How to check a DSLR camera when buying a Nikon. We check the camera before buying. How to check if your camera is stolen

How to check the camera correctly when buying. Nobody wants to buy a new camera, but it turns out that it is defective! I will try to outline in this article the basic rules for checking cameras. It will be mainly about models with interchangeable optics. Although, most of the points are relevant for checking the so-called "soap boxes" or compacts.

Before buying, try to decide on the model yourself. Do not trust sellers - their task is to sell more profitably, and you need a camera for specific goals and objectives. Better to contact large store with a stable history of existence. Perhaps in your city there is a brand store of a certain manufacturer - it is safer there. Take an interest in the availability of service in your city and the possibility of repairing this model.

Professionals take a laptop with them to the store to check the quality of the frames. I'm not sure if you will do the same, but keep in mind. If you can check, take a laptop.

How to check the camera. Visual inspection

Start your inspection from the packaging box - mechanical damage even on it is no longer a good sign. Make sure you have a manufacturer's warranty. This is not the same as the warranty of the service center. The presence of a warranty service center in the absence of even a mention of the manufacturer's own warranty indicates the most likely illegal origin of the goods. Check carefully that the numbers on the model and serial numbers match the camera and the warranty card.

There should be no marks on the camera body itself, packing bags intact, the screen is protected by a sticker. Fingerprints and scratches should be all the more absent. Inspect the screw connections, you will not see any tool marks if everything is in order. Make sure the memory card and battery compartments are easy to open and close. Internal compartments must have intact seals. There are rubber pads in the grip area, so that they do not come off.

The slightest deviation from the above parameters is a clear reason to be wary. In principle, if you find such signs, you can safely demand a replacement of the camera. If a separate lens is purchased for the selected camera, we carry out the same operation with it.

When the look suits you, move on to the next step. We put on the lens on the camera. We check the absence of backlash.

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Mechanics check

Testing mechanics includes the following:

We check how freely the battery and the memory card are installed.
We turn on the camera.
The battery charge may be at zero, then you need to recharge a little.
We carry out several frames in the "automatic" mode and check how the flash fires.
We turn on the shooting in a series, clamp the shutter camera until 5-6 frames in a row are taken (this is done to check the shutter performance).

How to check the camera matrix

Checking for the presence of broken and hot pixels

When wondering how to check the camera when buying, you definitely need to remember about checking the pixels. In simple terms, dead pixels are dead pixels that will appear on your photo as small colored dots. They are bad because they will be present in absolutely all frames in the same place. Usually, you won't even notice it if you don't know about the presence of such a problem. But sometimes it happens that they are superimposed on some important object.

To check the camera matrix for dead pixels:

You need to turn off noise reduction through the camera menu (if you don't know how, ask the seller), after checking, do not forget to turn on this function.
Set the camera to manual shooting mode "M"
By switching the focus to manual mode "MF",

The check is performed with the lens cover closed. ISO-800 sensitivity, shutter speed - a few seconds, in the sense that you need to press the camera shutter and take a picture.

If you find a small number of colored dots, then remember their location, set other settings: ISO-200, shutter speed - 1/800 or shorter.

How to check the camera for dead pixels - examples of such are circled

Consider the resulting image again. If the points remain - these are "broken" pixels and they will be in these places in all your images. If they disappeared, these are “hot” pixels, and they will appear only at slow shutter speeds and high ISO values, ie. when the matrix gets very hot.

Decide whether to buy a camera depending on their quantity.

Spots or dust on the sensor

In order to check the matrix for dust or stains, which may occur even on new cameras, you need:

Find a solid light colored surface - for example, a white A4 sheet.
Take a picture of this surface.

The resulting image should not contain any dark spots, the surface should be as uniform as in life. If spots are present, do not take this camera, as cleaning the sensor payable service, and there is nothing to start using the camera with.

Testing Autofocus Operation

You need to turn on the auto mode. Switch the camera to spot focus mode (if you can select the focus point in the viewfinder, then it is already selected).
Select the center point.

