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Author Topic: Post processing IQ180 files for resolution/camera test  (Read 10422 times)
timparkin
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« on: October 26, 2011, 09:13:48 AM »
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Hi folks, I've been working with a few photographers and engineers to organise a big camera test (as part of a retest for the IQ180/8x10 article featured recently). We're comparing the results from an IQ180 on with Alpa WA/Digaron 40, Cambo/Digaron 35 & Phase 645/Digital 45mm shot in a studio (without flash but with daylight lighting booth). We had photographers who use both large format and MFDB's with us including a Phase One distributor to make sure the photographs were taken correctly. For the 8x10 and 4x5 shots I am happy with post processing these having scanned them on a Howtek 4500 (and checked the scans on a microscope and against a colleagues ICG 800dpi scanner) but I am interested in opinions on the optimal post processing for these files.

When I'm comparing the 80mp files against the 8x10 4000dpi scans (40,000 x 32,000) should I up rez them and how and also in terms of sharpening etc, do I let Capture One handle everything on auto (probably not) or do I just get a raw capture and use Photokit? etc, etc. We will be printing them as well but they will also obviously be displayed on screen for people to assess as most people won't be able to get to the 'show' we're hoping to give.

I'm basically trying to avoid people saying "well you should have used Thromboid zero point resharpening with the inconvoluted zeta prime transform four paraboids below sigma 6 criteria" (obviously people may not use these words exactly but I hope you get the idea).

We've also shot a scenic to get an idea of colour and real world use (it was a windy day on a cliff edge, just right to test the "you can't shoot 8x10 on a windy day" theory) and the P45+ (which we shot on a Linhof Techno with the 70mm Digaron WA) has a very different colour to the IQ180 (shot with an 80mm on a Phase 645 body). How would you normalise the colour? The IQ180 had a lot better colour in my opinion and tallied a lot closer with the Portra 400 and had a flavour of Velvia in there as well (at least you could get it looking at bit like Velvia which is near impossible with the P45+ as far as I could tell).

Any feedback or help is greatly appreciated..

Tim Parkin
http://www.timparkin.co.uk
http://www.landscapegb.com
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ctz
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« Reply #1 on: October 26, 2011, 10:20:36 AM »
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great site (yours), tim!
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ErikKaffehr
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« Reply #2 on: October 26, 2011, 10:48:17 AM »
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Hi,

Regarding color matching I'm pretty much in favor of using a color checker as a reference. Grey squares stay gray and have right lab values.

Regarding sharpening I'd suggest that you check http://www.luminous-landscape.com/essays/back-testing.shtml, Bill Atkinson describes the methods used.

Finally, I would establish a certain size of image, like 70x100 cm and a certain PPI like 360 and size all images to fit that size. You may need to sharpen a little bit after resize to compensate for sharpness lost in resizing.

I read your two of your articles and they were great!

Best regards
Erik


Hi folks, I've been working with a few photographers and engineers to organise a big camera test (as part of a retest for the IQ180/8x10 article featured recently). We're comparing the results from an IQ180 on with Alpa WA/Digaron 40, Cambo/Digaron 35 & Phase 645/Digital 45mm shot in a studio (without flash but with daylight lighting booth). We had photographers who use both large format and MFDB's with us including a Phase One distributor to make sure the photographs were taken correctly. For the 8x10 and 4x5 shots I am happy with post processing these having scanned them on a Howtek 4500 (and checked the scans on a microscope and against a colleagues ICG 800dpi scanner) but I am interested in opinions on the optimal post processing for these files.

When I'm comparing the 80mp files against the 8x10 4000dpi scans (40,000 x 32,000) should I up rez them and how and also in terms of sharpening etc, do I let Capture One handle everything on auto (probably not) or do I just get a raw capture and use Photokit? etc, etc. We will be printing them as well but they will also obviously be displayed on screen for people to assess as most people won't be able to get to the 'show' we're hoping to give.

I'm basically trying to avoid people saying "well you should have used Thromboid zero point resharpening with the inconvoluted zeta prime transform four paraboids below sigma 6 criteria" (obviously people may not use these words exactly but I hope you get the idea).

We've also shot a scenic to get an idea of colour and real world use (it was a windy day on a cliff edge, just right to test the "you can't shoot 8x10 on a windy day" theory) and the P45+ (which we shot on a Linhof Techno with the 70mm Digaron WA) has a very different colour to the IQ180 (shot with an 80mm on a Phase 645 body). How would you normalise the colour? The IQ180 had a lot better colour in my opinion and tallied a lot closer with the Portra 400 and had a flavour of Velvia in there as well (at least you could get it looking at bit like Velvia which is near impossible with the P45+ as far as I could tell).

Any feedback or help is greatly appreciated..

Tim Parkin
http://www.timparkin.co.uk
http://www.landscapegb.com
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Sheldon N
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« Reply #3 on: October 26, 2011, 11:58:18 AM »
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Personally, I would  not try to do too much to the digital shots to make them look like the film shots. I would display them with just basic white balance and normal tonal corrections. Everyone knows that digital starts out a lot more like a "blank slate" and that a lot can be done in post. I think people are more interested in real world resolution than digital vs film "rendition". If you wanted to do your own post processing on the digital landscape shot to show how the finished file would look, you could toss up a small jpeg showing how you might have rendered the image if you were working it up as part of your portfolio. That's more of a sidebar though, people want to see what the native files look like.

On how to display the film vs digital crops vs uprezzing/downsizing. I would make a value judgement about at what dpi you stop gaining real detail in the scan. In other words, if you view the scan at 50% enlargement (2000dpi) and see that all the resolvable detail is shown, and viewing at 100% only shows grain or blur, then I would slightly downsize the film scan using photoshop Bicubic sharper. So the baseline essentially becomes "This is all that there is to see on the film". If someone is a doubter, you can always show a crop of the original scan for reference.  

The reason I suggest slightly downsizing the film scan is because I've seen some comparisons where the film scan is so high resolution that you don't really see image detail anymore, just blur and film grain clumps. It makes it harder to compare A vs B when you're looking at those.

For the digital files, I would just keep it simple and use Photoshop bicubic enlarger to take them up to the same size as the film scan. Maybe a *little* sharpening to taste if needed, but the less complicated the better. Genuine Fractals would be another option for enlarging, if you have access to that.
« Last Edit: October 26, 2011, 11:59:49 AM by Sheldon N » Logged

timparkin
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« Reply #4 on: October 26, 2011, 04:54:20 PM »
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I agree to a point but a high contrast shot can look sharper than a low contrast shot - perhaps I should show the raw comparison and then normalise the luminosity at least for a second comparison.

I agree about not showing stupidly enlarged files but it's good to show what is being captured at full scan resolution (fortunately there is detail so it's not an issue).

I'll have a go at genuine fractals - sounds like a good idea.

Tim
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Jack Flesher
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« Reply #5 on: October 26, 2011, 08:36:40 PM »
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I'll save you the trouble, because here is the likely result:

1) If your processed IQ180 files look bad compared your processed 8x10 files, the digital folks will claim your digital processing was flawed, or that you didn't know how to optimally use the camera and/or lens and/or software.

2) If your processed 8x10 files look bad compared to your processed IQ180 files, the film folks will claim you used a bad camera or a bad lens, or bad technique, and/or had a bad lab process your film, and/or didn't know how to scan or the lab you used scanned poorly.

In short, you will spend a bunch of time and prove nothing except to yourself.  

And here is the bit that seals your fate: The fact you are already asking how to best process the Phase files does not bode well for the outcome...  

Sorry, but I am being realistic not pessimistic: It will be virtually impossible to perform the test in a manner that will satisfy both extremes, especially if you are not already a recognized expert in both 8x10 capture and scanning as well as an expert in digital processing using Capture 1.
« Last Edit: October 26, 2011, 08:38:36 PM by Jack Flesher » Logged

Fine_Art
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« Reply #6 on: October 26, 2011, 08:59:09 PM »
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If its a 4000dpi scan that shows good focus there is nothing to complain about. That is quite representative of what any user would try to extract.

If you have a Phase rep 'helping the digital shot no one can complain about that either.

Lets see a shot of both prints together in the same shot to look at the overall feel of the picture. If someone doesnt like that they dont have to look.
Lets see crops of focused detail at 50%, 100% resolution.
Present what both are good at such as the smooth highlight shoulder of film; the dark details of digital.

Please, and thank you for taking the time to share it.
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EricWHiss
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« Reply #7 on: October 26, 2011, 10:51:14 PM »
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Thank you for redoing the comparison and I look forward to seeing your results.
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ErikKaffehr
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« Reply #8 on: October 26, 2011, 10:53:30 PM »
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+1

Erik

Thank you for redoing the comparison and I look forward to seeing your results.
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ErikKaffehr
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« Reply #9 on: October 26, 2011, 11:09:34 PM »
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Hi,

Tim scans at 4000PPI. Now, 4000PPI will give something like a 40k/30k pixel image. To match that size the IQ180 would need to be blown up almost five times linear.

I have looked at a 67 Velvia scan at 6000 PPI. Downsizing it to 3000 PPI and upsizing it I could not see any difference. Doing the same exercise to 2000 PPI and back the difference was clear. So I'd say that Tim's approach of scanning at 4000 PPI is reasonable.

