Home News Buyers Guide About Advertising
 
 
 
   
Page 6 of 19 FirstFirst ... 4567816 ... LastLast
Results 51 to 60 of 183

Thread: Apature

  1. #51
    Join Date
    Jul 2005
    Location
    Sydney, Australia
    Posts
    4,428
    Quote Originally Posted by Razr View Post
    I know it is not about Razr. I never said, inferred or "implied" anything remotely like what you’ve again l*ed about.
    It is still incumbent on you to post where and when I said something even remotely related to what you "inferred"; again.
    Quote please? Again as you wrongly infer what I said, you owe me and this forum an answer to my pointed question(s):
    where did I say what you inferred above?
    and this thread is not about Razr.
    You are getting more foolish every post you make. Read every post you made and see what I 'infered'. Maybe you are the only one foolish enough not to see that.
    Nikon D90, D80
    Nikkor 16-85mm AF-S DX F/3.5-5.6G ED VR, Tamron SP AF 28-75mm F/2.8 XR Di LD Aspherical (IF) macro, Nikkor 50mm F/1.4D, Nikkor 50mm F/1.8D, Nikkor AF-S VR 70-300mm F/4.5-5.6G IF-ED, Sigma 105mm F/2.8 EX DG Macro ||| 2x SB800 | SB600 ||| Manfrotto 190XB

  2. #52
    Join Date
    Dec 2006
    Location
    God's Country - Australia
    Posts
    10,424
    prove us and the whole photographic world wrong and post a photo with this new miraculous discovery of yours with the full exif. woops...thats right...i forgot...you a PRO who is too good to post photos for us plebs to look at.
    D800e l V3 l AW1 l 16-35 l 35 l 50 l 85 l 105 l EM1 l 7.5 l 12-40 l 14 l 17 l 25 l 45 l 60 l 75
    flickr

  3. #53
    Join Date
    Jul 2005
    Location
    Sydney, Australia
    Posts
    4,428
    I don't think RAZR can be serious. More likely he is trolling people to quote his nonsense. Anyone else has this impression?
    Anyway... this thread (not about Razr) has to be voted thread of the month for a laugh.

    Right now, he is testing his Pentax, Canon, Nikon, Panasonic systems with various lenses and showing us his professional scientific results at the same time. Go figure.
    Nikon D90, D80
    Nikkor 16-85mm AF-S DX F/3.5-5.6G ED VR, Tamron SP AF 28-75mm F/2.8 XR Di LD Aspherical (IF) macro, Nikkor 50mm F/1.4D, Nikkor 50mm F/1.8D, Nikkor AF-S VR 70-300mm F/4.5-5.6G IF-ED, Sigma 105mm F/2.8 EX DG Macro ||| 2x SB800 | SB600 ||| Manfrotto 190XB

  4. #54
    Join Date
    Dec 2006
    Location
    Melbourne, Australia
    Posts
    793
    Quote Originally Posted by Razr View Post
    Think of it this way: when you set your body/lens on Av and zoom, what happens to the aperture?

    Nothing
    : It's frozen in place: that's what "happens".
    Instead, your shutter speed "varies" (to balance the exposure).
    The opposite "happens" in "S" (Shutter priority) mode: your shutter is frozen in place while the aperture "varies" to balance the exposure.

    Got it?
    I think this is the problem that Razr has understanding. He thinks that when it's in Av that the aperture is stuck in place and that we can't change it. And that the opposite happens in shutter priority mode where the shutter is "frozen" in place while the aperture "varies" as he calls it. This varying of the aperture is not the same as a variable aperture lens.
    Nikon D700 | SB600 | SB-80DX | 2xSB-26 | 18-35 f/3.5-4.5 | 24-85 f/3.5-4.5G | 50 f/1.4 G | 105 f/2.8 VR | 70-300 f/4.5-5.6 VR

    flickr

  5. #55
    Join Date
    Dec 2006
    Location
    God's Country - Australia
    Posts
    10,424
    Quote Originally Posted by achuang View Post
    He thinks.
    given the content of this thread, thats a pretty presumptuous statement wouldn;t you say ?
    D800e l V3 l AW1 l 16-35 l 35 l 50 l 85 l 105 l EM1 l 7.5 l 12-40 l 14 l 17 l 25 l 45 l 60 l 75
    flickr

  6. #56
    Join Date
    Jan 2006
    Location
    Delfgauw, The Netherlands
    Posts
    2,207
    Razr, you really don't have a clue what you are talking about.

    The maximum f-stop of a lens - in other words, the maximum relative aperture of a lens - is in fact a fraction. With simple lenses, the f-stop can be used to calculate the physical size of the maximum aperture of a lens.

    The following formula applies for simple lenses (i.e. one element and an aperture curtain):

    aperture diameter = focal length / f-stop

    With modern lenses, which are made up of multiple elements, this is no longer valid. The focal length which must be taken into account depends on the position of the apperture curtain with respect to the various elements. Still, the formula helps to get a basic idea of lenses (which you obviously lack).

    With zoom lenses, the maximum aperture diameter is fixed. The lens does not automatically stop down when you zoom in. If you take a look at the Sigma 70-300, for instance, you will see that at 300mm the physical aperture is the same as at 70 mm. However the lens is not a fixed aperture lens, it is f/4-5.6.

    Why is that? When you zoom in, you increase the focal length of a lens, in this case from 70 to 300. Since the maximum apperture stays the same it follows from the above formula that the f-stop of the lens must increase.