The center focus point looks like this

Aim the center focus point over the subject of your choice, press the shutter button halfway. The camera will focus on the focus, then press the button all the way and take a picture.

Focus on different objects in turn, choose different removal of these objects. Those objects at which you were aiming (the place where the focus point in the viewfinder was aimed) should be sharp, closer and farther may be blurred.

The following experiment can be done. You will need to make a dozen frames at an angle of 45 degrees of some object with small details. The test is best done in natural daylight.

Let's set the mode to “A”, set the aperture to the widest one. ISO can be set to “auto”.

Autofocus should naturally be on.

Let's choose the center focus point.

We will select an object for shooting: it can be a piece of paper or a box with some letters, a newspaper, a ruler or a special test target.

Let's focus with the central point on a predetermined place. It is important to remember exactly where you are focusing. In the case of a test target, it is necessary to focus strictly on the designated spot. Usually it says “Focus here” at this place. We will use a sheet of paper in a cage, drawing a straight line in the center of it. We will focus on it.

We make sure that the focus point is exactly where you want to focus. Please note that once the camera has focused, it cannot be moved forward or backward. After all, if the distance between the subject and the camera changes by even a millimeter, focusing will fail and the test will not be accurate. If you suspect that the camera is still focusing wrong, take a few more test shots to make sure that the mistake appears systematically.

Let's examine the pictures: if the focus on most of the frames in the series was exactly at the point on which we focused, then everything is in order. If the focus in all shots has shifted from this point forward or backward, then the autofocus is missing.

Correctly. It can be seen that the focus is exactly where we were aiming: on the black line

Front Focus: Focus has run forward.

Back focus: the focus was behind the line, not on it.

How to check the mileage of the camera?

There are times when under the guise new technology unscrupulous seller sells used equipment. This can be a display sample or a return from a buyer. To avoid such a situation, it is worth rechecking the number of captured frames. If the camera is new, then the number of frames should naturally be close to zero.

You can verify the number of frames on different cameras in different ways.

In Canon-s it is very difficult: you need to connect the camera to the computer and use special programs like EOSinfo or the eoscount.com web application.
In the case of Nikon devices, everything is much simpler. It is enough to open any test picture from the studied camera and look into the EXIF data. It is important that the studied picture was taken in Jpeg. It is not worth editing the test snapshot in graphic editors: this way you can lose the necessary data. EXIF is shooting information data written to a photo file.

How can I view EXIF data? Brief information from EXIF can be viewed in many programs, but we need to deduce detailed information... It is convenient to do this through web services. For example via this regex.info/exif.cgi. Just upload the tested image there and the service will display the EXIF of this frame. We are interested in the "Shutter Count" column. It will record how many times the shutter has worked.

The acquisition of a new camera is a very responsible and exciting mission, which a novice amateur cannot cope with on his own. In my article I will talk about how to check the camera when buying, avoid common mistakes, share my experience and the main ways of choosing a high-quality working device, I will try to convey in a concise form main information and not overload you with specific terms.

So, my main tips for choosing a camera, which are universal for any device model, be it a DSLR or a compact camera with interchangeable lenses. Most DSLR buyers are faced with a painful choice of two parts of the camera - the "carcass" and the lens, each of which must be given careful attention. Further testing of the technique is divided into four stages:

inspection of the "carcass";
inspection of the lens;
checking the operation of the included camera assembly, that is, when the carcass and lens form a single whole;
direct verification of the basic properties of the camera.

In order to choose the right camera and not get into a mess when choosing it, you need to approach this process with all seriousness, have free time (at least 15 minutes) and cold prudence. Indeed, in case of some kind of breakdown, you will have to carry it to the warranty workshop and wait for an exchange. And this is additional nerves and a waste of time. Do you need it?

And now directly to a more detailed description of tips on how to check the camera upon purchase.

