Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Daytime Venus Rising Dip Short
    From: Bill B
    Date: 2012 May 03, 18:54 -0400

    On 5/3/2012 6:20 PM, Greg Rudzinski wrote:
    > I used an older 10 MP Canon Rebel with an adaptor to take a 1970's era
    > 200mm prime Pentax lens. The filter for the first photo had astronomy
    > mylar film over the lens (didn't work that good). The second image used
    > a pair of polarizers then the settings were at F22, ISO 100, and
    > 1/4000s. In iPhoto the image was cropped then adjusted for contrast,
    > exposure, etc.
    
    Most consumer or prosumer digital SLR's use an array smaller than the
    24x36 image on 35mm film, so the the effective focal length is about
    x1.4 for most brands and x1.5 for Nikon.  I doubt if full size arrays
    were an option (maybe for Canon) when you purchased your Pentax.  If you
    did purchase a full-size array back then you would most likely remember
    as the camera body would cost about the same as a new mid-sized car.
    
    I have used the double polarizers for long exposures of waterfalls etc.,
    but used a stack of neutral density (ND) gels for an eclipse.  Never
    occurred to me to try the polarizing filters. Duh!  Thanks.
    
    Bill B
    
    
    
    
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site