IQ difference between 44x33 CMOS and 24x36 CMOS

[DougDolde]

The problem I have found with really big prints, say 36x48 is the cost of framing.  Unless you are doing frameless canvas wraps it becomes very expensive and challenging.  Yes I do frameless canvas wraps and it's a good solution.

However I find smaller prints sell better because you can keep the price down.  Most people that buy in galleries are quite price sensitive.  And most galleries have size limits as well so you may be limited to showing only one really big piece versus two or three smaller ones.

I know for some people with BIG reputations this isn't such a big issue, but for me it is..

[cgarnerhome]

Real world for me is as follows. When I’m shooting in the field I usually leave some extra space around the subject to give me more flexibility in post processing.  If I’m shooting with a fixed focal length lens I may have to shoot even wider than I would like.  In addition, I might do a square crop or more cropping than I planned.  I also want the flexibility to print large.  Given all that, I find I almost never use my Nikon 850 and almost exclusively use my XF100.  In my case, 100Mpix is important. It’s not always about theory it’s about what works for you.

[Doug Peterson]

It’s not always about theory it’s about what works for you.

+1 except I would modify it to: "It's almost never about theory. It's about what works for you."

[eronald]

+1 except I would modify it to: "It's almost never about theory. It's about what works for you."

O learned Phase rep, pray tell us, did Phase also get some optimisations with the 50c chip?

Edmund

[siddhaarta]

O learned Phase rep, pray tell us, did Phase also get some optimisations with the 50c chip?

Edmund

According to this ... DR Fuji GFX vs. P1 Q250

... at least they seem to have squeezed more DR out of the same sensor .. or is there a problem with real ISO vs ISO setting??

[bjanes]

According to this ... DR Fuji GFX vs. P1 Q250

... at least they seem to have squeezed more DR out of the same sensor .. or is there a problem with real ISO vs ISO setting??

I don't think so. The Phase curves are shifted to the right, ? something to do with ISO amplification. The base ISO for the Fuji is 11.9 stops at ISO 100 and the Phase One is 11.92 stops at ISO 200. No significant difference in DR. However, there is a significant difference in price. A quick check on the web indicates that the P1 is US $35,000, whereas the Fuji is $5850. IMHO, the P1 is vastly overpriced.

Regards,

Bill

[bjanes]

*Of course you can print a grainy 35mm neg to 4 meters if you want. Anything can print any size, especially if you restrict viewing distance (as with a billboard ad). Here I mean "and still look good when viewed close up".

Why do you bring up printing from a grainy 35 mm negative? The thread is about comparing two CMOS sensors.

Bill

[Steve Hendrix]

I don't think so. The Phase curves are shifted to the right, ? something to do with ISO amplification. The base ISO for the Fuji is 11.9 stops at ISO 100 and the Phase One is 11.92 stops at ISO 200. No significant difference in DR. However, there is a significant difference in price. A quick check on the web indicates that the P1 is US $35,000, whereas the Fuji is $5850. IMHO, the P1 is vastly overpriced.

Regards,

Bill

Bill, I can't blame you for not being able to find an accurate price for 50mp Phase One options - Phase One pricing has often been a moving target:

https://captureintegration.com/phase-one-2018-summer-specials/
https://www.digitalback.com/product/phase-one-iq3-50mp/

$14,990 - IQ150/XF Kit w/80mm Schneider Lens
$26,990 - IQ350/XF Kit w/80mm Schneider Lens

Still quite a bit higher, but I think it is fair to the readers to inform them they don't have to spend $30,000 more than a Fuji GFX to get into a Phase One 50mp system, should they want to.


Steve Hendrix/CI

[ErikKaffehr]

Hi Bill,

Bill Claff's data use nominal ISO.

On older backs that DxO-mark has measured Phase One always overrated ISO by about one stop, probably in order to protect highlights.

That is probably what we see in the histogram on the Phase One DR is constant over 100 and 200 ISO.

Best regards
Erik

I don't think so. The Phase curves are shifted to the right, ? something to do with ISO amplification. The base ISO for the Fuji is 11.9 stops at ISO 100 and the Phase One is 11.92 stops at ISO 200. No significant difference in DR. However, there is a significant difference in price. A quick check on the web indicates that the P1 is US $35,000, whereas the Fuji is $5850. IMHO, the P1 is vastly overpriced.

Regards,

Bill

[ErikKaffehr]

Hi,

Note that DR is the same at ISO 100 and ISO 200. That essentially means that the both nominal ISO values are the same.

Best regards
Erik

According to this ... DR Fuji GFX vs. P1 Q250

... at least they seem to have squeezed more DR out of the same sensor .. or is there a problem with real ISO vs ISO setting??

[ErikKaffehr]

Hi Bill,

In Sweden we have the same dealer for Hassy, Phase and Fuji. Prices here in Sweden are:

Fuji GFX, body only: 69 995,00
Hasselblad X1D body only: 74 995,00
PHASE ONE XF IQ1 50MP: 258 750,00

The prices include Swedish sales tax and 1 SEK is 0.11 USD

Best regards
Erik

I don't think so. The Phase curves are shifted to the right, ? something to do with ISO amplification. The base ISO for the Fuji is 11.9 stops at ISO 100 and the Phase One is 11.92 stops at ISO 200. No significant difference in DR. However, there is a significant difference in price. A quick check on the web indicates that the P1 is US $35,000, whereas the Fuji is $5850. IMHO, the P1 is vastly overpriced.

Regards,

Bill

[ErikKaffehr]

Hi,

Being the OP, I would say this thread was intended to discuss the differences between 44x33 mm CMOS and 24x36 mm CMOS.

Not really stated, but the starting point was to compare the present generation of mirrorless DMF to best of breed 24x36 mm. It was also the idea of focusing on things observable or measurable.

The original posting indicated that:

• There was an observable difference between Sony A7rII and Fuji GFX in 40"x60", based on one of the few comparable images DP-review has published. This was expected.
• Comparing the Nikon D850 with the X1D, it was found that the X1D had a measurable advantage, like 20% linear scale. That was also expected.
• Some of the observed/measured advantage comes from the aspect ratio.

I would have expected lens quality to play a greater role than what the MTF calculations yielded. In part, that depended on that the lens used on the Nikon was quite good. The DPReview test chart has only slanted edges in the central part.

I would suggest that many posters under rate the importance of pixel size and pixel pitch. After all, it is the pixels that carry the information.

When 44x33 mm MFD goes 100MP, I would think we would see major improvement in image quality. It seems that both the X1D lenses and the GFX lenses are excellent designs. This assumption is based on the MTF data Hasselblad publishes for the lenses, Hasselblad's MTF data used to be reliable and on Jim Kasson's evaluation of Fuji lenses.

Best regards
Erik

[eronald]

Hi,

Being the OP, I would say this thread was intended to discuss the differences between 44x33 mm CMOS and 24x36 mm CMOS.

Not really stated, but the starting point was to compare the present generation of mirrorless DMF to best of breed 24x36 mm. It was also the idea of focusing on things observable or measurable.

The original posting indicated that:

• There was an observable difference between Sony A7rII and Fuji GFX in 40"x60", based on one of the few comparable images DP-review has published. This was expected.
• Comparing the Nikon D850 with the X1D, it was found that the X1D had a measurable advantage, like 20% linear scale. That was also expected.
• Some of the observed/measured advantage comes from the aspect ratio.

I would have expected lens quality to play a greater role than what the MTF calculations yielded. In part, that depended on that the lens used on the Nikon was quite good. The DPReview test chart has only slanted edges in the central part.

I would suggest that many posters under rate the importance of pixel size and pixel pitch. After all, it is the pixels that carry the information.

When 44x33 mm MFD goes 100MP, I would think we would see major improvement in image quality. It seems that both the X1D lenses and the GFX lenses are excellent designs. This assumption is based on the MTF data Hasselblad publishes for the lenses, Hasselblad's MTF data used to be reliable and on Jim Kasson's evaluation of Fuji lenses.

Best regards
Erik

I would say the Fuji has a 1 to 2 generation advantage in crispness over its 35mm rivals in the vegetation images published, this may be due to Fuji's manipulation of the fill factor as much as the sensor size. So I think the Fuji is more like an 80MP 35mm camera.

It's NOT obvious Hassy or Phase are the same. We would benefit from creating a serious thread/forum to discuss image quality assessment. I think enough people here are interested.

Edmund

[bjanes]

Hi Bill,

Bill Claff's data use nominal ISO.

On older backs that DxO-mark has measured Phase One always overrated ISO by about one stop, probably in order to protect highlights.

That is probably what we see in the histogram on the Phase One DR is constant over 100 and 200 ISO.

Best regards
Erik

Erik,

Thanks for the comment on ISO. DXO uses Ssat for their ISO measurements as documented here. This corresponds to ISO 12232:1998 and is what I think should be used for serious work with raw files. The 2006 versions added REI (recommended exposure index) which allows the manufacturer to use any arbitrary value that they desire, but is supposed to be used only with sRGB rendered files. As you state, Phase One often assigns a higher ISO, presumably to protect the highlights.

As you stated, Bill Claff uses the  manufacturer's nominal values.

On his charts the open circles for ISO indicate values beyond the normal analog range (fake ISOs). For Example, the base ISO of the Nikon D850 is 64, but ISOs of 50, 40 and 31 are offered and are shown as open circles on Bill's graph. On the DXO plots the DR for these fake ISOs do not change as with Bill's plots. These are merely overexposure and do not affect the ISO amplification or dynamic range. The Phase One offers a fake ISO of 100 as indicated by the open circle. The plot is shifted to the right because of the ISO manipulation to preserve highlights, and this does not indicate better DR.

I hope this clarifies the situation for some readers.

Best regards,

Bill

[ErikKaffehr]

Hi Edmund,

I would agree with your description on the crispness of the grass. But, I would attribute it to two different factors:



The other factor is that it seems that most GFX lenses are extremely sharp, at least according to Jim Kasson's testing.

• The GFX has significantly more vertical pixels. Once you start to interpolate an image it will be fuzzy. The Image I have shown was interpolated to 7087 vertical pixels. Starting with 6192 pixels is a much better starting point than 5304 pixels. For that reason the GFX image is less fuzzy.
• The other factor is that it seems that most GFX lenses are extremely sharp, at least according to Jim Kasson's testing.

Any camera with the Sony 44x33 would merit from the extra pixels.

Lenses are a different thing. As far as I can recall, Jim Kasson used to have a Hasselblad H3D39 which probably had the same 49x37 mm sensor my P45+ has. So far I know he has sold it.

But, before selling the H-system, he also tested some of his HC-lenses on the GFX and they performed far below the GF-lenses.

I would assume that GF lenses are sharper on 44x33 mm than the HC lenses on 44x33 mm. They are designed for a larger sensor. My understanding is that optical performance scales with dimension. So if you scale down a lens by a factor of two it will perform twice at good in lp/mm terms.

So, I would not expect H6D50c perform at the same level as the X1D.

This was seen a bit in a comparison I made with DPReview test images. The Pentax 645Z was quite close to the Sony A7rII in that comparison, even if it was paired with one of Pentax latest generation lenses (90 macro using ED-glass). Diglloyd found similar. The Pentax 645Z was not superior to the Sony A7r, with the lenses that he tested.

Phase One claims that their German lens design are superior (*), that may be the case. But, it seems that they are pretty classic designs, while the smaller formats have moved on more advanced designs. I started a discussion on that at DPReview: https://www.dpreview.com/forums/post/61114409

This posting may be of particular interest: https://www.dpreview.com/forums/post/61122175

The way I see it, the GFX offers significant image quality potential at a reasonable cost. It is priced like "pro bodies" from Canon and Nikon and lens prices are a bit like Sony's G-Master series.

Furthermore, I think that the GFX has a lot of potential for the next generation Sony sensor at 100MP.

The X1D is a bit more expensive, especially on the lens side, but I guess it has the same potential as the GFX.

The final question is if all that image quality is needed and if photographers can take full advantage of it.

The way I see it, if a Panasonic G9 is good enough for my needs, I will see little advantage from my A7rII. Would Sony release a 60-70 MP body in the A# series, I am not sure I would buy.

It can be smarter to spend the money on lenses or travel...

Best regards
Erik

I would say the Fuji has a 1 to 2 generation advantage in crispness over its 35mm rivals in the vegetation images published, this may be due to Fuji's manipulation of the fill factor as much as the sensor size. So I think the Fuji is more like an 80MP 35mm camera.

It's NOT obvious Hassy or Phase are the same. We would benefit from creating a serious thread/forum to discuss image quality assessment. I think enough people here are interested.

Edmund

[eronald]

Hi Edmund,

I would agree with your description on the crispness of the grass. But, I would attribute it to two different factors:


Best regards
Erik

It's not just the grass, it's the vegetation of that test on Jim's links.
I think it's partly the reduced fill - ie less low-pass smearing, described on the Sony link you kindly provided.

We should open a thread on technical issues and image quality to discuss this.
As it stands, if my conjecture on the meaning of this Fuji announcement is correct the Fuji may be substantially sharper than the Hassy, with the same lens.

Edmund

[vjbelle]

Not having used or tested the Hassy lenses for the X1D I can attest that the GFX lenses that I own are the sharpest I have seen using any of my layman tests.  This includes any Otus lens that I have owned and all of my large format lenses ( Schneider Digitars ).  The differences between my Digitar lenses and the GFX lenses is visible at 100% pixels but very subtle.  So at 100% pixels some difference can be seen at best apertures (f5.6 for GFX, f8-10 for Digitars).  Again, I want to stress these differences are visually very small.  I print 40 inches long side all of the time..... would I see this difference?  Never......  Hope this puts things into some perspective. 

Victor

[ErikKaffehr]

Hi,

Thanks for sharing. Just a few comments...

If a lens reaches maximum performance at f/5.6 it is a pretty strong indicator that is is sharper than a lens reaching maximum performance at f/11. The reason is that diffraction is the factor limiting a lens when stopping down and diffraction is just a function of aperture. So if a lens reaches optimum at f/5.6, it is by definition sharper than a lens reaching maximum performance at f/11.

That said, the lens reaching optimum at f/11 can still outperform a lens that is optimal at f/5.6, if it is combined with a better sensor.

The comparison I made was 100 cm on the short side, BTW. There were two reasons for that. One reason was that aspect ratio is different between 44x33 and 24x36. It is often seen that the 4:3 aspect ratio is more practical than 3:2. The other factor was that I wanted to go a bit beyond what I usually print. I have been pretty happy with my 30"x40" prints, from any format I have used. 

Best regards
Erik

Not having used or tested the Hassy lenses for the X1D I can attest that the GFX lenses that I own are the sharpest I have seen using any of my layman tests.  This includes any Otus lens that I have owned and all of my large format lenses ( Schneider Digitars ).  The differences between my Digitar lenses and the GFX lenses is visible at 100% pixels but very subtle.  So at 100% pixels some difference can be seen at best apertures (f5.6 for GFX, f8-10 for Digitars).  Again, I want to stress these differences are visually very small.  I print 40 inches long side all of the time..... would I see this difference?  Never......  Hope this puts things into some perspective. 

Victor