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Author Topic: IQ260 Usable ISOs?  (Read 3495 times)

drennon

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IQ260 Usable ISOs?
« on: June 12, 2014, 06:49:21 pm »

Hey Folks,

I'm trying to make myself hold out on jumping into medium format until a full frame CMOS back comes along...but I could be holding out for a good while. So, I'm considering going for a used IQ260. I want the full frame, I want long exposure, and I want to put it on a Contax 645.

So my question is: Can I use ISO 200-400 and get good results with this camera? I've looked for good test material but really I would appreciate some real-world feedback from those of you using any of the backs with this Dalsa sensor. I almost exclusively shoot Portra 160 & 400 right now, but someone recently told me they wouldn't go above ISO 50 on their H4D-60 at all...that just sounded kind of rough.

Thanks,

David
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Ken R

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Re: IQ260 Usable ISOs?
« Reply #1 on: June 12, 2014, 06:53:55 pm »

Hey Folks,

I'm trying to make myself hold out on jumping into medium format until a full frame CMOS back comes along...but I could be holding out for a good while. So, I'm considering going for a used IQ260. I want the full frame, I want long exposure, and I want to put it on a Contax 645.

So my question is: Can I use ISO 200-400 and get good results with this camera? I've looked for good test material but really I would appreciate some real-world feedback from those of you using any of the backs with this Dalsa sensor. I almost exclusively shoot Portra 160 & 400 right now, but someone recently told me they wouldn't go above ISO 50 on their H4D-60 at all...that just sounded kind of rough.

Thanks,

David

I own the IQ160 and results at iso 50 and 100 are superb. At iso 200 they are excellent. At iso 400 decent (full res mode) but with sensor + (15MP res.) they are excellent. In sensor+ mode even iso 1600 is pretty good. (again, on the IQ160, maybe the IQ260 is better in that regard)
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Doug Peterson

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Re: IQ260 Usable ISOs?
« Reply #2 on: June 12, 2014, 07:47:30 pm »

I've shot several weddings with an IQ260 at the full range of ISO values. I'd be glad to share those raws with you so you can make up your own mind on what's usable and what's not.

Paul2660

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Re: IQ260 Usable ISOs?
« Reply #3 on: June 12, 2014, 08:35:09 pm »

You first have to ask, is anything past the base iso of 50, really real?  This question has come up over and over, and Phase One, or a dealer has never really addressed it. 

CCD's don't really record iso's like CMOS, so when you push the chip by increasing the iso, as I understand it, you are not really you really are not increasing the gain like you would with CMOS, instead a marker is added to the metadata.  Capture One then sees that and works some interesting processing.  However again I don't think you are really taking the chip up past the base. 

On Getdpi, there was an interesting post where one user felt that the base of the 260 is really iso 100, not 50.  A lot was written on that issue also, but again Phase One or a dealer did not come into give an official answer.  I personally can't answer this, as I always either shoot at 50 or move to 200, mostly skipping 100 iso.  The OP on the Getdpi post's point was that images taken at 50 and 100 basically had the same signal noise and really did not seem any different. 

I own the 260 and previously owned the 160.  I had hoped that Phase One, by coming out with a new chip for the 260, would be able to pull more out of the the "higher iso" ranges of the 260, so far, I have not seen that.  In my use, if you push the 260 past 200, you will be not too happy with the results.  Lets say anything past 200 in non sensor plus, You can expect:

1.  Way too much noise in the shadows, enough that the image is really not useable for any details
2.  Considerable color saturation loss, albeit that some of this can be gained back in C1
3.  Overall image sharpness falls off especially in the finer details.

iso 200 is OK and can be used, in bright light/medium light, however again shadows will suffer.  If I am put in a position where I need iso 200 I will always do a 2x shoot, 50 and 200, using 200 to stop motion mainly wind. 

If you move to sensor plus, and 15MP, you can easily get to 400 and maybe 800, however I don't fee 1600 is that good, remember you are now 1/4 of the full resolution of the chip.  I just don't use sensor plus as to the resolution is the main reason I am shooting the back.  Nice idea, but there are plenty of 16mp cameras out there that can equal the DR of the 260 at 15MP. 

The 260, seems to me to have a bit better recovery on highlights, as on average I can recover 1/2 to 3/4 of a stop.  Again when shooting a tech camera this is important as I don't want to be burdened with a lot of attempts.  The tech solution does not currently offer 1/3 shutter speed settings, to you again are a lot more limited in the available shutter speeds, just full stops. 

