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Thread: Is it all about the size of the chip?

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    Subscriber Member KurtKamka's Avatar
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    Is it all about the size of the chip?

    Maybe it's more of a philosophical question as I'm not certain if there is a perfect answer. But, I'll throw it out there anyway. In trying to evaluate different MF alternatives, one of the major decision points is trying to understand the difference in IQ, DR and resolution between backs like the P25+ and the P30+.

    Do you stick with the fatter pixels and 22meg resolution of the P25+ for potentially greater DR or go with the microlenses and smaller pixels to gain a (significant/not so significant) jump in resolution/detail to 31megs? Any thoughts from this non-opinionated MF group?

    Kurt

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    Re: Is it all about the size of the chip?

    I view it the same way as the aps-c vs FF debate. Bigger chip with a reasonable number of fatter 'pixels' will always give better IQ (and some of that is in the eye of the beholder).

    However, the key thing here is 'reasonable'. Much like some are seeing as Canon moved from the 1Ds2 to the 1Ds3, the ramp in MP offers some modest bump in resolution, but there is a price to be paid in clean ISO ceiling, DR and the impact of in-camera NR, long exposures, etc., etc.

    I think a lot of the more naive (I'm being polite) D3 owners out there will be 'disappointed' when they start comparing shots between the D3 and D3x as MPs double within the same real estate.

    I would think one of the key determinants would be how large you want to print and if you'd need the extra MPs to have more meat to play with or not ; and if you need that bulk badly enough to pay the price (in very real $$ as well as DR, etc as you say) that come with those 'fatter' files.

    I would think 18-22MP on the larger (vs 35mm FF) would be sweet spot for a lot of folks. That said a 16MP square (36x36) CCD sensor with no AA filter as in the the CFV is very appealing.

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    Administrator Bob's Avatar
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    Re: Is it all about the size of the chip?

    As a un-opinionated non MF owner I have a few observations.
    From sampling theory we see that in order to resolve a periodic function, one must sample at a frequency at least twice the frequency of the sampled data.
    In intuitive terms, then if line pairs were considered, say alternating black and white, than a black pixel followed by a white pixel is the best you can do, and is the highest resolving capability of a given sensor.
    Given that basis, and ignoring the de-bayering algorithms that synthesize color information, we can generate the following theoretical resolving power:

    Camera sensor pixels max LP LP/mm M8Resfactor MaxPrintfactor
    M8 27.0mm 3916 1958 72.5 1.00 1.00
    D3 36.0mm 4256 2128 59.1 .82 1.09
    P20+ 36.9mm 4080 2040 55.3 .76 1.04
    P25+ 48.9mm 5436 2718 55.6 .77 1.39
    P30+ 44.2mm 6496 3248 73.5 1.01 1.66
    P45+ 48.9mm 7216 3608 73.8 1.02 1.84

    Neglecting for a moment anti-moire filters and other factors such as noise and lens capabilities we see that these various cameras have a fairly narrow range of resolving capability but a larger range of print size capability at the same on-sensor resolution. That means that given equal capability resolving power lenses the P45+ can produce a print that has linear dimensions 84% larger than the M8 with about equivalent on-print resolution. Further, I see no significant advantage to using the P20+ back at all, I'd rather carry an M8.

    Next let's think about noise.
    We often pixel peep and complain about noise that gets lost in printer dithering, but that being said, there are two factors that affect noise. One is the stochastic nature of photon distribution over the sensor and the number of them that must strike a pixel to raise it to a given charge threshold. The smaller the pixel size, the larger this stochastic noise will be. It is just the nature of light in the particle view of things (please don't get me started on the wave issues). This becomes worse as light levels get lower and at the theoretical lower limit at true DMax-limit there might be an equal probability of a photon strike on a pixel or not at a 50% noise threshold during the exposure duration. Of course that photon strike may or may not knock one electron's charge which is as low as we can expect to get and that is a function of lattice doping and other lossy factors such as passivation, reflection, metalization, and filter absorption. Being as lazy as I am, I am not going to calculate this, but I estimate that this loss amounts to at least an order of magnitude, but I digress. The bottom line is that for a given sensor technology, the ratio of pixel area determines the ratio of threshold dark sensitivity. In addition, CCD and transistor based sensor cells both suffer from a saturation phenomenon which roughly means that the larger the cell's area, the greater the number of quantizations of charge that may be theoretically measured. So, twice the area and twice the potential iso as well as twice the potential dynamic range.
    The M8 employs a 6.8 micron square pixel and shares this size with the P30+ and the P45+. The P20+ and P25+ are both 9 micron and the D3 is between at 8.45 micron.
    From this, given equivalent analog to digital conversion, I would assume that noise levels of the M8, P45+ and P30+ could be equivalent, the D3 would be lower, and the P20+ and P25+ lower still.
    How this translates into iso levels is a bit dependent on the quality of the a to d conversion as well as the manufacturer's decision on how much black level noise is acceptable in their nominal iso rating. What it means to us is that a large pixel sensor will yield lower noise and smoother gradations in the darks.

