What do these Specs mean?

[AussiePup]

I am trying to upgrade my xt kit kens and as I sort through the vast amount of information I was wonder what does the Depth of Angle and Groups / Elements actually mean (in english please :lol: ) and what influence should they have on my decision in comparing lenses? I am by no means ready for any L class lens.

And am I wrong in thinking that the maginfication factor is only important in Macro Lenses?

I appologize in advance if these topics have been covered I could not find anything specific in doing a search.:confused:

Thank you

[Wilt]

>>Depth of Angle<<
...you must have this term bolluxed up!
'Angle of View' is something that is published, about how wide an area is captured.
'Depth of Field' is talked about but not really a single spec as much as a Table full of information.

>> and Groups / Elements <<
...tells you how many individual pieces of glass (elements) which are glued together to make more complex lens design (groups). Probably of interest only to optical engineers!

>> and what influence should they have on my decision in comparing lenses?<<
...none at all. It is a bit like selecting a car because it has a 8 cylinder engine...the car may weigh more and have a less powerful engine than that other car with a 6 cylinder engine! Ignore spec, pay attention to delivered performance, in lenses or cars!

>>maginfication factor is only important in Macro Lenses<<
...Correct

[davidfig]

I'm certain this will start a flame war. But....

One thing you should consider is the number of blades in the iris of the lens. A lens with 6 blades is better then 5 blades. This helps in the area of bokeh. Rats, now I've just opened a can of worms. ;)

[AussiePup]

>>Depth of Angle<<
...you must have this term bolluxed up!
'Angle of View' is something that is published, about how wide an area is captured.


Your right! My brain said one thing and my fingers typed another:o. I did mean angle of view:o.

[peterdoomen]

Here are seven considerations to take into account when buying glass... the number of lens groups is not one of them ;-) Not directly, at least. Sure it impacts optical performance, speed and weight...

http://photography-on-the.net/forum/showthread.php?t=97056

PeteR.

[AussiePup]

I did not see that list.....that is great, I have been banging my head trying to figure out what to get.....very limited budget (about $500) but would like to get a flash too...

Thanks for the list peter.

[peterdoomen]

Well, if you want to get most bang for the buck, you might also want to consult this list of more than 130 lenses available for Canon mount:

http://www.aboriginemundi.com/photo (take the link to the excel file)

P.

[ron chappel]

I'd swap those priorities around on peters list but it's great to see such a thing-choosing lenses can be an incredibly tricky thing.

I'd say -
1.Choose the focal length you want?
2.Have a stab at the image quality you think you want
3. How much do you want to spend?
once these things are decided you have more to to go on (and wether you have to get a prime when you might want a zoom and vise versa).Ask on forums such as this one because certain lenses offer more/are better for the money.

Those things usually narrow it down to just a couple of lenses in each focal length which makes it a whole lot easier;)

And am I wrong in thinking that the maginfication factor is only important in Macro Lenses?
Very close! Magnification and (usually to a lesser extent) working distance are the big two. For example a 50mm macro lens can usually give 1:1 magnification just like the more expensive models-as long as you don't mind the front of the lens being only a couple of inches from the subject.This is why insect pics are easier with longer macro lenses because you are further away from them and they don't get so frightened.

One other aspect of macro lenses that is very important to some is-can the lens be usefull for other uses.For example on a full frame or film camera a 100mm macro lens makes a great portrait lens as well

[peterdoomen]

I'd swap those priorities around on peters list but it's great to see such a thing


That's indeed what you need to do... everyone has their own priorities, so the numbers in de list are more of an index than of an order.

Choosing "the" right lens might indeed be impossible... that's why most of us have more than one and some of us keep on swapping lenses.

P.