So sánh canon 24 70 và 28 70

These are simply among the highest quality and best performing zoom lenses ever designed and manufactured for full-frame 35mm and digital cameras. The EF 28-70mm f/2.8L lens was superceded by the EF 24-70mm f/2.8L lens. Both lenses are superb, and I hesitated replacing my 28-70 with the 24-70 because the older version of the lens was so good. However, the extra coverage at 24mm is very useful.

I had been skeptical of potentially exaggerated advertising statements from Canon proclaiming in effect that they had made a great L-zoom even better. They improved lens performance in the 24-70mm with respect to sharpness (resolution and 50% MTF [modulation transfer function]) except at 70mm. Linear distortion and chromatic aberration are still mild, but more noticeable in the 24-70 than in the 28-70 if you shoot with a full frame camera such as the EOS-1Ds.

• High resolution and contrast with excellent color Performance meets or exceeds that of non-L prime lenses
• Minimal to mild linear distortion
• Fast autofocus
• Superb construction The price of imaging excellence with these lenses:
• Heavy and large
• Expensive

Resolution and 50% MTF Performance Data

Link to Methods Used

24mm Resolution and 50% MTF are generally higher in the 24-70mm f/2.8L zoom than in the 24mm f/2.8 prime. The zoom has mild barrel distortion at 24mm. Corner sharpness in the EF 24-70mm is better than in the prime.

Linear Distortion

Linear distortion is slightly more severe in the EF 24-70mm lens than the EF 28-80 as would be expected for a wider range zoom. The EF 50mm prime also has linear distortion.

EF 24-70mm f/2.8L EF 28-70mm f/2.8L EF 24mm f/2.8 EF 28mm f/2.8 EF 50mm f/1.4 24mmmild barrel none 28mm negligible barrel negligible barrel none 50mm negligible pin cushion mild pin cushion mild barrel 70mm mild pin cushion mild pin cushion

Chromatic Aberration in Image Corners with EOS-1Ds

Mild lateral chromatic aberration in the far corners of images is a common finding in wide angle lenses used with the EOS-1Ds. The EF 28-70mm f/2.8L outperforms the EF 24-70mm lens in this area. Examples below in the table are from the far left upper corner of this chart.

EF 24-70mm f/2.8L EF 28-70mm f/2.8L EF 24mm f/2.8 EF 28mm f/2.8 EF 50mm f/1.4 24mmmild mild 28mm mild mild moderate 50mm mild none negligible 70mm negligible none

Gallery (mostly with the EF 28-70mm f/2.8L and EOS-1Ds)

Conclusion

The EF 28-70mm f/2.8L and EF 24-70mm f/2.8L are high quality professional zoom lenses that perform better in most cases than non-L prime lenses in their range in producing sharp, contrasty images with excellent color. The L-primes (e.g., EF 35mm f/1.4L) still offer a slightly higher level of performance. The EF 24-70mm offers the advantages of wider perspective at 24mm and generally higher MTF at wide angles than the EF 28-70mm f/2.8L. This better wide angle performance of the EF 24-70 comes at the cost of slightly lower 70mm MTF performance at wide aperture and slightly greater linear distortion and chromatic aberration.

The EF 24-70mm f/2.8L is compared with the EF 24-105mm f/4L IS and the EF 28-135mm f/3.5-5.6 IS lenses here.