DOF, sharpness, and distance to subject question

Discussion in 'Photography Beginners' Forum' started by mommy-medic, Feb 29, 2012.

  1. mommy-medic

    mommy-medic No longer a newbie, moving up!

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    First of all, I have tried to do significantly less posting and more searching and reading. I have learned and grown so much and wanted to say a huge thank you to those who are consistently helpful to posters with questions. Being able to search through old threads has been most beneficial.

    (Grr- accidentally hit "enter"- sorry if you're reading just the above and it makes no sense- standby- editing!)

    I have read time and time again on here NOT to shoot wide open on a lens with a large aperture. I have a 50mm f/1.4 and have been reading and shooting and reading and shooting. I am attempting to really and truly *know* the lens intuitively at smaller apertures before I try opening it up. (Don't get me wrong, I've played at all ends of it, but I understand that it's going to be soft wide open, I understand that its DOF is super tiny at 1.4, and I'm trying to get a better handle on other apertures of it before I go anywhere near that end.)

    "o hey tyler" and "pgriz" were very helpful in other posts with understanding focal lengths and focal length calculator.

    This brings me to my question- If I am shooting a subject from a distance of approximately 4 feet, and using an aperture between f/4 and f/6.4, are there any considerations I need to think about that I may be missing now? To elaborate- at an aperture of f/4 and a camera-to-subject distance of 4 feet, the calculator says I have a focal area between 3.86 feet and 4.16 feet, or an area of about 0.3 feet (4"). If I am shooting from 4 feet at an aperture of f/6.4 it says my focal area is 3.78-4.25 feet, or about 0.48 feet (6"). My camera-to-subject distance is flexible but I will be working in a small room, so the closest distance would be about 4', and the max would be about 8'. I am wanting to capture details and delicate features, so a focal area/depth of 4" to 6" will be perfect. What would you all advise that maybe I am not factoring in? Is one going to be super sharp or crisp over the other? Is f/4 still too open and destined to be soft? I did take some practice shots this evening and I do see an ever-so-slight difference in crispness- but then again my shutter speed was a bit faster with the aperture opened up more so shake may have been a slight factor. (Sorry I don't have any test images to post).

    It looks like I could even stop down to about f/11 and still have a pretty narrow DOF (less than 1'). I guess I am just looking for some feedback and advice. Obviously I will do some test shots and see what works best, but I don't want to preview images on my camera and maybe not realize that they are a bit soft until it's time to post process. So, experts- any words of wisdom? Advice?


     
    Last edited: Feb 29, 2012
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  2. Robin Usagani

    Robin Usagani Been spending a lot of time on here!

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    This makes no sense.
     
  3. 12sndsgood

    12sndsgood No longer a newbie, moving up!

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    im thinking she is saying that she has heard people say how if you say have a 35mm f1.4 lens that at 1.4 your shots are going to be soft. because its not at the optimum setting for the lens itself. basically don't shoot at the most extreme f factor on each end of the lens. and she's asking if at f4 is that too wide open to get the best photo, based on the distance away from the subject. or at least thats how im hearing the question.
     
  4. rexbobcat

    rexbobcat Been spending a lot of time on here!

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    Most large aperture lenses are sharp from about 2.8 onward. The photos will have probably very little difference in sharpness at the center of focus, however at the smaller aperture there will be more of the subject in focus.

    Also; no one said to not shoot wide open. They said to not shoot wide open until you know what you're doing.
     
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  5. mommy-medic

    mommy-medic No longer a newbie, moving up!

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    12- I think he replied while I was editing ( I hit enter and only the first part showed up initially). You are understanding my question correctly. Also, your response was your 666 post on the forum- not sure why I noticed that- weird. :) Hope I didn't over-complicate the question, I just want to know if there's anything I'm not taking into account or if I should try something completely different.

    Dave- Thank you! That does lead me the right direction (what you said about most being sharp above 2.8).
     
  6. Ballistics

    Ballistics Been spending a lot of time on here!

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    If you have an iphone or an android, download a DOF calculator. It will answer a ton of questions and take a bunch of guesswork out for beginners. Trial and error will prevail.
     
  7. Derrel

    Derrel Mr. Rain Cloud

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    Well, one thing you must realize is that that 4" to 6" depth of field extends, in the simplest possible wording, "straight out" from the camera, with the back of the camera being parallel to a subject. And you asked what you might be missing...well, what you might be missing is that, if you aim the camera downward, let's say at a table, and there is an "angle" of let's just say 30 degrees to the back of the camera, that 4 to 6 inch depth of field will be "distributed" in such a manner that ANYTHING that projects upward from the table, like say the top of a salt shaker, might very well be OUT of the depth of field zone. Sad, but true.

    This is why a view camera, with a movable, "tiltable" front standard is so,so useful in close-up and table-top photography. With a fixed-lens camera, with a fixed back, like your d-slr, the 4 to 6 inches of depth of field is calculated with the supposition that the camera's back will be in perfect parallel with the subject area.

    Let me put it this way: between 4 and 6 feet, with a 50mm lens,apertures in the range of of f/4 and f/6.4, provide little DOF, and CRITICAL focusing is essential. If the camera is "looking up" or "looking down" at a person's face, that "four inches" of DOF is an illusion, a farce, a fable--a place where reality and theory part ways...If you really want to be able to photograph freely, you need to use apertures like f/8 to f/13 at this close distance range of 4 to 6 feet.
     
  8. Derrel

    Derrel Mr. Rain Cloud

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    Sorry Schwetty, but the OP's initial post made a LOT of sense.
     
  9. mommy-medic

    mommy-medic No longer a newbie, moving up!

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    Derrel- thank you for your reply. I do understand what you mean by the angle, and plan on shooting parallel to my subject. (it would help if I elaborated I guess- I'm doing a newborn shoot tomorrow for the experience only and am wanting the most shallow DOF I can use for eyelashes, ears, lips, toes (not all at once) while still having my subject (specific body part) be sharp and not have softness due to too large an aperture. The space constraints are due to the layout of their home and best lighting. I am trying to slow down, take my time, and really compose my shots.

    Again thank you to everyone who has been so helpful. It can be so discouraging to read through threads and see the nasty remarks and condescending comments some people freely wield. Heck I've probably said something I shouldn't have a time or two as well but I've realized how crappy that is to do. I hope to continue learning and growing from this valuable forum! Thank you again.
     
  10. djacobox372

    djacobox372 No longer a newbie, moving up!

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    There's no hard rules... it's perfectly fine to shoot portraits at 1.4 as long as you can manage the DOF problems--the contrast and sharpness isn't the best wide open, but that's often flattering in a portrait. Before the advent of digital manipulations photographers used to use filters to, GASP, soften their images. Sharpness is overrated.
     
  11. EIngerson

    EIngerson Been spending a lot of time on here!

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    The sercret to those wide open shots is that the blur makes sense. Say you focus on the eyes of a baby. For that to make sense in the picture, the viewers focus has to be drawn to the eyes. If it's drawn to another part of the baby it will come across as a blurry picture. That's why people tell beginners to close the aperature down some until they learn to apply that shallow depth of field to the framing of the image.
     
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  12. mommy-medic

    mommy-medic No longer a newbie, moving up!

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    I can't grab the code off Flickr nor can I see the exif data (posting from phone at my fire station), but here is a shot I uploaded from phone to photobucket (which doesn't preserve the best quality so take it with a grain of salt). iirc I took this one pretty darn open and was tickled pink at the results when printed. I think I have a pretty good understanding of it, but never know what it is I don't know, if that makes sense.

    [​IMG]
     

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