[optimal] Re: Zeiss FF450 Plus flash/expopsure question
- From: Marshall Tyler <marshalletyler@xxxxxxxxx>
- To: optimal@xxxxxxxxxxxxx
- Date: Tue, 21 May 2013 20:20:13 -0400
Can you pull the flash sync cable and just use the viewing light??
Marshall
On Tue, May 21, 2013 at 6:31 PM, Michael Turano <turano@xxxxxxxxx> wrote:
> That being said you could put your own ND filter in the filter holder down
> on the camera body itself and see if it works (I think it would nock down
> the exposure for sure). Just make sure you secure it you don't want it
> falling into the machine.
>
> I do agree that the manufacturer of the digital system should be able to
> tune the sensitivity or add a filter at the sensor level. A flash level of
> 1 shouldn't blow out a test eye.
>
> FYI I also work for Zeiss.
>
> Mike
>
> Michael R. Turano, Jr., CRA, OCT-C
>
> Imaging Specialist
>
> C 917.826.9506
> F 917.591.1841
>
> turano@xxxxxxxxx
>
> Sent from my iPhone
>
> On May 21, 2013, at 5:12 PM, kevinlangton@xxxxxxxxx wrote:
>
> Group
>
> There is no ND slider for the FF-450 on the lower port. Fernando did you
> contact Merge / OIS to have the gain lowered on the digital sensor? The
> flash output should be able to give you an well exposed image if the sensor
> is properly set. Most digital imaging manufactures calibrate the sensor on
> sight to "marry" it to the retinal camera.
>
> Regards
>
> Kevin
>
> FYI I do work for Zeiss.
> Sent from my Verizon Wireless BlackBerry
> ------------------------------
> *From: * Noelle Pensec <npensec@xxxxxxxxx>
> *Sender: * optimal-bounce@xxxxxxxxxxxxx
> *Date: *Tue, 21 May 2013 17:05:36 -0400
> *To: *<optimal@xxxxxxxxxxxxx>
> *ReplyTo: * optimal@xxxxxxxxxxxxx
> *Subject: *[optimal] Re: Zeiss FF450 Plus flash/expopsure question
>
> From time to time we use an ND filter in the slider slot. On our FF-450
> plus, redfree images are often overexposed on the lowest flash setting for
> patients with blonde retinas and reflective pathology. The filter was
> purchased directly from Zeiss...
> On May 21, 2013 4:59 PM, "Fernando Corrada" <fcorrada@xxxxxxxxxxx> wrote:
>
>> Hi fellow Optimalers.
>>
>> Recently we purchased a new Zeiss FF-450 Plus IR camera to image with
>> a Merge/OIS WS5000 system. The only issue I have encountered is that the
>> flash output is quite strong for taking pictures of the DARC test eye. I am
>> using the lowest flash setting on the FF450 (1) and an ISO of 1oo on the
>> sensor.
>> I am curious about how other people have solved this issue. ND filter on
>> the WS5000 sensor or on the FF450 filter slider? Changed the sensor
>> sensitivity settings in the ini files? Or.....?
>>
>> I did call DARC and they suggested to take the color images with the
>> green filter (red free) in place but that did not work either. The colors
>> photos and the red frees are way overexposed. The FA images are fine.
>>
>> A level 2 tech at Zeiss said that I could not use the slider filter on
>> the FF450 with an ND filter. That it is only used for green filters & FA
>> filters. They did not explain in detail why it is not possible. I think it
>> should work but I do not have a gelatin ND filter to try it out. I imagine
>> that a 0.9 (3 stops) ND filter would be fine. The other possibilty is to
>> place an ND filter in front of the WS5000 sensor but I hate to expose the
>> sensor to dust and whatnot. What have you creative people have done? Thank
>> you in advance.
>>
>> Merge Healthcare/OIS is going to call me back with a solution which I
>> think involves an ND filter. Will see what they suggest.
>>
>> Fernando B. Corrada
>> Burlington, VT
>>
>
--
Thank you,
*Marshall*
Marshall E Tyler
sv *Silk*
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