How to avoid mistakes when buying

So, here are the basic tips for choosing a good device:

Don't rely on the seller. Before purchasing, you need to think carefully about which model you want, because in most cases in the store the seller will try to foist you on the wrong thing. This is a fairly common practice, familiar to many stores that are trying to shove a newcomer off a stale product under the pretext of its importance and relevance today. In fact, their task is to provide maximum value for their store, but not think about your wallet in any way. Therefore, in order to avoid such a situation, it is better to take a professional with you or prepare well for the annoying assaults of sellers.
Correct and confident choice of model. In fact, in the information age, it is not difficult at all. What prevents you from scrolling through Internet forums in advance, consulting with your friends for a choice, and already decently prepared to go to buy a camera.
The relevance of the choice. Take a model that will allow you to feel confident for several years, even if it was released a long time ago, but, thanks to its high performance, has not lost its relevance to this day. Sometimes these cameras are even better than newer models released more recently, and the price difference between them is significant.
Where to buy? To avoid the risk of counterfeiting and low-quality goods it is best to turn to stores that are well-established in the photographic equipment market. Even if the cost in them will be slightly higher. Remember the saying: "The miser pays twice." What a sin to conceal, some unscrupulous sellers give out their goods under the guise of new, but in fact it was imported illegally or was already in use.
You should not take a camera that is being sold by ad. After all, you do not reliably know why the owner is selling it, all of a sudden many defects of invisible to the naked eye may be hidden in it. But if for some reason you had to buy from your hands, then you need to thoroughly test it, because then you will not prove anything to the seller. In the case of a successful purchase, you save a significant amount of money, which is quite important in a difficult financial situation in the country. But at the same time, you do not receive any guarantee in the future, so you need to evaluate well all the pros and cons of this kind of purchase.
Have an understanding of the camera's control functions. Pre-download the instructions for use from the manufacturer's website and study well in theory how the shooting modes, sensitivity, autofocus, continuous shooting, focus points and other important parameters are selected. If you yourself cannot cope with all this, then take a knowledgeable person with you.
Take your memory card with you to the store. Usually cameras come without a memory card in the kit, so take it with you, it's not difficult at all.
Take along a laptop or tablet with a large diagonal. All the flaws of the taken pictures are much better visible on the big screen, if there is an opportunity to take the gadget with you, take it without hesitation.

I have listed the top tips on how to check the camera when buying, which every novice hobbyist should know. And now let's go directly to testing it.

Camera check

In front of you lies the treasured box with the camera, the seller stands over his soul with his advice and wants you to pay off and quickly dumped out of his store. Try to be cool, ignore some of his prompts, and learn to think for yourself. Depends on .

Visual inspection

Carefully inspect the camera box: there should be no mechanical damage on it. Find a manufacturer's warranty, not a service center, sometimes found in illegal goods. Carefully check the correspondence of the numbers on the box, camera and warranty card.

Pay attention to the package contents of the device: there should be no traces of use, the packaging bags are not touched, there is a protective sticker on the screen, there are no traces of fingerprints or scratches. The screw connections must be free from traces of touching the screwdriver, the memory card and battery compartments must be easy to open and close well, the internal parts must have intact seals. It is also worth taking a good look at the rubber pads in the grip area so that they do not come off. The slightest deviation from the listed parameters is a clear reason to be wary about the quality of the proposed device.

If you find any inconsistencies in the presentation, feel free to ask for the replacement of the camera. We carry out the same operation with the lens. If everything suits you in the appearance of the device, then proceed to the next stage. We put on the lens on the "carcass". In the absence of backlash and tight fit, we go further.

From my experience, I can safely say that of many manufacturers, the minimum claims usually relate to Canon products. Their cameras are so meticulously calibrated and run like clockwork that even the most demanding customers are satisfied with the testing.

Mechanics check

After it has been produced visual inspection camera, we proceed directly to testing the mechanics of the device:

Install the battery and memory card.
We turn on the camera.
If the charging is at zero, then we recharge a little.
We carry out several frames in automatic mode and check if everything is in order with the flash mode.
We turn on continuous shooting, hold down the shutter camera until 5-6 shots in a row are taken (this is done to check the shutter performance).

