Sharper Photographic Images – Part 2

orange hibiscus burst 400x400“We are here to awaken from the illusion of our separateness.”   – Thich Nhat Hanh

This morning I was sitting quietly in the back yard with my friend, the orange hibiscus. We were enjoying the warm sun, blue sky, slight breeze and singing birds. I felt like singing myself. What a wonderful experience to be able to participate in it all. My friend was sending out a welcoming energy. So I accepted its message and gathered its images. Not only have I had this fulfilling experience, but I have pictures that will remind me of this event every time that I look at them.  Simply miraculous (and no cost for film or processing).

This is my second blog on maximizing the sharpness of photographic images. In Part 1, I commented on reducing camera shake,  file size/resolution, file type, lens cleaning, tripod use, mirror lock-up and the shutter release cable (or remote control). Today I’ll cover the importance of: aperture, lens hood, polarizing filter, viewfinder cover and some issues that can arise with autofocus.

Aperture. In a nutshell, generally use: f/5.6 for flowers or other close-ups, f/8 for general purpose, and f/16 for landscapes. (If you are a trusting soul or pressed for time, skip down to “Lens hood”).

The aperture is the opening through which light passes to reach the sensor. With wide/large apertures the light passing through the periphery of the lens is distorted and cannot be focused. (Larger openings are referred to with smaller f/ stop numbers. For example, the size of the opening at  f/4 is much larger than at  f/16. Confusing at first, I know). This presents  your main subject in focus but with a blurred foreground and background.  As aperture size decreases (larger f/ number), this distortion goes away, but another type of distortion develops (diffraction). The aperture size for the least overall distortion and greatest sharpness for most lenses is f/8.  This generally provides the absolute best/critical  focus of which the lens is capable, although the foreground and background will necessarily be mildly out of focus. (Great for portraits or wedding photography). Smaller openings/apertures (f/16) cause everything to be slightly but equally out of focus. People perceive that everything is in focus. Thus a small aperture, f/16, is good for landscapes. (Too confusing? Then use your cameras preset programs/modes i.e. sports/action, portraiture, nighttime, etc. It will adjust the aperture.)

Use a lens hood if your lens has one available. Light that hits your lens at an angle, cannot be focused on the sensor. It shows up as a slight haze over your image. A lens hood blocks much of this angular light, increasing sharpness. Frequently the lens hoods need to be purchased separately from the lens. (Be sure to get it one made by the same company that manufactured your lens)

Use a polarizing filter when shooting in bright light. A polarizing filter decreases surface glare and reflections, increases color and prevents stray light from reaching your lens at an angle. Each of these increases the appearance of some of the details, and thus the perception of sharpness.  Many pro photographers use a polarizing filter 90% of the time (or more). The polarizing filter blocks light waves vibrating at right angles to the filter’s intrinsic alignment. So, before checking your exposure, rotate the polarizing filter 180 degrees to determine the position at which it is most effective in blocking the reflections.  On the downside, polarizing filters block enough light from entering the lens are that it acts like a 2 stop neutral density filter, requiring an increase of aperture size or slower shutter speed to compensate. (In auto exposure, your camera will make this adjustment). When shooting in bright light this is usually of no consequence. In addition, a polarizing filter may cause vignettes (darkening at the corners of your image) depending on the specific lens and polarizing filter that you are using.  On the helpful side, a lens hood is generally not needed with a polarizing filter. I am talking here about a good quality polarizing filter (like B&W ®). A cheap one may cause distortion and therefore create more blurriness than without it.

Cover the viewfinder of DSLR cameras unless you are hand holding your camera and actually looking through the viewfinder.  Viewfinders of cameras with moveable mirrors allow light to enter from the back and reach the sensor, giving a slight haze overall. This is particularly important when using a tripod or framing up only with the screen.  When one is looking through the viewfinder, most of the light is blocked by our head. Many DSLR cameras come with a slip-on viewfinder cover attached to the shoulder strap.

Continuous shooting burst of three frames: When shooting handheld or when using a tripod, but physically depressing the shutter button, there is usually some camera movement, even when a person is being careful to avoid such movement. However, when the shutter button is continually being depressed, all camera movement can be avoided. When a burst of three frames is made, the second frame is usually sharper than the first; and the third frame sharper than the second.

Auto-focus (AF) issues:

  • Operator error: Auto-focus was not set back to its all-points default after you modified it previously.
  • AF could not establish any focal point. When this occurs, generally a red box appears in the viewfinder or on the screen, indicating that no AF is established. (Some cameras will not even fire if AF cannot be established.) Because the central AF point is usually the most accurate, try setting AF to assess only its central point. (Auto-focus with central AF point over your subject and shutter button half way down, then recompose and shoot.)

