3 quick questions

iPhoto17 · May 9, 2012

1. when i went to get my new lens the guy at wolf camera told me about the symbol on my camera that tells me where the film would be if it were a film camera, why exactly would i need to know where the film would be if it were a film camera?

2. how water proof/resistant are the nikon DSLR's? i bought the D3000 a few years ago and only taken it out in dry weather, its been raining a lot here lately and would love to get some rain shots before it all dries up.

3. my dad was telling me about a magnifying ring of some sort he put between the body and the lens of the camera that zooms, do they make such things for the D3000? the moon has been fairly large lately and i got some good shots with my 200mm but i dont want to shell out money for a 700mm right now.

thanks in advance

Trever1t · May 9, 2012

1) WTF?
2) Put it in a plastic bag...the consumer cameras are not weather sealed.
3) Teleconverter.

480sparky · May 9, 2012

iPhoto17 said:
1. when i went to get my new lens the guy at wolf camera told me about the symbol on my camera that tells me where the film would be if it were a film camera, why exactly would i need to know where the film would be if it were a film camera?......

To find the nodal point when shooting panos.

Josh66 · May 9, 2012

iPhoto17 said:
1. when i went to get my new lens the guy at wolf camera told me about the symbol on my camera that tells me where the film would be if it were a film camera, why exactly would i need to know where the film would be if it were a film camera?

This mark tells you were the film/sensor plane is. This is where you measure from when you want to know (for example) how far away the minimum focus distance is. It should be on any DSLRs too.

It looks sort of like the symbol for diameter - a circle with a line through it. It's probably on the top of the body, near the prism somewhere.

edit
You can see it right next to the hotshoe in this picture:

IMG_9161 by J E, on Flickr

And next to the strap on the left side in this one:

PC290621 by J E, on Flickr

iPhoto17 · May 9, 2012

so that kind of helps direct you if you need to focus on something close by then?

on that first picture is that a film camera or digital? because my film SLR doesnt have the symbol

Josh66 · May 9, 2012

You have a D3000?

Nikon D3000 DSLR Review - Handling & Feel - Nikon Digital Cameras - Photoxels

Scroll down to the picture of the top of the camera. That mark is right by the right thumb wheel (close to where the strap attaches).

edit
Both of the pictures in my post are film cameras.

iPhoto17 · May 9, 2012

O|||||||O said:
You have a D3000?

Nikon D3000 DSLR Review - Handling & Feel - Nikon Digital Cameras - Photoxels

Scroll down to the picture of the top of the camera. That mark is right by the right thumb wheel (close to where the strap attaches).

yeah, i was just wondering what the symbol was good for

Josh66 · May 9, 2012

It tells you where the film/sensor plane is. Any time you need to know where that is, that's how you know.

Like, if you had a macro lens, and you were trying to figure out how much working room you would have with it. Say the lens has a minimum focusing distance of 10 inches ... you would measure that from that line, not the front of the lens.
Or, say you're trying to set some shot up, and you need the camera to be a specific distance away from the subject - that line is what you would take your measurements from.

Honestly, I rarely use that mark for anything - but if you ever had some reason that you needed to know where the film plane was, that mark shows you.
If you have a film camera that doesn't have that mark, it should be pretty easy to guess where it is. Open the back and look at how thick it is from the back of the camera to the front of the pressure plate. Knowing that, you should be able to get a pretty good idea where the film plane is on that camera.

Josh66 · May 9, 2012

What was the context of your conversation with the guy at the store? Was he just bragging that he knew what that mark was or something?

iPhoto17 · May 9, 2012

O|||||||O said:
What was the context of your conversation with the guy at the store? Was he just bragging that he knew what that mark was or something?

thats what it pretty much sounded like to me because i didnt even ask about the mark to begin with, i was just testing out a couple lenses before i bought one

iPhoto17 · May 9, 2012

O|||||||O said:
It tells you where the film/sensor plane is. Any time you need to know where that is, that's how you know.

Like, if you had a macro lens, and you were trying to figure out how much working room you would have with it. Say the lens has a minimum focusing distance of 10 inches ... you would measure that from that line, not the front of the lens.
Or, say you're trying to set some shot up, and you need the camera to be a specific distance away from the subject - that line is what you would take your measurements from.

Honestly, I rarely use that mark for anything - but if you ever had some reason that you needed to know where the film plane was, that mark shows you.
If you have a film camera that doesn't have that mark, it should be pretty easy to guess where it is. Open the back and look at how thick it is from the back of the camera to the front of the pressure plate. Knowing that, you should be able to get a pretty good idea where the film plane is on that camera.

this is the best explanation ive heard, this makes perfect sense to me, in my pentax k1000 the pressure place is very close to the back where the back opens