Checking for the presence of broken and hot pixels

A dead pixel is an inoperative element of the camera matrix, which stands out in photographs with a bright point. The hot pixel is usually not visible in normal shooting conditions, but when performed on high resolutions sensitivity or slow shutter speed turns into a conspicuous colored dot in the photo. A small number of them are allowed when shooting on high rates ISO, but no good if they are visible at low resolutions. “Bad” pixels are especially well visible against a black background. Moreover, they can even be visible to the naked eye on the off camera screen. The presence of broken and hot pixels is a serious reason to refuse to purchase a camera.

Checking the screen and control buttons

After checking the matrix, we proceed to testing for the operability of all buttons, levers and wheels of the device. Be persistent when communicating with the seller, ask him to tell what this or that button is for, do not hesitate to ask questions when something is not clear. Pay particular attention to the joystick, it should calmly respond to all presses in any direction.

Next, we proceed to check the main screen, it should not have any constantly burning dots in any color or not at all. If there is an auxiliary display, we check it in the same way. You should also check its backlight well.

Then we move on to the viewfinder, which should be free of dust, the slightest scratches, bubbles, and all focus point indicators should be clearly visible.

Checking for front focus and back focus

The next step when buying a camera is to test it for autofocus. Sometimes the lens does not focus at the designated point, but slightly behind it (back focus) or in front (front focus). If focusing is not correct at the designated point, sharpness may not be there. The most interesting thing is that front and back focus are found only in DSLRs. "Soap trays" and compact cameras do not suffer from such a defect, since they have a completely different focusing system. This problem is not so terrible when purchasing top-end cameras, where the shortcomings can be eliminated through the autofocus settings in the menu. Models are especially good at this. Canon, which are even here ahead of the rest.

In general, it is possible to accurately diagnose the presence of front and back focus only in a specialized service center, and the manufacturers themselves do not consider this to be a marriage. It is also possible that you will sin on the camera, getting blurry pictures, but in fact these will be your technical mistakes. In this case, you should try to take pictures differently or simply seek professional advice.

Color balance check

Further in the auto mode, I advise you to take several shots to check the color balance, autofocus and metering. It is best to do this from different places, the best option is indoor and outdoor shots. This allows you to fully see the combination of color shades under different types of lighting. We make sure that the white balance is not very much biased towards cold or warm tones.

The exposure itself should look even, without the presence of strong overexposures and the presence of too dead shadows. The autofocus is mainly influenced by the lens, therefore, we carry out a full-fledged operation of the camera system for the presence of noticeable misses when taking shots in the wide-angle and normal positions. In general, checking the taken pictures is actually a specific phenomenon, here it is of no small importance whether you like these photographs yourself.

If the answer is yes, you can start thinking about buying your chosen DSLR model. Also, be sure to look at the footage on the built-in memory card, suddenly some artifacts will pop up, which will immediately indicate that the device offered to you is not the first freshness, and the seller hid this fact. This is a very common case, which many unscrupulous companies simply do not pay attention to or forget.

Zoom Lens Check

Testing it is as follows: scroll the zoom control lever and look at the camera screen. The scale of the frame must change smoothly, without any jerks. A slight jerk is possible only at the beginning of the movement of the objective lenses and the defocusing of the image is quite acceptable.

If the manual mode is set, then no sharpness should be discussed at all. A positive test of a zoom lens is characterized by smooth changes in the picture when zooming in and out, the absence of crunches and noises from the outside. When checking the camera in a noisy place, you should bring it closer to your ear and carefully listen to the operation of the camera mechanisms.

Guarantee

Usually, branded salons of manufacturers (Canon, Sony, Nikon) offer a so-called "white" guarantee, according to which, in the event of a malfunction, the technician is sent to a specialized brand center. Under the "gray" guarantee provided by photographic equipment stores and large retail chains, in the event of a breakdown, the camera is returned to service center this organization. In general, I think there is nothing wrong with that. The most important thing is to check the equipment well before buying, then no problems will arise in the future.

