[3dem] Zeiss SCAI/ ZI Photoscan discontinued

[Steve Ludtke]

We got 2 or 3 of those as well, but found that A) they imit the field of view a
lot more than the custom-built solution and B) I believe there was a fair bit of
variability from holder to holder. (but it's been a while...)

----------------------------------------------------------------------------
Steven Ludtke, PhD              |        Baylor College of Medicine
sludtke at bcm.tmc.edu             |     Associate Professor & Co-Director
stevel at alumni.caltech.edu       | National Center For Macromolecular Imaging
V: (713)798-9020                |    Dept of Biochemistry and Mol. Biol.
F: (713)798-1625                |
                                |             Those who Do, Are
http://ncmi.bcm.edu/~stevel     |         The converse also applies

On Thu, 15 Nov 2007, Sacha De Carlo wrote:

> We have being using this one:
> http://www.bhphotovideo.com/c/product/218837-REG/Nikon_9247_FH_869GR_120_220_Rotating_Film.html
>
>
> without focusing problems, at least not detectable by eye or by sampling the scanned
> image with 1k by 1k or 2k by 2k FFTs...
>
> Sacha
> Boulder CO
>
> Steve Ludtke wrote:
>
>  We originally used an in-house modified glassless holder, and in fact, that's
> what we used on the 4A GroEL structure. Eventually we had too many problems with
> films that weren't flat, and built some glass holders using the FH869 holder as
> a base. We found that, while they were ok, there was variation in quality in the
> Nikon glass holders, and one would observe focus variation across the film. By
> carefully measuring the MTF across the film, and using varying numbers of pieces
> of scotch tape, with epoxy once optimized, we managed to get a glass holder that
> had very good performance across the film. You do lose some fraction of the
> film, perhaps 10-15%, but we simply accept this limitation.
>
> ----------------------------------------------------------------------------
> Steven Ludtke, PhD              |        Baylor College of Medicine
> sludtke at bcm.tmc.edu             |     Associate Professor & Co-Director
> stevel at alumni.caltech.edu       | National Center For Macromolecular Imaging
> V: (713)798-9020                |    Dept of Biochemistry and Mol. Biol.
> F: (713)798-1625                |
>                                 |             Those who Do, Are
> http://ncmi.bcm.edu/~stevel     |         The converse also applies
>
> On Thu, 15 Nov 2007, James Conway wrote:
>
>
>
>  Steve,
>
>
>
>  We turned our Zeiss off about 3 years ago and haven't used it
> since. We now use
> a set (they only cost ~$1k each) of Nikon 9000's. With a properly
> machined
> holder (the ones they ship require some minor modifications), we
> found that they
> outperformed our Zeiss in most respects. There is also a
> publication by Typke
> describing some technical evaluations of these scanners.  Whenever
> a new
> consumer grade scanner with apparent technical specifications that
> would make it
> useful to cryoEM comes out we evaluate it, and so far none of the
> other
> available 'consumer' grade scanners has performed as well as the
> Nikon (even
> though on paper some look better).
>
>
>  I would use the Zeiss, but I can't justify the cost - even
> maintenance is more than the Nikon! - so I bought a Nikon. I also
> bought the glass-cover holder which allows the film to fit without
> modification, and holds it flat. Of course, you can only scan about
> 1/2 of the area, but turning the film around gives you up to 2/3 the
> total area. The Zeiss, at least, gives you the whole film in one
> file, and I thought the later ones (like I had in Grenoble) were
> better than the early ones (like we used in Alasdair Steven's lab at
> the NIH).
>
> Did you ever try out the glass holder in the Nikon 9000?
>    FH-869G  "Film-Holder 869 Glass-covered" for medium format
> negative film
> If you haven't seen it, an image is here (can't find one on the Nikon
> web site):
>
> <http://www.bhphotovideo.com/c/product/218836-REG/
> Nikon_9241_FH_869G_120_220_Strip_Film.html>
>
> I would be interested to hear more of your holder.
>
> Best regards,
>
> James
> ----------------------------------------------------------------------
> James Conway, PhD.,
> Department of Structural Biology
> University of Pittsburgh School of Medicine
> Biomedical Science Tower 3, Room 2047
> 3501 5th Ave
> Pittsburgh, PA 15260
> U.S.A.
> Phone: +1-412-383-9847
> Fax:   +1-412-648-8998
> Email: jxc100 at pitt.edu
> Web:   http://www.pitt.edu/~jxc100/
> ----------------------------------------------------------------------
>
>
>
>
>
>  _______________________________________________
> 3dem mailing list
> 3dem at ncmir.ucsd.edu
> https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem
>
>
>
>
>
>