Why would i need full frame?

AdamLewis wrote in post #4055864
Hmmm

If Im reading this correctly, http://www.dofmaster.c​om/dofjs.html contradicts what you have to say.

50mm f/1.4. Subject 12m away.
40D DOF = 3.13m total.
5D DOF = 5.08m total.

Sounds to me the SMALLER format will produce the shallower depth of field. Please correct me if Im wrong.

No - because to get the same composition with the 40D and the 5D you need to use an 80 mm lens on the 5D. 30D/50 f/1.4 = 3.13 m; 5D/80 f/1.4=1.91 m.

DoF is influenced by subject distance, aperture, and degree of enlargement. That's why a 50 mm on a 30D will give you shallower DoF than a 50 mm on a 5D at the same distance and aperture. But you'll get the same DoF in the 2 if you crop the 5D photo to match the 30D photo and print the crop and the 30D full negative the same size.

twotimer wrote in post #4056138
In order to get the same composition from the same spot you need to use different focal lengths with a crop and ff camera which is why the dof and bokeh differ between the two sensor types. I think you may not understand that the field of view at any given focal length is totally different between a ff and crop camera which is why I suggested you try taking the photos at the two different focal lengths.

Gerhard

hello ive been saying equivalent all along?!

obviously based on two different focal lengths even with same zoom lens will be different but if it was manufactured perfectly etc and was same all way through the range thered be no difference?

so am i right that with equivalent focal lengths its exaclty the same?

two timer didnt get me...

Guys - quite splitting hairs... all this time debating you could be out taking pictures enjoying your gear - yeeeessh.....

Jon wrote in post #4058455
No - because to get the same composition with the 40D and the 5D you need to use an 80 mm lens on the 5D. 30D/50 f/1.4 = 3.13 m; 5D/80 f/1.4=1.91 m.

DoF is influenced by subject distance, aperture, and degree of enlargement. That's why a 50 mm on a 30D will give you shallower DoF than a 50 mm on a 5D at the same distance and aperture. But you'll get the same DoF in the 2 if you crop the 5D photo to match the 30D photo and print the crop and the 30D full negative the same size.

Ok, I see what youre saying about composition. However, Im just saying for the same lens, the smaller format camera will give you the shallower DOF, correct?

Tobiah wrote in post #4058783
so am i right that with equivalent focal lengths its exaclty the same?

two timer didnt get me...

With equivalent focal lengths, the FOV will be the same.

Like I said, the 20/30/40D or any Rebel, or any 1.6x crop camera with the EF-S 10-22 will provide the same FOV as any full frame camera using the EF 16-35.


However, a closer look at the DOF numbers for those "equivalent" focal lengths shows that the DOF are indeed different.

40D w/ 10-22 @ 22mm f/4 focused 10ft away, Total DOF = 12.3ft
5D w/ 16-35 @ 35mm f/4 focused 10ft away, Total DOF = 6.47ft

So even though the two cameras are providing the same field of view ( composition ) the larger format camera is providing a shallower depth of field.

Summary

Same lens = Smaller format has smaller DOF, but FOV is different
Equivalent lens = Larger format has smaller DOF, but FOV is the same

Jon wrote in post #4058455
No - because to get the same composition with the 40D and the 5D you need to use an 80 mm lens on the 5D. 30D/50 f/1.4 = 3.13 m; 5D/80 f/1.4=1.91 m.

DoF is influenced by subject distance, aperture, and degree of enlargement. That's why a 50 mm on a 30D will give you shallower DoF than a 50 mm on a 5D at the same distance and aperture. But you'll get the same DoF in the 2 if you crop the 5D photo to match the 30D photo and print the crop and the 30D full negative the same size.

YES! I was waiting for someone to get the BIG picture...lol. Thats all it is. A bigger picture. The cropies just blow theres up. That took a while! haha

AdamLewis wrote in post #4060425
With equivalent focal lengths, the FOV will be the same.

Like I said, the 20/30/40D or any Rebel, or any 1.6x crop camera with the EF-S 10-22 will provide the same FOV as any full frame camera using the EF 16-35.

40D w/ 10-22 @ 22mm f/4 focused 10ft away, Total DOF = 12.3ft
5D w/ 16-35 @ 35mm f/4 focused 10ft away, Total DOF = 6.47ft

So even though the two cameras are providing the same field of view ( composition ) the larger format camera is providing a shallower depth of field.

Summary

Same lens = Smaller format has smaller DOF
Equivalent lens = Larger format has smaller DOF

That summary is Ambigously confusing: EF-s lenses change the design similarities between non-crop bodies and crop bodies. It has nothing to do with the optics ratio. ( if you could slap the 10-22 on the the 5D you could just click on page one of this thread to go through it all again...haha)
EF-s lenses do something that no EF lens does. The inside mount elements extend closer to the film plane than normal EF lenses therfore changing the trig. The FF's cant mount those cause the mirror will slap the extended elements ( so ive heard).

