Better Understanding of Cameras

Jan 30, 201524 min read

Deviation Actions

Published: Jan 30, 2015

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Intro & History (updated 2/25/18)

I have been shooting with a decent SLR cameras since the early 80s. The term 'SLR' stands for ‘single lens reflex’ by using a small light weight mirror as the shutter, which in between shots reflect the image seen through the lens up into the view finder, so you see the actual image that will be recorded on the film, or digital sensor these days, with film being obsolete now. In modern digital photography we commonly use mirrorless cameras by having the sensor just continually record the image as a video stream to display on the view screen. This has revolutionized photography from the old days of using film with lots of moving parts, which can fail. These days even most smart-phones have a digital camera that exceeded the quality of the best 35mm film. If you are willing to pay around $3k for a camera body with a decent lens and a substantial memory card you can call yourself a Professional Photographer, but lighting is what really makes the difference. No matter what fancy DSLR camera you use without proper lighting you might as well continue to just snap images with your smart-phone.

Digital imaging has made photography faster by making it easier to capture the moment without winding to the next frame. Also added was reliable auto focus, a built in flash, along with capturing video as well. Digital images are far more practical to modify in post editing with relative ease, speed, and far more versatility. Then easily share them with thousands of people on-line. Although, there’s a lot misunderstood about digital photography by most people. Don't feel bad about this, since even most 'Professional Photographers' still do not understand the science and mechanics of photography. I will try here to break it down in more laymen terms to help you better understand this process in order to know how to take better pictures with whatever camera equipment you have. This is not about artistic vision. That's where you come in to add to this equation. But without a decent understanding of the mechanic you are just taking snapshots that will continue to frustrate you and fail to achieve the quality needed for printing poster size images. That is what truly separates an amateur from the professional photographer.

The 3 Different Camera Settings to Understand

Even the smallest or cheapest camera has very specific settings that are adjusted automatically without your knowledge, so you are unaware of these rapid changes. As with a common smart-phone the light meter has to quickly correct for the amount of light available in order to give you a decently exposed image. I know these details will seem overwhelming at first, but you only have 3 different settings to understand: Shutter Speed, Aperture, and ISO, which stands for 'International Organization for Standardization' (don’t bother to remember that last part). Each of these settings are important for the best possible clear image with vibrant colors, but they do not work in harmony to compliment each other. They are like having 3 different selfish children who each demand you full attention, which is impossible of course. Each of these requires a great deal of light on your subject for them to be set at their optimum setting for the best quality image possible. The dilemma here is to set one for the best quality will require you to sacrifice the other 2, unless you are able to increase the light input from your subject. Perhaps even enough light to temporarily blind your subject. Because of this requirement a very brief flash of light is used instead, which also consumes less energy from the battery than it would require to have constant bright light on your subject. As with with direct Sunlight, which is around 10X more candle power than what we have on a cloudy day, let alone the low light present indoors.

The Image Sensor

Most importantly is the sensor deep within the camera just behind the lens, which is a flat plate that receives what focused light comes through the lens, and is responsible to convert this into a digital image file for the computer in your camera to then record that image file to your storage device. This sensor is smaller than your thumb nail in most full size cameras. Yet, no bigger than a thumb tack in compact cameras. In a smart-phone this sensor has to be even smaller of course to fit within this very small space. It has to have an unimaginable number of tiny (microscopic) light sensors. Several millions actually. As many as 12 million in the newer IPhone 6, 7, & 8. That is over 3,000 horizontal line of image information, which are each 4,000 pixels wide in your smart phone camera. It's pretty much impossible to wrap your mind around how they can make such a thing so small. I do not understand the technology it takes to create these sensors, but they seem to some how make it work. This is not so different than how the human eye works. It is taking light that comes in through your lens focused onto the back of your eye to stimulate the many tiny cones, which then convert this into electronic impulses to send to your brain to convert into what you perceive as a recognizable image, while you compare this with your library of previously recorded images, all within a split second. After all this the image we see in our mind does not seem to have any dots or pixelation as it is called in digital photography. It is truly an amazing process we have yet to equal, which is also found in most every creature here on Earth; from the largest mammal to small bugs. The fact we have been able to engineer something similar like this is quite remarkable. Considering how this has taken scientist and engineers over half a century to get to this point, since the first black and white video cameras were used to record broadcast news with. It was not until the year 1999 they first sold a commercially viable color digital camera with a 2.77 meg sensor. At the cost of $6,000 USD. I have one still in working condition.

