Archived posting to the Leica Users Group, 2003/09/25

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Subject: Re: [Leica] DigiBack Website updated, maybe the philosophal sensor for Leica-M lenses
From: Jerry Lehrer <jerryleh@pacbell.net>
Date: Thu, 25 Sep 2003 13:44:53 -0700
References: <21560127.1064505353541.JavaMail.root@statler.psp.pas.earthlink.net> <026001c383a3$7ddd9f50$0e77c850@HomeVdschrick>

LUGers

What is the expression; "Figures don't lie, but__________"?

Jerry

Grégoire Vandenschrick wrote:

> you read it right, the CMOS WITH microlenses cannot handle the very wide
> cone of light produce by wide aperture optics. This is due to the microlens
> itself. Did you read all the description of the differnet technologies
> purposed to achieve a high fill factor? this is not what is used by Fill
> Factory. Maybe I miss the point here, but I don't plan to use the microlens
> array, because of that, but rather well the N-Well technology, wich frees
> the front of the CMOS form any microlens array, recovering so a more wide
> cone of light. And if this cone is not wide enough, then add the
> microfresnel array.
>
> Actually, I took a cone of +20° around the optical axis for the N-Well CMOS.
> This is based on what Kodak gives for the angular tolernace of their CCD
> WITH microlens. So, I'm rather tight on this, I'm practically sure the Fill
> Factory CMOS has in fact a more wide cone of light, but I took this to be
> sure.
>
> I would like to point something I forgot to tell. With such a cone of light
> of 20° around the optical axis (20° on both side, so a total angle of 40°
> ok?) even with the Microfresnel, one cannot achieve to gather all the light
> coming from the Noctilux (which is in the center of 30° around the optical
> axis, +60° on the total!). The Noctilux is in fact not a problem in the
> corner, but rather well in the center! Now, if we take the risk to consider
> that the Fill Factory N-Well CMOS has an angular tolerance of + - 30°, It is
> compliant with the Noctilux. In the corner, it is easily achieved by the
> microfresnel array.
>
> Do I miss something about your comment? I'm not sure about what you mean
> exactly.
>
> Best
>
> Greg
> ----- Original Message -----
> From: "Douglas Herr" <telyt@earthlink.net>
> To: <leica-users@mejac.palo-alto.ca.us>
> Sent: Thursday, September 25, 2003 5:55 PM
> Subject: Re: [Leica] DigiBack Website updated, maybe the philosophal sensor
> for Leica-M lenses
>
> > Gr?goire Vandenschrick <gregoire.vds@skynet.be> wrote:
> >
> > > the sensor compliant with the angles produced by Leica-M lenses could be
> > > done with existing technical solutions, go and have a look:
> > >
> > > on the flapback page, follow the "high resolution CMOS with microfresnel
> > > array" link, or go directly to
> > >
> > > http://users.skynet.be/fa420324/pages/CMOS.htm
> >
> > Quoting from the FillFactory description of the microlens CMOS chip:
> >
> > "not efficient with wide-aperture optics"
> >
> >
> > Doug Herr
> > Birdman of Sacramento
> > http://www.wildlightphoto.com
> > --
> > To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html
> >
>
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In reply to: Message from Douglas Herr <telyt@earthlink.net> (Re: [Leica] DigiBack Website updated, maybe the philosophal sensor for Leica-M lenses)
Message from Grégoire Vandenschrick <gregoire.vds@skynet.be> (Re: [Leica] DigiBack Website updated, maybe the philosophal sensor for Leica-M lenses)