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What do lens numbers mean ?

PostPosted: Wed Jul 26, 2006 2:47 pm
by seedyrom
Sorry for the absolutely basic question (I believe im in the right area though)... but i've searched and searched, and come up with so many answers that arent related to what i'm wanting to find out.

I am new. Really new. but what do the numbering differences between a 70-200, and 80-200 and a 80-400 actually mean ?

I note that the price difference between a AF-S 80-200mm f/2.8 IF-ED, and a AF-S VR 70-200mm f/2.8G IF-ED is over a thousand dollars ... and its the 70-200 that is more expensive.
They both have the silent wave motor ... is the VR worth that much extra?
I am assuming 80 is not neccessarily better than a 70.

Will the shots for someone looking to get a lens to take quick photos without much setting up, end up being that much better with a 70-200 ?


I have my flame suit on.

Cheers,
seedy

PostPosted: Wed Jul 26, 2006 2:55 pm
by Ree
numbers-wise...i kinda in the same boat as you but...

VR is for vibration reduction, and that helps reduce camera shake. which equals less shake and less change back!

saying this someone here will post an out of this world reply to help ALL of us who have a kinda understanding of our new toys!

PostPosted: Wed Jul 26, 2006 2:58 pm
by Greg B
OK seedy, focal lengths 101.

Every lens has a focal length, and that focal length tells you the field of view you will get.

A shorter lens, say 28mm, will give you maybe 120 degrees field of view.

A longer lens, say 300mm, will give you maybe 8 degrees field of view.

(I am completely guessing on the numbers here)

A 80-400 lens is a zoom lens which you can adjust from 80mm to 400mm and all lengths in between.

So, the smaller the focal length number, the wider your view.

There is a lot more to it, but this will do for now.

You need to get a book on photographic basics, it will really be helpful for you at this stage of your photography.

PostPosted: Wed Jul 26, 2006 3:01 pm
by Justin
Have a read of what http://www.naturfotograf.com/lens_surv.html says - the first couple of lines about the 70-200VR - '5' rating

A huge improvement over the AFS 80-200/2.8 and the AF 80-400/4.5-5.6 VR lens, this newcomer is a landmark achievement, and is clearly slated to be a legendary Nikkor


But he also notes the 80-200 f2.8 IF-ED would get a '5' if not for the tripod collar :roll:

careful with his reviews as he has reviewed a lot of older models which are easy to confuse.

Th VR is the big difference - but in practice from what I have read, the 70-200 has better bokeh and is better throughout the zoom and is overall a higher quality lens.

With a lens this fast (2.8) I would bo looking for lower light photography - so this is where the VR will really extend the usefulness of the lens. My 18-200VR takes great shots even down to 1/15 at 200mm

Edit: Stubbsy - fixed the url

Re: What do lens numbers mean ?

PostPosted: Wed Jul 26, 2006 3:03 pm
by macka
seedyrom wrote:I am new. Really new. but what do the numbering differences between a 70-200, and 80-200 and a 80-400 actually mean ?


These numbers refer to the focal length.

Check out the examples of different focal lengths on this page:

http://www.luminous-landscape.com/tutorials/focal_lengths.shtml

PostPosted: Wed Jul 26, 2006 3:03 pm
by Greg B
Check out this thread - dozens of handy links to invaluable information

http://www.dslrusers.net/viewtopic.php?t=98

PostPosted: Wed Jul 26, 2006 3:05 pm
by Ree
Greg B wrote:Check out this thread - dozens of handy links to invaluable information

http://www.dslrusers.net/viewtopic.php?t=98



wow! :shock:

PostPosted: Wed Jul 26, 2006 3:06 pm
by spaz
EDIT: I started typing this and there was only one reply!

Don't worry, there's lots of numbers to be confused at. With the example you provided:

80-200mm f/2.8

The numbers preceding the mm are the focal lengths achievable with this lens. An increase in focal length results in increased magnification of the subject and decreased field of view. To judge this realative to something you know, the eyes are approximately the same as a 50mm lens.

As there are two numbers, this lens is a zoom lens (meaning it can change focal length) and has 2.5x zoom (200/80). Hence zoom ratios are useless without knowing the actual focal lengths as a 12-30mm lens would also have the same zoom. A lens that has a set focal length is known as a prime lens.

The numbers after the f/ are the maximum aperture (f-stop) that the lens can achieve. Generally zoom lenses have a different maximum aperture for different places in the focal length range but these more expensive ones are capable of maintaining the same size.

If the aperture size changes it will be written as f/3.5-5.6 for example. For an explanation of what the number means you can read this. You'll see that the number is inversely proportional to the diameter of the aperture. As far as the photos are concerned - lower f-stop means wider aperture so more light (faster shutter speed) and also shorter depth of field

Hope this helped.

