11

Your camera is working correctly. Pretty much all modern SLRs for the past 60+ years have operated this way. There are several distinct advantages to doing it this way: The viewfinder remains brighter during composition. As the aperture is stopped down, the viewfinder gets darker and darker as less and less light is allowed past the aperture blades. The ...


10

You appear to be seeking to maximize the amount of background blur. Factors that increase background blur are: Distance to subject (closer) Distance to background (farther) Focal length (longer) Aperture (larger opening; smaller F-number). Sensor size in and of itself is not a factor. However, it influences focal length choice and working distances. ...


9

It is typically called "lens compression," where things farther away appear nearer to the subject/closer together. And the opposite of this is typically called "lens distortion," where something closer to the camera appears larger than it should... like someone's nose in a portrait. Neither effect actually has anything to do with the lens,...


7

The Exif standard says that: ApertureValue=2*log₂(FNumber) which is also: ApertureValue=2*log(FNumber)/log(2) There is even a nice conversion table: However, looking at my own photos (EOS 70D), I find that the exposure value and the FNumber are close to each other but not always equal, so this doesn't follow the table below for apertures => f/8. So I ...


6

If you open you manual and check on pages 452-453 there is instruction how you can set DISP or SET buttons to act as depth-of-field preview button. On higher class EOS cameras there is dedicated button for this function, bot not on EOS 250D. If you want permanent function you can't do this.


6

Depth of field refers to the distance between the nearest and farthest objects that appear "acceptably in focus"; it does not convey information about absolute sharpness in the resulting image. All lenses suffer aberrations of various kinds, and these aberrations tend to be the strongest at the perimeter of the lens, where they are harder to correct for. ...


6

White-Balance correction works best with a bright grey. Most grey surfaces work but precision is lower when the surface is darker. Correction will not work if any of the channels are clipped which is why too bright is a problem. The reason extreme brightness is problematic is that the camera is unable to figure out what transformation to apply if the ...


6

Long focal lengths (ie, high zoom factors) tend to remove depth because as the camera is far away, everything is shot from the same angle and this removes perspective. But is is really the distance that does it, cropping a picture taken with a shorter lens (but from the same place) would yield the same result.


5

Due to the wave nature of light (light travels as both a wave and a particle), the wave will bend around edges (much in the way that water going through a gap in a wall will bend around the wall). The light bends in the direction orthogonal to the edge. The effect is called diffraction and the "sunbeams" are called diffraction spikes. The effect ...


5

Because in the Nikon D3x00 and D5x00 series, as well as many previous entry level Nikon DSLRS and pretty much all Nikon 35mm film SLRs, the same mechanical motion actuates the mirror assembly and the aperture linkage. Once the mirror is up, the aperture can not be changed from the body. This worked fine when the mirror was always down until just before a ...


4

That observation is true. The nearer to the lens, the smaller the depth of field. If you use an online DoF calculator like e.g. https://www.dofmaster.com/dofjs.html you can easily see this. Example: full frame, 50mm f1.4 at 1m -> DoF appr 0.02m at 3m -> DoF appr 0.19m at 10m -> DoF appr 2.16m at 50m -> DoF appr 75.40m at 95m -> DoF ...


4

The earliest investigation of the right constant c that I am aware of is Petzval's 1859 On the camera obscura. The paper is predominantly about a new lens design he has created but he begins with an investigation of the optimum radius of a pinhole for resolution of the image. Resolution is defined as the ability to discern the difference of two very close ...


4

I dont understand Why the heck diaphragm changes only at the moment when the picture is taken its nonsense And I don't understand why you would want to handicap yourself by attempting to create a composition using anything less than 100% of the available light that you can get. What would stopping down the lens actually do for you? At moderate apertures ...


4

Your greycard is not filling the frame. That won't help at all. Fill the entire frame with it. Focus is not important. Right now, you have a huge area of 'not grey' for the system to contend with. The whole idea of the white balance preset is that you present it with a known quantity - an 18% grey field, completely filling the frame, in the lighting you ...


4

The f/2.8 in the name of the lens does not indicate fixed aperture in the sense of not being able to change it - it designates the widest aperture. You should still be able to set it to e.g. f/4 or f/8, but you won't be able to set it to f/2, because the maximum is f/2.8. The sense in which it is "fixed" is that you can use f/2.8 throughout the ...


