Just got a D40

[twilliard]

Hey Scooter

I too have the D40 and it seems that I am LOST in what all this stuff means.
I am looking at buying a different lens for my close up tank shots and for also my kids sports/school events.
The stock lens puts me too close to the shot. I almost have to be on the stage for my kids singing events. Also with the stock lens I cant get close enough to the coral I am shooting.
What does the MM mean in "English" and the F-stop when buying lenses. For example this lens- AF NIKKOR 180mm f/2.8D IF-ED seriously, what the heck is this? When I read this in English it is an Auto focus Nikon 180 what ever with an fixed F-stop of 2.8 IF-ED what ever that is.

I think a good link explaining these in English will help this thread.

$1200 is too much to make a "guess" when buying a new lens.

 

[Damsel13]

The sharpness between a $179.00 camera point and shoot is very apparent. Sharp

 

[MarineTeng]

alright i'll try and explain mm and f-stop the best i can.
mm is millimeters and refers to the focus point i think or length of the lens, what u need to know about it is, it is essentially zoom. for example 18mm is a fairly wide angle lens length and 36mm will be a 2x zoom because u double the length. so really 2x zoom is like 1/4 of the picture in full resolution. i hope that makes sense. So 180 is quite zoomed in. Another thing you can look at on lens specs is angle of view. which is marked in degrees.
f-stops refer to the size of the hole that the camera makes to let light to the sensor. The numbers are all actually 1/f2.8 in cases above. simply put the smaller numbers let in more light, so lenses are titled with the most amount of light they can let in with their f-stop. most cameras max out on the other end of smallest amount of light at f/32 or f/64. now one thing to note about the numbers is the amount of light let in to the numbers is not linear. here is a set of numbers taken from another site
1.4 2.0 2.8 4 5.6 8 11 16 22
now between each of the numbers the amount of light let in is doubled. so f1.4 lets in twice as much light in as f2.0 etc.
now one thing to look at for macro photography is maximum magnification ratio. true macro photography is when that ratio is 1:1. the ratio is describing the ratio of the image projected onto the sensor to the size of the object in real life. so i think pretty much all true macro lenses are fixed focal length (mm), but many zoom lenses claim to be macro lenses, but they don't produce the same ratio, usually 1:2 or even further from 1:1.

a quick note about other abbreviations in the titles of lenses
AF stands for auto focus
AF-S stands for auto focus too but it's faster than AF
HSM/USM hyper/ultra sonic motor even faster AF
IF stands for internal focus which means the front of the lens doesn't rotate when it focuses, helpful when using filters like circular polarizers and such (doesn't matter with UV filters)
ED refers to the type of glass i believe used in the lens, i may be mistaken on this one and don't remember pros/cons and such of it
DX - is a crop ratio thing, quick explaination - there are two types of cameras full format and crop kinds. DX lenses don't work on full format cameras. all lenses work on crop cameras. The D40 is a crop camera. essentially crop cameras just have smaller sensors and the DX lenses are made to put an image on that size of sensor not the bigger full format.
VR/IC/OS/IS - all the same thing, vibration reduction just different names for different brands. there are newer versions for each of them that are more effective then their predecessors.
a great place to look at reviews for camera lenses and such
slrgear.com

 

[Scooterman]

Well said, the only thing I think left would be ISO or sensitivity of the chip, higher ISO the more sensitive it will be, In low light you will need more or higher ISO to get the shot but typically at these high ISO levels you sacrifice quality little grainy over getting a dark picture.

 

[MarineTeng]

o here's a link to some of the pictures i've taken, i used a off brand macro lens Tamron and i've been satisfied with the results thus far, i put the lens i used under each picture
http://atengphotography.deviantart.com/gallery/
also given not all the pictures are from my aquarium, many are from the seattle aquarium

 

[Namyar]

Sorry have been away for a little will read up on the post you gave scooter. I will post more as I practice