Here are some reasons why AF may not work:

  • There is too little light. (You might try using flash.)
  • The subject  is too small for the auto-focus to sense.
  • The subject is moving.

Auto focus works, but chooses the wrong place to focus. To prevent this, either set the camera to assess only the AF point that lies over the subject or set it to utilize only its central AF point. With the shutter button held half way down, position this central AF point over your subject, then recompose and shoot.

Manual focus for people who wear glasses: If you take off your glasses before manual focusing, what seems to be correct focus will be wrong. There are two ways to avoid this problem. The easiest alternative is to have a diopter adjustment on the viewfinder.  (Diopters are the measurement of the strength of glasses.) Cameras come in three varieties: no available diopter adjustment, built-in adjustment and slip-on viewfinder adjustment lenses which are purchased separately . Many of the built-in variety have a range of -2 to +2 diopters. If your glasses are stronger than that, you will need to purchase a slip-on viewfinder adjustment lens  in addition to using the one that is built-in. The second alternative for wearers of glasses, is to purchase a Hoodman® eye cup. These are effective and convenient, but expensive.

I hope that this will be helpful to someone.  Comments, suggestions (and criticisms) are welcome.

At NaturePhotoRehab.com I assist clients in transforming their nature images into impressive works of art and they are proud to give as gifts or to hang on their own wall for inspiration. I offer retouching, complex processing and enhancements, enlargements, prints (up to 12in x 18in) and framing.

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14 comments on “Sharper Photographic Images – Part 2

  1. elmediat says:

    Great post. Thanks for visiting my blog. It is most appreciated.

  2. Thank you for the “Like” on my blog and the weath of information on your site to compliment your lovely images!

    • Thank you very much for your compliments. I hope that some of the information in my posts is helpful for you.
      I like your post-site. Some brilliant flowers. And good “flutterby” shots.
      Please let me know if you have suggestions for my future post topics.

  3. THank you for liking my page and for the wealth of information on your site to cimpliment the lovely images.

  4. WOW! Am I ever glad you dropped by my site, otherwise I would never have learned about you and your photography and your most excellent suggestions. What you had to say for today (I will read other posts later) was very helpful to me – especially the thought of using a lens hood. That, for some reason, never occurred to me in terms of flower photography (I could have used that advice earlier when I took the photos I posted today)! I will give it a try. I am generally very disappointed in my photos of flowers in bright sunlight. I almost always get a glare (as you can tell in the photos I took today), and I have toyed with aperture and ISO to minimize it, but have not come up with a solution that works consistently. i will try the hood!

    I love your hibiscus photo, and I am wondering what process you used. It has a “painting” effect, which I like very much!

    As you can probably tell from my amateur comments and questions, I am most definitely a rank amateur, but in the best sense of that word, in that I am a LOVER of photography! It has come to me at the right point in my life, when other forms of artistic expression were taken from me. So glad that God had another avenue for me to explore!

    I would really appreciate your writing about the number of pixels a camera is capable of. I am under the impression that there really is no particular advantage in the higher numbers, except as it relates to the size of the print(s) you wish to make or have made. The camera I have was a special gift, but it is a slightly older Canon EOS D20. Great camera, (my first DSLR), but I am not certain as to its pixel capability, I only know that the size of my photos generally is about 3500 x 2600. This is restrictive in printing, but only if I crop a photo for composition reasons. Because of that, I am trying to make certain my composition is right to start with, and that it won’t need any cropping, but I’m not always successful! Sometimes there are things I miss with the naked eye that are glaringly obvious when I see the pic on the computer!

    Please drop by my site any time, and I welcome and encourage you to make any sort of criticisms you feel would help me to improve! Thanks again, for the visit! i will most certainly be back here!

    • Thank you for your kind words and for requesting my input on some issues that you have experienced.

      You mentioned that glare is a problem when photographing flowers in direct sunlight. The lens hood that you mentioned will prevent a slight haze from occurring over the entire image caused by light striking your lens at an angle. This will increase sharpness but have no effect on reflections from the flower itself. The only way to reduce reflection or glare is with a polarizing filter. It works so well, that many professional nature photographers use a polarizing filter about 95% of the time. (I use it 99% of the time. It’s my most importance tool after the camera and tripod). The circular polarizing filters are most convenient. They screw onto your lens and are easy to rotate. Here’s an important point. Before determining the correct exposure for a frame, look through the viewfinder and rotate the polarizer 180 degrees back and forth (You’ll need to remove the lens hood to do this, but put it back on before shooting. You will notice that the shine is greatly reduced at one particular degree of rotation. Leave the polarizer in that position. (If the sun changes position or if you change the camera position, you will need to reset the polarizer again in this manner.). Cheap polarizing filters can cause distortion or vignetting. High quality polarizers are expensive. I recommended purchasing a used high quality filter from a reputable source such as B & H Photo/video in New York (BandH.com).

