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IQ250 movement tests on the 23/32/40/70/90 - desaturation and mazing artifact

Q: Are you a pro, a dealer, or trying to sell your gear at a higher price?

A: None of the above. I am a tech geek, and by being honest to reveal all drawbacks I even risk selling my gear for less should I need to sell in the future. For such reason, dealers tend to hate me.

Q: Why CMOS?

A: Because:

a) Currently only the Sony CMOS (H5D-50C, H5D-200CMS, CFV-50C, IQ250, IQ150, Credo50, 645Z) can match up against the Nikon D800E / Sony A7R in terms of dynamic range. At pixel peeping level for high contrast scenes, the IQ280 and the IQ260 gets inferior image quality in the shadow when compared against the Nikon D800E / Sony A7R. If you are used to Canon you may not appreciate the Sony CMOS, but if you are used to Nikon / Sony you would definitely like the Sony CMOS!

b) Live View is usable in both bright and dark conditions for critical focus and composition without harassment.

c) The fab process of the Sony CMOS is mature enough to avoid tiling issues.

d) The Sony CMOS can turn off darkframe NR for long exposure shots with virtually no impact on image quality, allowing twice the chance to capture great light during sunset / sunrise when compared against all CCD sensors.

e) Higher usable ISO means handheld shots would be possible under certain situations.

Q: I am a fan of larger sensors. Why should I bother with a small crop sensor?

A: I am not persuading you to buy the small crop sensor, but you may find useful information here to predict what would happen if a fullframe 645 CMOS sensor is ready - what would happen to the current Rodenstock HR Digaron lenses?

Q: Canon has announced their 50 MP 5DSR. Why should I bother with something like an IQ250?

A: If you stitch by movements with the IQ250 you get the same / similar pixel count as if you stitch with the IQ280 (i.e. in the >100 MP territory). It is not easy to do parallax free stitching with a Canon TS-E lens. According to the dpreview interview the 5DSR would perform similarly as the previous Canon sensors in terms of dynamic range and SNR. The Rodenstock HR lenses also perform at levels higher than or equal to the Zeiss Otus lenses, especially for wide angles. It is also easier to sort out filters for the 23HR, 32HR and 40HR than for the Canon 17mm f/4 L TS-E lens when you need perspective control by movements for long exposure shots (the Fotodiox filter is a huge monster to carry around).

Q: Why don't you spent more time taking real pictures rather than testing gear?

A: While I do shoot a few images I am not a pro. I am a gearhead and I enjoy the process of pursuing ultimate image quality, as well as shooting something that the others cannot easily shoot due to gear constraints. The process of experiments and discovery is fun, and the advancement of technology is exciting!

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Lenses tested this time (courtesy of Linhof & Studio!):

Rodenstock HR Digaron-S 23 mm f/5,6 (on ALPA 12 MAX with centerfilter)
Rodenstock HR Digaron-W 32 mm f/4 (on Linhof Techno)
Rodenstock HR Digaron-W 40 mm f/4 (on ALPA 12 MAX)
Rodenstock HR Digaron-W 70 mm f/5,6 (on Linhof Techno)
Rodenstock HR Digaron-SW 90 mm f/5,6 (on Linhof Techno)







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First of all here are the blue sky desaturation tests (white balance: Daylight, Kelvin 5000, Tint 0; highlight -33, shadow +33):




I would say that the desaturation does not bother me at all. Within the manufacturer specified image circle all lenses seem to hold strong and if there is any observed desaturation personally I would just fix it in post processing with a few mouse clicks. It may not be suitable if you do scientific images and color fidelity is critical, but for landscape work I would assume it to be OK. The wide angles seem to have a bit of desaturation in the corners when shifted. The 70HR-W seems to have some uncorrected magenta cast when shifted to the extreme. The 90HR-SW can do well even without LCC!

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Secondly, here are the mazing artifacts tests:

What are mazing artifacts and when does it happen for the Sony CMOS sensor? According to my experience to date (at the time of writing all LCC were done with Capture One v8.1), they most likely only occur when you shoot interior and there is a white wall (or other high key / simple texture) right within the region where the LCC shot has the purple-blue cast. It can be observed if you do pixel peeping at 100% pixel level. I have never observed such problem when I shoot outdoors (e.g. the blue sky). Below is so far the most stressful stress test that I can find for this phenomena:



How do movements affect these mazing artifacts? Below shows that movements along the longer edge of the Sony CMOS sensor do not affect the amount of mazing artifacts. (Actually later you would see that only movements along the shorter edge of the Sony CMOS sensor would have an impact):



So, what's the safe range of movements along the longer edge of the Sony CMOS sensor to avoid these mazing artifacts? Here are the tests results of the wide angles and you could evaluate the usable image circle using Digital Transitions' Tech Camera Visualization Tools by yourself:













Personally I would say that the safe range of rise (i.e. fall of IQ250 back for landscape orientation) is 6mm for the 23HR, 12mm for the 32HR and 16mm for the 40HR if you are picky with interior shots. However, the mazing artifacts on the 32HR are not prominent and it might even be usable beyond 16mm rise.

The 23HR on the IQ250 is like 17mm equivalent as of the 35mm format, which is even a bit wider than the 32HR on the IQ260. It is still the widest solution for long exposure shots with perspective control by movements without having to carry huge monstrous Fotodiox filters.

The 32HR on the IQ250 does not really need a centerfilter desperately as the dynamic range of the Sony CMOS sensor is really impressive. The lens is a beast and may continue to hold strong value if the fullframe 645 CMOS sensor is going to be based on the same technology as of the IQ250. (We do not consider the microlens array offset yet.) The only possible drawback is the mazing artifact issue if one is picky, but hopefully future software would be able to better compensate for this.

The 40HR on the IQ250 performs strongly and is versatile. If you own the 23HR then the 40HR is a great complementary. Personally I would assume it to be a safer bet for future fullframe 645 CMOS sensors.

The 70HR is sharp in the center (on par with the 90HR-SW) but the image quality degrades with movements towards the edge of the image circle and needs to be stopped down. Also it has color casts on the IQ250 when moved to the extreme. However given the size, weight and price I would still say it is a very reasonable choice!

The 90HR-SW is perhaps the new standard. It's a beasty lens as the 32HR. It has virtually no color cast on the Sony CMOS sensor as I was unable to hit the edge of the image circle with a crop sensor given the range of movements offered by the camera body. You can't go wrong with it except that it is bigger in size, heavier and more expensive than the 70HR.

So, what to expect next? Wide angles and sensor performance have been spear and shield for long. Symmetric design of wide angles is surely appreciated but for a sensor to achieve better dynamic range and high ISO performance there is a compromise that the lightwell has to be deep and the light shield has to be short, hence making the sensor more susceptible to crosstalk issues (color casts and mazing artifacts). Crosstalk is just one of the very many (digital) optical defect such like vignetting, MTF degradation towards the edge, distortion, chromatic aberration etc. With the Sony CMOS sensor you lose a bit of color or movement range but you gain the dynamic range, SNR etc, and when compared against the Canon / Nikon tilt-shift glasses you gain resolution as well (i.e. corner sharpness). Personally I would assume that this Sony CMOS + Rodenstock HR setup is of least compromise for landscape shots. For interior shots or other applications you might still prefer the larger CCD sensors for a generation or so.

The Samsung NX1 has introduced the first APSC back-illuminated CMOS sensor which is ray-angle friendly but I would assume it to be unable to achieve the same dynamic range as the Sony CMOS sensors do. This is one route for the 645 fullframe CMOS sensor (wide angle friendly, but less DR and SNR).

The D7000, D800E, A7R, IQ250 (similar Sony IMX094 sensor tech) tech is another route for a 80 MP 645 fullframe CMOS sensor (similar wide angle compatibility as tested this time, but great DR and SNR).

The NEX7, D5300, A7R-II tech is another route for a 120 MP 645 fullframe CMOS sensor (great DR and SNR, but will probably be incompatible with all current ultra wide angles).
 
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GrahamWelland

Subscriber & Workshop Member
This is excellent work and super helpful for anyone looking at the applicability of the CMOS sensor with the Rodies.

