Credo WS 60 or converted IQ160 or?

[Grayhand]

Some thoughts from the group would be appreciated :talk028:

I decided to let the eminent offer to upgrade my P45+ to a IQ260 from my camera dealer to pass me by.
The offer expired last week.

It would be nice with a "back of my back" that would be useful to some thing more than just check the histogram.
But I saw the info about the new Credo WS 60 and it made me think.
I have for a long time been using a modified camera for infrared.
But after using a Kodak 645 back without the IR-filter my old IR-camera was not the same any more.
I realized that I wanted a full spectrum back. And I don't want a monochrome back, I use film for that!

But when I brought my idea about the Credo WS to my dealer, he countered with an offer for a IQ160 modified without the IR-filter.
At a price that was even lower that the first offer for the IQ260 if I trow in my P45+ in the deal.

I realize that it can not be many that yet had a chance to play with bout the Credo WS and a modified IQ160
But If someone has any experience of handling Credo 60 and IQ160 any thoughts on that experience would be really helpful.
I do realize that I will trade 1 hour exposure for maybe one minutes exposure. But 95% of my exposures is shorter than 60 sec..
And I can use flm for long exposure.

So?

Or, is there a third alternative that I am unaware of?

Ray

 

[dougpeterson]

I just completed an article last month about the rise of Infrared and B+W imaging in medium format.

I've personally done IR photography with:
- Phase One P21 converted
- Phase One P45+ converted
- Phase One P45 unconverted
- Phase One Achromatic+
- Mamiya Leaf Aptus II 12 converted
- Phase One IQ260 Achromatic
- Phase One IQ180 IR
- Mamiya ZD with filter removed by me

And I've worked closely with several of our clients who have purchased other IR MFDBs, including consulting with them on file processing and filter selection and troubleshooting various focus/exposure/hot-spot issues.

Outside of digital backs I've also used an unconverted Olympus E-10 (aka "the slow tank"), an unconverted Nikon D2H, an unconverted M8, a converted Canon 5D, an unconverted Canon G10, Macophoto (now Efke) 820IR (both standard and Aura emulsions), and Ilford SFX200.

The difference between a Credo 60 WS and IQ160 IR will be the exact same as between a standard Credo 60 and a standard IQ160. Both are the same as their brother-models but with the IR-block filter replaced by a clear-glass filter.

Credo vs IQ:
- IQ has Sensor+. Credo does not.
- IQ has Focus Mask. Credo does not.
- Both have an onscreen 2-axis level. IQ embeds the roll/pitch into the metadata for auto-correction of horizon and perspective in C1. Credo does not.
- IQ has hard buttons. Credo uses soft buttons which light up.
- IQ USB-enabling firmware is released. Credo's is pending (but I'm confident it will come soon).
- IQ and Credo both come with 1 year warranty. IQ has available 5 year value-added warranty with loaner provision. Credo has available 3 year value added warranty with no loaner provision.
- User interface (layout of menus) is a bit different; I don't think either is better or worse.
- Color profiles are different. Nothing better or worse, just depends on your preference.
- List price for Credo is lower; though with various promotions, trade-ins, and kits pricing varies so best to work with your dealer on what they can do for both options.

Credo WS kit comes with a set of filters. IQ-IR kits are BYOF (Bring Your Own Filter).

Some thoughts from the group would be appreciated :talk028:

I decided to let the eminent offer to upgrade my P45+ to a IQ260 from my camera dealer to pass me by.
The offer expired last week.

It would be nice with a "back of my back" that would be useful to some thing more than just check the histogram.
But I saw the info about the new Credo WS 60 and it made me think.
I have for a long time been using a modified camera for infrared.
But after using a Kodak 645 back without the IR-filter my old IR-camera was not the same any more.
I realized that I wanted a full spectrum back. And I don't want a monochrome back, I use film for that!

But when I brought my idea about the Credo WS to my dealer, he countered with an offer for a IQ160 modified without the IR-filter.
At a price that was even lower that the first offer for the IQ260 if I trow in my P45+ in the deal.

I realize that it can not be many that yet had a chance to play with bout the Credo WS and a modified IQ160
But If someone has any experience of handling Credo 60 and IQ160 any thoughts on that experience would be really helpful.
I do realize that I will trade 1 hour exposure for maybe one minutes exposure. But 95% of my exposures is shorter than 60 sec..
And I can use flm for long exposure.

So?

Or, is there a third alternative that I am unaware of?

Ray

 

[dougpeterson]

Slightly off topic but here are some of my favorite pictures of my grandma's house. Phase One P45+ IR:

That was the last year she planted the garden. She's too busy playing cards now .

Amr (forum member here) has the most IR digital back experience of any customer I know of. Hopefully he can provide some thoughts.

 

[GrahamWelland]

Amr (forum member here) has the most IR digital back experience of any customer I know of. Hopefully he can provide some thoughts.

