Dear Simon,
I've found a similar diagonal distortion of the PSF induced by the DIC  
objective prism in our FV-1000/IX-81.   It is also apparent while  
looking at 6 um beads.  Another reason  it should be pulled from the  
light path whenever not collecting DIC, besides dropping the  
fluorescent signal by a small amount.

Regards,
Glen
Glen MacDonald
Core for Communication Research
Virginia Merrill Bloedel Hearing Research Center
Box 357923
University of Washington
Seattle, WA 98195-7923  USA
(206) 616-4156
[log in to unmask]

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The box said "Requires WindowsXP or better", so I bought a Macintosh.
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> Hi Mike,
>
> We have seen a similar problem to this, particularly apparent in DIC  
> transmitted light images.  However, of our two FV1000 systems  
> (located in different rooms), it is only readily apparent on one.   
> This has led us to believe it is a vibration issue, especially as we  
> can cause a more severe, but similar-looking problem by deliberately  
> introducing a source of vibration near to the microscope.  However,  
> if true, we have yet to isolate the cause of the problem vibration.
>
> While I'm here...has anyone properly investigated the effect of the  
> DIC objective prism in confocal fluorescence imaging?  I had always  
> assumed (rightly or wrongly) that it's presence didn't influence the  
> PSF, but last week I was imaging some subresolution beads and found  
> that, particularly on our IX81-based FV1000 confocals, the DIC  
> objective prism had quite a pronounced effect on the psf.   
> Specifically the psf was distorted along a diagonal axis and at the  
> point of focus, the bead appeared significantly larger with the  
> prism in place. The implication of this is that for confocal  
> fluorescence imaging, the resolution of the microscope is reduced  
> when the DIC objective prism is in place.  I've also looked on our  
> Zeiss Axiovert 200 and Nikon TE-2000 based systems which employ a  
> slightly different method of DIC and there the effect is much less  
> pronounced although noticeable.
>
> Simon
>
>
> -----Original Message-----
> From: Confocal Microscopy List  
> [mailto:[log in to unmask]] On Behalf Of MODEL, MICHAEL
> Sent: 07 October 2009 12:28
> To: [log in to unmask]
> Subject: exorcising spirits from Fluoview
>
> I apologize if this is a second message to the list, I think the  
> first one didn't go through
>
> We are having a bizzare scanning problem. Straight vertical lines in  
> an object become slightly zigzagged with a period of up to 6-7 scan  
> lines, and there also may be some oscillation in the intensity. The  
> period and the magnitude of this periodic noise depends on the scan  
> speed and the scan size. So far we (with the help of an Olympus  
> engineer) have established that:
>
> 1. It doesn't seem to be the scanner controller or the galvo mechanism
> 2. It does not seem to be the electric power in the building
> 3. It is not a mechanical vibration
> 4. It is not a computer
> 5. It is not the cables
> 6. It is not a 60 Hz noise
>
> Sometimes connecting the scanner controller to the outlet through a  
> long extension cord seemed to help which may suggest a problem with  
> grounding, but as soon as we concluded that, the trick stopped  
> working. The trouble could not be reproduced at the Olympus testing  
> lab.
>
> Has anyone experienced anything similar and successfully resolved  
> the problem?
>
> Many thanks in advance!
>
> Mike Model