obviously)

[attachment=1021:attachment]

[attachment=1022:attachment]
[a href=\"index.php?act=findpost&pid=79580\"][{POST_SNAPBACK}][/a]
Dear Eric

Yes the non-retro lenses certainly have bigger angle of incidence proble. However, these images look more like white balance. I can't believe LCC is causing the shift, in fact it is right on boresight.
also LCC is more in warmer colors.
I thing there could be some color shift but this looks like WB issue mostly

Victor
Logged
pixpop
Newbie
*
Offline Offline

Posts: 37


« Reply #29 on: October 10, 2006, 11:41:48 AM »
ReplyReply

Quote
Since Alpa don't make lenses, as far as I know, can we assume that you are using Schneider or Rodenstock non-retrofocus wide angles on an Alpa view camera,
and not having any colour cast problems with Phase backs?

I am curious because this is such a well-known technical isssue that even Phase dealers are open about in person, and you seem to be saying that you haven't had it yourself.

I may be missing something- can you clarify?

Andrew Parker
[a href=\"index.php?act=findpost&pid=79765\"][{POST_SNAPBACK}][/a]

yes of course. . .i use schneider wide angles on the alpa. and yes i have no lens cast problems. i am very careful to do white balance calibration for every condition. the only "well-known" technical issue for phase one regarding lens cast is if you use wide angle lenses on a horseman digiflex ii, or hassy flexbody or 905swc or other large format cameras with different tilt or swing settings. the lens cast problem is most visible on a neutral grey background and appears as a very green cast in one corner of the image that gets gradually changed to to a very magenta cast in the opposite corner of the image. i agree with victor that the image that eric submitted looks more like a white balance problem, not a lens cast problem.

pp
Logged
ericstaud
Sr. Member
****
Offline Offline

Posts: 384


WWW
« Reply #30 on: October 10, 2006, 12:30:36 PM »
ReplyReply

Hi Victor,

Have you used the 24mm digitar on the H25?  In the sample image you refer to had green on the left and magenta on the right.  I click-white balanced on the magenta to accentuate the green.  There is no place to click with the eye dropper to white balance an image with LC.  The very point is that the sensor is reacting to light coming at it from differing angles.  If I click on the right of the sample image I get green on the left.  Click on the left, get magenta on the right....  I used this this image because it is very extreme in the effect, but yet very easily correctable with the C1 pro LCC.  It works every time.  I have also spent a good deal of time with the H25 shooting on white seemless with a GX680.  The GX680 has swings and tilts with retrofocus lenses.  There is some ammount of LC in nearly every image (nearly every image also has a small ammount of swings and tilts).  I would never see this LC except for the fact I am shooting on white seemless where it is very easy to see a color shift of even 2 points magenta. Shooting other subjects with that camera I bet I would rarely notice any LC.

-Eric
Logged
narikin
Sr. Member
****
Offline Offline

Posts: 861


« Reply #31 on: October 10, 2006, 07:39:29 PM »
ReplyReply

I've never seen anything like that in 10,000 captures with my P45. at a loss to explain why you have that and I + many others dont. ever.
Logged
ericstaud
Sr. Member
****
Offline Offline

Posts: 384


WWW
« Reply #32 on: October 10, 2006, 08:04:17 PM »
ReplyReply

Quote
I've never seen anything like that in 10,000 captures with my P45. at a loss to explain why you have that and I + many others dont. ever.
[a href=\"index.php?act=findpost&pid=79861\"][{POST_SNAPBACK}][/a]


There are plenty of threads on the Phase One User forum about LCC.  The users over there talk about shooting the correction file like its a matter of course.  I have shoot with 6 different Phase One backs, all of them requiring correction.
-Eric
Logged
pixpop
Newbie
*
Offline Offline

Posts: 37


« Reply #33 on: October 10, 2006, 10:56:51 PM »
ReplyReply

Quote
There are plenty of threads on the Phase One User forum about LCC.  The users over there talk about shooting the correction file like its a matter of course.  I have shoot with 6 different Phase One backs, all of them requiring correction.
-Eric
[a href=\"index.php?act=findpost&pid=79865\"][{POST_SNAPBACK}][/a]

there are many people who post their issues on the forum only to discover that later they could figure it out themselves. maybe, you should post your issues with phase backs on the phase one forum or contact phase support directly. i'm sure someone at phase one tech support would be happy to help you determine the cause of your particular problems.  i was surprised not to see even one post from you on the phase one forum given the fact that you've shot with 6 different backs and had various issues with them. leaf backs have lens cast problems and now it has an even bigger problem. . .centerfold problems. as a matter of fact, leaf (yair) are saying that: "This app not only fixes the "Centrefold", but it also addresses any colour shifts and lens fall-off/ vignetting."

pp
Logged
khwanaon
Jr. Member
**
Offline Offline

Posts: 70


WWW
« Reply #34 on: October 11, 2006, 12:05:53 AM »
ReplyReply

Quote
I've never seen anything like that in 10,000 captures with my P45. at a loss to explain why you have that and I + many others dont. ever.
[a href=\"index.php?act=findpost&pid=79861\"][{POST_SNAPBACK}][/a]

why you have never had/seen this? simply because you did not have any comparison, a side by side comparison.

