Login or Join Now

Upload your photos, chat, win prizes and much more

Username:
Password:
Remember Me

Can't Access your Account?

New to ePHOTOzine? Join ePHOTOzine for free!

Like 0

Panoramas and Focal length

Join Now

Join ePHOTOzine, the friendliest photography community.

Upload photos, chat with photographers, win prizes and much more for free!

Leave a Comment
    • «
    • 1
    • »
    jembo
    jembo  10103 forum posts United Kingdom
    30 Aug 2011 - 9:34 PM

    My question goes out to anyone who has successfully created a panoramic image (multiple images stitched together).
    Is there an ideal focal length to use, or is it a case the shorter the focal length, the more you need to overlap to avoid lens distortion?

    Sponsored Links
    Sponsored Links 
    30 Aug 2011 - 9:34 PM

    Join ePHOTOzine for free and remove these adverts.

    User_Removed
    30 Aug 2011 - 9:54 PM


    Quote: Is there an ideal focal length to use,

    No.


    Quote: or is it a case the shorter the focal length, the more you need to overlap to avoid lens distortion?

    Not necessarily.

    This was shot using three images using a 10.5mm fisheye Nikkor on an Olympus E-P1. The necessary adaptor to fit the Nikon lens to the Olympus body meant that the Nikon-designed 180 angle of view was reduced by approx 30%. The three individual frames used for the finished image allowed for approx 30% overlap and were corrected in PS before combining in PTGui.

    There are 'Rules' of course - but then, 'Rules' are for guidance.

    Aren't they???

    Wink

    Last Modified By User_Removed at 30 Aug 2011 - 9:56 PM
    mikehit
    mikehit  46171 forum posts United Kingdom9 Constructive Critique Points
    30 Aug 2011 - 11:27 PM

    I have not done much panorama stitching but before the advent of affordable distortion correction the usual advice was to use lenses with a focal length of 40mm and up. The problem then is one of depth of field because at these focal lendths DOF is much less than with a wide angle lens.

    I am ready to be corrected but in order to do the stitching most effectievly the software has distortion correcton built in so that the picels line up. How much you need to do some correcton before dong the stitching I don't know. But Mike's image is pretty impressive Grin

    jembo
    jembo  10103 forum posts United Kingdom
    30 Aug 2011 - 11:27 PM

    That's a great photo.
    So presumably the software being used can make a difference.

    mattw
    mattw  105189 forum posts United Kingdom10 Constructive Critique Points
    31 Aug 2011 - 6:00 AM

    If you can keep the distortion to a minimum, it does make the stitching easier - so I do use a higher focal length (around 35 - 50mm) if I can.

    However it depends upon the shot you are trying to take, and where you can stand. Sometimes you have to go wide, and hope for the best with the stitching later.

    This one was taken at 17mm (5D and 17-40, so 'distortion city') , and managed to knit together fairly well.

    Last Modified By mattw at 31 Aug 2011 - 6:51 AM
    Nick_w
    Nick_w e2 Member 73818 forum postsNick_w vcard England99 Constructive Critique Points
    31 Aug 2011 - 7:54 AM

    As to the original question. Long lenses tend to be more forgiving in terms of distortion. They have little distortion generally, slight pin-cushion, ultrawide's on the other hand have quite large barrel distortion, so more unforgiving of sloppy technique.

    What I would say is theres a lot of good technical reasons for using prime lenses. The main 2 are:

    1. The focal length can't move when rotating
    2. The lens tends to be shorter, this means there is less off a problem with nodal shifts, nodal problems are usually encountered with wide angle lenses, with elements in the foreground - Ignore this if you have a pano head that caters for nodal correction.

    I tend to use a 20mm prime on full frame.

    One way to avoid distortions - Ensure the Tripod is level - this is something I'm meticulous about. (anyone who disagrees, try doing a seascape, where the horizon can ends up looking like a banana if you don't)

    For overlap - I'm not hard and fast but generally ca 50%, main reason's - it does help reduce distortion (certainly with ultra wideangles) - but its easy to eyeball in the field - note a feature on the right of the frame in first pic, then place it in the centre in frame 2 etc.

    Oh switch off autofocus, and do all the exposures in manual. (Which I tend to do anyway).

    This is one I prepared earlier.

    snapbandit
    snapbandit  102205 forum posts Northern Ireland3 Constructive Critique Points
    31 Aug 2011 - 12:31 PM

    Any I have done (the ones which worked best anyway) I generally have been using focal lengths of between 40mm to 70mm, mostly taking pics in vertical/portrait format overlapping at least a third into each frame, manual exposure taking meter readings from over the whole panorama and as has been said manual focus (normally using 'hyperfocal distance).

    Generally means I have a lot of images to 'stitch and I may be being a bit too cautious giving myself more work on the pc, but it seems to work best for me this way.

    My 2p

    Joe B

    jembo
    jembo  10103 forum posts United Kingdom
    31 Aug 2011 - 6:06 PM

    I do lock the focus off and use manual exposure settings, but one I tried to stitch the other day just wouldn't sit together how I hoped it would. I will try again. Thanks people.

    • «
    • 1
    • »

    Add a Comment

    You must be a member to leave a comment

    Username:
    Password:
    Remember me:
    Un-tick this box if you want to login each time you visit.