IR Image too soft

Discussion in 'Photography Beginners' Forum' started by rsenecal, Sep 8, 2006.

  1. rsenecal

    rsenecal TPF Noob!

    Joined:
    Sep 8, 2006
    Messages:
    1
    Likes Received:
    0
    I bought a $25 IR filter to put on my Canon Digital REbel. I took some photo at ISO 200 for 8 sec in manual focus. The image is soft. There are no detail. Could it be the filter. What are the standard setting for a infrared photography in daylight.
    Thanks
     
  2. ksmattfish

    ksmattfish Now 100% DC - not as cool as I once was, but still

    Joined:
    Aug 25, 2003
    Messages:
    7,021
    Likes Received:
    34
    Location:
    Lawrence, KS
    Can others edit my Photos:
    Photos NOT OK to edit
    Are you aware that you need to correct focus for IR?
     
  3. Orgnoi1

    Orgnoi1 TPF Noob!

    Joined:
    Aug 22, 2006
    Messages:
    481
    Likes Received:
    0
    Location:
    Upstate NY
    Can others edit my Photos:
    Photos NOT OK to edit
    First off you have to adjust focus slightly as was stated above... and then you are better off using a high aperture (f/8 - f/16) so that any minor corrections of focus can usually be taken up by the depth of field.
     
  4. LWW

    LWW TPF Noob!

    Joined:
    Aug 3, 2005
    Messages:
    1,206
    Likes Received:
    2
    Location:
    Dayton,Ohio
    I've not heard of focus adjustment for digital IR? Please explain?

    LWW
     
  5. Digital Matt

    Digital Matt alter ego: Analog Matt

    Joined:
    Jan 30, 2004
    Messages:
    5,346
    Likes Received:
    65
    Location:
    Santa Barbara, CA
    Can others edit my Photos:
    Photos NOT OK to edit
    Infrared is longer wavelength than visible light, and therefore focuses slightly differently. Lenses with a distance scale normally have a red mark for IR. In a normal landscape situation, using a wide angle lens, an aperture of f/8 or smaller will help.
     
  6. Dom0803

    Dom0803 TPF Noob!

    Joined:
    Aug 27, 2004
    Messages:
    96
    Likes Received:
    0
    I know you can get IR lenses that only let IR light in.. but I thought there was a filter over the CCD of a camera that blocked IR only letting visible light in... obvio not, but I saw a load of websites dedicated to hacking webcams and digicams to remove them so they only let in IR without the use of a filter.

    I may I add I tried to hack my old Finepix A202. Not only did I fail, but I got electrocuted.

    Twice.
     
  7. LWW

    LWW TPF Noob!

    Joined:
    Aug 3, 2005
    Messages:
    1,206
    Likes Received:
    2
    Location:
    Dayton,Ohio
    DM, I knew this was an issue with film but wasn't aware of it with digital.

    I've only done scenics in IR so far and all were shot at F11/F16.

    Is the focus point farther away then...and by approximately what percentage?

    LWW
     
  8. Arch

    Arch Damn You! Staff Member Supporting Member

    Joined:
    Jan 21, 2006
    Messages:
    8,487
    Likes Received:
    102
    Location:
    locked in the attic
    Can others edit my Photos:
    Photos NOT OK to edit
    I see you using a similar set up to me.... look at your 50mm 1.8... see the little silver dot to the left of the solid line on the lens body (between the line and the 11), thats your IR focus indicator..... so you'd focus the shot on auto... switch to manual and put the filter on..... then adjust the focus ring very slightly to line up with dot.... you should now have a focused position.

    Its useful to know if you need it...... i usually dont bother with it tho.... open the lens up to a wide angle and shoot between 16-22 (mostly 22 if its a nice bright day).... iv not had softness problems yet.
     
  9. Digital Matt

    Digital Matt alter ego: Analog Matt

    Joined:
    Jan 30, 2004
    Messages:
    5,346
    Likes Received:
    65
    Location:
    Santa Barbara, CA
    Can others edit my Photos:
    Photos NOT OK to edit

    There is no such thing as a lens that only lets IR light in. There are filters that block visible light. Yes, digital sensors have an IR blocking filter over them, but it does not block 100% of the IR spectrum. A mix of visible and IR light can create a pleasing image, and all that is required for digital is long exposures, anywhere from 5 to 30 seconds, and beyond.
     
  10. LWW

    LWW TPF Noob!

    Joined:
    Aug 3, 2005
    Messages:
    1,206
    Likes Received:
    2
    Location:
    Dayton,Ohio
    DM, I believe that across the pond in Brittania they refer to a filter as a lens?

    LWW
     
  11. Arch

    Arch Damn You! Staff Member Supporting Member

    Joined:
    Jan 21, 2006
    Messages:
    8,487
    Likes Received:
    102
    Location:
    locked in the attic
    Can others edit my Photos:
    Photos NOT OK to edit
    Nope? :confused:
     
  12. duncanp

    duncanp TPF Noob!

    Joined:
    Nov 15, 2005
    Messages:
    3,388
    Likes Received:
    43
    Location:
    Hemel, UK!
    Can others edit my Photos:
    Photos NOT OK to edit
    was just about to say so..
     

Share This Page