4

Flat light. That is, light that is either from behind the camera and very close to parallel to the lens' optical axis (such as an on-camera flash) or extremely well diffused such as on an overcast day. Smaller apertures (larger f-numbers) combined with longer focal lengths that force shooting from further away to get the same framing will tend to "...


3

The camera lens is adjustable as to its working diameter. This is accomplished using thin metal leaves that mechanically move -- thus changing the diameter of the circular light entry we call the aperture. This design is taken using the human eye as a model. The colored portion of the human eye has blue, or hazel or brown or green pigment etc. It is called ...


3

The AV (Aperture Value) is an expression that tells how many stops away from f/1 an aperture is. Since f/1 is zero distance from f/1, it has an AV of zero (0) Since f/1.4 is one stop slower than f/1, it has an AV of one (1) Since f/2 is two stops away from f/1, it has an AV of two (2) Since f/2.8 is three stops from f/1, its AV is three (3) ... and so on. ...


3

I am looking for such lenses as well. In general putting the aperture at the front or outside is avoided because not good; best is to put the aperture more or less in the center of the objective. With the aperture in front you'll have more aberrations and/or need bigger and more expensive design. Only in two cases the front aperture design is used: if the ...


3

Yes. That is to be expected. I cannot find the noise to be exceptional in any way. Any tap on the focus button, or any release would pretty much do the same. Note that the focus and aperture behavior on many Sony cams differ from AF-C to AF-S. AF-S always opens up the aperture and then steps down to the set aperture to make AF in low light more precise. ...


3

Different lenses have different behaviours, but as a rule of thumb: if you need maximum sharpness in the center but don't care about corners (for example you are shooting a portrait with shallow DoF), set your aperture to one step higher than lowest available. If you need sharpness across whole frame (typical landscape) start with f/8 and adjust as necessary ...


3

All recent Nikon entry level DSLR cameras, (including the most recent D3500 and D5600) have the option to display the aperture being used as a graphic display. Other Nikon cameras may also have this option. Here is page 208 of the D3500 manual which shows you how to choose this option. Canon entry level cameras have something similar called “Guided Mode”, ...


2

Distant background blur for a 50mm/F1.8 setting exhibits a blur diameter of 50mm/1.8 as measured in the focus plane. What is "distant"? Well, at double the focus plane distance, you already have half of that diameter. So assuming your wave was in focus, how large would a disk of 27mm diameter swimming in your wave appear in the image? That's the diameter ...


2

The biggest problem with repairing Nikon lenses yourself is that Nikon no longer sells replacement parts to anyone outsides Nikon's authorized service network, including third party repair shops. To make matters worse, as of March 31, 2020, Nikon is not renewing agreements with any current Nikon authorized outside repair shops that are not owned by Nikon. ...


2

Maximum recordable resolution based on sensor size and aperture (diffraction); for blue/green/red wavelengths (green being most important). The sensor's resolution is (mostly) irrelevant unless it is less than the diffraction imposed limit. And a perfect lens doesn't matter if it resolves to a resolution greater than the sensor's capability. Taken from ...


2

In my experience, extension tubes for Nikon (compatible with D70-D90 generation cameras and their lenses, at the least) are quite inexpensive, in the range from $30 to $100 for a set of three (three different lengths, can be combined in any combination). This is because there are no optics in the tubes, just carry-through for the electronic contacts and ...


2

Many cameras have the ability to show the image/exposure preview full time while in live view... which includes having the aperture stopped down to the exposure setting. But IMO this is of little benefit; because DOF (depth of field) is a variable that changes with the relative image size (size of image and viewing distance). I.e. trying to judge the final ...


2

The aperture is not affected by crop factor, so the aperture of the 800 mm lens with 2× teleconverter is just ƒ/11. So the image would be darker than the lens without the teleconverter by 2 stops. You would not have an aperture of ƒ/90. If you took an image of a particular subject with a full frame camera on the EF 800 + teleconverter combo, and then used ...


2

What aperture you should use really comes down to what you prioritise. I don't shoot a lot of landscape but for whatever reason I've found that I prefer the lower aperture at times as maybe I don't want everything in the picture to be super sharp, and that takes priority. I think you should set your aperture to what gets you your desired feel rather than aim ...


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