Page 2 of 3 FirstFirst 123 LastLast
Results 21 to 40 of 47

Thread: How to take macro shot?

  1. #21

    Default

    Originally posted by azone
    Yes, higher focal length will result in higher magnification. The formula goes like this:

    magnification factor = f / ( 1000 / d )

    At 10x zoom, the focal length of C750 is 380mm, so with a +4,

    magnification factor = 380 / (1000 / 4) = 1.52

    Hmmm..so for those photos that I see with only the insect head greatly magnified, does that mean that they used a lens that give a higher magnification factor?

    So if I were to get a +10 filter, it will be overkill? since the factor is 3.8?

    Nope, you can certainly zoom halfway, 3/4 way, etc. It just depends on how much magnification you want or how you want to compose your picture. The formula is just an indication of the maximum magnification you can achieve with your camera.
    So this means with a +4, the max magnification can only be acheived if I zoom all the way? In other words, if I zoom halfway at 190mm, my magnification factor will be 0.76? Does 0.76 mean that it will make it look smaller?

    Getting confused...

  2. #22

    Default

    Originally posted by NiVleK
    Hmmm..so for those photos that I see with only the insect head greatly magnified, does that mean that they used a lens that give a higher magnification factor?
    Yes.



    So if I were to get a +10 filter, it will be overkill? since the factor is 3.8?
    Depends if you really need such high magnification or not. If you dun, then no point getting one.



    So this means with a +4, the max magnification can only be acheived if I zoom all the way? In other words, if I zoom halfway at 190mm, my magnification factor will be 0.76? Does 0.76 mean that it will make it look smaller?
    Yes, at 190mm, the mag factor is 0.76. Yes, your subject will look smaller. Just rem that the higher the mag factor, the bigger your subject will look.

  3. #23
    Member
    Join Date
    Apr 2002
    Location
    Sembawang
    Posts
    159

    Default Thanks Guys!

    Thanks guy for all suggestions...

    I question regarding that flash bracket.. most of em only allows the flash to be mounted beside e cam.. so which that cast a harsh shadow on e other side of e cam?

    Phil

  4. #24
    Member
    Join Date
    Jan 2003
    Location
    Central Singapore
    Posts
    317

    Default

    Hi folks...

    Still no advice on where to get a cheap flash bracket????

  5. #25
    Senior Member
    Join Date
    Jul 2003
    Location
    Tampines, Singapore.
    Posts
    1,899

    Default

    Originally posted by azone
    Yes, at 190mm, the mag factor is 0.76. Yes, your subject will look smaller. Just rem that the higher the mag factor, the bigger your subject will look. [/B]
    Wait a minute! I am not understanding this correctly. At full zoom my focal length is 140mm so that gives magnification factor of 0.56 with a +4 filter. So the image captured will be smaller vs that taken without the filter? But I'm trying to get magnification here

  6. #26

    Default

    Originally posted by hwchoy
    Wait a minute! I am not understanding this correctly. At full zoom my focal length is 140mm so that gives magnification factor of 0.56 with a +4 filter. So the image captured will be smaller vs that taken without the filter? But I'm trying to get magnification here
    0.56 is still some form of magnification, and its definitely better than when not using the filter. With the filter, your cam can focus at around 25cm at full zoom, so you get some additional magnification. Without the filter, your cam cannot focus at such short distance, so the object looks smaller.

  7. #27
    Senior Member
    Join Date
    Jul 2003
    Location
    Tampines, Singapore.
    Posts
    1,899

    Default

    Originally posted by azone
    0.56 is still some form of magnification, and its definitely better than when not using the filter. With the filter, your cam can focus at around 25cm at full zoom, so you get some additional magnification. Without the filter, your cam cannot focus at such short distance, so the object looks smaller.
    Hi azone, thanx for helping sorry to be such a bother.

    Right now I use MF and focus distance of 15cm, so what will happen when I add the filter? I am hoping the answer is I will see a bigger object at 15cm.

  8. #28

    Default

    Originally posted by hwchoy
    Hi azone, thanx for helping sorry to be such a bother.

    Right now I use MF and focus distance of 15cm, so what will happen when I add the filter? I am hoping the answer is I will see a bigger object at 15cm.
    The filter helps you go be able to manually focus at a distance lesser then your current focus distance (I assume its 15)..so its a bigger object at less den 15 cm..

  9. #29

    Default

    Originally posted by djchris
    The filter helps you go be able to manually focus at a distance lesser then your current focus distance (I assume its 15)..so its a bigger object at less den 15 cm..
    I tot +4 filter should focus 1/4 meter only, you mean can focus shorter then that?

  10. #30
    Senior Member
    Join Date
    Jul 2003
    Location
    Tampines, Singapore.
    Posts
    1,899

    Default

    Originally posted by AntZ
    I tot +4 filter should focus 1/4 meter only, you mean can focus shorter then that?
    well, without any add-ons and at full zoom, I can manually dial the focus down to 15cm, this is the physical minimum the lenses are able to handle. After adding a +4 close-up, what should happen?

