To stop down a lens is to reduce the aperture, or increase the f-stop number - reducing the amount of light passing into the camera through by the lens.
This is done: ...
Stop down metering
Techniques Glossary Stop down metering
A TTL metering method that measures the light at the selected aperture .
Stop down
Changing the lens aperture to a smaller opening; for example, from f4 to f5.6. This increases depth of field.
(see Aperture, Depth of field & f-stop)
Stop
(see Aperture & f-stop) ...
Stop down. To decrease the size f the lens aperture. The opposite of open up.
Strobe. See Electronic flash.
Sync (or synchronization cord). an electrical wire that links a flash unit to a camera' shutter release mechanism.
Stop Down
To reduce the size of the Diaphragm in order to decrease Exposure or increase Depth of Field. The opposite of Open Up.
9) Stop down your aperture as much as your lighting situation will allow you to maximize your D.O.F. because depth of field is extremely shallow at 1:1 reproductions. If this is not enough, then increase your lights' output and adjust.
How to stop down
Start by setting your lens to the widest possible aperture (smallest f/stop). This number will vary depending on your lens. Assume your widest aperture is f/4 for the sake of this article.
Stop down to f/8 or f/11. This will turn bright points of light into multi-pointed stars.
Make sure your camera's automatic ISO feature is off, and shoot at the lowest ISO setting your camera has.
Stop down metering - TTL metering in which the light is measured at the picture-taking aperture.
Straight photography - term used to describe picture making with minimal manipulation of the photographic process.
If you stop down more you get sharper results, but if you stop down too far, diffraction gives you softer results, just like squinting your eyes. The very best aperture is someplace between these two, and I'm going to show you how to find it exactly.
As you stop down, wavefront error tends to decrease, though as you can see from the "x/f-stop" formula, diffraction limited resolution also decreases. What this means is that up to some point, stopping down will improve lens performance.
If you can't stop down the aperture you may be forced to shoot wide-open all the time, which would be unfortunate since that's where the lowest quality of the lens tends to be.
Telescope focussing problems and the Scheiner disc.
Visual method: stop down until the most out-of-focus parts look sharp under the lupe.
The first reason to stop down a lens is that the world might simply be too bright.
(You may prefer to stop down one or two f/stops to obtain the critical aperture of the lens for the sharpest image.) Make necessary exposure adjustments by varying the shutter speed.
You need to do that at wide-open aperture and maybe 1 stop down. In the analysis you should be able to find one image where the center is perfectly in-focus and another one where all four corners are in focus (due to the quite common field curvature ...
Program shift counts rear dial or thumb lever commands beyond the point where the aperture is set to its largest or smallest (F2 or F16), and requires those commands to be reversed before it will stop down or open up again ...
The same limitations regarding the necessity of using stop down metering apply to this approach.
You could reduce the aperture by one stop to f-11 (Stop down or close down). Now your film is receiving half as much light as it requires (underexposure).
Compact digital cameras may not be able to stop down more than f/11. But not to fear: the chips used in many smaller sensor camera may equate the f/11 depth of field to an f/22 on a DSLR.
This is a button or lever, which when manipulated, will stop down the lens to the aperture setting selected, allowing you to look through the viewfinder and actually see the depth of field.
Use the f-stop that covers required depth-of-field and don't stop down more than you have to. Smaller f-stops require slower shutter speeds which can cause blurred images due to wind, mirror vibration, and subject movement.
If you are shooting ISO 100 at 1/60 second and stop down from f/8 to f/11 your viewfinder will get darker. If LV = EV at ISO 100, we just went from LV 12 to LV 13 (consult the EV table to check me on this).
. Increase the illumination of the subject to stop down the aperture.
. Don't get any closer to the subject than you have to.
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Some lenses, like PC lens or attachment with a none dedicated bellow on macro photography, stop down exposure metering is required for correct reading. In photography, to decrease the size of aperture in a lens, e.g., to "stop down" from f/3.
to put it simple: when you change the shutterspeed one stop upward, you should change the aperture or the ISO speed one stop downward - as long as you don't use flash.
Then stop down for each exposure, to Æ'/2.8, Æ'/4 and so on, one stop at a time, all the way through to the end.
(2) As a verb, to "stop down" is to decrease exposure by reducing the size of the aperture or increasing shutter speed - e.g. a light meter reading may indicate that you should stop down by three stops for proper exposure.
To prevent the result from being overexposed, you should then stop down the lens aperture by roughly another 1/2 stop.
with tilts and swings allows the plane of focus to be skewed away from the parallel in any direction, which in many cases can bring the image of a subject which is not parallel to the lens plane into near-to-far focus without the need to stop down ...
Usually one can first meter using a larger aperture (so that the metered exposure time is under 30 seconds), then stop down as necessary and multiply the exposure time accordingly.
If you want increased depth of field you "STOP DOWN" the aperture but must compensate by slowing down the shutter speed to let more light in but this might result in subject blur.
Performance is often best at smaller apertures, and some people stop down to at least F8 or smaller with some lenses. Use a higher ISO, for example ISO 400, if necessary to use these small apertures.
It extends in front of and behind your focused subject, and gets deeper in both directions as you "stop down" your lens.
At close distances, depth-of-field is obviously limited even when the lens is well stopped down so focus has to be critical. However, I prefer not to stop down too much anyway because very small apertures can give soft images due to diffraction as ...
Modern cameras view at maximum aperture for the brightest possible image on the ground glass. When they must stop down to a small aperture like f/16 at the moment of exposure, ...
If you need most of your picture to be in sharp focus - such as a landscape scene - then you would "stop down the aperture," i.e. use a small aperture.
Shallow DOF
Great DOF ...
What exposure to use? Should you open up the lens? Should you stop down? What about lighting? Years back, for many photographers it was hard to pose these question, much less know where to go to get an accurate answer.
Changing the lens aperture to a smaller opening; for example, from f/8 to f/11. Some lenses, like PC lens or attachment with a none dedicated bellow on macro photography, stop down exposure metering is required for correct reading.
I have found that using focus lock with my DSLR can still lead to _slightly_ out of focus images. Recomposing your image with the focus locked will shift the focal plane, however slight it may be. If you stop down to f/8 or f/11, ...
For each shot, I would suggest taking three exposures: one based on what the camera tells you is the correct exposure, one a stop up and one a stop down. You never know which one you will like better.
Most of us end up printing larger than this at some point. Therefore, many photographers determine the aperture that the DOF tool indicates will produce the desired DOF. Then, they stop down the lens one stop to add a bit of a safety margin.
Some cameras offer depth-of-field preview buttons, which when pressed, stop down the lens to the selected aperture to show a preview of what's in focus and what's not.
Also a camera accessory that, when inserted between lens and camera body, extends the lens-to-film distance for close focusing or macro photography. Some retain the automatic functions where some have to stop down the lens for manual exposure ...
Knowing this, you could make the intelligent decision to use the first lens wide-open for a shorter shutter speed, to minimize camera shake -- but stop down the second lens, risking camera shake to get rid of the lens softness, ...
 See also: Stop, Aperture, Camera, Lens, Photograph
  
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