I'm going this route myself and it's really helpful to see the performance of the 23 & 40mm lenses with movements with these backs.

:thumbs:
 

tjv

Active member
It would be very interesting to see how C1 with the IQ150/250 and Credo 50 series compares to Phocus and the 50c when it comes to LCC / scene calibration and the reduction or suppression of mazing artefacts. I'm very, very happy to see your results with the 32HR and 40HR. Goes to show the advantage of retrofocus lenses on the CMOS.
 

Paul2660

Well-known member
Voidshatter:

Great work, Any chance to link to the full size crops? or tests? It would be nice to see them in a larger view.

I apologize if I missed a link.

Thanks
Paul
 

Dogs857

New member
Fantastic stuff Void.

This is extremely useful information for anyone looking at taking on the CMOS sensors. Very well done, good information and thorough testing.

Pity all my wides are SK, but I can't afford one of these backs anyway :D
 

f8orbust

Active member
Brilliant post - hugely useful - thank you.

Why, oh why, don't the DB manufacturer's themselves produce stuff like this...
 

tjv

Active member
Because they want the dealers to work for their money? That's one way to keep prices high, I guess...

I would have thought that the technical camera manufacturers AND dealers would be the ones posting these kinds of thorough tests, actually. DT has posted the most thorough, although nothing as useful as this IMHO.

Brilliant post - hugely useful - thank you.

Why, oh why, don't the DB manufacturer's themselves produce stuff like this...
 

f8orbust

Active member
To be fair, maybe they've got more important things to do - like designing the packaging of the corporate candy for instance:

 

f8orbust

Active member
I would prefer to think they don't than they do ... but choose not to publish. Remember the consternation when the IQ180 was released and everyone who had invested in S/K wide angles suddenly found out that the DB they had just upgraded to didn't play ball ? Nothing on the P1 website at launch informed potential buyers of this issue, so if they did testing and kept it to themselves, well...
 

fmueller

Active member
An exhaustive set of tests proving what has been known almost from day one. The new CMOS sensors don't play well with shifted lenses on tech cams. The reps from CI and DT have been very forthcoming with this on this forum and with their customers. As for Phase One's failure to "disclose" this, I don't fault Phase One for advertising what their DB's can do rather than what they can't do.
 
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Paul2660

Well-known member
Just a bit of a different opinion.

No offense intended, but where are those exhaustive tests? Can you point to them. I have followed the 250 pretty darn close since the day it was announced. The only "tests" I know of are the ones by DT, back in Feb of 2014. I was all over those tests, and spend months going over the various files. If there are others I am remiss and would like to see them.

The DT tests were indoors, in poor light and IMO did not really give a great showing of any of the sensors involved, besides showing that the 250 greatly outperformed the other CCD sensors in shadow DR.

The only other true outdoor testing I know of was on this site, the review that Guy did of the Credo 50, and that did show a lot I will agree, but I still don't feel it's exhaustive. Guy did give anyone the ability to pull the raw files down, with no "if you are a client" restrictions.

As for Phase One, I don't agree that they have provided anything, they have left it up to the various dealers to provide testing. I know of no link on Phase One's site showing really anything of significant information besides just basic marketing info and that. They may have tested internally sure, but nothing I know of has been published for the general public.

I know of no landscape shooter who has been sponsored by Phase One to shoot extensively with the 50MP chip, with either a tech camera solution or DF and Phase One glass. There has been some information posted on weddings, and action shooters, on the Phase site with the 250. At the time I checked Joe Cornish is still using the 260, but that might have changed. Joe has been greatly published by Phase One with his work on the 260.

Some other examples that I find very lacking:
1. The wealth of information that other members on this site have provided on ways to tether with the Surface pro, in the field. This vastly improved the usability of the current CCD backs and the CMOS ones. This is a huge advantage for Phase One over the competition, yet, nothing has ever been officially published.
2. The fact that the use of a strong Variable ND filter GREATLY improved the use the live view on the current CCD backs. I can't impress enough just how much better Live View is with this solution. It works and works well, outdoors and in bright light. Again nothing from Phase One.

