Hey all you photographer types

[Justin A.]

I think I'm a wee bit lost in reference to aperture settings. I know that the lower the f/#, the more light the aperture allows through, and vice versa. But, what is the point of using a higher f/#, other than some added sharpness? Does it increase/decrease depth of field? I've been hunting diligently elsewhere, but everyone gives the same answer...could I get a human answer here please? Thanks everyone!

[Jack M]

Smaller aperture (bigger f/#, like f/8, f/11, etc) = greater depth of field = more of the scene in focus. Helps improve sharpness of less than perfect lenses.

Larger aperture (smaller f/#, like f/2.8) = less depth of field = less of the scene in focus. This gives you effects like this where the eyes are in focus, but the ears are not.

[Justin A.]

THANK you. It all makes sense now. Every other answer I've seen has been (In my best nasaly professor voice) "The larger the aperture, the more light makes it to the medium, the smaller aperture the less light hits the medium. Each stop is equivalent to doubling the amount of light....blah blah blah" Thank you for your good answer Jack.

[Gecko]

what jack said is correct however what he means is more apperant if you are using Telephoto lenses which have by design a reduced depth of field. Using a wideangle on the other hand you would be hard pressed to achieve a shallow depth of field like his example at any aperature. As a rule of thumb for most lenses, close 2 stops for your sharpest photos.

[fin]

I don't know Jack, your explanation does not cover all circumstances IMHO.

For example, if I was traveling at the speed of light in my car (lightly modified) and decided to take a picture facing backwards what type of light would I expect and what setting to use then?

And what if I was going to take a photo of a photo and wanted to change the focus point on the original photo?

Come on, at least cover all possibilities in your responses. Your this close to being banned.

[Gecko]

I don't know Jack, your explanation does not cover all circumstances IMHO.

For example, if I was traveling at the speed of light in my car (lightly modified) and decided to take a picture facing backwards what type of light would I expect and what setting to use then?

And what if I was going to take a photo of a photo and wanted to change the focus point on the original photo?

Come on, at least cover all possibilities in your responses. Your this close to being banned.

Fin open two stops it back light speed

You can't change the point of focus when you take a picture of a picture...I know this because I have done a few thousand slide copies

Nor for that matter can you see the face of someone you shot's back just by flipping the negative though convincing someone this is is true is both easy and amusing to watch

[Jack M]

For example, if I was traveling at the speed of light in my car (lightly modified) and decided to take a picture facing backwards what type of light would I expect and what setting to use then?

Set your camera on 'P' mode - that stands for "plaid".

And what if I was going to take a photo of a photo and wanted to change the focus point on the original photo?

Brittney's vajayjay will not come in any clearer.

Come on, at least cover all possibilities in your responses. Your this close to being banned.

pssh. ban this!

[Jack M]

As a rule of thumb for most lenses, close 2 stops for your sharpest photos.

I could just google this I'm sure, but this way is more fun. I'm pretty sure a "stop" is double or half the light of the next stop, right? But what does this equate too in terms of shutter speed and aperture?

Assuming a constant shutter speed, is going from f/2 to f/4 one stop? And assuming a constant aperture, is going from 1/60 to 1/120 one stop?

(bad example, I don't think 1/120 exists on most cameras, but you get the point)

[bjvircks]

be careful about diminishing returns... as you stop down aperature to gain depth of field your shutter speed needs to get slower to get an equivalent exposure. This introduces the possibility of camera shake spoiling the image if you are a shutter button puncher, not too stable to begin with, had too much coffee, using a long lens to spy on the gal across the street. (oops... too much info... ) Finding the right blend of aperature and shutter speed can be an art.

edit: what does the 'B' shutter speed setting stand for? 'Bonehead' for trying this setting??? (hint: has to do with air)

[Jack M]

edit: what does the 'B' shutter speed setting stand for? 'Bonehead' for trying this setting??? (hint: has to do with air)

Bulb. Shutter stays open as long as you hold the shutter button down. Not sure why this is called "bulb" and not "hold" though.

[bjvircks]

DING DING DING we have a winner! Bulb is the correct answer!

comes from the days when shutters were held open for LONG exposures by air pressure created by the photographer squeezing a bulb attached to a thin tube which ran over to the shutter mechanism. This isolated the camera from the photographer's movements.

I used this kind of thing years ago when I mounted cameras out on the wingtips of hang gliders. I had to be certain to allow some 'bleed' or else rapid altitude changes would sometimes use up all my film without me knowing.

BJV

[Gecko]

Jack what I should have said is most lenses sharpest photos are shot closed 2 stops from the widest aperture. So if it's a 2.8 lens then optimal sharpness would be 5.6...and no opening from f2.0 to F4 is 2 stops not 1 as 2.8 is between those on any lens F2.0 or faster...As a USN Photographer I have spent a lot of time doing equivalent exposures in my head along with plotting IFGA aerial photos and many other photo related things. I often tend to gloss over steps because I forget that most people don't think photographer as part of their day.

B= Bulb which is a setting to manually control the shutter speed. Good for doing night shots where you shoot for seconds to minutes. And on digital camera Bulb is mostly done by remote :D

Edit another challenge for you...tell me what lens is needed on a Nikon D200 to shoot an aircraft carrier from a distance of 2 miles, and what altitude does the aircraft need to be/fly at? I've plotted this enough times that I use it to go to sleep at times...my wife has learned not to ask (what are you thinking about)

[wavechaser]

comes from the days when shutters were held open for LONG exposures by air pressure created by the photographer squeezing a bulb attached to a thin tube which ran over to the shutter mechanism.

I have always been told that "bulb" (B) came from when shutters were not yet synched to flash "bulbs" so the lens had to be held open (by any means) while the flash was fired.

[Jack M]

Edit another challenge for you...tell me what lens is needed on a Nikon D200 to shoot an aircraft carrier from a distance of 2 miles

You'd need a Canon for that. :p

[Justin A.]

Edit another challenge for you...tell me what lens is needed on a Nikon D200 to shoot an aircraft carrier from a distance of 2 miles, and what altitude does the aircraft need to be/fly at?

I don't know, but I do know that the vigenetting of this kit lens that came with my D70s is sure dissapointing :( . Upgrade ahead.

[Gecko]

You'd need a Canon for that. :p

OK wise guy...I chose a D200 because I knew the chip size and could use that in the computations but since you went the Nikon Vs Canon war. Everything else the same and use a Canon EOS 5D. Just as a hint the altitude could be the same or the lens length but not both....

Justin...what filter do you have on the 18-70mm? you have to use a thin ring filter or it will indeed vignette. I love that lens though as it does more than any lens I have used other than the Sigma 18-125mm

[Justin A.]

I have a Quantaray qmc-1A on the lens. It does look a little bit thick, I didn't even think that it could be the filter's fault. Any sugguestions for a non-vigenetting filter?

A Few Examples of said Vigenetting.

[wavechaser]

That dog face shot should be the photo contest next month! :lol:

[Gecko]

yeah that looks like it's the filter ring, but an easy way to check is to remove it and shoot a bit...all I can recommend is to go to a good camera shop and look at a number of filters. find one with a thin ring that works for you and your budget (B&W filters don't fit anyones budget)

[bjvircks]

Air bulb shutter control significantly predates 'flash bulbs'. Think of large glass plates, manually applied emulsions, full daylight exposures taking several seconds.

[Vahur]

I have a Quantaray qmc-1A on the lens. It does look a little bit thick, I didn't even think that it could be the filter's fault.

It's lens fault actually, as vignetting exists even without filter. DX design is at fault here (but not only, as I've observed quite strong vignetting also with Nikon's AF-S 24-120 VR lens, which is full frame lens. ).

If you shoot NEF and have Nikon's Capture/Capture NX, then it can be eliminated quite easily (probably other software can be used as well, but no personal experience here).

This vignetting was main reason, why I sold my kit lens along with D70 (upgraded to D200 ).

[Gecko]

I shoot NEF/RAW and always crop wideangles to fit so I truely may not have noticed...then again if I'm shooting below 24mm I tend to use my 12-24mm Sigma

BTW I can't believe no one has even tried my challenge...it's only a little math/geometry/trig