Conclusion

In my article, I tried to tell you the basic rules of how to check the camera when buying, which beginners usually face. I hope this will help you avoid problems and get the maximum pleasure from working with high-quality equipment. After all, well-taken pictures are a guarantee positive mood and maximum satisfaction from the work done.

If we take into account experienced photographers, they, of course, do not bother so much when buying, practically not paying attention to the appearance of the new device. In this they are helped by a trained eye and extensive experience in taking pictures. Professionals for short term can appreciate all the charms and disadvantages of the device on which they will work in the future.

But all this does not come immediately, but as a result of painstaking work. Everyone was once amateurs and could not immediately pick up good camera with a swoop, once they also meticulously examined the equipment they saw in the store. If you choose from the main brands offering products to Russia, then in many respects I prefer Canon.

If you liked my article, or find it useful and interesting, then be sure to share it with your friends on your social networks:

Download program EOSInfo for Windows you can follow this link http://www.astrojargon.net/files/misc/setupeosinfo.exe

For Mac — http://www.astrojargon.net/files/misc/40dshuttercount.dmg

After installation, launch the program, and connect the camera via USB cable to the computer. It will show the shutter counter, camera model, firmware version, and some other data.

How to find out the mileage of Sony NEX and A7 cameras (A7R, A7S)

To check the mileage of Sony NEX cameras, as well as full-frame models of the A7 series, it is better to use this service http://tools.science.si/index.php. On this site you can also check mirror Sony cameras Alpha.

Here is a list of cameras that are supported by this service:

SONY Alpha E-mount: NEX-3 NEX-C3 NEX-F3 NEX-3N NEX-5 NEX-5N NEX-5R NEX-5T NEX-6 NEX 7 A3000 A3500 A5000 A5100 A6000 A7 A7r A7s

SONY Alpha A-mount: A230 A290 A33 A330 A35 A37 A390 A450 A500 A55 A550 A57 A58 A65 A77 A77M2 A850 A900 A99

It is as easy to use as the first website. Just upload your RAW image to the site and click the "DO IT" button.

After that, you will get the following result, this is the mileage of the camera:

Often, buying a used camera is the only option to get yourself a more modern and advanced photographic equipment. After all, prices for high-quality digital photographic equipment remain relatively high, and at the same time, there are models on the secondary market that were considered novelties a year or two ago. It is no secret that many people prefer to quickly get rid of their "obsolete" cameras and other equipment, only after hearing about the appearance on the market of any new model.

Therefore, among the offered used cameras, it is quite possible to find a suitable option, both in price and in technical specifications... The only thing left to do is to choose and check a used camera correctly. Unfortunately, you can easily get into trouble here if you do not have sufficient experience and relevant knowledge. Let's try to give some recommendations for choosing compact and used SLR cameras.

Choosing a used camera

People can sell their photographic equipment for a variety of reasons. Someone is constantly chasing the most modern cameras and therefore changes them in their arsenal literally like gloves. Someone was presented with a camera as a gift, but he is not particularly keen on photography and therefore there was no use for this gift. But there is a category of people who have already encountered technical problems when working with their camera or used it a lot, and therefore decided to get rid of the camera, passing it off as "practically new." These sellers, unfortunately, deliberately keep silent about hidden defects. The problem of choosing a camera in the secondary market is precisely to distinguish such unscrupulous people who offer problematic photographic equipment from normal sellers.

Already initially at the stage telephone conversation it is recommended to clarify some details with the seller and, in particular, to ask, how many pictures were taken with this camera. This issue is especially relevant when choosing a SLR camera, because it is no secret to anyone that the shutter is very susceptible to wear and tear.

Each SLR camera has its own shutter speed limit, so it is desirable that the already depleted resource of a used camera does not exceed half of this limit. If you do not, there is a risk of incurring the additional costs of replacing the shutter after purchasing the camera.

