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Torger, I used dcraw to convert a raw file from a Hasselblad H3DII-39 to FITS format, and I found that the 16th bit was hardwired junk. The 15th bit appeared to contain real data, but of course that data only consists of oversampled noise variations, so it's pretty worthless.The IIQ file format also records only 14 bits, so even if the IQ260 has 16 bit A/D converters, the 2 last noisy bits are not recorded to the file, a wise engineering decision as it's just noise that would bloat the file. If one likes to look at those two extra bits of noise one should get a Hasselblad camera, as far as I know their format stores the full 16 bits coming out from the A/D converters.
If you think pixel pitch, i.e., 100% monitor view, is the criteria for DoF, then the IQ250 will still have less DoF simply because it has smaller pixels than the IQ260: 5.3um vs. 6.0um. An f-number equivalent of about 1/3 of a stop, which will be pretty insignificant.The results will, however, differ from a comparison made at 100% on screen.
The IQ250 sensor is from Sony. It is being supplied to Phase, Hasselblad, and Pentax. It is uncertain how Sony is going to supply the MFD market. I don't know how much I would bet on a FF 6x.4.5 sensor from Sony.Interesting news about the bit depth. As far as long exposures go, I'd sometimes push the p45+ as far as 10-15 minutes (I did a 3 hour one once for fun)
The idea of the iq180 is tempting given their used prices. I could sell my p45+ if I didn't keep it and have the 180. I've heard that back has tiling issues with skies though.
It appears I have 4 options:
1. Keep the P45+ (and most likely purchase a profoto 8a or two with my current 25% edu discount on profoto gear)
2. Keep/sell the P45+ and get an IQ180
3. Trade in the P45+ with around $20k for an IQ250
4. Trade in the P45+ with around $20k for an IQ260
I'm somewhat hesitant about the 250 because they most likely will inevitably release a full frame version of it. The debate on the frame size is interesting, especially with Will's above statement comparing both to my 1.1x crop sensor. I however do admit that I am not exactly keen on the idea of spending $20,000 to move to a smaller sensor than I currently have.
Rick,The idea of the iq180 is tempting given their used prices. I could sell my p45+ if I didn't keep it and have the 180. I've heard that back has tiling issues with skies though.
You know, that makes a lot of sense (not just financial).I have also seriously considered just keeping the P45+ and getting an a7r with the metabones adaptor to use canon lenses. It'd cost me around $17,000 less to go that route :chug:
Paul, I hope this recent thread didn't make you have doubts about its base ISO. I don't think I've ever posted more often in a single thread than I did in that one - just working hard to straighten out the misconceptions.The 260 will do great at base iso (not sure if it's 100 or 50 now)
I didn't keep up with that thread as I was traveling but I thought the OP was suggesting the exposure at ISO100 was identical to ISO50 on the IQ260 suggesting it is a fake setting pulled down by C1.The manufacturers aren't stupid enough to put in fake "pulled" lower ISOs (as it's identical to just setting +ve exposure compensation on your meter i.e. forcing overexposure).
Without wanting to re-ignite the whole thing again here - it would be best if you would just read that whole thread through - but let me summarise it thus: there is only one ISO setting for a given MF CCD where applying the metered exposure conforms to the saturation-based ISO standard - the placement of the recorded RAW intensity of a grey-card with respect to the saturation level, the amount of headroom above that in units of stops, and so on. If you set a higher ISO and go with the new metered exposure for that ISO, you underexpose everything and signal to noise suffers. If you could set a lower ISO and go with the new metered exposure for that ISO, you'd overexpose everything (highlight stuff that shouldn't saturate, does).I didn't keep up with that thread as I was traveling but I thought the OP was suggesting the exposure at ISO100 was identical to ISO50 on the IQ260 suggesting it is a fake setting pulled down by C1.
Are you saying you know the manufacturers (Phase One) are not stupid enough or just assuming? I've not seen captures to evaluate but if the results are identical at both settings (exposure, DR, noise) then why use the lower (fake??) ISO?
Not quite; towards the end of the thread it emerged that he was imposing the same exposure at the two ISOs. And then he attached significance to getting the same results from both! But obviously, same quantity of light, same sensor efficiency, same noise, same gain = same results, regardless of the ISO tag.I thought the OP was suggesting the exposure at ISO100 was identical to ISO50 on the IQ260 suggesting it is a fake setting pulled down by C1.
I'm being kind to them by assuming they're not stupidAre you saying you know the manufacturers (Phase One) are not stupid enough or just assuming?
Jim,notified today about the IQ150:
IQ series digital backs | Specifications
wonder if this will offer the same advantages of the 160 compared to the 180 with respect to wide angles
The IQ150 is identical to the IQ250 except for it's lack of wifi and it's warranty (all IQ2 now come with a 5-year warranty including a loaner provision while IQ1 come with a standard 1-year warranty):notified today about the IQ150:
IQ series digital backs | Specifications
wonder if this will offer the same advantages of the 160 compared to the 180 with respect to wide angles