If you are able to zoom into a typical digital photo larger than full resolution you can see the individual pixels, or squares of color that comprise an image. This sensor needs a certain amount to light to properly read the color each pixel is to represent, which can be over a million variations of color and contrast for each pixel. For low light situations when the sensor does not have enough light input they added internal software to brighten up the image that would otherwise be worthless, since it is way too dark. They have called this 'ISO setting', which is short for the International Organization for Standardization, but no need to memorize this detail. Just what this means to your image capturing.

ISO Setting

This is one of the most misunderstood aspects of photography. In the camera this has to do with the clarity and color saturation capability of the image sensor, depending on the limitations of the available light when restricted by the other 2 setting of your camera: shutter speed and aperture. This is one aspect that has nothing to do with a physical moving part. Strictly speaking this is only done with internal software, where the image is altered with those software enhancement of your image to lighten a dark under exposed image, as discussed above. This terminology for cameras had come from back in the time of film use; which is the sensitivity of that roll of film exposure to light. Back then we had to buy certain rolls of film for the light conditions we had to work with. Then change the whole roll of film as needed when lighting had changed. We had to use up all those frames before we could change that roll with a different ISO film, or just waste those unused frames, since there was no way to reload that roll later. The problem with film was how the more sensitive the film was we sacrificed clarity, or a noticeably grainy image with flat color. Which does not make for good clear prints of course. Some would try to pawn this deficit off as their ‘artistic style’. Such as using cheaper black & white film; claiming it is artsy. Such as with suggesting a poorly focused image as a ‘soft focus style’, instead of setting up better lighting to get a good clear shot. These days it is easy to blur or speckle a digital image in post editing if you believe that’s what you really want as an artistic edge, but it is imperative to have the best possible clear original image to start with, since you loose image quality with every change you make to a digital image. There’s really not much you can do to fix a bad image afterwards. Although, this software can make it look better, but you will sacrifice image quality with each alteration. As a professional it is our job to know what it takes to get the best possible sharp image. Anything else is inexcusable. Shooting with an expensive full frame DSLR camera in anything other than it's lowest ISO setting is a waste of that camera's capability. You'd be just as well off or better to use your smart-phone with a much smaller sensor, if you are having to jack up the ISO setting for those sort of low light conditions.

When jacking up the ISO on a camera it is not actually making the sensor plate more sensitive to low light, since that would be a physical impossibility. That is a common misnomer about digital cameras. If they could do this there would be no need for a lower ISO setting, which then requires a lot more light. The manufacturers has just embedded software to brighten a very dark image. This software is really no different than image editing software on your computer. The real test is if you were to shoot the same subject at the lowest ISO with the same settings you will see exactly what the sensor is really seeing before the internal software has to brighten up such a dark image the best it can. It really is no different than what you have to do in post to try and save a poorly exposed image. Since there is so little data to work with in the original image file it does the best it can, but again there are those physical limits of what can be done to try to accurately fix such a dark image. Is that pixel blue or red? Some have noise reduction software as well for a second stage fix, but of course that blurs the image a bit. Many people think that expensive camera is able to take great pictures in low light, but they have just been fooled by that hidden software. The reality is that any alteration to the original image file is a loss of image quality, even if it looks like it improved that image. This is an advantage when trying to recover an image that was terribly underexposed, since the only other option would be to delete that image. When you have a loss of data there is not a lot that can be done to fix it without loosing image quality, in comparison to a well expose image. It is like as if your got a novel with 3/4 of the pages randomly ripped out and you had to somehow reconstruct that story as the author had intended with such limited information available. Although software does not have it's own imagination too fill the blanks as we have in the human mind. Archeologist also have to piece together a story of our distant past with very limited evidence available to them, so their ability to recreate the past is limited and flawed at best. When this amazing software in the camera has to guess at what color the sensor is seeing (since it does not have reliable information to work with) it cannot make a good clear image with accurate and vibrant true color. The speckled look of ALL high ISO images when viewing in full resolution is called ‘camera noise’. Think about the logic of how there would be no reason to shoot at a lower ISO setting if they could magically jack up the sensitivity of the sensor. The lowest ISO setting your camera has is how much light your camera’s sensor really does need to properly record an image. If not, you are just blindfolding your camera in a very real sense. It would be like pulling your T-shirt over your face while watching TV. Try it and see what detail you loose. Or to run a marathon with a gag over your mouth and nose; making it very hard to breath when you require a great deal of oxygen to feed to your over-worked muscles. Why would any Pro cripple the capability of their camera hardware like that?

