Why are some photographers still using film cameras?

Why is it called the master? Of course he has his reasons! "Resistance"? "Color is not as good as color reversal film"? "Masters all live in earlier times"? "When I get old, I won't need ps for post-production"?

If it's really like the above, you should call the masters!

Digital cameras don't have large frames, and nothing can shift the axis to correct perspective like technical cameras. Maybe you haven't seen Digital Back! Why not say that the elderly are reluctant to spend money on digital cameras?

Look what they say!

"Film imaging is a chemical reaction imaging through the chemical silver salt on the negative under illumination. for

Color film is exposed in layers (RGB is divided into three layers). The point imaged by the optical lens corresponds to

A group of silver salt molecular groups. This group of molecular groups may not all react, but depending on the light, some react completely.

Part of the reaction is incomplete, and the molecular cluster density per unit area determines the light transmission or reflection at this point.

The characteristics of the emitted light form the image we see, so the concept of density is only available when film imaging (digital)

The density of the image is determined by CCD). At this point, the difference between film imaging and digital imaging is huge, but film imaging is not the case.

The concept of pixels! !

Digital imaging is the tiny electricity generated by the migration of electrons generated by the photosensitive unit of CCD under the irradiation of incident light.

The change of voltage or current is amplified by analog-to-digital conversion and converted into digital images, and finally displayed on the display with the help of the computer.

Of course, if you want to develop it into a photo, you still have to fix the image through photochemical reaction through a process similar to film imaging.

On an image paper.

From the above principles, we can easily find that the principle difference between digital imaging and film imaging is huge.

Reflect:

1) The first is the requirement for light. Film imaging requires a certain amount of light to make the silver salt molecular groups react chemically.

This requirement is determined at the time of film production, assuming that a film needs 1000 lux (note lux.

The unit is the brightness unit, which is not necessarily appropriate here. I just use it to illustrate the problem. Only in this way can silver salt molecular groups be enough.

Sufficient response, then the film can not be exposed below this illumination, but it is different for CCD, in the case of low illumination.

You can use software to increase the magnification of the amplifier circuit and still be exposed (although this may cause some thermal noise, after all,

Can be imaged). Therefore, the sensitivity of film is worse than CCD, and everyone who has used film should know the color inversion.

Film requires very strict exposure, and friends who have burned film equipment should understand how important the accuracy of exposure is.

2) Film photography and digital photography are different in details. Anyone who has studied painting knows how to represent an object.

Stereoscopic? The depth of color is very important! Due to the limitation of digitization process, digital imaging is not continuous, but step by step.

Molding. An 8-bit advertisement has only 256 ratings from the darkest to the brightest. If we shoot a monochromatic ball, then this ball

The digital image consists of 256 color rings, and changes such as 15. 1 are merged into the digital image.

15. But film photography is basically continuous because there are a lot of silver salt molecular groups at a point.

You can show the difference between 15 and 15. 1 above, so that we can see the complete color gradient of the ball.

This is why many people make digital imaging too dull. In addition, since the CCD reacts to light too easily, this

After the upper and lower limits (or tolerance) of 256 levels are too large, the jump between each level is also large, and the effect will be worse, so

In fact, digital cameras reduce this tolerance as much as possible by controlling the amplifier circuit, and the bigger the digital camera, the better.

In order to shoot more content, because the light changes when shooting, the contrast changes at any time. But the decrease of tolerance will change with time.

Cameras are difficult to use (after all, not many people practice exposure well), so this is a compromise, and this tolerance is as good as possible.

The negatives of this film are very close. Although the film changes almost continuously, small tolerance can still bring better transition performance.

3) color representation, or color resolution, for film, because it is layered exposure, so each optical point

All colors can be displayed, but the commonly used CCD (except X3-CCD) uses four or three black and white.

The photosensitive unit has a filter to express the color, so there is a problem. Suppose a green light spot is imaged right here.

On four cells, CCD can display the correct color, but if a green light spot is only imaged on the red cell.

The color is wrong. Results On the one hand, the improvement of CCD pixels requires the improvement of lens resolution, but the improvement of lens resolution

This kind of dislocation is more likely to happen, that is, the purple edge or green edge phenomenon we see on high-pixel digital cameras.

This situation cannot be solved unless a structure similar to X3-CCD is adopted. In addition, because of this, the existing

The color resolution of a digital camera is only 1/4 or 1/3 of its black and white resolution. Therefore, most colors are difference algorithms.

Calculated, this algorithm will lead to errors where the color or brightness changes greatly, and different factories will handle the errors differently.

Home algorithms are different, but in principle, we must keep details and reduce errors (which may be manifested as noise at this time)

Is another kind of noise different from CCD thermal noise). Different manufacturers are different. So the noise is

This is not a bad thing in some cases. "