Advice: To independently determine the "mileage" of the camera, you need a raw image from the camera under study in graphic editors. Information about the number of shutter releases is recorded in the EXIF of each frame, so this data can be easily found using a program, for example, in the ShowExif program, see the value of the Total number of shutter releases parameter or in the popular IrfanView, with plug-ins, see the Total pictures parameter (Press “E "When viewed).

To begin with, you need a snapshot from the desired camera, unprocessed with graphic editors.

A record of the number of shutter operations is recorded in the EXIF of each frame, so it is easy to find out using a special program.

Use ShowExif, see the value of the Total number of shutter releases parameter.

or IrfanView with plugins, see parameter Total pictures (Press "E" while viewing).

In general, if you buy some serious SLR camera, then you should find out in more detail the entire history of its use from the owner. After all, such cameras are often used in rather extreme conditions. As for inexpensive compact cameras, here as such information about its history and the number of shots taken will be much less important.

Camera check

Of course, the most important step in buying a used camera is to thoroughly check it for any hidden defects or malfunctions. In general, such a check is not much different from checking a new camera in a store, it just needs to be done more carefully. You should start by checking appearance devices.

It is necessary to pay attention to various chips, cracks and scratches, and if found, check with the owner about their origin. Inspect all screw connections on the camera - they should not show any traces of being unscrewed with a screwdriver. You can shake the camera a little to make sure that there are no extraneous sounds, clanks and backlash.

Advice: Defective pixels are of two types, "broken" - which are not illuminated and "hot", which are always illuminated with one color. To check for "broken" - you need to open the aperture as much as possible and photograph a brightly glowing object out of focus (for example, a sunny sky). The matrix will be flooded with uniform light, but the "broken" pixels will remain black. "Hot" are checked with the lens closed at a slow shutter speed. The picture field will be black, and defective pixels will glow. You can also check for defective pixels using the Deadpixeltest program.

You also need to carefully inspect the camera lens. Check the housing for any scratches, then inspect the lens surfaces for a perfectly smooth and clear lens. Autofocus should work smoothly, without jamming or extraneous sounds. If you suspect that the lens and its mechanics are already worn out, you should postpone the purchase. After all, the cost of a possible subsequent repair of the lens will be very high.

Finally, it remains to check the controls and electronics of the camera. It is not an unnecessary precaution to make sure that absolutely all buttons, wheels, and levers on the camera are working properly. Try activating different shooting modes and camera functions. There is less risk that later you still find any defect related to the camera electronics. After taking a few test shots, evaluate the white balance, focus and metering performance. It is very important to remember to check the built-in flash as well.

Only after such a comprehensive inspection and checking the performance of a used camera can a decision be made about whether it is worth buying. It is possible that during the check you will find some small defect that practically does not affect the quality of the picture. But it will allow you to bring down the price a little when discussing a deal with the seller.

It should be noted that if you are looking for a budget compact camera, then the likelihood of running into an unscrupulous seller in the secondary market is lower than buying a more serious, semi-professional SLR camera there. The thing is that in a compact camera, in principle, there are much fewer mechanical components that wear out most quickly during operation. And it is, accordingly, easier to check the operability of the mechanisms of a compact camera.

By and large, you just need to be convinced of the stable operation of the zoom and the quality of the lens. But with a DSLR it is worth "tinkering" and take a closer look at checking all the camera mechanisms, of which there are many more. And you should never hesitate to ask the seller clarifying questions. Sometimes such questions really help to protect yourself from buying a camera that is already close to depleting its resource.

Of course, even the implementation of these recommendations cannot guarantee that you, in the end, will acquire high-quality photographic equipment that can serve you for more than one year. Unfortunately, sometimes you just can't guess. One used camera, dropped several times and completely soaked in the rain, can safely work for a very long time. And the other, seemingly completely new, and practically not used by anyone, unexpectedly fails, not having worked out even half of its resource. However, these practical advice choosing and checking a used camera can still help you reduce the risk of buying digital photographic equipment with hidden faults and defects.

Before you buy reflex camera Surely, after thinking about which model of equipment to choose, everyone faces the next task, where to buy a camera and how not to buy a “defective” model. In this article, I would like to give you a couple of tips on what to check when buying a DSLR camera.