If you want to have good clear vibrant images you absolutely need to set the camera to the lowest an ISO setting. In most cameras this is ISO 100. When shooting on ‘Auto’ setting your camera will commonly default to 800 ISO for a faster shutter speed, which will defeat the purpose of using a decent DSLR camera, but the engineers had learned people are very frustrated if they get a lot of motion blur from a slow shutter speed. Other than the limited lens and lighting options of the camera in your smart-phone that tiny sensor does not require nearly as much light, which may have as low as an ISO capability of 25 in bright direct Sun light.

I know some better cameras will have an impressive camera noise filter when saving images off in a compressed jpg image file, but the same image in the RAW file format shows how much camera noise there really was. When the camera filters out that camera noise you lose a great deal of image clarity. In post editing you can jack up the color saturation, but those colors will not look as proper or natural.

Why More Light for a Low ISO Setting is So Essential!

It is imperative to have the most clear original image file possible to work from, so any alteration you make will minimize the loss of image clarity and accurate color representation in your final edit. When saving an image it is also important to not compress the image file at all. If you lose data from compressing an image file there is no way to get that back. If for sharing these images on-line you need to make them a smaller file size you should always have a saved copy of that full size image in a different folder, or rename it, so you are able to retain the final edit uncompressed file for when you need it for printing or continued alterations. To compress an image file w/o making the image smaller that software has to grab a group of pixels, average the color samples within that group to make that whole group all the same color to reduce that image file size, which clearly is a loss of data and makes the image look blotchy or blurry. Resizing the image smaller will also make the image file smaller by converting that group of pixels into just a single pixel, but you cannot just reverse this process after this data has been lost. Resizing it larger again will just make it more blurry looking. If you use a sharpening tool it only increases the contrast, but is not really restoring that damaged image. You’d have better luck stretching a shrunken sweater. Again you are losing image quality with every step you take to improve your image, even if it seems to look a lot better. If you have just one bowl of soup can you stretch it out for a party of ten people by just adding more water? It is kind of the same thing.

Shutter Speed

This is nothing new to photography, but some digital cameras have improved on this from a mechanical shutter to be faster with more accurate response time using a polarized cover over the sensor. The shutter/mirror has physical limitations of how fast it can respond with the weight, springs, and motors used in a DSLR. Many cameras we use these days are a mirrorless camera, which show you a live view monitor. Such as with your smartphone or point and shoot cameras that do not have an optical view finder. Shooting hand held the shutter speed should be above 1/80 of a second. I know that seems very fast, but remember with a slower shutter speed just depressing that shutter button will jostle the camera enough to give you a motion slurred image. Even while shooting still life objects remaining perfectly still. Without a tripod I try to shoot above 1/100 second. It is best if you can set it above 1/125 if you are shooting people who may be moving slowly no matter how still they try to stand. Just a blinking eye can be quite a noticeable movement for a head-shot. Unless you are shooting faster moving sport scenes you should not need to go above 1/160 second. Most sport action shots should not need over 1/500 setting. As an example here I captured this very fast spinning propeller on a plan in flight. It was rotating so fast you could not see it at all with the naked eye. I shot this at several different shutter speeds all the way up to 1/2500 before the prop looked completely still, but you are not likely to have nearly as fast of a moving subject as this.

Of course a faster shutter speed means less light is available to expose your camera sensor. If you were to use a faster shutter speed than recommended you are unnecessarily sacrificing the other 2 settings that provide a better image quality, so why would you do that? If you want to avoid the artificial look of using a flash and your subject can hold pretty still choose a slower shutter speed, so you can jack up the other 2 settings, but to do this you will need a good steady tripod, as you are not going to be able to hold the camera steady enough to shoot below 1/60 second w/o substantial blur. With a decent tripod you can drop the shutter speed way down to leave the ISO low and a higher aperture to take amazing clear shots even at night with up to a 30 second long exposure. If you are shooting very cooperative people or a sleeping dog this can work, up to a point.

Here is an example of a 3 second exposure in low light to achieve the best quality image my camera can produce with just the available light of this coffee shop at night:

This low light image was captured without flash or a tripod. I just rested my camera on the table we were sitting at with the lens propped up a little with my hat. I set the camera to the lowest ISO 64 at f/9. I used the timer to activate the shutter, so I didn't jostle the camera depressing the shutter release. I had not asked this subject to hold still. I just got lucky he had not moved much during that 3 second long exposure. So, keep in mind this is something you can do without expensive bulky equipment and lots of set up to capture low light shots like this. Avoid the common mistake to jack up the ISO setting and the lowest wide open aperture, or you will then later see it was not a usable image capture. Realizing now that moment is gone forever. Most DSLR cameras can have up to a 30 second exposure, but you will need a very steady base to hold your camera completely still during this long exposure time. I have found even a cars or trucks driving near by can shake the ground enough to blur your image during a long exposure. Indoors having someone walk near by can flex the floor too much and blur your image.