    BTW this is the Canon G5.

    Does it mean that I can now position the cam nearer than 15cm (even though the cam "thinks" it is 15cm) because the add-on lens have altered the optical geometry?

  11. #31

    Default

    Originally posted by djchris
    The filter helps you go be able to manually focus at a distance lesser then your current focus distance (I assume its 15)..so its a bigger object at less den 15 cm..
    no .. u cannot use closeup filter for a distance focuse at 15cm ...


    Originally posted by AntZ
    I tot +4 filter should focus 1/4 meter only, you mean can focus shorter then that?
    Yes , you are right .... only 1/4 m only ...



    To hwchoy ,
    When using a +4 filter , you suppose to turn off the macro mode.
    See my Photo Gallery at the Clubsnap

  12. #32
    Senior Member
    Join Date
    Jul 2003
    Location
    Tampines, Singapore.
    Posts
    1,899

    Default

    Originally posted by megaweb
    no .. u cannot use closeup filter for a distance focuse at 15cm ...



    Yes , you are right ....



    To hwchoy ,
    When using a +4 filter , you suppose to turn off the macro mode.
    like that siong leh, use a close-up lens, but now must stand further back, not sure if it'll end up (ahem) LPPL?

    Actually when I switch to MF the macro sign goes away, and still can bring down to 15cm at full zoom. I suppose the best is to find a filter and try it, I'm actually going to do that, just have to find the time.

    Or perhaps some kind G3/G5 owners here can try it and see?

    thanx for all your help again, much appreciated. I'm really new to this photography thing, but want to document my fishes, have to try to be a darn good photographer also
    Last edited by hwchoy; 17th July 2003 at 12:01 AM.

  13. #33

    Default

    so which one is better, the default macro setting for G5/G3 focus at 15cm or put +4 filter focus at 25cm? can I say that focus closer at 15cm should have more magnification?

  14. #34

    Default

    Originally posted by AntZ
    so which one is better, the default macro setting for G5/G3 focus at 15cm or put +4 filter focus at 25cm? can I say that focus closer at 15cm should have more magnification?
    ..... got to test it out see which setup has more magnification

    -G3/G5 built-in macro mode : 15cm
    -G3/G5 (full zoom) + closeup +4 filter : 20 to 25cm

    anyone can test ?
    See my Photo Gallery at the Clubsnap

  15. #35

    Default

    Theoretically, given that the max focal range for G3/G5 is 140mm, +4 filter should yield to a maximum of 0.56X mag based on formula that Mag = focal length / (1000/diopter strength).

    The question now is what’s the maximum magnification of these cams without any accessories at the closest possible distance?

  16. #36
    Senior Member
    Join Date
    Jul 2003
    Location
    Tampines, Singapore.
    Posts
    1,899

    Default

    Originally posted by Sgt. Pepper
    Theoretically, given that the max focal range for G3/G5 is 140mm, +4 filter should yield to a maximum of 0.56X mag based on formula that Mag = focal length / (1000/diopter strength).

    The question now is what’s the maximum magnification of these cams without any accessories at the closest possible distance?
    How to go about measuring this? I can try out the procedure, perhaps take a picture of a ruler?

  17. #37

    Default

    Originally posted by hwchoy
    How to go about measuring this? I can try out the procedure, perhaps take a picture of a ruler?
    Yes take a picture of a ruler ...
    See my Photo Gallery at the Clubsnap

  18. #38
    Senior Member
    Join Date
    Jul 2003
    Location
    Tampines, Singapore.
    Posts
    1,899

    Default

    Originally posted by megaweb
    Yes take a picture of a ruler ...
    here it is, MF, full zoom, 15cm focal length.


    thanx much.

  19. #39

    Default

    the ruler looks like out of focus leh

    anyway it abt 6cm which is abt 1:2 or 0.5x magnification ... so not much different than using a closeup +4 filter


    note : 1:1 = 36mm x 24mm or 3.6cm x 2.4cm
    See my Photo Gallery at the Clubsnap

  20. #40
    Senior Member
    Join Date
    Jul 2003
    Location
    Tampines, Singapore.
    Posts
    1,899

    Default

    Originally posted by megaweb
    the ruler looks like out of focus leh

    anyway it abt 6cm which is abt 1:2 or 0.5x magnification ... so not much different than using a closeup +4 filter


    note : 1:1 = 36mm x 24mm or 3.6cm x 2.4cm
    yah the ruler don't look so good, done without flash so maybe handshake.

    how do you calculate magnification? Is it the length of the subject divided by 36mm? So I can see the ruler is 56mm does it mean mag = 0.64?

    Shot these last night with built-in flash and MF, 1/200 shutter priority:




    It is cropped from 2592×1944 to 1400×1050 (resized to 2272×1704) so you can see I could use lots of magnification. These kind of thing is my primary need, would you suggest stacking two +4 filter? or perhaps a +10? Is it possible to stack two 250D?
    Last edited by hwchoy; 18th July 2003 at 10:10 AM.

Page 2 of 3 FirstFirst 123 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •