Fuji GFX 100 Studio Test image at DPReview needs a reshoot....

[ErikKaffehr]

Hi,

I have found that Imaging Resource test shots suck. Absolutely useless for sharpness evaluation. The main reason is that slanted edge targets are not flat. Also, the targets used are probably not proper size for sharpness evaluation. For 24x36 mm you would need a target like 100x150 cm, absolutely well aligned. I think IR falls short on that.

Lens gear tests may be better, but sample images (on IR) are simply useless!

Best regards
Erik

Imaging-resource also have their samples up.

[ErikKaffehr]

Hi,

I have had some private communication with Rishi Sanyal. He says that they have not achieved optimal focus. DPReviews will reshoot the image, once they have final firmware from Fuji.

I think that this is a difficult time for testers. Access to test samples are limited while potential buyers are much interested in early results, but early results are error prone.

Best regards
Erik

Hi,

The Fuji GFX 100 holds a lot of promise, offering a modern Sony CMOS sensor at a reasonable 10k$US price point. Therefore I eagerly awaited DPRs studio test image. It seems that there is some serious shortcoming of that test image.




Measuring and plotting MTF indicates that sharpness is worse than on the GFX 50S.

So, what is the problem?

• It could be a bad sample of the lens. I would consider this to be a possible explanation.
• Correct focus has not been achieved.
• Camera vibration?
• IBS causing unsharpness?

From the EXIF, it seems that electronic shutter was used.

I have mailed Rishi Sanyal at DPReview a few days ago, no response yet.

Best regards
Erik

[dmward]

There has also been at least on post on a Fuji rumor site that all the lenses will need a firmware update to accommodate the focusing technology in the 100.
That may have contributed to the problem with the test.

[ErikKaffehr]

Hi,

That may be a good point. When I test lenses I would use an automatic focusing rail, like Stackshot and take images at 2.5 mm intervals. That is useful for finding out things about the lens, but it is not practical in the field.

Finding out maximum performance, fine stepped focus bracketing makes some sense.

Best regards
Erik

There has also been at least on post on a Fuji rumor site that all the lenses will need a firmware update to accommodate the focusing technology in the 100.
That may have contributed to the problem with the test.

[SrMi]

Hi,

I have had some private communication with Rishi Sanyal. He says that they have not achieved optimal focus. DPReviews will reshoot the image, once they have final firmware from Fuji.

I think that this is a difficult time for testers. Access to test samples are limited while potential buyers are much interested in early results, but early results are error prone.

Best regards
Erik

Thank you, Erik, for detecting and reporting the issue with DPR's studio scene.

[ErikKaffehr]

Hi,

What Rishi mailed me, they revised their protocols to assure optimal focus. But he said that the final images had bad focus.

I am not doing lens testing a lot but I learned to use an automated focusing rail and shoot say 40 images 2.5 mm apart to get optimal focus.

With focus by wire focusing, firmware is involved in maintaining focus, especially with linear motors.

Best regards
Erik

I'm glad they confirmed what I suspected, that they mis-focused.

However, this does not alarm me in any way, nor does it trigger any concerns over the Fuji lenses or getting sharp images out of the GFX 100 sensor. I have seen occasional mis-focuses from DP Review tests for years, even on little micro 4/3 sensor 16mp images. So this has nothing to do with increasingly difficult tolerances, lots of pixels, etc.

Over the years, most of the images they produce in that scene have been reasonably, expectedly sharp, just there is the occasional miss. I see this as nothing more than that and DPReview's response confirms that.


Steve Hendrix/CI