Crop or cram? Pixel density versus the big view…
Detail section comparisons
Finally, for those who can’t use the bandwidth to view the pBase file (it is pretty exhausting) here are three detail crops. The first crop is a 600 x 400 pixel 100% section of an Alpha 900 file as seen already:
Next, a 600 x 400 pixel crop from an Alpha 700 file which has first been REDUCED to 3960 pixels wide to match the actual size of the A900 APS-C crop:
Finally, a 600 x 400 crop from an Alpha 380 file which has also been REDUCED t 3960 pixels wide:
Allowing for differences between lenses, I feel that the Alpha 380 yields the finest detail and highest sharpness of the three, for a given final output size – the Alpha 700 has the least visible noise, but is also fairly soft in rendering. The 700 image would lend itself best of all to unsharp masking for reproduction.
Here is a different set of three, all taken with the 70-200mm Sigma at 200mm, and all resized this time to match the Alpha 380 – so the A700 and A900 sections are enlarged to 14.2 megapixel equivalent, from 10.7 and 12.2 respectively:
Alpha 380 – native size
Alpha 700 scaled up to match
Alpha 900 scaled up to match. Please remember – none of these files are sharpened for capture, or unsharp masked for web, none have noise reduction applied. I do not believe the softness of the A900 result is due to focus, it’s purely down to enlarging the data that little bit more.
This is not an unexpected result, as the 14.2 megapixel CCD is well-proven for high resolution results. What makes the difference is that the A380 ISO seems slightly understated, and ISO 200 can be used where 250 or 320 would be needed on the 700 for the same midtone brightness. All three cameras do a good job of retaining difficult highlight tones in the cricket whites but overexposure is to be avoided if possible!
– David Kilpatrick
A very interesting comparison……
Three generations of Alpha – ok, well two and a half, because the A100 was the first generation!
The improvements in the image quality are quite interesting to note. The A900 has better quality than the A700, but the A380 is possibly the best for a small resolution image. It would be interesting to see the direct comparison (at 100%) between the three cameras, with the same lens at the same settings. I am sure that the 24Mpx A900 will produce better detail in a print or overall image, because of the relatively smaller pixels, but the A380 may well surprise us all.
Thanks for taking the time to think this one out!
Yes, I think the 14 megapixel sensor is up to the quality of the A100 sensor, probably better. It has a better handling of highlight to shadow range, and more subtle colour. The colour is the biggest difference, some will prefer the A100. I definitely think it could be used in a better body, and the complaints made about high ISO noise are not entirely justified. It can turn in very good results at 400 and 800.
Hi Davie, good article…
what is your opinion about this 14MPx CCD??
Do you think this CCD could be use in a better body??
Do you think this 14MPx CCD can reach the imagen quality of a100 sensor??