June 26th, 2009 Rob Sheppard
I often find there is some confusion about digital exposure. It really is not like film in that you can change exposure for “creative” purposes. Certain exposures will simply give you poor color and tonality, not creativity.
Digital has some unique needs and one of them is “enough” exposure. Without enough exposure, no work in RAW or any program will give you the best color and tonalities in the dark tones with minimal noise. Your sensor has limits and it has a “sweet spot” for exposure. RAW cannot overcome the limits of the sensor. If you give more exposure (as long as highlights are not blown out), you can always darken the image with little loss of color or detail. If you don’t have enough exposure, you can never brighten it to gain the best color or tonality because the color and tonality have not been captured.
Consider this. You photograph a scene with a light red, a middle tone green and a dark blue. With the right exposure, the sensor will deal with all of them well. Overexposure is a problem because it will push the red to a light tone that loses saturation and tonality, even though the green and blue will have okay color and tone.
Underexposure will now push the red darker and the green darker, but this might not be a problem, as long as they will still be in a range that can be handled by the sensor. Unfortunately, the blue will drop in color and tonality, and it will pick up noise, no matter what camera you use. The blue will be below the optimum range of the sensor because it was dark to begin with.
The sensor is very different than our eyes. When we see a dark color, it still shows with the original color to our eyes. When a sensor “sees” a dark color from underexposure, that color loses saturation or chroma, and fine tonal details are lost in that color as well. Colors then look “muddy” or mushed together in tonality. While you can “recover” such tones and colors, they will never look as good as the original scene because the sensor never saw those tones and colors well.
Posted in Digital Photo Techniques, Digital camera techniques, landscape photography, nature photography | 1 Comment »
June 24th, 2009 Rob Sheppard
I am in New England right now visiting family, then I am going to be at a NANPA Road Show outside of Providence, RI, this weekend. It is raining. And from what I have learned, it has been raining for a while. No, there is no petrified wood in New England, but the photo here is a sample of rain photography that is worth talking about.
Recently I had a student in one of my BetterPhoto.com classes say that they could not complete an assignment because it was raining. Now I admit that it can be challenging to photograph in the rain, but not impossible. Sometimes the rain can even be part of the photography. It is really hard for me to be in a beautiful location and not photograph, rain, shine, whatever.
I was driving through Northern Arizona earlier this year and I wanted to photograph at the Petrified Forest National Park. That is a really cool location with all of this “wood” scattered across the landscape. But I was truly “driving through” and had part of one morning to photograph there, no more. A storm had come through and it was very wet.
As I drove and saw the gray clouds, I debated not stopping at all. But I really wanted to visit this interesting place, so I kept on course. I enjoy being in unusual landscapes even if I can’t get the best photos. Yet, the day was really gray and not promising.
I got to the park and took a few photos of some shifting fog in part of the area, but it wasn’t all that exciting photographically. Then I remembered my flash (this is true, even though I have a flash with me at all times, I sometimes forget I have it!). I started shooting by underexposing the scene for the existing light and giving proper exposure for the flash. This is very easy to do with manual exposure. Simply set an exposure that is dark for the scene without flash, then use the flash normally. The flash exposure system will give a correct exposure for the flash, while the camera will underexpose the natural light.
This often results in a dramatic, interesting light in the photo, especially when the flash is used off camera (I usually use a cord for this as it is more reliable than wireless when outside). And it was true here. I had fun playing with the flash and the natural light exposure, changing my shutter speed to change the background brightness, while the petrified wood in the foreground stayed the same brightness from the flash (which is keyed to the f-stop for exposure).
I will probably try some flash photos while I am here in Maine. Or maybe something else. Regardless, I will come hope with some photos of nature, rain or not. I am not much worried about light rain and my Olympus E-3 as it is a professional level camera with excellent seals against light rain. I will use my flash in light rain, too, just keeping it in my jacket until it is ready to use.
But even heavier rain won’t keep me from photographing (and the rain has not always been light here). I always keep a cover for the camera and lens that I can put over the gear as needed, plus I have a small umbrella that is perfect to keep over head as I work the camera on a tripod. For covers, I find the shower caps from a hotel work great for most cameras. I also have an OpTech rain sleeve to go over camera and larger lens as needed.
