asylum1972 Loc: Hilton Head Island, SC

Santa says I've been very naughty this year, but I'm still holding out for a Canon EF 70-200mm f/2.8L II IS Zoom Lens.

In looking over different specs and reviews online, I see mentioned that on a crop body camera, this particular lens is effectively 112mm to 280mm.

Can someone explain to me in layman's terms how that works? Does that mean my crop sensor has more "reach" than a full body sensor?

I currently shoot on a T2i, but looking to complete phase 1 of my upgrade which is lens first, then phase 2 is body second.

Jay Pat Loc: Round Rock, Texas, USA

Photojosh is a poster on this site and writes about photography.
Check out this link (hope it works) and scroll down to where he explains about crop sensor.


http://www.expertphotography.com/a-beginners-guide-to-photography

Pat

GoofyNewfie Loc: Kansas City

Great site- Thanks J Pat
Here is a direct link to that particular question:
http://www.expertphotography.com/5-steps-to-understanding-the-crop-factor

ALYN Loc: Lebanon, Indiana

HUH ?????? Can you put that down to where I can understand it ????
ALYN

GoofyNewfie Loc: Kansas City

If you've never shot 35mm film before this could really be confusing because of the lack of reference.

See the photo below:
Compared to a full-frame (FX) sensor, you're basically "cropping" or using a smaller part of the image when you use a DX or crop sensor. DX lenses are made to only cover the area of the smaller sensor. You'll probably get vignetting (darkeninng of the corners) if you use one on an FX camera, unless it detects that it has a DX lens attached.

If I have a 70-200 lens on a full frame Nikon D-700 it gives about the same angle of view as the 50 -150 Sigma on a D300 (actually 75- 225)

ALYN Loc: Lebanon, Indiana

THANKS ! Been taking pix for 50 years and never knew that. Learn something new every day !
ALYN

GoofyNewfie Loc: Kansas City

I use my DX cameras for shooting sports because of the crop factor. I like the extra reach w/o the weight and size. Portraits and other things where I want less depth of field, I use a full frame sensor. The shorter the lens, the more depth of field. (Not always a good thing) That's why the point & shoot photos look the way they do with everything in focus. The sensors on those cameras are tiny.

Jay Pat Loc: Round Rock, Texas, USA

GoofyNewfie,
Thanks for that post and well said!
Here is a different way off looking at it.

Camera #1 is a full frame sensor camera. This is the more expensive camera, the high dollar camera.

Camera #2 is a crop sensor camera. This is less expensive and is probably more popular.

Take these two cameras and mount a 50mm lens on both.

So, now we will take a picture of the same bridge.

Camera #1 is the blue lines and this is the image it produces (what is sees).

Camera #2 is the red lines and this is the image it produces (what it sees).

For prints, the red frame will be enlarged for prints the same size as camera #1.

This is the difference of the two sensors with the same lens and same scene.

Camera #2 is called a cropped sensor because it sees less of the image that camera #1 sees. The image of camera #1 has been "cropped down" or "zoomed in".

Out in the field, does this mean much? Well, there is a difference. I think the biggest difference is on the wider(lower numbered) end. The lens guys are now making wide angle lens that start out with at 17-18mm and go up.

I'm offering this as a general explaination. In my opinion, a simple explaination as I understand it.

Please keep in mind, my level of expertise is "snapshot guy"...

I hope this helps!!
Pat
*************************************
Now, see you two had a conversation while I was working on this.

GoofyNewfie Loc: Kansas City

That about covers it, and you are correct about the wider end of things. A few milimeters makes a bigger difference there.

asylum1972 Loc: Hilton Head Island, SC

Hey snapshot guy, that was an excellent explanation!! I see that full sensor bodies are still out of my price range. Will go with a higher end crop body when the time comes. Looking at the Canon 7D for my next.

Lucian Loc: From Wales, living in Ohio

It is quite easy to remember and different for each camera but in general, if the sensors are the same the crop factor is the same. So for Canon the factor is 1.6 and for Nikon it is 1.5. That means that the sensor is .6 times the size of a full frame or .5 times the size. Therefore on a Nikon 35mm film camera or full frame digital, the 100mm lens comes out at 100mm but on the Nikon DX or cropped sensor, that will equate to 150mm but that lens ona Canon croped DX sensor, it would give you the effect of having a 160mm lens. Why? Because the sensor is only showing .5 or .6 of the full framed image, so it has the same effect as if you were to enlarge that section (.5 or .6) of that full frame image, so technically it would be an enlargement of a part of that full frame. Make sense?

So a 50mm Nikon lens comes out to be an effective 75mm lens on DX cameras and a 50mm Canon lens comes out to an effective 80mm lens. Same with the zooms, just do the arithmatic of adding .6 or .5 to the number of the zoom range, so a 50-300mm zoom at say, 270mm would be 432mm on a Canon and 405mm on a Nikon DX camera. The benefit of Nikon over Canon sensor is in the wide angle range, it is more of a wide angle with a Nikon camera than with a Canon.

Hope this makes sense to everyone.