As far as getting a 50MP back to test, one of the most common responses by the dealers is "demo" the back. That is not that easy due to insurance issues. I have been able to demo every other camera and lens I have needed, except Medium Format backs.

Travel to NYC and or Atlanta is not really a good solution either as I would rather demo the back in my photographic subject matter.

Lensrentals.com has greatly improved over the past 2 years and it would be great to see a similar solution for MFD. I am a single shop owner, I work out of my home and don't have a separate building, so getting rental insurance for my business is in the 2K range and just too much for 5 days of use. It's also too costly to change my insurance to another carrier due to the rest of the coverage I have. That may just be my issue, but I feel that the back rental is very hard to do and there should be a better solution.

As far as I know of the crops that Voidshatter provided are the first real test to show just how well the Rodenstock lens solutions will work on the 50MP CMOS. They were outdoors, in good light with blue skies. Blue skies tend to be the worst offenders on the hue and color shift issues, at least from my work. What I have seen from his work is that with moderate shifting, 12mm to 15mm with the Rodenstock glass, the 50MP CMOS is viable. If you can live with the cropped view, which is still a big consideration for me. However based on his results, I can now see a lot more possibilities for this sensor.

The images that Darr posted about a month ago, also pointed to the fact that the 50MP CMOS backs may not be as hard on tech shifts as was once thought. She was also willing to share those raw files.

Paul
 

kdphotography

Well-known member
I don't see Phase One as trying to "hide the ball" from anyone. Imho, it's all part and parcel of chasing technology and upgrading to the latest and greatest offerings. I truly doubt you'll hear from Canon advising consumers that save for their "L glass" series of lenses (and a smattering of offerings from third parties like Zeiss that their other lenses probably aren't the best choice for their new 50MP 5Ds/r....

And at the same time, if Phase One ever did offer up some sort of "definitive test" it would be received with an eye towards bias/marketing. Really. So here the independent dealer network, at least those that have credibility behind them, does provide some insights on equipment, performance, and perhaps a combination of platforms and digital back solutions/recommendations based on individual needs/wants/desires. And of course, individual user reports from the small growing GetDPI family help. ;)

Because of the subjective nature involved in user needs/wants/desires, it's hard to beat personal experience. In other words, a "test" posted on the forums may not necessarily form an accurate conclusion for every user. I guess you'd call that a statistical hasty generalization.

Events like CI in Carmel are great ways to try new equipment. I wish there were more of these types of events. We're looking forward to Lake Tahoe...

ken
 

Dogs857

New member
I guess it would depend on how big the tech camera market is in regards to Phase One sales.

I think if the majority of sales are aimed at the DF+ bodies and lenses, then movements become less of an issue for them. I would bet the IQ250 works wonders on the DF+. So long as the Phase One products work with Phase One gear then their job is really done. If you want to use the Phase One product on another platform, then you will need to test it out to make sure it works with the equipment you have.

No worries.
 

dougpeterson

Workshop Member
As far as getting a 50MP back to test, one of the most common responses by the dealers is "demo" the back. That is not that easy due to insurance issues. I have been able to demo every other camera and lens I have needed, except Medium Format backs.

Travel to NYC and or Atlanta is not really a good solution either as I would rather demo the back in my photographic subject matter.

Lensrentals.com has greatly improved over the past 2 years and it would be great to see a similar solution for MFD. I am a single shop owner, I work out of my home and don't have a separate building, so getting rental insurance for my business is in the 2K range and just too much for 5 days of use. It's also too costly to change my insurance to another carrier due to the rest of the coverage I have. That may just be my issue, but I feel that the back rental is very hard to do and there should be a better solution.
Paul, did you look into APA Insurance. I personally use them for the Camera Equipment Insurance that I use, and it costs me about $450 a year (plus the very reasonable price of being an APA member) and covers 40k of rental equipment at a $500 deductible. Here's my agent - I've never had to make a claim, but they've been professional and efficient any time I've needed them. Karen Stetz, Agent, APA Insurance Services, Phone: 877.269.9021
 