Color and details at 50 never disappoint me, it's where the camera likes to be shot.  However even at iso 50, I have found that 1/2 of a second can make a huge difference in the noise again in the shadows.  I noticed this on a shoot last month where I found a big difference in noise between 1 sec and 1/2 a second at iso 50. 

Look back to the Digital Transitions post in this forum from back in late Feb, early March, where a series of testing was done indoors, with a 250, 260 and 280.  The 250 basically can be taken to 1600 and still produce a full resolution image with very low noise.  You also have the ability to pull up the shadows on the 250 as much as 1.5 to 2 stops and still have excellent details, this just will not be the case on a 260 or 280 for that matter.

Phase One, may still come out with a firmware update, (I am now starting to doubt it) that will show more improvement for 260 images.  However with CMOS as the primary goal now, I am not sure that too much R&D is being done to the CCD chips anymore.  In the past, when there was not any CMOS to show, Phase did pull some amazing rabbits from their R&D hat on various CCD chips. 

I am a landscape shooter, my website, are show below, PM me if you would like some images taken with a 260 in good light at 50 and 200.  I would be more than happy to send you some.

I also would strongly state, find a dealer, and work with them on this decision.  It's a huge purchase.  The values of CCD backs are falling, and if and when a full frame CMOS is delivered  by Phase One, most likely 2015, the value of CCD's will fall further.  Remember before the IQ250, there really was no other game, just CCD if you were looking for a MFD back. and the values held up well. 

Sincerely
Paul
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Paul Caldwell
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Ken R

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Re: IQ260 Usable ISOs?
« Reply #4 on: June 12, 2014, 10:51:54 pm »

I for one love sensor + when shooting people and even products when I do not need the high resolution of a 60mp file but want the characteristics / look of the larger format and/or the awesome tethered workflow the IQ back + C1 provide. The sensor + file might be 15mp but it is a glorious file. Best 15mp file I have ever seen. It is really superb.

Of course if you want full, high resolution images at any iso then the IQ250 is the ticket. I for one still prefer the look of the ccd and most importantly the look of the large chip. The difference is akin to the one between an APS-C (1.5x crop) or APS-H (1.3x) cam and a full frame 35mm sensor cam.

The 60 and 80mp chips are still the largest digital sensors made today (for consumer use).
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Joe Towner

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Re: IQ260 Usable ISOs?
« Reply #5 on: June 13, 2014, 02:19:46 am »

ISO 200 and 400 are good, just not as good as 50 and 100.  It depends on what you're shooting, what you expect from it, and how you're using it.  Take the time to find your dealer and get a little in depth with them.  It may be that shooting at 200 and pulling it up a stop in post suits your needs better.  This is where you as an artist get to define your look and technique for achieving your end product.

Keep in mind that the Hasselblad H4/5D-60 is a Kodak chip, not the Dalsa chip in the Phase, so how it performs is very different.  Different sharpness, tones, color, it's just a completely different beast.

And yes, I REALLY don't like ISO 400 on my H4D-50, but 200 is usable, but 100 & 50 is where I live.  I was chatting with some fellow 'togs earlier this month and they laughed at my wanting to shoot an RZ with film or Fuji pack film, something to the effect of 'I hope you like ISO 100' then realized I'm already shooting at that!
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tjv

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Re: IQ260 Usable ISOs?
« Reply #6 on: June 13, 2014, 05:24:41 am »

The Hasselblad H4/5D-60 uses the same Dalsa chip as the IQ160, not a different Kodak chip.
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Steve Hendrix

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Re: IQ260 Usable ISOs?
« Reply #7 on: June 13, 2014, 09:15:42 am »

I'll just add that I have always characterized digital backs (with a few exceptions, notably the 18MP/31MP/40MP Kodak sensor-based products) as 50-200 usable range products when making recommendations. I feel this is a good conservative appraisal to keep expectations in proper perspective. However, as I've shot with the newer backs, I feel that 400 becomes more of a possibility - if shot in the right light, the right subject key, and the right exposure. At least more so than before when 400 just seemed a bit too clumpy to my taste.

There's a lot of situations I wouldn't use it in, and I place a high importance on finding the most optimal quality setting for reproduction in most settings - lowest ISO possible, sharpest aperture possible, etc, so ISO 50/100 and f/8 - ish are common settings, but I wouldn't kick ISO 400 out in a lot of cases where I would have in the past. When you venture past there, YMMV.


