full frame


for me i think there is not much difference. anyway if you are considering upgrading to a FF next time, you should get the FF lens. i started using FF lens since i bought my first canon cam 50D.
 

No problem at all since the lens which covers full-frame will completely cover a APS-C sensor. It does the other way round though.
 

wat the down side of using a full frame lens on a non full frame body?

Field of view changes, for a FF lens to use on a APS-C crop sensor you will end up with a narrower view as the lens is meant for FF: 35mm (36*24).

Example : To get the same field of view as a 24mm lens on the full frame camera, you will need a shorter focal length lens (e.g. 16mm for nikon factor in the crop of 1.5) when used with the APS-C crop sensor. In fact if you put that same 24mm lens on a APS-C crop sensor, the angle of view decreases to the extent that it's now the same as that of a 36mm lens mounted on a full frame camera.

Hope this clarifies :)

Upside is most APC sensor will stand to benefit from the sweet spot (sharpness) that FF offers since only the center portion of the FF lens is used.
 

wat the down side of using a full frame lens on a non full frame body?

the downside is you pay extra money and carry extra weight for hardly any benefit :bsmilie:

but it's "future-proof" as claimed by many, in case you decide to buy a full frame camera when the prices fall below $2000... hehehehehe... i ain't holding my breath. DX works just fine for me!
 

The downside is it costs usually abit more than "crop lenses" and is usually heavier. Sometimes the zoom range may be awkward on a crop sensor as well.

IQ wise, its usually great with no downsides especially since you get to use the center of the image circle formed which is usually sharper than the edges.
 

downside is that the cameras are normally heavier :p

other than that i don't see any significant issues since im a wide-standard focal length user.
 

resolution.
FF lens r usually not optimise for the center of the pic.
it really shows when using FF lenses on aps-c body.
 

Huh??
It's often been said that using a full frame lens on an APS-C body allows you to utilize the "sweet spot" of the lens.
This seems to contradict your point, unless I've mis-read...
 

F

Upside is most APC sensor will stand to benefit from the sweet spot (sharpness) that FF offers since only the center portion of the FF lens is used.

This is the biggest advantage of all. :thumbsup:
 

resolution.
FF lens r usually not optimise for the center of the pic.
it really shows when using FF lenses on aps-c body.

Huh??
It's often been said that using a full frame lens on an APS-C body allows you to utilize the "sweet spot" of the lens.
This seems to contradict your point, unless I've mis-read...

You can refer to dpreview website, for certain lens they have reviews for both FF and APS-C DSLR.

For example, the review of Sigma 50mm F1.4, the performance on FF is much better.
for APS-C:
http://www.dpreview.com/lensreviews/sigma_50_1p4_c16/page4.asp

for Full Frame:
http://www.dpreview.com/lensreviews/sigma_50_1p4_c16/page5.asp

I'm no lens scientist but I believe that this is one of the most over-rated "benefit" of APS-C sensors...

Bro bengchiat talked about resolution... lenses which have not-so-high resolving power will show their weakness on a high-mpx crop factor body, whilst may not be obvious to most eyes on a full-frame body.

Rmb, a 1.6x crop factor image is essentially a 33% crop of an image from it's full-frame image size.

The main advantage of a crop-factor body is greater pixel magnification, corner performance (since you're not even using the corner of the FF lens) and less vignetting.

Sharp in the centre does not mean sharper on a crop factor body.
 

Last edited:
I'm no lens scientist but I believe that this is one of the most over-rated "benefit" of APS-C sensors...

Bro bengchiat talked about resolution... lenses which have not-so-high resolving power will show their weakness on a high-mpx crop factor body, whilst may not be obvious to most eyes on a full-frame body.

Rmb, a 1.6x crop factor image is essentially a 33% crop of an image from it's full-frame image size.

The main advantage of a crop-factor body is greater pixel magnification, corner performance (since you're not even using the corner of the FF lens) and less vignetting.

Sharp in the centre does not mean sharper on a crop factor body.

I have to disagree here, FF bodies like the 5DM2 and D3X have even greater pixel density than most "crop" bodies out there which will be a even greater test of the "resolving power" of lenses, especially when edge resolution is taken into account.
 

I have to disagree here, FF bodies like the 5DM2 and D3X have even greater pixel density than most "crop" bodies out there which will be a even greater test of the "resolving power" of lenses, especially when edge resolution is taken into account.

Sabee, I think you are mistakened with regards with full-frame pixel density exceed most crop bodies. However, you are certainly right that corner performance is also a decisive factor, this is usually better on a crop factor body since you only utilise the centre of the lens.

Eos 5DII, 21 mpx - 6.4 µm

Eos 30D, 8.2 mpx- 6.4 µm

Eos 450D, 12.2 mpx - 5.1 µm

Eos 7D, 18 mpx - 4.3 µm

As seen from these values of pixel size, pixel density on a 5DII is lesser than most crop-factor bodies.
 

Sabee, I think you are mistakened with regards with full-frame pixel density exceed most crop bodies. However, you are certainly right that corner performance is also a decisive factor, this is usually better on a crop factor body since you only utilise the centre of the lens.

Eos 5DII, 21 mpx - 6.4 µm

Eos 30D, 8.2 mpx- 6.4 µm

Eos 450D, 12.2 mpx - 5.1 µm

Eos 7D, 18 mpx - 4.3 µm

As seen from these values of pixel size, pixel density on a 5DII is lesser than most crop-factor bodies.

You are right - my math failed me, should have relied on actual pixel density numbers instead.
 

Personally not really a downside for me at all but a plus. Just remember to choose the right len factored in the crop factor for your current APS-C camera. For example, if you need a 50mm len just buy a 35mm FF len. Next time when you upgrade to a FF you already have a 35mm len.
 

Last edited:
I'm no lens scientist but I believe that this is one of the most over-rated "benefit" of APS-C sensors...

Bro bengchiat talked about resolution... lenses which have not-so-high resolving power will show their weakness on a high-mpx crop factor body, whilst may not be obvious to most eyes on a full-frame body.

Rmb, a 1.6x crop factor image is essentially a 33% crop of an image from it's full-frame image size.

The main advantage of a crop-factor body is greater pixel magnification, corner performance (since you're not even using the corner of the FF lens) and less vignetting.

Sharp in the centre does not mean sharper on a crop factor body.

Thanks for pointing that out! :)
Yes, I confused corner performance with resolution...
 

You can refer to dpreview website, for certain lens they have reviews for both FF and APS-C DSLR.

For example, the review of Sigma 50mm F1.4, the performance on FF is much better.
for APS-C:
http://www.dpreview.com/lensreviews/sigma_50_1p4_c16/page4.asp

for Full Frame:
http://www.dpreview.com/lensreviews/sigma_50_1p4_c16/page5.asp

Hmm.. interesting stuffs. I should learn to interpret such charts :thumbsup: