Questions about "MM"

[Silentwisher]

So how does "mm" convert to actual range. Like 15-88mm equals to how much distance? Just something that I have never known.

[Roll_Program]

It's basically the distance the lens takes to converge the light that enters it.

The more length in millimeters the lens shows, the longer the "zoom" will be.

[url]http://en.wikipedia.org/wiki/Focal_length[/url]

[ep9832]

mm now just refers to the angle of view. For example a 28mm lens gives you an angle of view of 75 degrees (However that's on a full frame sensor/35mm film, it should be wider on larger sensor/film sizes, and tighter on cropped sensor sizes).

[Silentwisher]

Thanks you!

[editline]19th October 2011[/editline]

Also if a lens is say a solid 200mm lens and not a 70-200. Can that 200mm still zoom or is it stuck at that?

[Trogdon]

stuck at it

[Silentwisher]

interesting. So what would the point of those kind of lenses be?

[Trogdon]

let in more light.

[Bek___]

So much light. 500mm f/2.8. SO MUCH LIGHT

[Silentwisher]

Interesting. I have been looking at these lens:

800mm
[url]http://www.usa.canon.com/cusa/consumer/products/cameras/ef_lens_lineup/ef_800mm_f_5_6l_is_usm[/url]
100-400mm
[url]http://www.usa.canon.com/cusa/consumer/products/cameras/ef_lens_lineup/ef_100_400mm_f_4_5_5_6l_is_usm[/url]

I cant decide on which one I should shoot for first. I have watched some videos online but that only helps so much. Any ides on which one I should rent first?

[Bek___]

100 - 400mm. Seems more practical IMO

[Silentwisher]

[QUOTE=iWumbo;32851566]100 - 400mm. Seems more practical IMO[/QUOTE]
Practical how?

FYI: In the future I need something that can pack some serious range. As of right now tho I dont. With that being said alot of people say that the 100-400 push pull system is not a good idea cause I can get dirty easier.

[Bek___]

Well it really depends on what you're shooting. I just think that the 800mm is a bit too far for most things. If you're shooting lions in the wild and are afraid to get mauled. Get the 800.

[Silentwisher]

So lets say...I need to be able to shoot from a football game to a flying object like bald eagle or a plan\helicopter.

[Bek___]

I THINK 400mm should cover it. But I'm not too sure. I don't own a telephoto myself.

[Silentwisher]

O ok. By chance do you own a macro?

[Bek___]

I don't do macro photography. So I do not.

[Silentwisher]

So what lenses do you have? Btw

Im a canon owner. and the only lens I have is the 18-55mm that came with the camera.

[Bek___]

I have the 18-55mm and also the 50mm f/1.8 II. I don't have many lenses. But the 50mm and possibly another 35mm are all I will need for what I do.

[Silentwisher]

Alright I got ya. I was creepin on your flickr and I like alot of the photos you got!

[Bek___]

Thank you very much!

[ep9832]

[QUOTE=Silentwisher;32851678]So lets say...I need to be able to shoot from a football game to a flying object like bald eagle or a plan\helicopter.[/QUOTE]

The 100-400mm should be more than enough. On your camera (assuming you have a Canon APS-C sized sensor) this lens is an equivalent 160-640mm. I wouldn't worry about its smaller aperture if you're doing most of your shooting outdoors.

[Silentwisher]

[QUOTE=ep9832;32852063]The 100-400mm should be more than enough. On your camera (assuming you have a Canon APS-C sized sensor) this lens is an equivalent 160-640mm. I wouldn't worry about its smaller aperture if you're doing most of your shooting outdoors.[/QUOTE] I have a Rebel t2i.

[editline]19th October 2011[/editline]

[QUOTE=NielsGade;32852064]I have a macro[/QUOTE] What is a good starting macro lens?

[Silentwisher]

Insects

[Silentwisher]

[QUOTE=NielsGade;32853719]tamron 70-300mm[/QUOTE]

Alright :) Will look into it :) This will work on a canon correct?

[Trogdon]

yeah just make sure you buy the lens in an EF mount (not F mount). Your camera uses EF lenses

[Silentwisher]

[QUOTE=Trogdon;32864376]yeah just make sure you buy the lens in an EF mount (not F mount). Your camera uses EF lenses[/QUOTE]
Alright thanks for the info :eng101:

[Uber|nooB]

[QUOTE=Silentwisher;32851366]interesting. So what would the point of those kind of lenses be?[/QUOTE]

ones that have just one focal length are called prime lenses. despite the fact that they can't zoom, they generally have advantage in other areas over zooms, such as having less aberration, higher spatial resolution and wider apertures, all because there don't need to have compromises in the optical design that zooms tend to have

for example, say you have a 17-55mm zoom; it's better if it's designed to have alright image quality over the entire range, than, say, really good quality at 55mm and absolutely terrible at 17

[editline]20th October 2011[/editline]

the last point is also why cheap zooms with really huge ranges (like 17-200 or something) don't tend to be that great

[Silentwisher]

So then I come back to 100-400mm lens I see alot of now. Im interested but some people say it starts to under perform towards the 400.