DOF has no real world difference between FF and 1.6 crop or 1.3 crop CANON DSLR bodies. They are designed as such. The distance from the end of the last element on a EF lens mounted to any EOS body to its sensor will be ( for the most part lol) identical PERIOD.
Now can someone please explain how depth of field will be different between 5D and a 5D that i went into and sliced up the sensor to look like a 20D's

AdamLewis wrote in post #4060425
With equivalent focal lengths, the FOV will be the same.

Like I said, the 20/30/40D or any Rebel, or any 1.6x crop camera with the EF-S 10-22 will provide the same FOV as any full frame camera using the EF 16-35.

40D w/ 10-22 @ 22mm f/4 focused 10ft away, Total DOF = 12.3ft
5D w/ 16-35 @ 35mm f/4 focused 10ft away, Total DOF = 6.47ft

So even though the two cameras are providing the same field of view ( composition ) the larger format camera is providing a shallower depth of field.

Summary

Same lens = Smaller format has smaller DOF
Equivalent lens = Larger format has smaller DOF

to achieve the same FOV with a FF camera you have to get closer or use a longer lens, either of which results in shallower DOF (1.3 stops).

ed rader

mikeassk wrote in post #4060683
That summary is Ambigously confusing: EF-s lenses change the design similarities between non-crop bodies and crop bodies. It has nothing to do with the optics ratio. ( if you could slap the 10-22 on the the 5D you could just click on page one of this thread to go through it all again...haha)
EF-s lenses do something that no EF lens does. The inside mount elements extend closer to the film plane than normal EF lenses therfore changing the trig. The FF's cant mount those cause the mirror will slap the extended elements ( so ive heard).

DOF has no real world difference between FF and 1.6 crop or 1.3 crop CANON DSLR bodies. They are designed as such. The distance from the end of the last element on a EF lens mounted to any EOS body to its sensor will be ( for the most part lol) identical PERIOD.
Now can someone please explain how depth of field will be different between 5D and a 5D that i went into and sliced up the sensor to look like a 20D's

The shortback focusing has absolutely nothing to do with what Im talking about nor, as far as I can tell, what the OP was wondering.

All Im saying is that an EF-S 10-22 ( Im only using the EF-S part because its an actual lens model. You can omit that if it adds to your confusion ) on a 1.6x crop body will provide you with the exact same FOV as the EF 16-35 on a FF body.

As for DOF not having a real world difference; Go run the numbers at DOF master or check some other links around here. If FOV is the same between a 1.6 crop body and an FF body, DOF will not be the same.

what did I start? all its shown me is I don't need a 5d lol


wonder if the companies will produce L quality glass designed specifically for crop bodies... then that would eliminate I bought a ff so I could use my L glass wide argument...

Tobiah wrote in post #4061094
what did I start? all its shown me is I don't need a 5d lol


wonder if the companies will produce L quality glass designed specifically for crop bodies... then that would eliminate I bought a ff so I could use my L glass wide argument...

EF-S 17-55 and the 10-22 are both as high of quality optically as Canon can make. I own the 17-55 and I love it more than I can say. Nice range ( for a crop body ), f/2.8, and IS...You just cant go wrong.

Tobiah wrote in post #4061094
what did I start? all its shown me is I don't need a 5d lol

wonder if the companies will produce L quality glass designed specifically for crop bodies... then that would eliminate I bought a ff so I could use my L glass wide argument...

You dont NEED a 5D, but if your main interest is landscapes & portraiture then the 5D is about as good as it can get.

Once you use one you realize what you have been missing, I went back to an APS-C body the other day & it was like "what is this small dark viewfinder" sure you can use a 10-22 to get a WA shot, but in my view its not the same, its a make do situation, I have used both systems (1.6x & FF) & I have never seen the level of detail that I am getting now from a 1.6x body, even using the same lens!

AdamLewis wrote in post #4061002
The shortback focusing has absolutely nothing to do with what Im talking about nor, as far as I can tell, what the OP was wondering.

All Im saying is that an EF-S 10-22 ( Im only using the EF-S part because its an actual lens model. You can omit that if it adds to your confusion ) on a 1.6x crop body will provide you with the exact same FOV as the EF 16-35 on a FF body.

As for DOF not having a real world difference; Go run the numbers at DOF master or check some other links around here. If FOV is the same between a 1.6 crop body and an FF body, DOF will not be the same.

RIGHT! IF FOV is the same... FOV should never be the same between these sensors without some tinkering. IE: Lens changing or subject to camera movement... That is the dilema. But under the same distance and lens conditions the DOF will be identical.

[QUOTE=Tobiah;4054786]

I can get as wide as I want with my sigma 10 to 22mm

[QUOTE]

But i could get wider with same lens and 5D ...