Atik Cameras Forum
Support (Please note, this is primarily a user forum, for direct Atik support, please email support@atik-cameras.com) => 3- and 4-Series Cameras => Topic started by: Dave Watson on January 09, 2013, 06:33:00 pm
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Hi,
With regard to the 383L+ camera Atik specify the following
Distance from top of T-thread to focal plane: Approx 17mm
Optical window thickness: 2mm
You would normally add 1mm to the back focus of a scopes reducer for the refractive index of the glass filters, the question is should you also add ~1mm to compensate for the cameras optical window?
QSI, for instance, don't actually quote a mechanical sensor distance from the front of the camera, they actually quote the "Optical" distance which takes the refractive index of the optical window into account.
Regards,
Dave
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I would say yes BUT I have always found it pays to experiment with FF distances by +/- 5mm as the quoted ideal spacing has never given me iideal flatness.
Chris
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Hi,
I have just been checking the mechanical drawings for the 383L camera and I have noticed that the wording used is "Optical Backfocus = ~17.5mm".
Can someone from Atik confirm that this OPTICAL backfocus does or does not take into account the reflective index (0.68mm) of the cameras optical window.
I am using a Tak FSQ85EDX with a the Q-Reducer that needs a metal backfocus distance of 72.2mm and with the Baby-Q this distance is very critical, a tolerance of +-0.5mm had been banded around but not confirmed.
Can anyone help.....thanks.
Regards,
Dave
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Hi Dave,
Yes, it's optical distance, with both optical windows taken into account (CCD and camera's).
I find it very unlikely that a 0.5mm tolerance is required for a reducer...
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Hi Rui,
Brilliant, thanks for your answer.
I agree with you about the 0.5mm, however, Tak America say it is very very critical but won't say exactly what the tolerance is.
Regards,
Dave