Saturday, 4 December 2010

Base Map

I've been trying to create a base plan for Calverley Grounds for Monday at A1 with contours and spot heights.  I've come up with the above from Digimap then taken into Photoshop.  It was set at 1:500 at A1 in Digimap but for some reason it is too short and too narrow.  I saved it as an A1 in Powerpoint and it shows this clearly, help...

3 comments:

  1. Hi
    Forgive me… I worked with Grant last year and can’t resist taking a sneaky look at your year blogs from time to time.

    Anyway, when importing a scaled image into Photoshop and you wish to retain the correct scaling, the image must be at the same dpi (dots per inch) as the blank A1 sheet in Photoshop; ie they should both be set to the same dpi.
    If the image being imported into Photoshop is set at say 150 dpi and the Photoshop A1 sheet is set at 300 dpi then the imported image when pasted onto the A1 image will be half the expected size as Photoshop cannot interpolate the missing 150 dots per inch.

    I always work at 300dpi as it means I know I am consistent with the number of dots per inch and I have enough data in the image to edit and crop heavily if needed. It does have the disadvantage of creating large files but I can live with that; I just PDF them or save them as jpegs before printing.
    Anyway, in your case my guess is that the imported drawing had a lower dpi than the A1 blank page in Photoshop.
    To correct this check what dpi the contour map is set at and create a new A1 blank sheet at the same dpi. Then import the contour map into the blank A1 sheet. All scaling should remain intact.

    When I create a scale drawing in Photoshop now, I always scan in an image of my scale rule with the scale of the drawing I intend to produce visible on the rule. It’s a really useful check that everything in your drawing is being created at the scale you expect.
    Hint… if you always work at the same dpi your scaling will remain correct when going from one software suit to another. Hope this helps.

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  2. thanks for this paul, a real help- im going to have a go at this today and hopefully it is as easy as you make it sound!!-
    thanks again for the tips!
    adele

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  3. Thanks again Paul, I will have a go when I've finished putting up my Christmas tree.

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