are APS C lenses suitable for use on FF cameras?

[Isaiahfortythirtyone]

most APSC lenses, e.g. tokina 12-24, tamron 11-18, sigma 10-20 can be used on Full frame cams from a certain focal length.

but i read somewhere on bob atkins that these lenses were not 'designed' to be used on FF cams.

i don't understand this. why is it not 'designed' for FF? is it because APSC lenses have a lower resolving power that cannot match FF sensors?

anyone can explain? :think:

 

[user12343]

tink it's the smaller glass elements (hence smaller image circle) used in these lens that gives strong light fall-off at the corners of the FF cams at certain focal lengths and shd be reduced if the aperture is stopped down a fair bit.

 

[Isaiahfortythirtyone]

anyone else? :think:

 

[Snoweagle]

Those lens you mentioned are similar to the Canon EF-S lens. I've tried mounting my friend's tamron 18-200 Di II on my EOS 30 and it has a dark frame around the image circle and is still visible even at maximum zoom.

As said in the previous post, these lens have a smaller image circle and thus cannot fill the entire frame of a 35mm SLR or a FF DSLR. You can still use these lens to take pics on a FF SLR system but all the pics will have this dark frame around the sides and corners.

 

[Isaiahfortythirtyone]

hmm thats not what i remember with my previous sigma 18-200. i could take pics on my film SLR from abt 25mm onwards. im asking for lenses like the tokina 12-24 and tamron11-18, cos i know these lenses are supposed to be able to take pics on FF from a certain focal length.

assuming that they can cover the whole image circle, woudl the resolving power be high enough for FF?

 

[Ah Pao]

assuming that they can cover the whole image circle, woudl the resolving power be high enough for FF?

That, you will have to consult the MTF charts for the respective lenses for their resolution. The main reason why "digital" lenses cannot be used on FF cameras is because the smaller imaging circle they produce cannot cover the full 35mm frame, and you'll get vignetting.

If you are looking for a cheap way to get wide angle coverage on a FF cam, sorry to say you'll be disappointed because it will cause vignetting at the wider end of the lens - which defeats its purpose if you want to use it on a film SLR.

 

[lsisaxon]

hmm thats not what i remember with my previous sigma 18-200. i could take pics on my film SLR from abt 25mm onwards. im asking for lenses like the tokina 12-24 and tamron11-18, cos i know these lenses are supposed to be able to take pics on FF from a certain focal length.

assuming that they can cover the whole image circle, woudl the resolving power be high enough for FF?

The Sigma 12-24 DG EX is specified for full frame. You may want to consider that. In fact resolving power needs be higher for a smaller sized sensor to achieve the same pixel count because each pixel would have to be smaller.

 

[mpenza]

hmm thats not what i remember with my previous sigma 18-200. i could take pics on my film SLR from abt 25mm onwards. im asking for lenses like the tokina 12-24 and tamron11-18, cos i know these lenses are supposed to be able to take pics on FF from a certain focal length.

assuming that they can cover the whole image circle, woudl the resolving power be high enough for FF?

The centre would be good but the edges on a FF (if there's no vignetting) might not have the contrast, sharpness and resolving power (since they're not designed for FF!).

 

[Isaiahfortythirtyone]

mpenza: yea i think your explanation sounds logical. no la i'm not looking to save money. but rahter, was thinking that if i buy a sigma 10-20mm, it would be nice if i can use on FF from like 15mm onwards etc. guess that was wishful thinking ;p