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The flattening or compression effect is not caused by a particular kind of lens, it applies to all lens in the same way. Actually, this property of lenses applies to our own eyes as well. The factor that affects flattening is the distance from the camera to the subjects. Consider the following exercise: Place two friends 1 meter away from each other. ...

The only other factor you need is the height of the object in real life (otherwise you could be photographing a model which is much closer to the camera). The maths isn't actually that complex, the ratio of the size of the object on the sensor and the size of the object in real life is the same as the ratio between the focal length and distance to the ...

In this sort of situation, the normal approach is to use a focusing rail which allows fine and controlled adjustments to be made. There are several available on the market, with some under £50, but it would be possible to make one yourself, if you have the right tools.

I believe the effect has to do with the RATIO of distances from the camera to various parts of the subject / scene. For example, if you take a wide-angle shot of a person's face, their features are exaggerated because the camera-to-nose distance might be half of the camera-to-ear distance. On the other hand, consider the same shot taken with a telephoto ...

Many (possibly most) modern SLR lens systems return focus setting data to the camera. Potentially the precision of data returned could be high - something better than 1% of range would be possible and meaningful with modern systems. However, it appears that most if not all systems use a simple gray-coded* system with perhaps 16 steps. Number of steps ...

Why work so hard? I think you are making this much harder than it has to be. Getting something to be exactly 640 pixels in the image will be difficult, require careful measurements and accurate calculations and is very error prone (and for something really close the internal construction of the lens makes a huge difference and this will be impossible to ...

A non-obvious answer is to increase the light. Because macro photography has such a small depth of field we're often forced to balance the aperture setting with avoiding camera vibration. Adding some off-camera strobe will nicely fix both problems. The burst itself will act as the shutter if you want it to, by getting about 5-6 stops between the flash ...

As noted @matt-grum, the most simple formula to estimate distance to the object is pinhole projection formula: where x is the size of the object on the sensor, f is focal length of the lens, X is the size of the object, and d is distance from nodal point to the object. x and f, and X and d are measured in the same units, e.g. mm and m respetively (to ...

TLDR: No because you need an additional variable, either the height of what the subject is that fills the frame or the distance at which you are focused (infinity doesn't work though). Long answer... To do this you can use simple trigonometry, but you would need to know either the current or desired distance to subject or the size of your subject ...

the only relevant thing is that the same light which falls on your main subject falls on your card. The field of view, distance and so on don't enter in the equation. but you have to be sure that by standing near the subject you don't influence in any way the light, which is not always easy since our eyes are very quick to adapt to variation and they ...

According to the FAQ for the particular calculator you're using, the calculations are performed for a thin lens, and hence the front nodal point of the lens should be used. The author recommends using the front surface of the lens, on the assumption that the front nodal point is somewhere inside the lens, and this assumption will yield a conservative ...

It's actually far simpler than any of the answers posted so far! You don't need trigonometry, or field of view calculators at all, all you need is multiplication and division! Firstly (all else being equal) the size of your object in the image is directly proportional to the focal length (if you double the focal length you double the size). So if you know ...

Yes for most camera systems: For Canon EOS, select EF and EF-S lenses transmit distance information through the EF mount. For Nikon, D- and G-type Nikkor lenses transmit distance information through the F mount; this is what the D designation means. G lenses are the same, only without an aperture ring. For Sony, all current lenses transmit distance ...

Theoretically the only factor you should need to adjust for in the following equation when zooming is the focal length: distance to object (mm) = focal length (mm) * real height of the object (mm) * image height (pixels) --------------------------------------------------------------------------- object ...

This is in the FAQ for the calculator site you refer to. In short, the equations used assume an abstract mathematical lens, not a real-world one. Except for macro or other extreme-closeup photography, this is perfectly fine — it doesn't really make much difference where you measure from. Assuming the measurement is from the front of the lens gives a ...

In addition to @jrista's detailed answer, you may also wish to experiment with focus bracketing. This technique involves taking many photos of the same macro scene with many different focus points, and then composing a final, fully-in-focus-image from the images. I haven't done it myself, but I imagine that it could be a very useful technique for your ...

Macro focusing can be a difficult task, even with the proper tools, as DOF can be so thin (sometimes just millimeters thick, or with extension tubes, even thinner.) There are a couple techniques you can use to focus at extreme macro scales. The cheapest, and obviously the simplest, is to move the object if it is mobile. You can usually get a very fine degree ...

Are you sure you are changing the "height in pixels" value as well? When you zoom, the focal length and the height in pixels change, while everything else stays the same. If the height in pixels stays the same when zooming, then the subject distance is changing.

It is possible to estimate the distance to the subject using the auto focus. But to do this you need a camera model of your whole camera system, body and lens. You would most likely have to model this yourself, which will take quite some time and effort. The accuracy would likely be very different for different systems. Your model would probably contribute ...

This depends on both the camera and lens, both must support communication of such information. Nikon introduced the feature with their "D" lenses (later "G" lenses can do it as well). According to Nikon's glossary, the following bodies can use that information: F6, F5, F100, F90X, F80, F75, F70, F65, F60, F55, F50, PRONEA S, PRONEA 600i, D2 series, D1 ...

There is an EXIF field named "Subject Distance." If you use a camera that populates that field (and can be controlled by your controller software), you could just use the EXIF data from the picture. I just looked at two images from my old Canon SX10IS that have values in that field, and the picture where the subject was closer had a smaller number: so ...