      Even the polarizer cannot eliminate the entire glare from direct sunlight. So, except when the sun is at a low from angle rising or setting, I avoid shooting in direct sunlight. Often I use a translucent white reflector or diffusion screen to create shade. Occasionally I use my body or a hat to create shade, but that’s only useful if I can also shade the background at the same time.

      Thank you for your interest in my technique for the orange hibiscus. It has 4 parts. The lighting: I was outdoors using a tripod and shutter release cable (remote control works as well) and a circular polarizing filter. The light from the left was direct sunlight reflecting off a bright white wall, at an angle of 75 degrees from the side, so almost complete side lighting. This brings out detail. The light from the right was direct sunlight diffused through a translucent white reflector which also created the shade. This provided backlighting coming from 45 degrees behind the flower, giving the petals a glow.

      2) Raw processing: I always process raw format images first in The Raw Converter in Photoshop Elements; then secondly in Photoshop Elements full edit mode. (This combination will greatly improve sharpness and detail). Other programs, like Canon’s Digital Photo Pro will make similar adjustments, but are more cumbersome. Which editing software program and version do you use? (I have a specific reason for asking.)
      Raw processing: Use exposure or brightness sliders to move the histogram all the way to the right side edge. Increase sharpness. Make any other changes that you like and convert your images to the tiff format.

      3) Edit tiff files: (In Photoshop Elements (PSE), use “full edit” mode. To bring a glow to the petals (I use color curves in PSE), increase highlights, mid-tone brightness and mid-tone contrast. To separate your flower from the background, select just the flower before making these changes. Next choose everything except for the flower (In PSE it’s easy. Stay with your same selection of the flower, go to the Select menu near the top of the screen and click “inverse”. Now you’ve selected everything except for the flower). Make opposite lighting changes to all that is not flower. Specifically, decrease highlights, mid-tone brightness and mid-tone contrast. Then after making any other changes that you like, save this image as a baseline. Next apply a moderate amount of sharpening. We saved the image prior to sharpening, because you may wish to experiment with different amounts of sharpening or other adjustments later. But once you have applied this type of sharpening, any additional changes may produce bizarre results. For sharpening, the “unsharp mask” works well (I know it’s a weird name, but it’s a common technique for sharpening.

      4) These adjustments will give you much of the effect that you are looking for. However I also used a technique call expanded depth of field/focus, also called focus stacking. This allows every part of the flower to be in tack-sharp focus, which provides much more detail. Specifically I took 25 images of the flower, all identical except for the plane of focus. The initial image of the set was focused on the closest part, the end of the stamens. Each subsequent image was focused 1/8 inch further back. Then, the magic of Helicon Focus software selects out only the well focused portion of each frame and creates a composite which shows the entire flower in focus.

      You raise a good question about older cameras and pixel count. Your Canon D20 is an excellent choice for your first DSLR. It is well built, with plenty of features and has an 8.2 megapixel CMOS sensor. You are correct in pointing out that image quality depends on more than simply megapixel count. Other important factors are pixel size, amount of random firing (electronic noise), focusing ability of microscopic lenses just above the pixels and the quality of the in-camera processing. Your camera should give excellent results up to at least 10in by 12in enlargements. Smaller sized images will not show as much detail as most of the newest sensors, but should be plenty good enough (For years, National Geographic accepted images as low as 6 megapixels). I had an 8 megapixel camera for years. It consistently produced impressive results up to 10in by 12in prints.

      Thank you for requesting my input. I will add much of this information to future blogs.

      • Great stuff, and I thank you – I will be testing some of that out. Tell me, do you have a e-mail address I could send a photo or two on occasion for you to give me some ideas on processing it? I understand if you would rather not disclose it here, but I will give you mine, because everybody already know it anyway! ptohlinecalhoun@gmail.com

        Thanks again for the input! I’ll always have tons of questions!

      • Thank you for asking for my assessment of some of your photos. I would enjoy having you emaila few of your photos to me for my opinion. My e-mail address is mike_harroun@yahoo.com.

  5. nathanhadley says:

    Thanks for the advice! Really helpful. I have much to learn!

    • Had to switch a couple things around, but I’m “nathanhadley”

    • Thank you for your kind words. I am glad that some of that blog was helpful to you. Every good photographer is always learning. (Thesecret is to keep increasing complexity slowlyso that it’s interesting, not overwhelming).Are there any particular topics that you would like me to cover in the near future?

  6. kiaman2012 says:

    Fabulous image & photography!

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