Entry Level Lens

[Do'Urden's Eyes]

any one mention the EF-S 55-250mm IS? relatively cheap wide range of focal lengths... shouldnt put your price over 800

 

[Overread]

Its a good suggestion though a single word of caution.
The EF-S range of lenses are and well worth getting, but they only work on the canon crop sensor bodies - not on the full frameones. That means that they are also at their focal length as stated on the lens on a crop sensor as they are made specifically for those bodies.

This is not a problem unless you are aiming to build up a good lens set and then go for a fullframe camera body - if that is your intent then this is one lens that won't follow you to the fullframe body - it will remain with you on your cropped sensor camera, so its not going to waste totally.

Just something to consider if you are building up a kit -

 

[Steph]

That means that they are also at their focal length as stated on the lens on a crop sensor as they are made specifically for those bodies.

What do yo mean? Are you implying that the focal length quoted on an EF-S lens is the 35mm equivalent? If that's the case you are wrong. A 55-200mm EF-S lens is equivalent to a 88-320mm on a 35mm camera in terms of field of view. All focal lengths quoted on dSLRs lenses are the true focal lengths, not the 35mm equivalents.

 

[Overread]

That confuses me - I was under the impression that for an EF lens on a crop sensor DSLR would yeald an effective greater focal length than is stated on the lens as a result of the sensor not seeing the whole area captured by the lens - thus leading to the impression that (for a given MP size - thus final photo dimensions) the lens was more zoomed in.
Whilst on a full frame camera DSLR the sensor would see the whole that the lens can capture and (again for the same MP size) thus show a less zoomed in result than on a crop sensor.

Then I thought that as EF-S lenses are made for cropped sensors there would be no artificial zooming as the sensor is seeing the whole that the lens can capture - thus no boost to effective focal length

??

 

[sburatorul]

this problem has been bugging me too. i have a nikkor 18-55mm af-s DX and a 50-200mm af-s DX. I know DX is made specifically for crop factor bodies, so does that mean the focal length is the real one or should i multiply it with 1.5 to get the 35mm equiv.? i'm confused. sorry to pollute the topic but i think this will help all.

 

[Stratman]

Multiply it, BUT, it doesn't make it a longer lens, it just has the same field of view as a longer lens. So a 50 mm lens is 50 mm regardless of what camera you use, but on a crop sensor, it will have the field of view of a 75 mm lens.

 

[Overread]

true - but what about the EF-S lenses which are made for crop sensor -

 

[Stratman]

Makes no difference if the lens was made for a crop sensor or not. The sensor is smaller than film, so the field of view is smaller regardless of what lens you have on the camera.

 

[prodigy2k7]

So what is the difference then in FoV in EF-S and EF in a crop body?

Lets imagine you have a Canon EF 25mm F/1.4 USM
and you also have a brand new EF-S 50mm F/4-5.6 (made up lens)

Would the FoV be the same?

 

[Dao]

So what is the difference then in FoV in EF-S and EF in a crop body?

Lets imagine you have a Canon EF 25mm F/1.4 USM
and you also have a brand new EF-S 50mm F/4-5.6 (made up lens)

Would the FoV be the same?

hee hee .. not to be picky :mrgreen:
But ... the made up lens seems to have problem ... a prime with variable Max. apertures ... Do you mean EF-S 50mm F4?

As for the EF vs EF-S, I believe focal is a focal length. The only different is the Field of view. 50mm lens is always a 50mm lens regardless of whether it is a EF or EF-S lens. Correct me if I am wrong. :blushing:

 

[prodigy2k7]

hee hee .. not to be picky :mrgreen:
But ... the made up lens seems to have problem ... a prime with variable Max. apertures ... Do you mean EF-S 50mm F4?

As for the EF vs EF-S, I believe focal is a focal length. The only different is the Field of view. 50mm lens is always a 50mm lens regardless of whether it is a EF or EF-S lens. Correct me if I am wrong. :blushing:

That is what I am asking, EF vs EF-S
EF 25mm vs EF-S 50mm
Same or diff focal field of view?

 

[Dao]

Well... I believe ..

a EF 50mm and EF-S 50mm (make up lens) will have the same Field of View on a Rebel XT.

 

[prodigy2k7]

Well... I believe ..

a EF 50mm and EF-S 50mm (make up lens) will have the same Field of View on a Rebel XT.

ugh I am just getting more confused.

We know EF-S it closed to the mirror right? But what does that do? In comparison to regular EF...

Like blah im just confused lol...

 

[JustAnEngineer]

The cameras with APS-C size sensors (e.g.: EOS Rebel XSi and EOS 40D) crop the middle out of the image that you would see with a camera with a full-size sensor (e.g.: EOS 5D and EOS 1Ds Mk. III). The lens is still doing the same thing--the camera just captures the middle part of the image. This is the same field of view that you would see if the full-frame camera had a lens with 1.6 times the focal length.

The lens itself does not change when you put it on a different camera.

EF-S lenses only fit on cameras with the APS-C size sensor. If you were able to put them on a camera with a full-frame sensor, the vignetting would be very bad, since the lens doesn't pass a full-frame image.

You might like this article:
http://www.the-digital-picture.com/Canon-Lenses/Field-of-View-Crop-Factor.aspx


Back to the OP's question:
If you get the Rebel XT with the kit EF-S 18-55mm f/3.5-5.6 USM lens, you might consider adding the EF 50mm f/1.8 ($90) and EF-S 55-250mm IS ($265) lenses to it. The 50mm f/1.8 lens will provide sharp images, low-light usability and shallow depth of field, while the 55-250mm lens provides telephoto zoom.

 

[Bifurcator]

Or these too:
http://jimdoty.com/Digital/fov_crop/fov_crop.html
http://www.digitaldingus.com/articles/fov/fovef2.php
http://www.sphoto.com/techinfo/dslrsensors/dslrsensors.htm
http://www.johncornicello.com/articles/sensortalk.html
http://www.tutorial9.net/photography/crop-factor/

Jeez, how many are there that say the same thing?

This looks the most complete: http://www.luminous-landscape.com/essays/Equivalent-Lenses.shtml

luminous landscape has allot of great articles actually - it made my book mark list awhile back.

I think my camera is 1/2 the size of that little tiny one on the bottom-right there.