    If you think about it, this is logical. If you make the angle from which you can capture light smaller, you will get less light if the size of the diaphragm stays the same.

    So, to make a long story short. If you zoom in, the physical aperture stays the same, but the amount of light that will reach the sensor will decrease. Hence, the f-stop will be smaller.
    Putting your camera in the full manual mode, in apperture priority or using it entirely manual with the aperture ring does not matter.

    EDIT: I started typing this two hours before actually posting it, I was away from the computer in the meantime. This is why I said lots of things that had been said before (they hadn't been posted yet when I started typing). My appologies for that.
    Last edited by Prospero; 10-24-2007 at 07:33 PM.
    Nikon D-50
    // Nikkor 70-300 f/4-5.6 VR // Nikkor 50 mm f/1.8
    // Sigma 17-70 f/2.8-4.5 ...// Nikon SB-600
    // Sigma 10-20 f/4-5.6......// Nikon Series E 135 mm f/2.8
    // Kiron 105 f/2.8 Macro....// Manfrotto 190XPROB + 488RC4
    // Nikkor 35 f/1.8..........// Sigma 500 mm f/8

    My website: http://www.dennisdolkens.nl

  7. #57
    Join Date
    Dec 2006
    Location
    Melbourne, Australia
    Posts
    793
    Quote Originally Posted by Rooz View Post
    given the content of this thread, thats a pretty presumptuous statement wouldn;t you say ?
    Point taken, I don't think i'll be posting on this thread. I have to go off to an exam now anyway. maybe i'll try Razr's method of taking photos when I go take pictures of my sister's newborn.
    Nikon D700 | SB600 | SB-80DX | 2xSB-26 | 18-35 f/3.5-4.5 | 24-85 f/3.5-4.5G | 50 f/1.4 G | 105 f/2.8 VR | 70-300 f/4.5-5.6 VR

    flickr

  8. #58
    Join Date
    Oct 2006
    Posts
    461
    Quote Originally Posted by achuang View Post
    Do you know of the Canon 100mm macro lens?
    Well any macro lens really. The higher the magnification and the closer the subject the greater the light fall off. [/quote]
    the aperture still has a limit to how wide it can go.
    Why do you guys keep repeating that asinine conclusion when in fact, I have never mentioned such?
    Let's say the aperture is any random width, say 15mm wide at 17mm focal length. If this is a constant aperture zoom
    Youíve already segued off topic. The topic is not constant aperture zoom(s) but does aperture priority lock the aperture in place no matter what: at least that is my thesis.
    lens then the aperture size must actually get larger as you zoom in since the longer the focal length the larger the aperture size must be.
    Again, since you gave no aperture value, your argument fails for its lack of merit.
    Why do you think the expensive telephotos are so large. If the aperture stays at 15mm all the way until 70mm, then it is a much smaller f/stop than when at 17mm.
    You are free to mumble that Mantra all you want: itís wrong, particularly so when you fail to note what mode/setting your camera is in. If Av (Aperture priority), the aperture (regardless of setting) is locked down tight and cannot move (open or close). Disprove my thesis by demonstrating how the aperture is not fixed in place in Av and M modes.

  9. #59
    Join Date
    Dec 2006
    Location
    So Calif
    Posts
    3,226
    Quote Originally Posted by Razr View Post
    Please post the exact statement and post# where I said so.

    Of course you won't find it.
    ---->>"The aperture stays the same in "Av" and "M" (MANUAL) mode, no matter what focal length you choose, making any f/2.8-f4.5 etc. lens a "fast"-constant apeture lens throughout the zoom range."

    You've implied it here. Others have repeatedly argued that the lens will not be f2.8 over the entire range which your statement implies. You have never clarified your statement. But the lens will be constant aperture as you say, at f4.5 (minimum aperture at maximum zoom), but that is hardly "fast".

    Added: You apparently have "aperture" and "f-stop" confused. You set the "f-stop" on your dial or ring. Because f-stop = focal length/aperture, as the focal length increases, the aperture must increase to keep the constant f-stop - which might have been what you meant, but not what you've said, repeatedly.
    Last edited by SpecialK; 10-24-2007 at 07:49 PM.
    Pentax K20D/K5/15/21/40/70/10-17/12-24, Sigma 17-70 2.8-4.5/150-500, Tamron 90 Macro/70-200 2.8, Canon SX20 IS/Elph 500HS
    (formerly Pentax 50 1.4/50-200/55-300/K100D, Sigma 18-50 2.8/70-300 APO, Tamron 28-75, Viv 800, Tele-Tokina 800, Canon S3 IS, Samsung L210)
    http://s133.photobucket.com/albums/q78/KylePix/

  10. #60
    Join Date
    Jan 2006
    Location
    Delfgauw, The Netherlands
    Posts
    2,207
    Actually, neither in aperture priority of full manual mode, the aperture is locked tightly in place. If you select the maximum f-stop at the widest focal length and you zoom in, you will see the f-stop change.

    Just try it; if you actually posses the camera you claim you have....
    Nikon D-50
    // Nikkor 70-300 f/4-5.6 VR // Nikkor 50 mm f/1.8
    // Sigma 17-70 f/2.8-4.5 ...// Nikon SB-600
    // Sigma 10-20 f/4-5.6......// Nikon Series E 135 mm f/2.8
    // Kiron 105 f/2.8 Macro....// Manfrotto 190XPROB + 488RC4
    // Nikkor 35 f/1.8..........// Sigma 500 mm f/8

    My website: http://www.dennisdolkens.nl

Posting Permissions

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