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Doug Peterson

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Re: IQ260 Usable ISOs?
« Reply #8 on: June 13, 2014, 09:19:29 am »

David, I've worked with many photographers on the topic of mid and high ISO performance. You'd be amazed how subjective and varied the word "usable" is. The same file can be judged by one person to be "highly usable" while another user considers that same file "complete garbage". So I'd again emphasize that you should either do your own testing (best), work with a dealer that can provide varied real-world raw files for you to make your own evaluation from (not as good as your own test but still pretty useful) rather than rely on comments from users who may have very different needs, expectations, aesthetics, and use than you (better than nothing, but just barely".

Think of a similar question like "will the xyz car be fast enough for me?" being answered by a professional race driver, an andreneline junky, a soccer mom, a professional delivery man, and a teenager. Probably better to look at real world results and do a test drive, no?

Paul2660

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Re: IQ260 Usable ISOs?
« Reply #9 on: June 13, 2014, 10:19:32 am »

I do wish that someone would address the whole issue of just what is happening with a "higher" iso setting on CCD.  Please correct me if I have a incorrect understanding of the physics, which is entirely possible.  But I don't think it's a good practice to set people's mindsets that the iso steps on a medium format CCD is like stepping up the ASA of film or iso of a CMOS chip.  The effects are totally different and very dependent on the raw software being used to convert the file.  The iso tag is a meta tag and you are not pushing the chip up in gain.  If that is incorrect, please correct me with the facts. 

My whole point is that folks looking for a MFD back the first time are basically thinking that the CCD in the back is working the same as a CMOS chip they may be more familiar with, but I don't believe that is the case. 

The post that Wayne Fox made several years go, on getdpi showed this very clearly, I tried to find that post, but was not able.  But as I remember Wayne showed that iso 35 on his IQ180 and iso 200 were basically recording the same information on the chip and the push was being made by C1 in post.  That's how I remember it.  The point being when you increase iso on MFD, you are not pushing the gain or changing anything.  I realize the LCD or tethered PC shows an increase respectively, however I don't think the actual chip is being pushed.  Wayne's post was very well done and showed examples. 

What I am trying to get to is, that with a CCD chip "is there really a high iso", or just meta settings that are seen in worked up in C1.  I understand that Sensor plus is a totally different binning 4 to 1.  It would be nice to have this explained.

Paul
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Paul Caldwell
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jerome_m

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Re: IQ260 Usable ISOs?
« Reply #10 on: June 13, 2014, 12:04:19 pm »

I do wish that someone would address the whole issue of just what is happening with a "higher" iso setting on CCD.

As far as I know, it really depends on the design of the individual back. Some cameras have an analog amplifier before the A-D converter and that amplifier is turned up for higher iso. Other cameras simply take every picture at base iso and shift the bits around to emulate higher iso. This does not necessarily give worse results.
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Ken R

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Re: IQ260 Usable ISOs?
« Reply #11 on: June 13, 2014, 12:10:41 pm »

I do wish that someone would address the whole issue of just what is happening with a "higher" iso setting on CCD.  Please correct me if I have a incorrect understanding of the physics, which is entirely possible.  But I don't think it's a good practice to set people's mindsets that the iso steps on a medium format CCD is like stepping up the ASA of film or iso of a CMOS chip.  The effects are totally different and very dependent on the raw software being used to convert the file.  The iso tag is a meta tag and you are not pushing the chip up in gain.  If that is incorrect, please correct me with the facts.  

My whole point is that folks looking for a MFD back the first time are basically thinking that the CCD in the back is working the same as a CMOS chip they may be more familiar with, but I don't believe that is the case.  

The post that Wayne Fox made several years go, on getdpi showed this very clearly, I tried to find that post, but was not able.  But as I remember Wayne showed that iso 35 on his IQ180 and iso 200 were basically recording the same information on the chip and the push was being made by C1 in post.  That's how I remember it.  The point being when you increase iso on MFD, you are not pushing the gain or changing anything.  I realize the LCD or tethered PC shows an increase respectively, however I don't think the actual chip is being pushed.  Wayne's post was very well done and showed examples.  

What I am trying to get to is, that with a CCD chip "is there really a high iso", or just meta settings that are seen in worked up in C1.  I understand that Sensor plus is a totally different binning 4 to 1.  It would be nice to have this explained.

Paul

Hi, I just did a test with my IQ160. I photographed a portion of my kitchen in my apartment. Light level (measured in EV using an incident meter) was 8.3. Not ultra low but but low. Quality of light was pretty bad since the windows (my main light source) have a greenish tint.