The color cast problem with Phase, Leaf and Sinarbacks is a fact, being it with MF bodies or shifts/tilts. How to handle this is another issue. I know that I dont have any problem with my Sinarbacks, being it my SB 54 H or my eMotion 75.

Once you have put side by side an corrected and non-corrected image, the problem will jum at your eyes!

Aon
Logged
ericstaud
Sr. Member
****
Offline Offline

Posts: 384


WWW
« Reply #35 on: October 11, 2006, 12:53:17 AM »
ReplyReply

Hi PP,

I have not posted once on the Phase One forum because I have not had ANY issues with their backs.  I am in weekly contact with 4 other phase shooters I am friends with.  I have a very helpful camera dealer.  Most of my questions for Phase One were answered before they had an official user to user forum.  I have used their product happily since the 6mp LightPhase back (remember, the one that was a step-up from the H6 because it was 16 bit instead of 12 bit).  They work exactly as they are designed to.  Lens cast calibration is so well known and documented that there is no need to ask further questions.  I shoot a calibration file run the LCC and the files look perfect.
Logged
Eric Zepeda
Jr. Member
**
Offline Offline

Posts: 89


WWW
« Reply #36 on: October 11, 2006, 01:14:05 AM »
ReplyReply

I use a cambo wds with 35 and 47 digitars and a P25. Lcc is just part of the workflow. As Eric said, doesn't mean the sensor is defective or anything, it's just what happens with wide lenses on the Kodak sensor. Honestly, I don't think it's that big of a deal...anyone remember CC filters, reciprocity failure and all the other things that went along with LF film? If Phase or Kodak improves things down the line, great. Until then I'll do what's necessary to deliver top quality files to my clients.
Logged

pixpop
Newbie
*
Offline Offline

Posts: 37


« Reply #37 on: October 11, 2006, 11:35:41 AM »
ReplyReply

well said eric and eric. but i think it's important to note that people like myself who don't use wide angle lenses on large or medium format cameras with tilt and shift, but do use wide angles on cameras such as hassys or alpas in a non-shift capacity, might not ever see lens cast. i've shot calibrations and run lccs to make a point in order to show no difference between the files. If your shooting with tilt and shift, you're going to get lens cast no matter which digital back you're using.

pp
« Last Edit: October 11, 2006, 02:44:38 PM by pixpop » Logged
narikin
Sr. Member
****
Offline Offline

Posts: 861


« Reply #38 on: October 11, 2006, 05:41:46 PM »
ReplyReply

Quote
why you have never had/seen this? simply because you did not have any comparison, a side by side comparison.

The color cast problem with Phase, Leaf and Sinarbacks is a fact, being it with MF bodies or shifts/tilts. How to handle this is another issue. I know that I dont have any problem with my Sinarbacks, being it my SB 54 H or my eMotion 75.

Once you have put side by side an corrected and non-corrected image, the problem will jum at your eyes!

Aon
[a href=\"index.php?act=findpost&pid=79894\"][{POST_SNAPBACK}][/a]
sorry - its not that simple. of course I HAVE done comparisons and used the LCC card, and there is no difference with my main camera set up (Contax 645) yes, I know thats a retrofocus wide angle etc etc, but the point is that there's a lot of Phase users (the majority?) who are like me, use MF DSLR's, and dont see LCC ever. I'm sorry for those who do suffer, but please remember its non-existent as a problem for a lot of people.

Oh well, this thread is well and truly gotten hijacked to yet another LCC one, so thats the end of my original enquiry.
Logged
ericstaud
Sr. Member
****
Offline Offline

Posts: 384


WWW
« Reply #39 on: October 11, 2006, 06:20:45 PM »
ReplyReply

"sorry - its not that simple. of course I HAVE done comparisons and used the LCC card, and there is no difference with my main camera set up (Contax 645) yes, I know thats a retrofocus wide angle etc etc, but the point is that there's a lot of Phase users (the majority?) who are like me, use MF DSLR's, and dont see LCC ever. I'm sorry for those who do suffer, but please remember its non-existent as a problem for a lot of people."

If the thread you started had been about a retrofocus camera then what you are saying would make sense Narikin.  Using the Contax as an example of how your Phase back does not have LCC is pretty much hijacking your own thread.  The Alpa does not use retrofocus lenses.  Can you tell us which lenses you have used with the Alpa and the Phase One back?  You must have done this before to declare that LCC is off topic regarding the use a an Alpa 12TC and the P45.  

-Eric
Logged
Pages: « 1 [2] 3 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad