full frame and wide angle

Monroe · Jun 5, 2008

Hi,
Being new to photography, I've tried to do some research and I'm still not understanding something so I'm hoping you guys can explain this to me.

A full frame digital sensor like the Canon 5D---am I understanding that you'd actually SEE more in the frame of your shot? If so, why would one need to get a full frame if they had...say... a nice wide angle lens? I do realize that these 2 things probably have nothing to do with eachother, but in just looking at a photo isnt it possible to see the exact same 'framed' photo?

Thank you for your help on this, I really appreciate it.

WDodd · Jun 5, 2008

Say you have a 50mm (which on a 35mm is considered normal, or what you would see with your eyes) on a full frame sensor 5D, your actual focal length would work out to be 50mm. But, on a crop body like the Rebel XT that I have, 50mm works out to be what an 80mm (50mm x 1.6) would look like on a 5D.

I used to use a 24-105 on my film camera and a 18-55 on my XT and at the widest points it would be about the same. But then you get into issues with image quality at the widest points of the lenses, plus the quality of a full frame sensor on a 5D is going to be a lot better.

Hope that clears it up.

tirediron · Jun 5, 2008

What you see in the viewfinder of any camera depends on the lens attached to the camera. What you are referring to is the "crop" factor that affects cameras with less than full-frame (35 neg equivalent size) sensor. This crop is in round terms 1.5x, therefore, a 50mm ("Normal" lens for 35mm/full-frame) will have an effective focal-length of 75mm on a DX framer (most DSLRs except the D3, EOS1D series and 5D). Basically, you get more telephoto for your money, but lose on the wide-angle end.

Looking at a photo, you have no idea of what lens, sensor or anything else was used.

Hope that helps,
~John

Big Mike · Jun 5, 2008

A full frame digital sensor like the Canon 5D---am I understanding that you'd actually SEE more in the frame of your shot? If so, why would one need to get a full frame if they had...say... a nice wide angle lens? I do realize that these 2 things probably have nothing to do with each other, but in just looking at a photo isn't it possible to see the exact same 'framed' photo?

In 'practical' terms...there isn't much difference. If you use a 24mm lens on a 5D or a 35mm L on a 40D...the resulting field of view is pretty close. So yes, if you have a good wide angle lens for your 'crop' camera, then you wouldn't need to get a 5D for it's wide angle abilities.

Actually, this is sort of thinking about thing backwards. It wasn't that long ago that 35mm film was the standard. So a 24mm lens was wide and 17mm was ultra wide. That's they way it was for decades.
Then when DSLR cameras started using APS-C sized sensors, 24mm was no longer very wide and 17mm was only wide, not ultra wide.

Full frame cameras like the 5D, are just giving us back the size of medium that many of us were used to. It's also because many lenses were and still are designed for that size of sensor/film.

There are other advantages of larger sensors. The biggest is probably the image quality and low noise levels. The 5D, the 1Ds mk III and the Nikon D3 all have very good image quality and low noise, even at higher ISO levels.

The problem is that full frame DSLR cameras are still very expensive. The good news is that APS-C sized sensors are getting better all the time. Cameras like the 40D and D300 have outstanding image quality at a much lower price than a full frame camera.

Socrates · Jun 5, 2008

Monroe said:
Hi,
Being new to photography, I've tried to do some research and I'm still not understanding something so I'm hoping you guys can explain this to me.

A full frame digital sensor like the Canon 5D---am I understanding that you'd actually SEE more in the frame of your shot? If so, why would one need to get a full frame if they had...say... a nice wide angle lens? I do realize that these 2 things probably have nothing to do with eachother, but in just looking at a photo isnt it possible to see the exact same 'framed' photo?

Thank you for your help on this, I really appreciate it.

Read these:

http://support.nikontech.com/cgi-bi...T0xJnBfc2VhcmNoX3RleHQ9ZHg*&p_li=&p_topview=1
and
http://support.nikontech.com/cgi-bi...T0xJnBfc2VhcmNoX3RleHQ9ZHg*&p_li=&p_topview=1

Alex_B · Jun 5, 2008

Big Mike said:
In 'practical' terms...there isn't much difference. If you use a 24mm lens on a 5D or a 35mm L on a 40D...the resulting field of view is pretty close.

wrong way round!

24mm on a 40D are similar to 35mm on a 5D !