Originally posted by gump Accepting that the product of a full-frame will be better than my K-70, my question is how much better?
I think you have asked a great question, and expressed it well. I shoot with a K-3 II and have wondered the same thing.
I don't think that it's practical to compare the products (i.e., image outputs) numerically on a basis of percentages. We really can't say that format X is "n% better" than format Y.
One way to compare the two formats is to consider their final,
printed outputs. Generally, a full-frame camera will offer larger, better quality prints at the same ISO sensitivity.
Here's what
Imaging Resource says about the two cameras. Note that the K-1 allows better prints at higher ISO sensitivities -- perhaps 2 stops worth. Higher ISO settings allow you to take good pictures in lower light at smaller apertures or faster shutter speeds.
K-70:
Pentax K-70 Review - Image Quality Pentax K-70 Print Quality Analysis Terrific 30 x 40 inch prints at ISO 100/200; a good 13 x 19 inch print at ISO 1600; a nice 5 x 7 inch print at ISO 6400.
ISO 100/200 both provide terrific printed images at 30 x 40 inches and larger - as large as you want to print until your resolution tops out. These images showcase crisp fine detail and rich color reproduction, with a nice vibrance throughout the image.
K-1:
Pentax K-1 Review - Image Quality Pentax K-1 Print Quality Analysis Excellent 30 x 40 inch prints and larger at ISO 100/200/400; a good 24 x 36 inch print at ISO 1600; a nice 8 x 10 inch print at ISO 12,800.
ISO 100/200/400 images printed at 30 x 40 inches are simply stunning. The level of fine detail and "pop" in these prints rivals most any model that's passed through our test lab. Wall display prints are possible at larger sizes, until resolution catches up and individual pixels become noticeable, which given the 36.2-megapixel files would not be until very large prints indeed.
- Craig