Posted in Digital Photo Techniques, Digital camera techniques, landscape photography | 1 Comment »
June 15th, 2009 Rob Sheppard
Because “clipping”, the cutting off of tonality at the left or right side of the histogram, can cause you problems, it is worth paying attention to. But to arbitrarily define how a histogram should look or act is asking for trouble. If you look at a histogram and look at clipping without looking at the photo will lead you astray. The histogram is a guide, not a “speed limit” sort of thing that will get you arrested by the histogram police should you ignore it.
Let’s look at what is going on. All clipping tells you is that the scene’s pure white and pure black start beyond the limits of what you are seeing in the image. There are many situations where you will photograph and the histogram will clip automatically because the contrast range of the scene is beyond the capabilities of the camera. That means that no matter what you do, even if you adjust the histogram in the computer to “no longer” clip, you cannot recover detail that was never captured, which is what the clipped histogram will show.
But that might not matter. We don’t need to see every detail in a scene in order for a photograph to be successful. In fact, many times, we do not want to see every detail. If we were to look at the great photographer, W. Eugene Smith, and his work (he is considered by many to be the father of modern photojournalism), we would quickly discover that most of his images were “clipped” compared to the original scene or the negative. He went for a very dark sort of image in order to better communicate his vision to the viewer.
Black tones and dark areas are very subjective. We generally want to have at least something pure black, meaning those tones are just starting to clip. But some images, especially when processed with the tonal information RAW has, look better with the dark areas having no tones, just pure black, meaning the clipping is higher. On the other hand, whites tend to be very sensitive to clipping. Often we want the white tones to just barely hit the end of the histogram, just under clipping. But sometimes we have scenes that have very bright light or reflections that distract from our subject — in that case, we can let them go pure white, making more of the image “clip’, but keeping our important detail.
The important thing is not whether we clip or not clip, but what happens when clipping occurs. Is this good for the photo or bad for the photo? Does the picture look better or worse? Will it print or reproduce properly?
Posted in Digital Photo Techniques, Digital camera techniques, nature photography | Comments Off
June 13th, 2009 Rob Sheppard
One thing I see a lot of is what I like to call “muddy dark tones.” This is when the dark parts of an image have their tonalities sort of mush together like the tones of mud. The photo here is from Machu Picchu and has dark tones in it, but they have life and vitality in them, giving life to the photo. Where things are black, they are black and not trying to be dark tones.
Muddy tones can be avoided first when shooting. The first thing to understand as there is no such thing as an arbitrarily “correct shape” to a histogram. You cannot control that — that is a function of the scene. What you want to do is be sure is that there is no large gap at the right side of the histogram — that is a problem for a lot of reasons, including:
- you are not using the sensor efficiently or in its most optimum range
- you are compressing dark tones
- you may be getting less than the full range of tones the camera can handle
- you can increase noise.
In processing your image, you can look to see what is happening to the left or dark side of the histogram. Opening it up can help, depending on the scene. That means having a calibrated monitor in order to see this. With Photoshop or Photoshop Elements, this usually means working the low end of Curves (shadow and dark for Elements’ Color Curves) or using a Screen technique for layers and changing the opacity of the layer (note on that at the end of this blog).
I really like some of the controls in Lightroom 2 that allow you to open dark tones and give them definition so they do not look muddy — this includes the Fill slider (but be careful not to overuse it or the scene will look unlike anything that exists on this planet) and the shadow and dark sliders of the Tone curve. A challenge with all of this is that the world doesn’t follow rules very well! Growing as a photographer means, to a degree, gaining experience with all sorts of conditions and recognizing how different conditions change the way we interpret exposure.