    So, for my money I have decided that:
    For low light hand held stuff I got a D3
    For portable use with decent performance I am keeping my M8
    When I want larger prints (and I just might) it makes no sense for me to buy anything less than the P25+ unless I am willing to invest in MF lenses with M8 equivalent lens quality which would indicate the P45+ or maybe I just want the MF way of doing things.

    -bob

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    Subscriber gogopix's Avatar
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    Re: Is it all about the size of the chip?

    it is a tough trade, but I can say that, having had the P25, P45 and P45+ the main advantage of the P45 over 25 beside the scale, is that normal post needs NO sharpening for up to 11x16.
    the penalty in size did not seem to matter; the 9 mcn 25 had no better noise than 6.8 P45.

    The P45+ added a bit for less noise, but most 'PLUS" advantage was in better screen etc.

    the 30+ is intirguing since it has small pxls but higher ISO, and from files, it works. Also, the 30 gets back some telephoto since the crop translates to more pixels in center so actually MORE reso;lution if you blow up for wildlife say (it is why I am considering)

    All great backs though.

    I am sure SInar and Leaf also have technology improvements so pixels dont tell the complete story

    Anyway, Kurt, pleased to see you are considering. Then you can sell that other stuff.!

    Victor

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    Subscriber Member KurtKamka's Avatar
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    Re: Is it all about the size of the chip?

    Rob and Bob, thanks for the responses. Excellent break-down of the information.

    Victor, you crack me up. If I go the MF route, one system is the odd man out in the MF, D3 and M8 love triangle. I'm certain I know which one you'd boot to the curb.

    Kurt

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    Administrator, Instructor Guy Mancuso's Avatar
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    Re: Is it all about the size of the chip?

    Victor there is more to the Plus series than just a better LCD.

    Here is just a sample from the Phase site and actually I can't find the right section on the Plus series but here is a idea .

    New Digital Back Features
    • Patent pending XPose+ technology enables exposures of up to 1 hour, providing photographers
    with the time to create fantastic images by using creative techniques such as extreme light
    painting. Challenging location work, which often forces photographers to compromise on
    image quality and creativity, benefits from noise-free images at extreme temperature changes
    due to XPose+.
    • New live preview feature with a scalable focus window supports an effective workflow
    between the professional shooter, the art directors and stylists on large production jobs.
    • A unique and patented level meter to ensure the perfect horizontal setup with very high
    precision.

    Best in Class Color Reproduction
    • Opticolor+ is a unique image processing algorithm, delivering high color accuracy in deep
    shadows as well as capturing perfect skin tones.
    • Dynamic+ technology ensures less noise at all ISO settings and breaks through previous
    photographic limits such as the ability to work in very low light.

    Workflow Gains
    • The P+ series includes the new Capture One 4 RAW workflow software to speed the handling
    of RAW images. The software features capture rates of up to 70 per minute (with the P 21+
    digital back), booting times close to 1 second, unlimited burst capacity, and support for
    compact IIQ RAW format.
    • Capture One 4 also provides immediate preview generation and image processing of high
    resolution 120 MB TIFF in less than 20 seconds.
    • The Capture One RAW software is easily integrated with Adobe®’s Photoshop, Adobe®’s
    Lightroom, Apple®’s Aperture and iView®’s MediaPro.

    The P+ Series:
    • P 45+: 39 mega pixel top of the line shooter with unlimited burst sequences.
    • P 30+: 31.6 mega pixel top quality fashion shooter with superior moiré control.
    • P 25+: 22 mega pixel all-round shooter optimized for large format photography.
    • P 21+: 18 mega pixel fast and flexible high-end DSLR alternative.
    • P 20+: square format, 16 mega pixel all-round studio portrait shooter.
    Photography is all about experimentation and without it you will never learn art.

    www.guymancusophotography.com

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    Administrator Bob's Avatar
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    Re: Is it all about the size of the chip?

    I like the P45+ and the P25+
    I see no advantage for my purposes to the P20+ and the crop on the P30+ was annoying since the bodies are optimized in general for a larger sensor.
    -bob

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    Re: Is it all about the size of the chip?

