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Phase One IQ250 - 11 things you need to know, and Q&A

pedro39photo

New member
Its sad but its true, 15 years ago anyone in photography, amateur or professional or just a police...could identify that a hassy 500cm or a mamiya 645 was in fact a photo camera.
Today the DMF its a niche so small that in the field working with my H3D II sometimes even photographers ask me what its that? Huh? this say very very much about the industry.

We need a 28MP full frame 645 or 6X6 for 6.000 or 8.000$ entry level DMF system, to bring again a huge numbers o amateurs and newbies profissinals to this segment. ( not 6.000$ in a used system)
I am thinking if in the present the photography schools still show the advantages of the Medium Format ??? or the 2 major brands invest marking in this segment?

my best regards, and this medium posts are always a passion threat....hehehe

My wish list - A 48x48mm 28MP back for 7.000$

Pedro
 

Shashin

Well-known member
Why not?

If you were intending to shoot high ISO with any other format camera, why not use a MF camera instead, for the larger sensor and all that entails?

I mean, think about it: why did people use MF cameras with film? The same film emulsions that 35mm users used, including the "high ISO" ones like Konica SRG3200, Agfachrome 1000RS, Ilford Delta 3200 - all available in 120 format.

And sure, there were MF film photographers who never wanted to use anything faster than Velvia 50 or Tech Pan rated at ISO 35 - just as now, there are MFD photographers who never want to use anything above ISO 50 on their P45+ or IQ160. But the difference is that the film guys could load up a roll of ISO 3200 film anytime they wanted, whereas the DB guys cannot crank their back to a full-res ISO 3200. OTOH, their FFDSLR brethren can.

That's what this is all about: the long-overdue restoration of the universality (format independence) of camera sensitivity, which was the norm pre-digital. As I prefer using MF systems, that is why I've been clamouring for MF CMOS for years now.

Over the past decade, it seems to me, a malaise has seeped into the minds of MF users: a resigned attitude that we cannot shoot high ISO digitally, therefore we should never expect to do so again, and that there's something amiss with anyone who says "Hang on, there is really something wrong with this situation. Why do we tolerate that now 35mm kicks our butt in basic sensitivity, even though we used to kick its butt by sheer size advantage with the same emulsion qualities?"

But restore the sensitivity playing field, and once again, it's just a factor of sheer size advantage. Medium format is finally back on top, in every scenario!

For me, that's why the Sony CMOS-sensored DBs are a cause for celebration. They might not get it completely right in this first iteration - nearly all of us would like a bigger sensor than 44x33 mm, and I'm particularly annoyed at the P1 mandatory dark frame, which is both unnecessary and damaging - but look at the bigger picture: it's as good per pixel as a D800E (yup, the same D800E which was to be MFD's assassin) but it's 70% bigger. Don't you see the amazing possibilities?

Ray
Amen.

All the rules photographers like to make up about what you can and can't do with a camera are simply arbitrary. Fortunately, there are photographers out there crazy enough not to know those rules exist.
 

Altdo

New member
...I'm particularly annoyed at the P1 mandatory dark frame, which is both unnecessary and damaging...
I'm onboard with your entire statement...all but this bit.

Hasselblad H5D 60 = 32 Seconds MAX
Leica S = 8 Seconds exposure MAX (limitation of LS Lenses)
Pentax 645D = 30 Seconds exposure MAX
Leaf Aptus II = 32 Seconds exposure MAX
Leaf Credo 40/60/80 (at ISO 50) = 1 Minute exposure MAX
Phase One IQ260, IQ250, P20+, P21+, P25+, P30+, P45+ = 60 MINUTES MAX!!!!

To suggest that a black frame is unnecessary seems rather ill informed. Phase One is able to do what no other digital system can, the cost is a perhaps inconvenient black frame but clearly it IS NECESSARY! And lets not forget they've been doing it since 2007. I would think that in the 7 years since, if they could find a way to make it unnecessary, they would have.

I can understand someone not enjoying the wait but clearly it's there for a reason. If it wasn't absolutely necessary do we really believe it would be forced upon us by Phase for sport? Also, to say it's damaging seems strange, as without it the image would not be usable, being 1/2 of a complete capture.

Ultimately I, like you it would seem, don't enjoy waiting for a black frame to take place but I accept it as the cost of getting a RAW file unparalleled in quality to any other device at long exposures and as there are no alternatives I accept it as part of the "secret sauce" that makes this possible.
 
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torger

Active member
The black frame is there also for short exposures.

And you have it for DSLRs too. On my Canon 5D I've turned on black frame for all exposures above one second. And 30 seconds is not max, it's only max for the auto exposure. Bulb you can expose for as long as you want, longer will lead to more noise of course though. A few minutes should be no problem though with any DSLR.