dougpeterson

Workshop Member
VoidShatter: Great tests; thanks for sharing. Having run dozens of digital backs tests in the last 8 years, including this IQ250 Tech Cam Test) I'm especially sensitive to criticizing someone else's tests. Moreover, this test looks very well organized and especially well executed! That said, there are a few items to consider when interpreting the results, which I hope you'll accept in the spirit it is intended; it's also very likely you're aware of the below, but (unless I missed it) they are not discussed in your report and so someone only reading your report may miss them. Your effort in such testing is greatly appreciated and a great contribution to the Phase One community!
- The color desaturation issue is not equal for all colors. Magenta colors in areas of green-cast and green colors in areas of magenta-cast are especially affected. It's also not just strictly a desaturation issue but also reduces the ability to see subtle variations of color (though in my experience the desaturation becomes problematic before the loss of color discrimination for most subjects). So with other subject matter it may become apparent prior to where it shows in your testing. Naturally if you are shooting for B+W you can go much further.
- The cause of Mazing in larger movements is pretty complicated. It's not absolutely limited to smooth areas of tone, it can absolutely happen outside (it has in other tests we've run; remember that I shoot many GB of tests and personal shooting that never get formalized into a research report) and subject matter does matter, so in worst-case scenarios it could kick in a few mm of movement less than it has in your testing. Naturally the opposite can also be true!
- As shown in our Tech Cam testing the 250 can be used very effectively, including with movement, on a variety of Rodenstock lenses; however, notable to some users, the IQ260 (or IQ160 or P65+) and other backs/sensors are usable for a larger set of movements on those lenses. The IQ250 has a LOT to offer tech camera users, but if you are, for instance, a pro interior/architecture shooter who finds their back ever-against-the-wall and want to be able to get the most movement out wide angles (including Rodenstock) it's important to be aware of that.

Frankly - we don't care which one of these backs someone buys :). But we do care about happy customers and invest heavily in the research/testing/real-world-shooting to provide advice about the pros/cons of each option to help facilitate them.

You can imagine a LOT depends on the photographer as to how these sorts of results should be interpreted. If I'm working with a pro interior shooter who isn't interested in a in-the-weeds level of technical knowledge I'm going to be reticent to recommend a combo that can result in mazing which can easily go unnoticed unless each image is reviewed at 100% - that could ruin a production and cause grievous damage to their career (I don't think I'm exaggerating here, even if it's a worst-case scenario). If I'm dealing with an hobbyist-landscaper for whom a minor amount of mazing in the corner of a frame might be viewed as a minor annoyance (a bit of Photoshop cloning and voila) that same issue could be inconsequential compared to the ease of learning tech-camera focus/composition with the IQ250 Live View.

---

As a comment on Phase One providing such testing... Phase One has always relied on their network of Value Added Partners (aka dealers) to provide potential buyers the resources they need regardless of what specific and/or niche needs they might have or non-Phase gear they want to use a back with. We at DT attempt to do a good job of this by providing our clients access to raw files from our extensive catalog of testing, advice from that testing and our non-test real-world-shooting and the experience of our other clients, as well as the opportunity to test/evaluate equipment at our facilities or via a rental-toward-purchase. We also try to participate as much as possible in forums like this, both to share what we know, and to learn from the other users. For instance when tests like this one are published we point users to them to supplement our own testing.
 
so in worst-case scenarios it could kick in a few mm of movement less than it has in your testing
Thanks for the notes Doug! :thumbs:

Would you mind sharing RAW files (or PM me a link) of an example in which the mazing artifact occurred outside the blue-cast region of the LCC shot?
 

f8orbust

Active member
As a comment on Phase One providing such testing... Phase One has always relied on their network of Value Added Partners (aka dealers) to provide potential buyers the resources they need regardless of what specific and/or niche needs they might have or non-Phase gear they want to use a back with...
For that to work you have to have great dealer. Sadly, US representation is not representative of the global Phase One dealership network. Elsewhere it's either non-existent, or takes the form of a ‘one man band'. With respect to the latter - the dealer is simply not going to be able to perform the sort of testing required because: 1) they don’t have the time, and/or 2) they don't have access to the lenses/equipment required.

This is why - IMO - testing needs to be done locally (Phase One HQ), and the results distributed globally for inspection and discussion.
 
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