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Author Topic: How to hack a sinar back ... for use on r6k8i  (Read 4019 times)
Adina
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« on: February 26, 2008, 02:14:59 AM »
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Hi,

my rollei6008i has a problem ... they will give only a flashsync pulse when:

 - aperture AND exposure time NOT on "A"  
 - or the corrector switch is on +1/3 lw or above

The Sinar adapter will not set the sensitivity, so the camera will always operate
at 100ISO (+1/3lw from the corrector switch).

I made a PCB to emulate the sensitivity switch from the filmback.
For 25ISO you must place a 4,72kOhm resistor between pin1 and pin2
and 0Ohm between pin2 and pin5.

(pin3, pin4 and pin6 ar not on the PCB,
-> pin1 - pin3 slider switch for the filmback
-> pin4 - pin6 filmtransport switch for the filmback
)

The little white piece is a SMD resistor.
I place the PCB with double-sided tape in the Sinar back adapter.

The MFDB has now a bas sensitivity from 25ISO. With the corrector switch
i can now use the range from 25 +1/3lw to 400 +2/3lw.    


(sorry for the image quality, but i can't use the "right" camera    )

Greetings
Adina
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rainer_v
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« Reply #1 on: February 26, 2008, 03:21:48 AM »
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super....
how you tested out the resistor values and contacts without having fear to destroy something?
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rainer viertlböck
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www.tangential.de
Graham Mitchell
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« Reply #2 on: February 26, 2008, 03:22:47 AM »
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Quote
The MFDB has now a bas sensitivity from 25ISO. With the corrector switch
i can now use the range from 25 +1/3lw to 400 +2/3lw.
[a href=\"index.php?act=findpost&pid=177433\"][{POST_SNAPBACK}][/a]

You mean the camera, not the MFDB, right?
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Graham Mitchell - www.graham-mitchell.com
Graham Mitchell
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« Reply #3 on: February 26, 2008, 04:55:07 AM »
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The Sinarback's setting of ISO 25 is more like ISO 50. I know that when I shoot using ISO 25 and auto exposure, I generally get perfect exposure if I set the exposure compensation to '+1', not '+2'. Therefore I would want the camera to be set to ISO 50 if using the lowest sensitivity setting on the back. Apart from that, cool project. If only there was a way to set the camera to all the possible ISO settings of the back.
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Carl Glover
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« Reply #4 on: February 26, 2008, 05:48:54 AM »
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Graham,

Is that the case with the latest firmware upgrade? I thought that it was meant to get the backs' ISO's more in line with those of the camera.

I tend to work at ISO 50 but do find that I have to to a bit of tinkering before the histogram is happy, maybe this is why.
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rainer_v
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« Reply #5 on: February 26, 2008, 05:52:59 AM »
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Quote
The Sinarback's setting of ISO 25 is more like ISO 50. I know that when I shoot using ISO 25 and auto exposure, I generally get perfect exposure if I set the exposure compensation to '+1', not '+2'. Therefore I would want the camera to be set to ISO 50 if using the lowest sensitivity setting on the back. Apart from that, cool project. If only there was a way to set the camera to all the possible ISO settings of the back.
[a href=\"index.php?act=findpost&pid=177450\"][{POST_SNAPBACK}][/a]

iso25 ( iso 50 with e75 )  is perfect with brumbaer tools. it has at least one stop more headroom in the highlights than CS.
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rainer viertlböck
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thsinar
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« Reply #6 on: February 26, 2008, 06:45:18 AM »
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The latest firmware update sets the nominal ISO from 25 to 50 (up to ISO 400) for the SB eMotion 54 LV / eMotion 22, and from ISO 50 to 100 (up to ISO 800) for the eMotion 75/75LV

Best regards,
Thierry

Quote
Graham,

Is that the case with the latest firmware upgrade? I thought that it was meant to get the backs' ISO's more in line with those of the camera.