The thing is that with my DSLR you can choose to turn off black frame subtraction if that's better suited for your current application. The problem with Phase One backs is that the user is not provided with that option.

It's true though that Leaf Aptus backs have limited their exposure to 30 seconds max, ie you can't lengthen it even if you want. Which is a bit boring for me which is shooting in cold conditions at times where much longer exposures would be possible, if just the back's software would allow it. I agree with Ray that it's unfortunate when the MFDB software artifically limits what the photographer can shoot.
 

Altdo

New member
The Black frame is only there for short exposures on the Phase back for the first. Then, if nothing changes, the same is applied to consecutive exposures.
This is why the first exposure takes an extra beat while following shots are faster, the black calibration is collected on the first frame and applied to the rest.

Over 1 second however, each frame collects it's own black calibration data.
 

LKaven

New member
I suspect this sensor runs very warm, warmer even than the D800 sensor, and that the black frame subtraction is needed even at handheld shutter speeds, and especially with use of live view. Remember, this is an Exmor, and all of the active gain stages and A-D are on the sensor, and multiplied out by the number of columns. This sensor is the home of the bluish-magenta haze.
 

Paul2660

Well-known member
Another nice feature Canon has with the Dark frame is it runs totally in the background in the buffer on the more advanced models of full frame DSLRs, allowing you to continue to shoot on longer exposures. If you are shooting a series of 5 to 10 sec exposures you can leave it on and will see no problems as it just finishes in the background. After a series of 30 second exposures around 6 or 7, you will start to see the long noise reduction start to run out of buffer and stop the camera for a few seconds. It still gives you much more freedom than say Nikon which is a 1 sec+1 sec equal process, so shoot a 30 sec, wait 30 sec while frame is written in the foreground, not background. This is true for any exposure of 1 second or longer with Nikon. Phase apparently runs it on exposures but only locks the camera at 1 sec or longer, by lock, I mean you can't shoot again and the LCD shows the dark frame is running. I have never seen any discussion if DSLR's are running it on all frames or just exposures of 1 sec or longer.

Example, you can take a 45 minute exposure with a 6D, 5DMKII or III with dark frame on, and when the first 45 minute exposure is done, you can get off at least one more shot before the camera buffers out. Back in the days I shot only long single exposures before stacking this was huge advantage for Canon since you were getting more out of the camera/battery. And since the shots were 40 minutes the files will most definitely be much cleaner. Nikon is like Phase One in that if Long exposure noise reduction is on (Dark Frame) then you are locked out until the dark frame finishes.

Leaving Long Exposure Noise reduction on while stacking, won't work as after about 10 to 15 exposures (say 2 min each) the Canon will buffer out for a while. Always seemed strange to me that you could get 2 40 minute exposures off before the Long Exposure Noise Dark frame buffered out but on shorter exposures it happens much faster.

I would also assume that this chip is going to have a bit of heat, but not sure why it would be any more than the same sized CCD.

I have not seen any of the Phase One recommended temp ranges for the longer exposures as on the 260 and P45+ a 1 hour exposure was only listed at outdoor temps of 69 degrees F or lower and low to moderate humidity.

Paul
 

johnnygoesdigital

New member
it's as good per pixel as a D800E (yup, the same D800E which was to be MFD's assassin) but it's 70% bigger. Don't you see the amazing possibilities?

There's good intentions in your overall comment, however, it's this part that will continue to poke MFD. Yes, for some only MFD will get those really big gallery wall prints, or a certain DOF. For some the "look" isn't about size, but of functionality, as it relates to investment.
 

stephengilbert

Active member
For some the "look" isn't about size, but of functionality, as it relates to investment.

Wait, are you saying that the Nikon costs less? Why would anyone pay more for something when they can get something different for less?
 

yaya

Active member
Leaf Credo 40/60/80 (at ISO 50) = 1 Minute exposure MAX
The Credo 80 is rated to 2 minutes, not 1 minute as you have suggested, but it should be mentioned that there is no "handbrake" in the firmware so nothing stops you from keeping the shutter open for as long as you like, on any of the Credo models...

I've done 3+ minutes on the Credo 80 at 35iso (and low ambient temp mind you) with decent results

Yair
 

synn

New member
Hi Yair,

That's interesting to know. Never knew about the "No handbrake" deal. Do you think 2 minutes is possible with a Credo 40 at around 25 degrees ambient?
 

dougpeterson

Workshop Member
Do you think 2 minutes is possible with a Credo 40 at around 25 degrees ambient?

Capture is possible. Whether the results are acceptable to you is something which would be better for you to answer with your own test (or having your dealer test for you if you don't already have one).

Also depends hugely on whether you mean 25F or 25C. If you mean 25C the answer is a definite no. 25F puts it in the realm of possibility with the question of acceptable quality falling on you.
 
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