I used the following exposure settings and camera/back setting combinations:

meter iso / back iso
iso 50 / iso 50
iso 100 / iso 100
iso 200 / iso 200
iso 400 / iso 400
iso 800 / iso 800
iso 800  / iso 50
iso 800 / iso 100
iso 800 / iso 200
iso 800 / iso 400
iso 200 / iso 50
iso 200 / iso 100
iso 100 / iso 50

iso 200 / iso 200 sensor +
iso 400 / iso 400 sensor +
iso 800 / iso 800 sensor +
iso 1600 / iso 1600 sensor +
iso 3200 / iso 3200 sensor +

Long story short,

Yes, shooting at iso 800 camera setting and back set at iso 800 and comparing it to the shot with the back set at iso 50 but the camera setting identical (1/8 s @ f13 on both)  and raising the exposure slider in the iso 50 shot on C1 4 stops resulted in similar files. The iso 50 shot was a HAIR cleaner in some areas but in most it was almost identical.  

The sensor + files look cleaner than the shots made at equal iso in non sensor + mode (well the iso 200/400/800 ones since iso 800 is the max the back allows in non sensor + mode) even when I take the full res files and downsample them to 15mp size. At iso 800 the difference is pretty significant even though the iso 800 shot on full res mode looks good. At iso 200 the difference between sensor + and full MP is much less so since the 60mp file still looks great.  

Again, results do vary depending on subject and light conditions but this gives me a general idea of how the system behaves at different iso settings.

Of course, as in ALL cameras the lower the iso and the better the light the better the results and the more maleable the file will be.

Bottom line the IQ160 back is very very versatile and not just an iso 50 capture device.
« Last Edit: June 13, 2014, 12:14:15 pm by Ken R »
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Paul2660

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Re: IQ260 Usable ISOs?
« Reply #12 on: June 13, 2014, 12:15:51 pm »

Ken,

Thanks for the testing.  It pretty much confirms my thoughts.  I fully agree sensor plus is a totally different result.  For my work, I have pretty much determined that the 260 was not a good decision, and instead I should have opt'd for a 280 or used 180, (for the sensor plus at 20MP).  There just too many times I need a faster shutter speed and can't get there at 50. 

Your test is showing the same results Wayne got, so I guess there is not much reason to push the iso, but instead go ahead and under expose 50 since as you point out, the files are a tad cleaner, and I bet will have more overall detail. 

Paul
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Paul Caldwell
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Ken R

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Re: IQ260 Usable ISOs?
« Reply #13 on: June 13, 2014, 12:55:01 pm »

Ken,

Thanks for the testing.  It pretty much confirms my thoughts.  I fully agree sensor plus is a totally different result.  For my work, I have pretty much determined that the 260 was not a good decision, and instead I should have opt'd for a 280 or used 180, (for the sensor plus at 20MP).  There just too many times I need a faster shutter speed and can't get there at 50. 

Your test is showing the same results Wayne got, so I guess there is not much reason to push the iso, but instead go ahead and under expose 50 since as you point out, the files are a tad cleaner, and I bet will have more overall detail. 

Paul

When working untethered out in the field and just using the rear lcd for image review its best, IMHO, to use the higher iso so that the previews on the lcd look good.

Looking at my shots again I see that at iso 200 there is very little advantage to using sensor + unless you want the smaller file. At iso 400, sensor + has an edge but the full res file still looks quite good at that iso that the decision is tough.  At iso 800 and above its best to use sensor +.

I have no clue how the IQ180/280 compares but of course the  larger file in sensor + mode is an advantage. 20mp is plenty for a lot of things although again I find that the 15mp sensor + file is too.
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Doug Peterson

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Re: IQ260 Usable ISOs?
« Reply #14 on: June 13, 2014, 05:35:59 pm »

Sensor+ at ISO200 is more about post-processing flexibility in the shadows than straight-on processing. If you lift the shadows heavily you'll find the 200+ files take abuse better (albeit at a lower resolution) than the 200 full-res files.

A 200+ file will take a tremendous amount of adjustment in C1 and still show super clean and smooth.

alajuela

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Re: IQ260 Usable ISOs?
« Reply #15 on: June 20, 2014, 11:35:47 am »

I have an honest question. I understand the difference in the CMOS / CCD iso issue -- CMOS actually amplifies the signal which CCD does not, it only tells the software to slide the "histogram"

Now for the question - on CCD if I shoot iso 50 / f11  @ 1/125  will my file be smaller than iso 100 / f5.6  @ 1/60?

I am asking this question based on the experiences that overexposed files are larger than underexposed files.

Also making the assumption that larger files have more information  IE. details and tonal transitions.

If one file is larger than the other - would that not be the better file to work with?

I will try this out this weekend, but would like to know it even my assumptions are correct - just trying round out the concepts, fit it all together

Thanks

Phil
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