Note on using Screen: Add an adjustment layer to your photo (Levels works fine). Click okay (if needed) without actually doing to the adjustment. This gives you an adjustment layer without any adjustments. Now go to the Blending Modes. They will say Normal by default and are at the top left of the Layers palette. Click on Normal to get a blending modes list. Then select Screen. Your photo will get lighter, but most of the effect is in the dark areas. Use the Opacity of the layer to tone this adjustment down, reducing Opacity until things look right. You can also use the layer mask with your adjustment layer to selectively allow or block the Screen adjustment.
Posted in Digital Photo Techniques, Digital camera techniques, Lightroom, Photoshop, Photoshop Elements, Photoshop techniques | Comments Off
June 11th, 2009 Rob Sheppard
This is not specifically a photo blog, but it is about something that all of us using computers and digital photos should be aware of. There is now something called “scareware” that can affect your Windows computer (it is not attacking Mac directly that I can tell). And even with the utmost of care on your part, this can get through and cause problems. Yesterday’s USA Today had a very good article about it that can be seen on the USA Today’s website.
Basically, what is happening is that “crooks” (for lack of a better word) hijack websites so that a fake warning appears on your screen saying you may have problems with your computer so that it needs to be scanned. Clicking either Scan or Cancel will cause unwanted action to occur. The bogus scan will claim to find viruses and direct you to a shopping cart for some sort of virus protection software. Now the problem is that if you decline, you will continue to get endless warnings that can be hard to get rid of.
The answer is to get rid of that first warning when it first appears. The only way to do this successfully is to use Task Manager. Press Ctrl-Alt-Delete to access a menu that activates Task Manager. Click the applications tab, scroll to the offending message application in the list, click it, then click End Task. This seems to be the only way to get rid of this scareware.
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June 7th, 2009 Rob Sheppard
As editor-at-large of Outdoor Photographer, I still get to see some interesting gear that I might not see otherwise. Every once in a while I like to comment on some gear that I have found interesting and useful.
Spyder Cube (from DataColor, www.datacolor.com) — this is quite an interesting little cube. At first, I have to admit, I was a little wary that this would be all that helpful. It is designed to make custom color calibration in the computer with RAW. I am not a big fan of auto white balance and setting white balance when processing RAW. There are a lot of problems from that. However, there are times that it really is hard to get a good white balance. Custom white balance can help, but the Spyder Cube is another alternative. And once I started using it, I was converted that it does indeed work quite well. It is a cube about the size of a golf ball that you put into the scene you are working with and take a picture of it. The cube has gray, white and black sides, along with a hole in one black bottom side that gives an “absolute” black. You then use the gray for white balance and you can use the white and blacks to check white and blacks in the scene. This is something that would have been great when I was doing corporate photography where the light can be all over the place and a pain to color balance. It is small enough to keep in a camera bag for those situations where you really need that extra help in getting a good white balance.
Vacu-Pod (www.vacu-pod.com) — I met Michael Corlew at a couple of programs I was doing this year and he showed me his Vacu-Pod. Michael is a bird photographer who had been looking for something that would securely hold a good-sized ballhead and a camera with a big lens, all on a soft rubber “grip” tightened by a lever to create a vacuum seal. This is absolutely terrific for working a wildlife refuge from a car. You can mount the pod on any smooth service, such as a window. It is rock solid (but always remember to turn off the car when shooting!). It can also be “vacuumed” to a pie pan, a really interesting idea, for sandy conditions. Low angle shots in the desert and on the beach have long attracted me, but they also scare me because of all that sand so close to the camera. The pie pan keeps the sand away from the camera and lets you get your camera solidly mounted close to the ground.
WD-TV (from Western Digital, www.wdc.com) — now this has been around for a while, but I had not seen it. So many of us have excellent high-definition TVs that would be great to use for displaying photos, if you had an easy way of doing it. This is that easy way. This little black box will play your images directly from any USB storage device. You can put your photos onto a USB jump drive or play directly from a USB hard drive. I like going from a separate storage device rather than a hard drive storing all photos. I have no interest in doing a slide show of all my images! Plus, like many people, I shoot a lot of images at a given location that will look too similar if you went through them all. Yes, you can control what is shown from your drive through WD-TV, but for me, it is just easier to keep my “slides” separate for this purpose on their own drive.