The most common defects in modern SLR cameras are:

Camera condition: not new / "gray"

Some photo salons have special programs for testing the camera, as a rule, any testing for additional money, but if you bring a laptop with you with the programs installed, you should be given the opportunity to test the camera yourself. Be sure (if this is your first DSLR) first purchase a memory card, since it does not come with the camera, and without a card you will not be able to test the camera.

Let's start in order:

Camera status

Initially, before purchasing a camera, carefully examine the carcass itself, whether there are any scuffs, the condition of the accessories in the box (everything must be properly packed), also pay attention to the instructions, it must be in Russian (then the probability that the product not "gray" anymore). Be sure to check the availability of the warranty from Canon (after purchase, check that it is correctly filled in).

Check the number of shutter releases. There are special programs on the Internet for this, with detailed instructions... Specialist. programs are not suitable for all DSLR cameras, search for exactly the equipment that you plan to buy (example: a utility that is suitable for Canon with Canon DIGIC III (or IV) DSLRs processor).

Matrix defects. Broken and hot pixels

Defective pixels on the matrix are pixels that differ in color from the main background of any photo: dead pixels / hot pixels. Broken pixels are always visible in the pictures, if they are, then you should not take the camera, hot pixels are detected at long exposures (more than 1/60), when they are detected, the decision to purchase whether or not there is a camera is at your discretion, a small number of them is permissible (not more than 20).

To check this defect on the Internet, there is also a useful program DeadPixelTest.exe - it is easy to find and install on your laptop.

If there is no program at hand, then a manual test may be suitable:

1. Set the mode "M", aperture F5.6, ISO100, focusing mode MF.
2. Set the shooting mode with a delay of 2 seconds. and turn off the noise reduction ("Noise Reduction")
3. Cover the lens with the lens cap.
4. Take three shots: with a shutter speed of 1/3 sec. 1/60 sec. and a picture with noise reduction turned on with a shutter speed of 2 sec.

5. The resulting images are downloaded to the computer, and examined in the editor, increasing the brightness, looking at the presence of dots.
If there are distinct blue or red dots in the picture, at short exposures, then this is a broken matrix, the camera is defective, but if the dots are observed at long exposures, then a small number of them is permissible, and you make a decision.

Incorrect operation of the focusing system

1. Checking the operation of the "optics matrix" bundle

In this case, you need to test the carcass directly with the optics that you plan to purchase. If the test result is unsatisfactory, then the optics should be replaced and the case tested with different optics. If incorrect operation is observed with all lenses, then the camera body itself (carcass) should be replaced.

Example: Canon Optics 18-135mm F3.5-5.6

We take 6 shots, focusing on an object far enough from you, with the settings:

F 18mm, aperture 3.5 and 8.0.
F 50mm, aperture 5.0 and 8.0.
F 135mm, aperture 5.6 and 8.0.

We upload pictures to a laptop and study them carefully. The purpose of the test: the drop in sharpness to the corners or edges of the frame should be uniform at all focal lengths.

An example of a malfunction:

The left / right corner of the frame is very blurry compared to the other corners of the same frame.

2. Revealing BF and FF

The task of any focusing system is to choose the position of the objective lenses so that the object on which the photographer is aiming is within the depth of field (DOF), i.e. in focus.
Possible malfunctions: the problem of "back-focus", BF (depth of field in the picture lies behind the subject) and "front-focus" FF The depth of field in the picture lies in front of the subject.

You will need a tripod, patience, and an object (a specially printed sheet for checking is best, it is also available in some showrooms in Fig. 1.). We put the camera on a tripod so that it is at the same distance from the object and the "shake" is excluded.

We set the parameters:

1.Single AF., MF - manual focus
2. Select the central focus area.
3. Mode of shooting with delay (Seftimer).
4. Take 5 shots, aiming at the above line (in the picture). After each shot, place your palm in front of the camera lens (to change the focus position)!

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