[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: [APML] The next great scanner?
Thanks for sharing your experience, Duncan.
> I have a similar problem with ghosting around bright stars with my
> Minolta dual scan 2. It goes away if I do a multi-pass scan and use a
> more precise focus.
I'm not quite sure how a multi-pass scan can help with a ghost image,
like the type I get. Averaging multiple scans of the same thing can only
reduce the random noise, whereas a bright ghost is systematic noise (it
is _always_ +, not randomly + and -). Unless I have the wrong
interpretation of "multi-scan"...
Since you say that more precise focus also helps, I reckon that focus
was probably the root of your problem. I've tested different focal
heights on my flatbed and it doesn't make a difference to the
ghosts/trails. That, plus the directionality of the ghosts, makes me
convinced that my problem is sensor or illumination based, not focus based.
So I guess that different types of scanners can present quite different
problems, requiring quite different solutions.
Ray "who can live with it, but would still like to know if anyone has
sussed it" Butler.
> cheers
>
>
> Duncan
>
> Lane, Jason R wrote:
>
>> Hi guys,
>>
>> This exactly describes the issue I have with my HP Photosmart
>> s20...little rainbow-like ghost reflection nearby. Uncoated optics,
>> for sure.
>>
>> -----Original Message-----
>> From: astro-photo-bounces@seds.org
>> [mailto:astro-photo-bounces@seds.org]On Behalf Of Matthias Felsch
>> Sent: Monday, October 04, 2004 6:34 AM
>> To: Discussion of Film Astrophotography
>> Subject: Re: [APML] The next great scanner?
>>
>>
>>
>> "Ray Butler" <ray.butler@nuigalway.ie> wrote:
>>
>>
>>
>>> When scanning slide films, whenever there is a star on a dark
>>> background ("dark" meaning somewhere
>>> at or above the rebate density, but somewhat less than the sky fog
>>> limit), there is a faint little
>>> 'trail' or 'ghost spot' left on both sides of the star image. .....
>>> .......
>>> Has anyone else noticed this effect?
>>>
>>
>>
>> I once tested a Minolta Multi Pro, which had similiar ghost effects, but
>> I think they were stronger than the ones you describe.
>> Each brighter star had a rainbow- like ghost reflection nearby.
>> Minolta Japan did find out that the reason was a glass plate
>> positioned in front of the ccd- sensor to protect it.
>> This glass was NOT coated.... <g>
>> When they modified this particular scanner with a coated glass, the
>> ghosts were reduced by 95 %. The remaining 5% were tolerable in my
>> opinion.
>> Unfortunately the scanner had a second flaw, so it was returned...
>>
>> Regards
>> Matthias
>>
>> www.mfelsch.de/astro/index.html
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>> Ray "who nonetheless considers the Epson 3200 to have been a great
>>> buy at the time" Butler
>>>
>>>
>>> Kevin McCarthy wrote:
>>>
>>>
>>>
>>>> Canon has just released their 9950F flatbed scanner, which will
>>>> accept a whole roll of 35 mm, and
>>>> two strips of 120 format. They claim that it is so good that they
>>>> are discontinuing their line
>>>> of dedicated film scanners. In the flatbed realm, the current best
>>>> model seems to be the Epson
>>>> 4870, which has been favorably compared to dedicated Nikon MF film
>>>> scanners. I would like to
>>>> hear any opinions as to how the new 9950F and year-old 4870
>>>> compare. Curiously, Canon does not
>>>> mention a Dmax value. An initial review of the 9950F is here,
>>>> although he (Vincient Olivier)
>>>> plans to follow up with an in-depth review shortly:
>>>>
>>>> http://www.photo-i.co.uk/News/Sept04/Canon%20scanner.htm
>>>>
>>>> He has an in depth review of the current champion Epson 4870 at:
>>>>
>>>> http://www.photo-i.co.uk/Reviews/interactive/Epson%204870/page_1.htm
>>>>
>>>> Here is some info from Canon:
>>>>
>>>> http://consumer.usa.canon.com/ir/controller?act=ModelDetailAct&fcategoryid=120&modelid=10446
>>>> I
>>>> did see some grousing on a German site that the Canon software is
>>>> "too automatic", also some
>>>> concern that third party software such as Digital Ice and SilverFast
>>>> may take a while to be
>>>> available for this scanner.
>>>> It may still be too early to tell if this has a real performance
>>>> edge over the 4870. Being in
>>>> the market for a MF scanner, it caught my interest. On another
>>>> note, Nikon LS-8000 can be had
>>>> for ~ $1500 if you are willing to buy a refurb, more like ~2000
>>>> otherwise. Opinions, anyone?
>>>>
>>>> Kevin McCarthy
>>>>
>>>> _______________________________________________
>>>> Astro-Photo mailing list
>>>> Astro-Photo@seds.org
>>>> http://seds.org/mailman/listinfo/astro-photo
>>>>
>>>
>>> --
>>> Dr. Ray Butler (ray.butler@nuigalway.ie || ray@physics.nuigalway.ie)
>>> Lecturer, Dept. of Physics || Computational Astrophysics Laboratory
>>> National University of Ireland, Galway, University Road, Galway,
>>> Ireland.
>>> Tel: +353-91-524411 ext. 3788 FAX: +353-91-525700
>>>
>>> _______________________________________________
>>> Astro-Photo mailing list
>>> Astro-Photo@seds.org
>>> http://seds.org/mailman/listinfo/astro-photo
>>>
>>>
>>
>>
>> _______________________________________________
>> Astro-Photo mailing list
>> Astro-Photo@seds.org
>> http://seds.org/mailman/listinfo/astro-photo
>> _______________________________________________
>> Astro-Photo mailing list
>> Astro-Photo@seds.org
>> http://seds.org/mailman/listinfo/astro-photo
>>
>>
>>
>>
>>
>
> _______________________________________________
> Astro-Photo mailing list
> Astro-Photo@seds.org
> http://seds.org/mailman/listinfo/astro-photo
--
Dr. Ray Butler (ray.butler@nuigalway.ie || ray@physics.nuigalway.ie)
Lecturer, Dept. of Physics || Computational Astrophysics Laboratory
National University of Ireland, Galway, University Road, Galway, Ireland.
Tel: +353-91-524411 ext. 3788 FAX: +353-91-525700
_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo