Focal length/depth of field/f/stops: What is focal length? What is the focal length of a +2 diopter close-up lens? How much does the addition of a +2 diopter add to the focal length of...

John Brown Loc: New Mexico

What is focal length?
What is the focal length of a +2 diopter close-up lens?
How much does the addition of a +2 diopter add to the focal length of a 100 MM lens?
How can you have a lens that is physically longer than 18 MM and yet have a focal length of only 18 MM?
How many MMs are in an inch?
What is the name of the nearest star?
What is Depth of Field?
What is the depth of field of a pinhole camera?
When you go from f/5.6 to f/8 how have you changes the light value?

JimH Loc: Western South Jersey, USA

Got a test you need to fill out?

For #6 - Define "Star" - Bruce Willis lived up the road for a while..does he count?

traveler90712 Loc: Lake Worth, Fl.

John Brown wrote:

What is focal length?
What is the focal length of a +2 diopter close-up lens?
How much does the addition of a +2 diopter add to the focal length of a 100 MM lens?
How can you have a lens that is physically longer than 18 MM and yet have a focal length of only 18 MM?
How many MMs are in an inch?
What is the name of the nearest star?
What is Depth of Field?
What is the depth of field of a pinhole camera?
When you go from f/5.6 to f/8 how have you changes the light value?

Why the questions?
If your serious about them, I will suggest you first research for you answers first, then if your unable to find them, ask them here, one at a time.

25.4 MM to an inch.
Stars are in Hollywood or it 93 million miles away and it's called SOL

saside Loc: live in pueblo co

John Brown wrote:

What is focal length?
What is the focal length of a +2 diopter close-up lens?
How much does the addition of a +2 diopter add to the focal length of a 100 MM lens?
How can you have a lens that is physically longer than 18 MM and yet have a focal length of only 18 MM?
How many MMs are in an inch?
What is the name of the nearest star?
What is Depth of Field?
What is the depth of field of a pinhole camera?
When you go from f/5.6 to f/8 how have you changes the light value?

For extra credit. Define the universe and give three examples.

JimH Loc: Western South Jersey, USA

saside wrote:

For extra credit. Define the universe and give three examples.

:thumbup: :mrgreen:

Nikonian72 Loc: Chico CA

John Brown wrote:

What is focal length?
What is the focal length of a +2 diopter close-up lens?
How much does the addition of a +2 diopter add to the focal length of a 100 MM lens?
How can you have a lens that is physically longer than 18 MM and yet have a focal length of only 18 MM?
How many MMs are in an inch?
What is the name of the nearest star?
What is Depth of Field?
What is the depth of field of a pinhole camera?
When you go from f/5.6 to f/8 how have you changes the light value?

John Brown, you know the answer to all of these questions! You are just looking to start a debate between wannabe experts. For shame!

P.S. - When you lay M&Ms side-by-side, you can only get 3.5/inch. When you stack them, you can get 6/inch.

JimH Loc: Western South Jersey, USA

Let's have one anyway.. I think there are 25.39999 millimeters to an inch. So there.

:)

traveler90712 Loc: Lake Worth, Fl.

Picky, Picky, picky. :wink:

JimH wrote:

Let's have one anyway.. I think there are 25.39999 millimeters to an inch. So there.

:)

Nikonian72 Loc: Chico CA

JimH wrote:

Let's have one anyway.. I think there are 25.39999 millimeters to an inch. So there.

What did I tell you! Now Sinatraman will chime in, and English Wolf, and Rhino, and Julie, and me!

JimH Loc: Western South Jersey, USA

traveler90712 wrote:

Picky, Picky, picky. :wink:

JimH wrote:

Let's have one anyway.. I think there are 25.39999 millimeters to an inch. So there.
:)

But if I use a UV filter, and shoot in JPEG, then there's 25.4000000000000000000001. Please critique my cat.

JimH Loc: Western South Jersey, USA

Nikonian72 wrote:

JimH wrote:

Let's have one anyway.. I think there are 25.39999 millimeters to an inch. So there.

What did I tell you! Now Sinatraman will chime in, and English Wolf, and Rhino, and Julie, and me!

Where's Roger Allen when you need him.

pounder35 Loc: "Southeast of Disorder"

Since this thread is a waste of time and space I'll add to the waste. I think the formula is the square root of IR x the square root of IL divided by the square root of IR + the square root of IL.

saside Loc: live in pueblo co

Photograhs are all about light and how you use it. Since E=M(C squared) How do I takes a picture of a black hole? Do I have to be massively large? Be extreamly energnitic? or both?

JimH Loc: Western South Jersey, USA

saside wrote:

Photograhs are all about light and how you use it. Since E=M(C squared) How do I takes a picture of a black hole?

Go around to the other side. Like the Polish astronauts, who when queried about the extreme heat dangers of their mission to the Sun, said "It's ok, we're going at night..."

dirtpusher Loc: tulsa oklahoma

love the cat picture
1 in = 25.399999999972568 mm

try this link see it will help answer all that
http://rick_oleson.tripod.com/whatsadiopter.pdf