Aperture Affects Focal Depth

The aperture is where you get good or very poor focal depth differences when shooting closer than 50 feet away. Very close macro photography can have less than 1/8” focal depth at a low aperture setting. Common head shots can have less than 1/2" focal depth, where the eyelashes may be in focus, yet the eye brow hairs are not, as well as the actual eye surface. A higher aperture gives you more focal depth by closing off the light inside the lens. Like how you squint your eyes to see better in low light, but of course this requires much more light to do this. That is because it is closing up the lens with a mechanical iris inside the lens. As small as a pin-hole at the highest aperture setting. This is just like the colored part of your eye that opens or closes to help adjust for the amount of light coming through: dilate, or constrict. This usually happens w/o conscious thought or our even noticing the difference between how much light is outdoors on a sunny day, to the low light of indoors, which will have less than 10% of the candle power in comparison to direct Sunlight. The closer you are to your subject the less focal depth you will have, so a zoom lens can help to stand further away from your subject to increase this focal depth. Which also happens to reduce lens distortion quite a bit as well. Head shots will appear to have a smaller more fattering looking nose in the center of their face, which is one reason why selfie shots tend to look so unflattering. I tend to shoot above f/8 for decent results. If I have enough light on my subject I will jack this up to f/13 or higher for portrait work.

Summing This Up

All these 3 settings can give you a better or worse images. You will need to decide what you are willing to sacrifice in order to get the shot you want with what light you have to work with. Unless you can dramatically increase the amount of light on your subject with natural or artificial light from a flash. Auto setting can be very helpful to take decent pictures, but if you are shooting where the results are less critical try to discipline yourself to shoot in manual mode as much as possible, where you have to pick each setting of your camera to help get more familiar with what they do. Then frequently check the results before taking another shot to see how they are turning out. Over time this will help to train your eye to get more familiar with how these setting affect your pictures with the available light. Learning what setting you need to have with or without a flash in order to get a good exposure without relying on your light meter will help teach you a lot about the mechanics of photography. Then you can add your artistic edge to the image you are trying to capture. This will enable you to take control of what your camera setting are. It takes time, but what do you have to lose? You should be able to train your eye within 6 months to know what the best setting is for most any light situation.

For indoor hand-held shooting you will most always need the built in flash or a speed light to achieve a decent image. Using the built in flash I tend to use ISO 200, 1/100, at f/8. Unless you’re only a few feet away this often will make a fairly dark image that can be brightened up in post editing, which is easier to fix than an over exposed image. Close up flash shooting you can optimize these setting to ISO 100, 1/160, at f/13 or higher. Outdoors in the daytime the flash will only help within 15 feet or less, but can still improve your image with fill light to brighten up the shadowed areas. An overcast cloudy day is not much more light than indoor shooting, so the setting are not much different, but keep in mind how the flash will not help while shooting objects further away. With direct Sunlight or studio lights you want to use the lowest ISO possible, 1/125 to 1/200 shutter, and f/13 or higher aperture.

Although, for outdoors distant landscape shot you do not need a tight aperture like that to get everything in focus. It is only subject less than 50' away that are so problematic for good focal depth. For landscape shots you can shoot wide open at f/3.5 in favor of a low 100 ISO and faster shutter speed. If you are shooting hand held you should be above 1/200 shutter speed, since the tiniest movement as you push down the shutter release will blur the image of objects so far away. It is always best to use a tripod for landscape photography even when you have plenty of light. You can also set the timer to trip the shutter for you, so there is less camera jitter. If you are not shooting manual I would highly recommend you do, so you have complete control over these settings. Most cameras set on Auto default to a high ISO, so you can have a faster shutter speed. Any artistic images should be shot at the lowest ISO to get a good color saturation and no camera noise. The lighting and camera settings have more to do with a good shot than the price of your DSLR or lenses. Better equipment can marginally help, but that does not help at all if they do not know how to use it. I see many 'Professional Photographers' using a $6k camera with a $12k lens on it shoot at a high ISO, so their images turned out no better than if they had just pulled out their smart phone to get that shot.

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Best luck, and let me know if this helps your photography.