What looks most reasonable to me is to:

1) Make a basic conversion of the IQ180 image using default settings in C1
2) Upres to 2000 PPI and sharpen to taste
3) Downres 8x10" image to 2000PPI and sharpen to taste
4) Analyze and draw conclusions
5) Upres IQ180 image from original to match 8x10", sharpen to taste
6) Analyze and draw conclusions

I'd assume that there will be no clear winner/looser. Digital has advantages in some areas, noise, sharpening, handling of low contrast detail. Analogue has some benefits of it's own, but they may be harder to demonstrate. Negative film will definitively handle specular highlights better than digital but may lack in other areas. They are different animals.

Best regards
Erik


I'll save you the trouble, because here is the likely result:

1) If your processed IQ180 files look bad compared your processed 8x10 files, the digital folks will claim your digital processing was flawed, or that you didn't know how to optimally use the camera and/or lens and/or software.

2) If your processed 8x10 files look bad compared to your processed IQ180 files, the film folks will claim you used a bad camera or a bad lens, or bad technique, and/or had a bad lab process your film, and/or didn't know how to scan or the lab you used scanned poorly.

In short, you will spend a bunch of time and prove nothing except to yourself.  

And here is the bit that seals your fate: The fact you are already asking how to best process the Phase files does not bode well for the outcome...  

Sorry, but I am being realistic not pessimistic: It will be virtually impossible to perform the test in a manner that will satisfy both extremes, especially if you are not already a recognized expert in both 8x10 capture and scanning as well as an expert in digital processing using Capture 1.
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Jack Flesher
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« Reply #10 on: October 26, 2011, 11:41:22 PM »
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Guys, I would love to be proved wrong about how the results from this test will play out. So show me Cheesy



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timparkin
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« Reply #11 on: October 27, 2011, 03:06:35 AM »
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I'm a bit dissapointed in that response to be honest Jack. Here are a few details of the test:

I'm working with Joe Cornish who is one of Europe's top landscape photographers and has been working with Phase and Capture One for a few years and I have also had the CEO of Direct Digital Imaging (DDI) operate and attend the photoshoot and also spent a morning with me post processing the files. I also use Capture One to process my DSLR files so am hardly unfamiliar.

I am not asking advice how to use Capture One, I'm asking advice on how people approach the post processing of files. As there is no right or wrong in post processing, I was canvassing opinion so I can try a few different methods to see which may work better. For instance, I'm also talking to Julian Calverly (IQ180 owner) who has a different post processing approach to Chris Ireland (DDI).

As for your points

1) The IQ180 files look bad.

Well if we can't get a good IQ180 file with a professional user and a CEO of a company that sells Phase products in the room using Alpa, Cambo & Phase gear with the best Schneider and Rodenstock glass and with the files post processed by said CEO and checked by said professional I think there is a problem with the camera/software?

2) The 8x10 files look bad

Again, we had three large format photographers in the room and have solicited opinion in advance on how the test should be run, including small variations in focus, multiple shots to discount vibration, film sag, taped film and three different makes of holder to double check (Toyo, Fidelity and Chamonix). We also had the camera mounted on a 5 series gitzo with a second 3 series gitzo supporting the front and used Fujinion 240A and APO Symmar 360 lenses at a range of apertures.

The film was dev'd by Peak Imaging but I held back a couple of shots to dev myself and confirmed that the results were consistent.

The film is being checked on a microscope (to which I can attach a camera) and has been scanned on a Howtek 4500 with a backup scan done on a Fuji Lanovia and an 8000dpi ICG. I am also getting a third opinion from a pro scanner in the US (Lenny Eiger). Three scans should be enough I think.

Personally I don't care how many people complain about the test - at least there is one being done rather than just a lot of hot air being bandied about.

As for 'spending a bunch of time proving nothing except to myself' - strangely I've had so much interest in this that I have had people offering money to help support the test and have had companies lending software, services and equipment with an insurance value nudging a quarter of a million dollars.

You are a bright guy Jack, I was really hoping to get a useful response.

Tim
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Graham Mitchell
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« Reply #12 on: October 27, 2011, 03:42:11 AM »
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I'm looking forward to seeing the results.
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« Reply #13 on: October 27, 2011, 03:51:56 AM »
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First of all thanks for going through the trouble of tackling such a test.
I would not do any sharpening, let the person looking at them do his own "magic".
Choose a very good area with details and contrast and crop that area to be downloaded as a 16bit tiff but that the files have exactly the same end points and mid tone value, do not try to colour correct, there the voodooists can perform their own dance.
Give us your conclusions with the help from the specialists that helped and let the reader draw his/her own conclusions and try to prove otherwise themselves.
Make the raw files available to download and do not respond to any critic only to positive comments.
If you have used the "best" available to you, there is not much more that can be expected.
You are entering stormy waters, look forward to seeing your effort and good luck with the project!

