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Author Topic: Leaf - Centerfold Issue with Dalsa Chip  (Read 6912 times)


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Leaf - Centerfold Issue with Dalsa Chip
« on: September 10, 2006, 02:04:18 pm »

As some of you may know, leaf Aptus digital backs have been reported to have a issue with a vertical line exhibiting a change in gain where the two halves of the Dalsa chip are joined together.

About 6 weeks ago I discovered that my Aptus 75 has this problem. I shoot my architectural work with an Alpa 12 SWA, 24, 35 and 47mm digitar lenses. When using any amount or rise/fall the vertical line becomes quite evident.

I have been in very deep and detailed discussions with my dealer about my options with respect to a replacement back and whether or not this problem will and/or has been fixed. Leaf has said that this is an isolated condition and that they will replace the back for me. That was 6 weeks ago. At that time I was told that I was #3 on the list to get a new back (my back was 1 month old at that time).

It seems that from what I have been told the centerfold or vertical gain line problem may not be an isolated incident. I do not know the exact stat but reliable sources from Leaf have reported that only 1 or 2 out of every 125-200 backs that are being shipped have the centerfold! If accurate, this means that that a large number of Leaf Aptus 75 backs in use have this tolerance defect.

The problem seems to extend beyond the Aptus 75, possible to the Aptus 22 and others, I have received several emails from folks with Aptus 65's and 22 complaining about the same issue.

Leaf did send a gain adjustment program as a temporary fix but the program has some very nasty side affects on the file such as changing the gamma of the raw file and blowing out the highlights. It will also only run on Apple Mac and not on a PC.

I am very disappointed that Leaf has not come out and announced that there is a problem and provided customers and dealers with solid and pertinent information. We were told that Leaf will replace the backs only for architectural shooters who use camera movements. This is unfortunate as there are reports of the centerfold issue showing up in chips and cameras that are not using movements.

No one wants to hurt Leaf, I have thought long and hard about taking this public and decided to do so in the hope that Leaf will react and show a sense of concern and urgency that in my opinion has been lacking.

I respectfully ask Leaf to address this problem and tell us what they (Leaf) is doing with respect to a long term and comprehensive solution. In addition LC10 is a disaster, it is light years behind other raw developers and may be especially so once the new Capture One is released. It is slow and a PC version is still vaporware.

My decision regarding a new or alternative medium format back is in the formative stages, I love the Leaf product and the look of it's file. I am absolutely disgusted with the sense of concern and urgency that has displayed with respect to this matter.

I have heard from my dealer;

It seems that the information coming from Leaf has been only half accurate.

From what I am now being told Leaf has determined that all of the digital back senors are made up of two sections. The problem is once of a tolerance error in joining the two sections at the Dalsa factory.

The delay in replacing the backs is due to delays in obtaining good sensors from the factory. Leaf has indicated the current crop of backs coming from the the factory either do not have the problem, don’t have it to the same degree, or has it in fewer numbers. The delay appears to be due to Dalsa working on the problem and being unable to ship the sensors reliably.

I am anxiously awaiting a replacement bacl.
« Last Edit: September 12, 2006, 08:35:52 am by mkravit »


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Leaf - Centerfold Issue with Dalsa Chip
« Reply #1 on: September 10, 2006, 02:30:13 pm »

Does anyone know if the stitching of two chips are limited to ones from Dalsa? How about ones from Kodak?

Jae Moon


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Leaf - Centerfold Issue with Dalsa Chip
« Reply #2 on: September 10, 2006, 03:26:15 pm »

There is another thread  here which discusses this at length


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Leaf - Centerfold Issue with Dalsa Chip
« Reply #3 on: September 11, 2006, 04:43:02 pm »

dear friends,
i had exactly the same problem with my aptus 75. jair from leaf offered to organize the exchange of my back but the leaf dealer in vienna performed a software recalibration on my back (gain adjustement???) and the  'middle line' problem seems gone, at least with the 47mm schneider digitar lens. i still have to test my other lenses.
i can report that THIS problem does not appear on the P45 back. there the main problem is colorshifts, which can easily be software corrected (in  windows and in OS). these shifts also appear on my leaf back, maybe to a somewhat lesser extent (sometimes notreally) but there is no software fix so far for windows users.
all in all i am a bit confused: should i insist on an exchange of my leaf aptus 75 back after all or not? which problems will still appear? although i appreciate jair's fast response to me, i think some more openness on leaf's part about their sensor problems would be in order.


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Leaf - Centerfold Issue with Dalsa Chip
« Reply #4 on: September 13, 2006, 09:02:10 am »

This from Leaf;

Dear Michael,

As you mentioned, we are currently dealing with a problem found in certain backs which show an abrupt tonal change at the center of the image when in landscape orientation. A user has called this phenomena “the Centerfold effect”. It occurs mainly when using shift & tilt on large format cameras equipped with wide angle lenses where the distance between the sensor and exit pupil of the lens is short.

We want to share with you the current Leaf R&D activities directed towards a quick resolution of this issue, some of which you are aware:

1) During May, we released a utility called the Custom Gain Adjuster. This software enables the user to correct the above effect in a batch-like fashion retroactively after the shoot. We have received customer feedack about the shortcomings of this version and a new version is ready for release immediately. We will notify customers where to obtain the updated application.

2) You may be familiar with the User Gain functionality within Leaf Capture 8. This function is utilized in tethered mode and enables creating and using gain corrections for specific lenses. We have developed a new version of Leaf Capture 8 which will produce User Gain files that can be loaded to the Aptus back and used during any shoot (including portable shooting).
This application is also ready for immediate release to customers who need it.

3) Leaf R&D is very attentive to customer needs and has made a serious effort to supply these solutions in as short a time as possible. We have been restrained in answering the customer forums before having something concrete to say.

We believe the solutions described above will answer the problems currently felt by some of our customers.

Best regards,

Shachar Kedem | Director, Service & Support | Leaf
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