Posted in Equipment thoughts | Comments Off
June 4th, 2009 Rob Sheppard
I have started a new blog totally unlike this one with a friend, Chuck Summers. It is called SeeingCreation.com. Chuck is a pastor and a very fine photographer. He and I have talked for a long time about creating something with a spiritual connection to nature and nature photography. I know it is not for everyone, but check it out and see — seeingcreation.com. We will be posting regularly with nature photography and thoughts about nature from a spiritual side.
Posted in Nature, nature photography | 4 Comments »
June 1st, 2009 Rob Sheppard
No, this is not some odd racial blog. The blacks in your photograph, i.e., those areas of pure black, and the whites, i.e., those areas of pure white, are of critical importance to your photograph. I feel that they must be set first in adjusting any digital photo. This comes from consistent problems I have seen with a lot of images that we dealt with at Outdoor Photographer magazine, plus PCPhoto and Digital Photo Pro. And it comes from seeing consistent problems in images that are printed or used in other media. This is also from traditional darkroom work. You will find Ansel Adams discussing the same thing regarding prints. Without a solid black and white in a print, for example, you do not use the media to its fullest, so contrast and color never look their best … but with a qualification — some scenes do not have this full range of black to white, such as a foggy day. This is one reason why photographers used to love Kodachrome — its blacks were exquisite and really affected the rest of the image.
Unless you are shooting JPEG and have adjusted your in-camera processing accordingly, you will rarely get optimum blacks straight from a digital camera. Camera engineers create an image file coming from the sensor (and this is very much so for RAW files) that is a compromise that will work for all sorts of photography. They can’t predict what the camera will be shooting, so they give something that will work for everything, with the proper adjustment in the computer later. This usually means elevated blacks so that dark areas are easier to process.
Weak blacks show up in prints and I still see them in publications all the time. Unfortunately, the published page “needs” a full use of its range of tonality or the photo looks compromised next to other images that do. I have discussed setting blacks and whites in Photoshop, and there are free videos on my website that cover this, too (www.robsheppardphoto.com). I have discussed this in my books on Lightroom, too. And I would like to address it here, too, especially because it so strongly affects nature photography.
Setting blacks is usually the first thing I do in the Develop module. I will do any cropping needed before that, but I usually don’t crop images much. Blacks are very easy to set. You simply press the Alt or Option key then click and drag on the Blacks slider. This will make your photo change to a black threshold display. Move the slider until blacks start to appear. Setting blacks is very subjective — sometimes I quit as soon as I see any pure blacks, sometimes I will go further if I want stronger blacks in the photo. Anywhere you see black in this screen will be a pure black in the photo. Where colors appear, color channels are maxing out. Sometimes I will use them for my “blacks” when the image is strongly colored and blacks don’t readily appear.
Next I check whites. Whites are controlled by the Exposure slider (this is a little bit of a misnomer — while sometimes this will “correct” an exposure, usually you will want to affect overall exposure after setting whites and blacks by then working midtones with the Tone Curve). Whites are tricky in Lightroom, and I suspect this is because of the unique color space used “under the hood” in Lightroom. You can use a white threshold screen by pressing Alt or Option as you drag the Exposure slider, but I find that when whites appear here, the photo usually looks overexposed. So I use the histogram and watch where the end of the histogram falls as I adjust Exposure. I want at least part of it to nearly touch the far right side of the histogram, but I still watch the photo to be sure I am not going too far.
Once blacks and whites are set, you will usually notice an improvement in tonality and color for the photo. It often looks like you removed a “gray” filter. Then I will set the Fill slider to a degree — I really don’t like the look of an image when this is pushed too far to the right. It creates shadow tonalities that are unlike any natural shadow tonalities. I usually find the Recovery slider dulls photos too much, so I don’t use it much. I then go to the Tone Curve which allows you to really adjust dark, middle and light tones in natural ways.
This summer, I will be doing a number of videos and other electronic media to help photographers with Lightroom and more. I will keep you informed as these are completed.
Posted in Digital Photo Techniques, Lightroom, nature photography | Comments Off
