Chuck,
Understood, thanks ^^
---
Michael
On 16 August 2010 20:25, Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>wrote:
> You shouldn't have any need for a circular polarizer on a view camera.
> A linear polarizer should work just fine, be cheaper and, I think,
> somewhat more effective.
>
> Chuck Norcutt
>
>
> Michael Wong wrote:
> > Thank you very much, Jeff.
> >
> > I understood I should put CF on the wide angle lens to avoid fall off but
> as
> > you said, it's very expensive. But I think I'll go to get one finally.
> >
> > Btw, I searched internet & found the website for Schneider large format
> lens
> > information:
> >
> https://www.schneideroptics.com/ecommerce/CatalogSubCategoryDisplay.aspx?CID=162
> >
> > But it seems not many information provided. Such as what size of CPL to
> be
> > applied to 72XL ............ or what kind of CF to to applied ......
> > Is any good website with more information provided? Thanks.
> >
> >
> > ---
> > Michael
> >
> >
> >
> >
> > On 16 August 2010 01:11, Jeff Keller <om-list@xxxxxxxxxxx> wrote:
> >
> >> Hi Michael,
> >>
> >> I downloaded the photo and used the eyedropper in Photoshop to check the
> >> color values at the top of the image.
> >> Top Left:0 6 52 Top Center:0 15 74 Top Right:0 3 48
> >>
> >> I think it is the expected light fall off of the lens imposed over a not
> >> exactly uniform sky. The bright white cloud probably makes the left side
> >> both brighter and seem even brighter. Even within the specified IC there
> is
> >> light fall off. As mentioned by Wayne, the bottom of the photo has light
> >> concrete which exaggerates the difference.
> >>
> >> The IC specification is often a soft limit. It may be specified because
> of
> >> either reduced resolution and/or light reduction. It is also specified
> at a
> >> specific aperture. Stopping down further improves the vignetting for
> some
> >> but not all lenses (G-Claron is the one the many stop down and use way
> >> beyond the specified IC).
> >>
> >> The center filters are expensive but they do show up on ebay from time
> to
> >> time. Some LF people actually prefer to have some soft vignetting and
> don't
> >> correct it. My personal preference is revealed by ebay 250677002916.
> Black
> >> and White users are less likely to want a CF.
> >>
> >> Best wishes,
> >> Jeff
> >>
> >>
> >> -----Original Message-----
> >> From: Michael Wong [mailto:mialop@xxxxxxxxxxxx]
> >> Sent: Sunday, August 15, 2010 9:29 AM
> >> To: Olympus Camera Discussion
> >> Subject: Re: [OM] Visited Macau
> >>
> >> Jeff,
> >> I understood but I don't know why vignetting at right upper corner only.
> >>
> >> According information from largeformatphotography.info, the max rise of
> >> 72XL
> >> is 47.75mm
> >> http://www.largeformatphotography.info/lenses/LF4x5in.html
> >>
> >> My Ebony SW45 can be rised max 60mm, I'm not sure did I rise the front
> >> panel
> >> near the limitation of 72XL caused vignetting?
> >>
> >> Maybe I have make a mark at my camera to remind me the max rise for
> 72XL.
> >>
> >>
> >> ---
> >> Michael
> >>
> >>
> >>
> >> On 15 August 2010 15:14, Jeff Keller <om-list@xxxxxxxxxxx> wrote:
> >>
> >>> Hi Michael,
> >>>
> >>> I don't know if you've come across this: many LF cameras have the
> corners
> >>> of
> >>> the focus screen clipped off so that when everything is set up
> including
> >>> the
> >>> aperture stopped down you can look through the corners to see if the
> >>> aperture is round. If your focus screen has clipped corners you should
> be
> >>> able to see any mechanical vignetting show up as a football shaped
> >>> aperture.
> >>>
> >>> The Super Symmar XL's are thought to have the greatest light falloff
> but
> >>> the
> >>> IC on your 110 SS XL is so large you shouldn't have a problem with it.
> >> The
> >>> 80mm SS XL had a recent discussion:
> >>>
> >>>
> >>
> http://www.largeformatphotography.info/forum/showthread.php?t=65234&highligh
> >> t=center+filter<
> >> http://www.largeformatphotography.info/forum/showthread.php?
> >> t=65234&highligh%0At=center+filter<
> http://www.largeformatphotography.info/forum/showthread.php?%0At=65234&highligh%0At=center+filter
> >
> >>>
> >>> The Schneider center filter for the 72mm XL has a 112mm front filter
> >> thread
> >>> so that a second filter could be attached to it and not cause
> vignetting.
> >>> The lens has a 95mm thread which they surely believe is fine for a
> single
> >>> filter. The lens has a 226mm IC and would thus cover a 5x7 film with
> >> little
> >>> room left for shift/tilt.
> >>>
> >>> The Super Angulon 90mm f8 has a IC of 216mm so it can handle about an
> >> inch
> >>> of shift from center.
> >>>
> >>>
> >>
> http://www.schneideroptics.com/info/vintage_lens_data/large_format_lenses/su
> >> per-angulon/data/8-90mm.html<
> >> http://www.schneideroptics.com/info/vintage_len
> >> s_data/large_format_lenses/su%0Aper-angulon/data/8-90mm.html<
> http://www.schneideroptics.com/info/vintage_len%0As_data/large_format_lenses/su%0Aper-angulon/data/8-90mm.html
> >
> >>>
> >>> The schneideroptics website has a lot of information but finding it
> seems
> >>> to
> >>> require a search engine.
> >>>
> >>> Best wishes,
> >>> Jeff
> >>>
> >>> -----Original Message-----
> >>> From: Michael Wong [mailto:mialop@xxxxxxxxxxxx]
> >>> Sent: Saturday, August 14, 2010 7:46 PM
> >>> To: Olympus Camera Discussion
> >>> Subject: Re: [OM] Visited Macau
> >>>
> >>> I have same experience for my old Super Angulon 90mm F8, is the
> >> vignetting
> >>> easy to perform for wide angle lens?
> >>>
> >>>
> >>> Thanks, Jeff.
> >>>
> >>>
> >>> ---
> >>> Michael
> >>>
> >>>
> >>>
> >>> --
> >>> _________________________________________________________________
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> >>>
> >>>
> >> --
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> >>
> >>
> >>
> >> --
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> >>
> >>
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