I tend to work at ISO 50 but do find that I have to to a bit of tinkering before the histogram is happy, maybe this is why.
[a href=\"index.php?act=findpost&pid=177461\"][{POST_SNAPBACK}][/a]
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Thierry Hagenauer
thasia_cn@yahoo.com
Graham Mitchell
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« Reply #7 on: February 26, 2008, 07:18:22 AM »
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Graham,

Is that the case with the latest firmware upgrade? I thought that it was meant to get the backs' ISO's more in line with those of the camera.
[a href=\"index.php?act=findpost&pid=177461\"][{POST_SNAPBACK}][/a]

Yes, but if the original poster is talking about ISO 25 then he must be using old firmware.
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Graham Mitchell - www.graham-mitchell.com
Adina
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« Reply #8 on: February 27, 2008, 03:25:19 AM »
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Yes, but if the original poster is talking about ISO 25 then he must be using old firmware.
[a href=\"index.php?act=findpost&pid=177472\"][{POST_SNAPBACK}][/a]

I have the new Firmware ...
Yes, the MFDB has now ISO 50 -> ISO 400 ...
But with the adapter and the groundsetting of ISO 25 on the camera, i can
overexposure +1 with ISO 50 setting on the back.

If the adapter should have ISO 50, you must use 2 resistors.
~4 kOhm resistor between pin1 and pin2
and ~700Ohm between pin2 and pin5. (at the moment i am not know the exact values,
the ISO switch on the filmback is a voltage divider ..., at ISO 6400 you have 0Ohm between pin1 and pin2 and 4,72kOhm between pin2 and pin5.

@rainer_v
"how you tested out the resistor values and contacts without having fear to destroy something?"

I have dismantled an old polaroid back ...  
Earlier i have dismantled a 6*4,5 back because it hat a problem with the
filmtransport, so i know the switches ...

An other way is to patch the camera firmware ...  
There is a Intel 8051 µP Derivat in my camera with a EEPROM on the side ...    

Greetings
Adina
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Prakash Patel
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« Reply #9 on: February 27, 2008, 01:06:49 PM »
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iso25 ( iso 50 with e75 )  is perfect with brumbaer tools. it has at least one stop more headroom in the highlights than CS.
[a href=\"index.php?act=findpost&pid=177462\"][{POST_SNAPBACK}][/a]

Assuming that one of the things that the firmware addresses  is coordinating the digital back iso to the meter in the Hy6.

Two questions(maybe this is a Sinar or a question for Thierry):
If the new iso for the e75 going to be 100 instead of 50...............is this just a graphical change in the menu of the back or is the sensitivity of the sensor actually addressed?
Does this mean that the image quality is actually changing or is it just a mathematical coordination to an in camera light meter..............so we won't be discussing that the e75 50 iso is really like the other backs 100 iso. In other words, if I do a 30 second exposure with a e75 with the old firmware
and compare it to the same 30 second shot with taken with another e75 with the new firmware will there be a difference in image quality or will they be the same?

Will the new firmware change effect the range of the highlight recovery when using the brumbaer tools.

I am very happy with the file quality of the e75 with the old firmware and brumbaer tools.
Since it is not reversable by the end user, is it even advisable to load the new firmware other than using it with the Hy6?
« Last Edit: February 27, 2008, 09:40:19 PM by Prakash Patel » Logged

thsinar
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« Reply #10 on: February 28, 2008, 05:10:03 AM »
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Dear Prakash,

the new firmware does not change the sensitivity of the eMotion backs (of the sensors) at all: it is merely a "nominal" ISO correction, from ISO 25 to 50 for the e22 & e54 LV, and from ISO 50 to 100 for the e75 & e75 LV.

So nothing is changed or altered in terms of image quality.

Best regards,
Thierry

Quote
Two questions(maybe this is a Sinar or a question for Thierry):
If the new iso for the e75 going to be 100 instead of 50...............is this just a graphical change in the menu of the back or is the sensitivity of the sensor actually addressed?
Does this mean that the image quality is actually changing or is it just a mathematical coordination to an in camera light meter..............so we won't be discussing that the e75 50 iso is really like the other backs 100 iso. In other words, if I do a 30 second exposure with a e75 with the old firmware
and compare it to the same 30 second shot with taken with another e75 with the new firmware will there be a difference in image quality or will they be the same?

Will the new firmware change effect the range of the highlight recovery when using the brumbaer tools.

I am very happy with the file quality of the e75 with the old firmware and brumbaer tools.
Since it is not reversable by the end user, is it even advisable to load the new firmware other than using it with the Hy6?
[a href=\"index.php?act=findpost&pid=177766\"][{POST_SNAPBACK}][/a]
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Thierry Hagenauer
thasia_cn@yahoo.com
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