Photo Jottings

Full frame results using the Sony A900 below.

Check out the differences when using a film or full frame camera below.  I’m only pointing out the noticeable issues as compared to the APS-C bodies, so if I don’t show it here, the results are not significantly different enough to warrant posting an additional set of images in this section.

Light fall-off

Light fall-off is moderate at 70mm, F/4, but it isn’t all that noticeable in real shots, see image below.  One stop down and everything looks good.  No real problems at 400mm F/5.6.

Full image from A900 below.

Here’s a 70mm F/4 shot highlighting the worst of the light fall-off.  It’s hardly noticeable even against a uniform blue sky.  The picture almost looks like an oil painting, why is that?

70mm corner samples next.

The 70mm corners show very gradual improvement up to F/8.  I threw in a center crop for comparison.  Obviously there isn’t as much contrast in the corners, but the results here are still good for full frame, and wouldn’t be noticeable unless greatly enlarged, like I’m doing here.  These crops were taken from the extreme corners, exposure differences are from light fall-off.

400mm corners below.

The 400mm corners sharpen up a little as you stop down, but not much, and there isn’t much difference between the sharpness changes above, and the APS-C shots.  The corners aren’t as sharp as the centers, but they still hold up well, and don’t forget you’re looking at 100% crops of the full image, at normal enlargements or viewing sizes, you’d never see any difference.  You can see the lateral color fringing in the crops above, this type is seen along the edges of the image, and doesn’t go away by stopping down the aperture.

Distortion next.

There is very mild pincushion distortion at the short end, and moderate pincushion as you reach 400mm on the A900.  At full zoom, the distortion looks to be about the same as the Sony 70-300mm G, but less around 70mm.  I’d say this lens does a real good job at controlling distortion.

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Bonus section with comparisons to other Sony lenses!

First, a look at the area covered by 400mm, then 300mm.

Here we see what the difference is between 400mm, and 300mm.  The top row shows 100% crops from the business card taken from 50′ (15m) away.  The second row shows the sharpness difference if you greatly enlarged your shot, say for instance, using your 70-300mm G at 300mm, as opposed to using the extra 100mm length with the 70-400mm.  The texture of bird feathers will really show this difference when you’re up close.  If you don’t enlarge your images, or look at them blown way up on a computer screen, the differences you see above wouldn’t be noticeable.  Both left side images are the same.

The subject above, and below, is a standard sized business card, taken at a distance of about 50′ or  15 meters.

The top row shows the difference between the Sony 70-400mm G lens, and the Sony 70-300mm G, taken at 300mm, F/8 with the A900.

You’ll notice the sharper shots in the middle row when using an APS-C camera, (A700 here) due to the crop factor and pixel density.

The last row shows a big difference when comparing the 70-400mm G with the 500mm F/8 reflex lens.  The huge difference is not as apparent with real subjects at long distances through atmosphere, but the contrast on the 500mm reflex is obviously lower when compared to the 70-400mm @400mm, see larger real-life crops farther down the page.

Sony tele-converter results and recommendations.

The Sony tele-converters seem to provide only a slightly sharper image when compared to an upsized shot with no tele-converter used.  I do this so the image sizes match up and are easier to directly compare.  The difference using the 1.4x is noticeable, but only upon very close inspection, and the same for the 2.0x.  The differences you see here will not be noticeable unless you look at 100% crops, or print huge enlargements.  All images above were taken at 400mm, using the A900.

Please note; the Sony tele-converters are not compatible with auto-focusing on this lens, so you’ll be focusing manually, no easy task, especially without the “type M” screen in your camera.   You’ll also be getting F/8 with a 1.4x, and F/11 using the 2.0x at 400mm.  EXIF data shows the tele-converter used, and the corresponding focal length.  Don’t use the tele-converters much below 400mm, it makes no sense.

Comparison of the Sony 70-400mm G, and the Sony 500mm F/8 reflex below.

Th two 100% crops show the difference between sharpness of the two lenses, even though the 70-400mm G lacks the reach of the 500mm reflex lens.   The 70-400mm G image was upsized to match the 500mm reflex lens image.  The 70-400mm shows more contrast, (check the rock out at lower right) even upsized, which shows either this lens is really good, or the 500mm reflex isn’t so good, or a combination of both.  If I used a 1.4x tele-converter, the 70-400mm would be slightly sharper yet.  People who own the 500mm reflex and purchase the 70-400mm should consider getting rid of their 500mm reflex in my opinion.  The A900 was used in the crops above.  Heat shimmer was present, and the crops above are indicative of the average shot.