PostPosted: Wed Jul 26, 2006 3:07 pm
by gstark
Ree wrote:numbers-wise...i kinda in the same boat as you but...

VR is for vibration reduction, and that helps reduce camera shake. which equals less shake and less change back!


Seedy, Ree,

Ok, great questions, both of you.

Yes, VR means Vibration Reduction, and yes, it helps to reduce camera shake.

First of all, for the Canon users, this feature is called IS, which means Image Stabilisation.

It works by using sensors and computers in the lens. These sense the small movements of your hands as you are trying to get an image, and they anticipate and compensate by moving one or more lens elements to compensate for your movement.

The manufacturers claim up to three stops of exposure may be gained by the use of this facility. That might mean that you may be able to hand-hold a camera for a longer duration shutter speed than what is normally considered to be acceptable, without your image appearing to be affected by camera shake.


VR/IS may be of use in some instances with marginal lighting conditions, but it does nothing to addreess the matter of subject movement. This may or may not be a concern for the photography that you're engaging in; it's simply one tool of any that is now available for your use.

For my part, I have two VR lenses, and I am most impressed with the implementation of the technology, and what it can do.

PostPosted: Wed Jul 26, 2006 3:40 pm
by avkomp
out of idle curiosity seedyrom, wonder where abouts in ermington you live??
you will note that I am also in ermington.

I may be in a position to run over some stuff with you.

Steve

PostPosted: Wed Jul 26, 2006 5:16 pm
by seedyrom
avkomp wrote:out of idle curiosity seedyrom, wonder where abouts in ermington you live??
you will note that I am also in ermington.

I may be in a position to run over some stuff with you.

Steve

Hi Steve.
Not sure how much I should say publicly - I don't know if I need to worry about nasty elements reading this and coming to rob me. I am near Hughes Avenue .... South side of Ermy .. towards the industrial estate.

That being said about security ... you should be careful too ... I think I can see your gear from Google Earth :lol:
Image

PostPosted: Wed Jul 26, 2006 6:11 pm
by avkomp
seedyrom: I am down near there also. around boronia st.

not too worried about google earth seeing that pic, sadly that lens isnt mine and I only had the use of it for the weekend.

I believe he still has it for sale if you are interested!!
600mm f4 (manual focus though) and around 10kg worth of lens

Steve

PostPosted: Wed Jul 26, 2006 6:34 pm
by Gordon
Since it hasnt been mentioned here, keep in mind the relationship between the f/number and the cost of the lens. For every f/stop faster you can usually at least double the cost!

Gordon

PostPosted: Wed Jul 26, 2006 6:45 pm
by gstark
seedyrom wrote:
avkomp wrote:out of idle curiosity seedyrom, wonder where abouts in ermington you live??
you will note that I am also in ermington.

I may be in a position to run over some stuff with you.

Steve

Hi Steve.
Not sure how much I should say publicly - I don't know if I need to worry about nasty elements reading this and coming to rob me


Hey, guys, get a room! :)

Or at least, exchange phone numbers or email addresses via PM, and take it from there.

PostPosted: Wed Jul 26, 2006 6:47 pm
by gstark
Gordon wrote:Since it hasnt been mentioned here, keep in mind the relationship between the f/number and the cost of the lens. For every f/stop faster you can usually at least double the cost!


Which means that a hypothetical Nikkor 70-300G f/2.8 will cost $0.35, :)

PostPosted: Wed Jul 26, 2006 9:13 pm
by Yi-P
Here is some of my brief explanations...

The very first number in a lens with the "mm" is focal length, as other said, this is how FAR or how MUCH you can see. The higher it is, the further you see, the lower it is the more you can see.


The second number with the "F" on it, not that "F" we use normally on the streets ok? Is indication of how big the lens can open up. The smaller the number it is, the bigger the lens can open. And as a general formula, smaller this "F-number" is, the more you will say to the "F-ing" high price. :lol:
At least, im glad the 50/1.8 is a rule breaker. :P

PostPosted: Wed Jul 26, 2006 10:24 pm
by ozimax
gstark wrote:
Gordon wrote:Since it hasnt been mentioned here, keep in mind the relationship between the f/number and the cost of the lens. For every f/stop faster you can usually at least double the cost!


Which means that a hypothetical Nikkor 70-300G f/2.8 will cost $0.35, :)


Which also means that a Tamron 70-300 f5.6 should be about....hang on while I calculate....they have to pay me $460 to take it!! :D Bit like buying a Daewoo or a Kia...(sorry for all the Korean car owners on the forum) :lol: