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IIQ S or L?


New member
Any drawbacks to using IIQ S format?

I can see all normal COne functions are working, cannot really see any artefacts or issues with the small files. Any views?



Staff member
I have not seen any particular issues using IIQS however I am in the habit of using IIQL when shooting landscape but I do shoot IIQS shooting models tethered.
I am very happy with the results in capture speed improvement while tethered.


New member
Lightroom recognizes IIQ, but not IIQs. ...... I don't know about any difficulties in Photoshop.


Active member
In most situations there is no difference but when I first got my p65 I did some tests and noticed colour graduations are not as smooth, especially in darker areas of the image. Makes them look a little grainy so I always now stick to IIQL.


New member
Thanks everyone for the input.

Gareth, I also noticed quite a bit more noise in the shadows during some long exposure test shots. There is a slight unfairness here, that I had done more live view prior to shooting the IIQ S files, maybe the heat has more bearing. More testing in order for me.


Craig Stocks

Active member
Lightroom 3.5 now supports IIQ S files, at least for my P65+. I assume that was part of the upgrade from 3.4 to 3.5 since Adobe listed the Phase One backs as newly supported cameras. Older versions of LR handled the IIQ L files, but not IIQ S.


Workshop Member
At base ISO for a short exposure and no shadow recovery or exposure push applied there is zero meaningful difference.

At higher ISOs, longer exposures, or if you add aggressive shadow recovery or push the exposure there will be more noise in the shadow of the IIQ-S.

The math used in the IQ series for IIQ-S (on the latest firmware) is improved from the math used in the P+ series. So the quality of IIQ-S is somewhat better.

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New member
Doug, thanks for the clarification.

After some testing my default will be IIQ-S. In the case of high ISO Sensor+, longer exposures, or where I really think I'll be pulling the shadows I'll switch to IIQ-L, exactly in-line with Doug's message actually!