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yaya
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« Reply #14 on: October 27, 2011, 04:10:04 AM »
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First of all thanks for going through the trouble of tackling such a test.
I would not do any sharpening, let the person looking at them do his own "magic".
Choose a very good area with details and contrast and crop that area to be downloaded as a 16bit tiff but that the files have exactly the same end points and mid tone value, do not try to colour correct, there the voodooists can perform their own dance.
Give us your conclusions with the help from the specialists that helped and let the reader draw his/her own conclusions and try to prove otherwise themselves.
Make the raw files available to download and do not respond to any critic only to positive comments.
If you have used the "best" available to you, there is not much more that can be expected.
You are entering stormy waters, look forward to seeing your effort and good luck with the project!



My thoughts exactly!

Thanks for taking the time to do this test Tim. If you feel like getting some Leaf image quality and Leaf Capture "magic" in the mix just give me a shout:-)

Yair
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timparkin
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« Reply #15 on: October 27, 2011, 04:13:54 AM »
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First of all thanks for going through the trouble of tackling such a test.
I would not do any sharpening, let the person looking at them do his own "magic".
Choose a very good area with details and contrast and crop that area to be downloaded as a 16bit tiff but that the files have exactly the same end points and mid tone value, do not try to colour correct, there the voodooists can perform their own dance.
Give us your conclusions with the help from the specialists that helped and let the reader draw his/her own conclusions and try to prove otherwise themselves.
Make the raw files available to download and do not respond to any critic only to positive comments.
If you have used the "best" available to you, there is not much more that can be expected.
You are entering stormy waters, look forward to seeing your effort and good luck with the project!

Thanks CED - I'll definitely do this as a baseline but I think I'll also apply our combined voodoo for people who don't have the skills or haven't the time. The obvious conclusion will be "they're all different cameras" :-)

As for stormy waters, I've been there before when redesigning a website for one of the biggest programming communities online. Trying to get the concept of design and marketing across to open source software developers created some extreme comments stopping just short of death threats :-) If I can cope with that I can cope with a few online naysayers and ner do wells - as you say the best tactic is to ignore them. If people are being critical constructively, I'm happy to engage though.

Tim
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timparkin
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« Reply #16 on: October 27, 2011, 04:15:36 AM »
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My thoughts exactly!  Thanks for taking the time to do this test Tim. If you feel like getting some Leaf image quality and Leaf Capture "magic" in the mix just give me a shout:-)     --   Yair

Thanks - I don't suppose you are in the UK are you? Might be a bit difficult if not.. I woudn't know who to approach in the UK regarding Leaf.. I should add that we're going to be running a comparison of the IQ180 vs P45+ on the Linhof Techno hopefully as well, just to see what the differences are. From what I've seen so far, the colour from the IQ180 is very nice and a lot better than the P45.

Tim
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yaya
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« Reply #17 on: October 27, 2011, 04:29:50 AM »
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Thanks - I don't suppose you are in the UK are you? Might be a bit difficult if not.. I woudn't know who to approach in the UK regarding Leaf.. I should add that we're going to be running a comparison of the IQ180 vs P45+ on the Linhof Techno hopefully as well, just to see what the differences are. From what I've seen so far, the colour from the IQ180 is very nice and a lot better than the P45.

Tim

I'm in London...we have 3 UK dealers plus a regional sales manager who takes care of Phase One, Leaf and Mamiya

BR Yair
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marcmccalmont
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« Reply #18 on: October 27, 2011, 07:29:42 AM »
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I'm more with Jack, who cares? apples and oranges will the IQ240 be compared to 16x20 film of course not!
Excellent results from 4x5 film and excellent results from an IQ180 (with a technical camera!)
I'm so happy with my IQ180 and my Rodenstock HR lenses, that's all that counts.
Remember Film has had 100 years or more to mature, at best digital in in it's adolescence.
I can always stitch and HDR if I need more.
Marc
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Marc McCalmont
timparkin
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« Reply #19 on: October 27, 2011, 07:45:16 AM »
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I'm more with Jack, who cares? apples and oranges will the IQ240 be compared to 16x20 film of course not!
Excellent results from 4x5 film and excellent results from an IQ180 (with a technical camera!)
I'm so happy with my IQ180 and my Rodenstock HR lenses, that's all that counts.
Remember Film has had 100 years or more to mature, at best digital in in it's adolescence.
I can always stitch and HDR if I need more.
Marc

So that would be a "No, I don't have any recommendations" then? :-)

Tim
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