    Bob - thanks for supplying a nice summary. I too have kept my M8 system, bought into D3 and sold my Canon system - much for teh same reasons you site above. However I garner significant benefit from teh resolving power of my Schneider lenses on an Alpa with a MFD back - benefit enough for me to now be investing in a Rollie Xact view camera system for more studied work - employing a range of Rodenstock and Schneider optics. A luxury that comes at a cost - after 'encouragement' from Marc Williams

    My move into MFD in three forms now removes any possibility that my hobbyist's indulgence and any lack of ability an be blamed on equipment.

    Still I take some comfort from forcing myself to sell 2 very complete 35mm systems in Canon and Leica R - the proceeds of which have paid for my big boy Hasselblad a few lwnses and teh soon to arrive Xact system.

    Kurt - People develop their preferences over time using this stuff. I guess I spoilt myself starting with a Leaf Aptus 75. I sold that back only to replace it with an H3D-31 so I could use the Phocus software from Hasselblad - only to replace that camera with the H3D11-39 once having proven the benefits of the Hasselblad work-flow.

    The great thing for people that are starting out in this exploration is that there is now a greater abundance of used and refurbished backs to choose from. Your potential entry point from a cost perspective is much much lower than mine was just 3 years ago.

    I do believe that the Phase One partnership with Mamiya is going to deliver a very competitive product to the market. Irrespective of back choice though - I would encourage you to consider the Mamiya camera and lenses as a more than adequate system.

    Regarding your question specifically - given the right light and technique, any MFD back will deliver an Image IQ significantly better than any 35mm system I have used.

    Good Luck
    Pete

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    Super Duper
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    Re: Is it all about the size of the chip?

    Kurt, I think one of the components of this is what camera/lenses you may wish to use and how you use them.

    If I were to favor a Contax 645, I'd want to know which back would best realize the system's capibilities ... is a P25+ enough for the optics (as Irakly believes), and does the P45+ reach a point of dimminishing returns considering the incremental costs? Does a 31 meg back further the capibilities of the fast aperture Contax/Zeiss lenses by providing a stop more speed, thus making it worth the money? ... but if used on a technical camera is no longer on the shopping list?

    If, like Peter A, you intend using a back with a view camera or ALPA with their unquestionably superior APO/Digital Schneider or Rodenstock optics, does the 39 meg back loom dominate and worth the money in order to full-fill the system's abilities? ( MO the answer is YES, trust me on this : -)

    My array is a M8 for light travel and fun street; Nikon D3 for necessary DSLR advantages and lowest light work at weddings; a Canon 1DsMKIII because it adapts to a very wide array of "fun" lenses; a CFV-II that delivers images beyond what it scientifically should be producing compared to other systems; and the big boy H3D-II/39 with a choice of H/C and V glass ... but truely shines on a Rollei Xact.

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    Re: Is it all about the size of the chip?

    Kurt,
    What you need to do is test all these backs for yourself just the way Guy did when he was in San Juan... and give yourself enough time to do it thoroughly. If you're leaning towards Phase I'm sure Lance will be happy to work with you on this. Flying to Florida at this time of year is pretty cheap and you're welcome to stay at my half-way house for photographic junkies

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    Re: Is it all about the size of the chip?

    Marc,

    The more I look at your gear the more I get the feeling that your philosophy is just to buy them all

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    Administrator, Instructor Guy Mancuso's Avatar
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    Re: Is it all about the size of the chip?

    Well I agree testing them out and getting a feel for them is the true road to bliss on this stuff. Been really thinking about this for GetDPI to do more things that revolve around getting all the players in the same house and let folks play. Seriously as David said even with my long time experience nothing beats getting the damn thing in your hands and shoot it, figure it out and than analyze everything about it like I did with the Phase backs and in turn I actually bought one. I can't sleep now. LOL It should be here hopefully most of it today. The Phase body should be here in a few weeks . Once again first in the oh **** line of being a beta tester.

    Sorry folks but Marc is my hero. I love him, at least he gets out there buy's this stuff and figure out what is the best for him and his words of wisdom usually ring true. I tried not to listen to him much in the past because I knew it would cost me money but he is too hard to ignore
    Photography is all about experimentation and without it you will never learn art.

    www.guymancusophotography.com

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    Re: Is it all about the size of the chip?

    When it comes to Marc's gear I say look at his work! Regardless of what system he is shooting the results are most often spectacular. JMHO

    Woody

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