NewBie Here....Explain To Me About The Different Lenses Please...

Ayumi · 26th March 2002

i am currently using a canon elan 7e....
my lense is a ef 28-105 f/3.5-4.5 II usm....
can someone please kindly explain to me the different lenses available in the market????
why is it some 100-300 lenses are cheaper than those 50mm lenses???
whats the difference???
wat does usm mean?
wat does the f/3.5-4.5 mean?
wat does wide-angle lense mean?
TIA

crazyhorse · 26th March 2002

USM stands for ultrasonic motor. Basically it's a motor that has faster and quieter autofocus than non-USM lenses. Some 50mm lenses are very expensive because of the aperture and glass elements. For example, the EF 50mm F1.0L USM costs much more than EF 100-300 F4.5-5.6 USM because of its large max aperture of F1.0 as compared to F4.5 A larger aperture lets more light than a smaller one. Smaller F-numbers let more light in. So, F1.0 lets in much more light than F4.5. Some zoom lenses have variable apertures. So, the 100-300 lens above has a max aperture of F4.5 when the focal length is 100mm, and a max aperture of F5.6 when you zoom to 300mm.

In the 35mm (135) film format, a focal length of 50mm is called a standard lens because the viewing angle is roughly equivalent to the human eye. Lenses which have a focal length of less than 50mm are called wide-angle lenses, while lenses which have a focal length of above 50mm are called telephoto lenses. A wide angle lens has a larger viewing angle which is useful for landscape photography. A telephoto lens magnifies the image which is useful when you can't move close to the subject (like in motor vehicle races).

Ayumi · 26th March 2002

what does letting more light into the lenses help??
clearer pictures at night only???
or any time of the day??
sharper image???

u mean those lenses with less than 50mm focal length....have wide angle capability....it can take in more details??? can i see anything different through the eye-piece??? something like a panorama (SP)?? if yes....does it mean that the camera will squeeze in more details into the photo? doesnt this imply the image will be smaller???

ps..i still dont know the terminology of the camera's components...so if u dont understand what i am talking about....please say so....thanks

tomshen · 26th March 2002

There are many good books about photography in the National Libraries and I found them very informative and systematic for self-learning. Also lots of online sites offer valuable user-based reviews and info. some linkes here:
http://www.dpreview.com
http://www.photographyreview.com/reviewscrx.aspx
http://www.photo.net/bboard/q-and-a-...category=Canon
http://www.luminous-landscape.com

Personally I found digital photography can shorten the learning curve but digital SLRs are still exp as per now. Shooting film forces you think more carefully. Either way, we are told IT'S THE MAN BEHIND THAT BOX MAKES THE DIFFERENCE.

26th March 2002	#1
Ayumi Member Join Date: Mar 2002 Posts: 122	NewBie Here....Explain To Me About The Different Lenses Please... i am currently using a canon elan 7e.... my lense is a ef 28-105 f/3.5-4.5 II usm.... can someone please kindly explain to me the different lenses available in the market???? why is it some 100-300 lenses are cheaper than those 50mm lenses??? whats the difference??? wat does usm mean? wat does the f/3.5-4.5 mean? wat does wide-angle lense mean? TIA

26th March 2002	#2
crazyhorse New Member Join Date: Mar 2002 Location: Singapore Posts: 27	USM stands for ultrasonic motor. Basically it's a motor that has faster and quieter autofocus than non-USM lenses. Some 50mm lenses are very expensive because of the aperture and glass elements. For example, the EF 50mm F1.0L USM costs much more than EF 100-300 F4.5-5.6 USM because of its large max aperture of F1.0 as compared to F4.5 A larger aperture lets more light than a smaller one. Smaller F-numbers let more light in. So, F1.0 lets in much more light than F4.5. Some zoom lenses have variable apertures. So, the 100-300 lens above has a max aperture of F4.5 when the focal length is 100mm, and a max aperture of F5.6 when you zoom to 300mm. In the 35mm (135) film format, a focal length of 50mm is called a standard lens because the viewing angle is roughly equivalent to the human eye. Lenses which have a focal length of less than 50mm are called wide-angle lenses, while lenses which have a focal length of above 50mm are called telephoto lenses. A wide angle lens has a larger viewing angle which is useful for landscape photography. A telephoto lens magnifies the image which is useful when you can't move close to the subject (like in motor vehicle races).

26th March 2002	#4
tomshen Senior Member Join Date: Feb 2002 Posts: 3,719	There are many good books about photography in the National Libraries and I found them very informative and systematic for self-learning. Also lots of online sites offer valuable user-based reviews and info. some linkes here: http://www.dpreview.com http://www.photographyreview.com/reviewscrx.aspx http://www.photo.net/bboard/q-and-a-...category=Canon http://www.luminous-landscape.com Personally I found digital photography can shorten the learning curve but digital SLRs are still exp as per now. Shooting film forces you think more carefully. Either way, we are told IT'S THE MAN BEHIND THAT BOX MAKES THE DIFFERENCE.