Correction. Amr has more experience and IR/Full Spectrum or converted backs than perhaps NASA or the art restoration & forensic crime labs. :thumbs: :ROTFL:

 

[Grayhand]

Thanks Doug for the link and the comparison between the two models.
If they are more or less of the same generation and with the same quality on the LCD-back,
then I think there is no doubt that I will go for a IQ160 because of Sensor+ and Focus Mask.
And after three backs from P1 I will stay in the family if possible

Really nice IR photos, I especially like the last photo from under the tree.
Here the Wood effect really is working good.

But generally I really want some more tonal gradient in the leaf and grass today when I makes photos somewhere in the IR spectra.

I work professionally in the 8-14 micro meter range with IR but that is to far down the sloop for most subject,
so I like to work in the borderlands between visible and near IR range for "normal" photos.

I include a photo from the Kodak 645 back without any filter, so it is a full spectrum photo. It is of a tree in bright sunlight.
The photo I made with my "normal" converted IR camera gave the same bright foliage for the tree, as in your photo, of your tree.
But the Kodak back here gives a different rendition of the subject.
It might be hard for some to see the difference, but for me it makes a world of difference.

So a full spectrum back gives me all the possibilities in one setup!

Ray

 

[ondebanks]

Hi Ray - Ray here

I've also been using the Kodak DSC645M for this. With this back, I can take 3 quite different spectral variants of any scene: normal visible, visible + IR, and IR-only (with an IR-pass filter over the lens). It's a real pity that among the portable DBs of this millenium, only the Kodaks and Mamiya ZDs were designed with this capability.

"Or, is there a third alternative that I am unaware of?"

Yes, I believe there is.

Upgrading to a Credo or IQ certainly buys you a better user interface, but I would caution that these backs with Dalsa sensors have poor IR response in comparison to the Kodak sensors. Poor in the sense that their spectral response is both lower in sensitivity (quantum efficiency) and shorter in bandpass. The Kodaks go out to 1150nm, where Silicon basically becomes transparent to light; whereas the Dalsas are already petering out by 950nm.

On top of that, the Bayer CFA filters for the green and blue pixels have almost no IR leak in the Dalsa sensors; in other words, almost all of the IR effort is carried by the red pixels; just 25% of the total pixels are actually gathering any significant amount of light and resolving details.

The Kodak DB sensors, by contrast, feature a very strong and early IR leak for the blue and green pixels, so that they are equal in IR sensitivity to the red pixels from about 800nm and up. This means that with an IR-pass filter, it behaves like an "achromatic" back and you don't actually need to de-Bayer the RAW images; no interpolation means more detail and sharpness.

So what would I do? Well my "third way" would be to get your P45+ converted to full-spectrum (simply swapping out the IR-block filter for a clear one of equal optical path length), and thus open it up to all that IR sensitivity and resolution. And retaining your long exposure capability as well!

Have fun, whatever you decide to do!
Ray

 

[dougpeterson]

I would caution that these backs with Dalsa sensors have poor IR response in comparison to the Kodak sensors. Poor in the sense that their spectral response is both lower in sensitivity (quantum efficiency) and shorter in bandpass. The Kodaks go out to 1150nm, where Silicon basically becomes transparent to light; whereas the Dalsas are already petering out by 950nm.

On top of that, the Bayer CFA filters for the green and blue pixels have almost no IR leak in the Dalsa sensors; in other words, almost all of the IR effort is carried by the red pixels; just 25% of the total pixels are actually gathering any significant amount of light and resolving details.

The Kodak DB sensors, by contrast, feature a very strong and early IR leak for the blue and green pixels, so that they are equal in IR sensitivity to the red pixels from about 800nm and up. This means that with an IR-pass filter, it behaves like an "achromatic" back and you don't actually need to de-Bayer the RAW images; no interpolation means more detail and sharpness.

So what would I do? Well my "third way" would be to get your P45+ converted to full-spectrum (simply swapping out the IR-block filter for a clear one of equal optical path length), and thus open it up to all that IR sensitivity and resolution. And retaining your long exposure capability as well!

Have fun, whatever you decide to do!
Ray

In my experience with both sensors you speak of the lower sensitivity to very-high IR spectra like 950-1000 is actually beneficial. Very few (essentially zero) medium format lenses are well corrected for that range, so a sensor which is sensitive to them will be harder to get sharp images with. Given that you're on a tripod the

The RGB bayer per-color IR sensitivity-via-leak is a fair point. But in practice I find the higher inherent dynamic range of the newer sensors and the really excellent high-saturation processing of Capture One v7 renders that theoretical advantage moot in practical imaging. Especially given the very large benifits of having live view and 100% review on-back which, when shooting infrared, is even more useful than it is when shooting visible (given the increased difficulties focusing in the IR space and the occlusion of the viewfinder when using an visible-block filter).

I'd pick the Credo-WS or IQ-IR over a P+ IR back any day. Of course, I don't have to pay for either, so my choice is blissfully limited to which tool I think will be more enjoyable and effective to use.

The notable exception would be of course if you were doing astronomical or scientific imaging in which your content-of-interest was in the 950-1000nm range to which the Kodak is significantly more sensitive than the Dalsa.

 

[jagsiva]

Why not consider the IQ 260 Achromatic - No Bayer issues....

 

[yaya]

+1 for what Doug is saying...

The Credo WS is generating a lot of interest in the art conservation market and I've done numerous tests at some of the leading institutes in Europe.

Many of those have been using film or modified DSLRs such as the Fuji S3Pro (Super CCD) but all of them are excited with the ability to capture and record 60MP or 80MP of fine detail beyond 950nm. It is true that the Red channel is more sensitive than G and B but this actually works really well with the high power tungsten lights that is used by everyone

 

[Grayhand]

Thanks Ray for the interesting information and the "third alternative perspective".

I really have to check out the conversion of the P45+ to a full spectrum back.
My eminent "agent" here in Sweden, Martin Widen, is on summer holiday rest of July, but when he get back...

I just got the offer from P1 about refurbished IQ160 and a new ADF+.
Once again waiting for Martin to get back for an offer with a price tag for that package.
Maybe that package for an IQ160 plus an conversion of my P45+ gives me a good combination of both old and new for a reasonable sum?

I am only interested in full spectrum and full color information. I don't really have to be able to go so high up in wavelength.
Here I will only work with reflected electromagnetic radiation from the objects that I takes my photos of. 0.7 micro meter equals roughly 500 degrees Celsius and for me I really don't need much longer wavelengths than 0.8 micro meter for the kind of photos I have in mind.

When I work with the longer wavelengths, then I am only interested in the electromagnetic radiation that is actually radiated from the object as a function of its temperature.
10 micrometer is roughly 20 degrees Celsius. But here I have to work with lenses made of Germanium due to the fact that glass more or less totally opaque above 2.5 micrometer.

So thanks for a lot of interesting informations and viewpoints, it is aways best to surf on others knowledge compared to be sucked under by my own ignorance :salute:

Ray

 

[Shashin]

To add to Ray's point about the cut on properties of the Kodak sensors, since the red is basically passing IR and the blue and green increase transmission as they go into NIR, you can actually get a separation of "color" with deBayering. This is an image taken with a Pentax 645D. The "color" separation is done with WB in ACR. I don't do enough IR to say how useful or predictable it is--the little I have done has had mixed results. This is simply a test in my garden.

 

[ondebanks]

Why not consider the IQ 260 Achromatic - No Bayer issues....

But no long exposure capability, unfortunately.

Why they didn't give the Achromatic version of the IQ260 the same long exposure circuitry as the regular IQ260 is a mystery to me.

The P45+ Achromatic retained the same excellent long exposure capability as the regular P45+. That was the model to follow.

Ray

 

[ondebanks]

In my experience with both sensors you speak of the lower sensitivity to very-high IR spectra like 950-1000 is actually beneficial. Very few (essentially zero) medium format lenses are well corrected for that range, so a sensor which is sensitive to them will be harder to get sharp images with.

That's a good point, and I guess it sort of compensates for the resolution loss due to the red pixels doing all the work.

The notable exception would be of course if you were doing astronomical or scientific imaging in which your content-of-interest was in the 950-1000nm range to which the Kodak is significantly more sensitive than the Dalsa.

Yes indeed.

Ray

 

[jagsiva]

But no long exposure capability, unfortunately.

Why they didn't give the Achromatic version of the IQ260 the same long exposure circuitry as the regular IQ260 is a mystery to me.

The P45+ Achromatic retained the same excellent long exposure capability as the regular P45+. That was the model to follow.

Ray

Good point. yes, with the P45+ you would retain the long-exposure, but not with the Credo.

I do have the IQ260 Achro on its way, and was originally hopefull that it would have the same features as the IQ260 color. However, it is based on the P65+/IQ160/Credo 60 sensor and does not. However, the base ISO is higher and so while not getting the longer shutter speeds, should still get the overall exposure needs I am looking for.

My primary interest in the Achro is for B&W and so far, sample images are looking good. Good luck on your quest. You could also try finding the old P45+ Achro which I believe retained the P45+ long-exposure traits.

 

[aeaemd]

I traded the achromatic + for the 260 act., It is rather difficult to do long exposures with the ach+, it tends to overexpose by up to 3 stops in daylight, I had to stack three big stoppers at time. I don't know about you all, I am not big fan of stacking filters it really affect resolution which is the strongest point of using B&W backs.

 

[yaya]

Here's a link to a mini review done by Andy Finney from Infrared 100: Infrared 100: 60 megapixels of near-infrared

BR

Yair