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MF sensor B&W conversion
- Thread starter aztwang
- Start date
V
Vivek
Guest
As posted above, you can venture to do it yourself or convince Dan at maxmax to do it at your risk.
Dan (maxmax), btw, is a straight shooter, highly reliable and recommended.
Dan (maxmax), btw, is a straight shooter, highly reliable and recommended.
thompsonkirk
Member
IMO the real question is whether or not one should do it in the first place. Are you shooting IR files, or IR simulations? If the latter I would think you'd gain by retaining the original RGB fie.
One of the most useful features of larger sensors is that one can use the color sliders to shift tones at advantageous points in the BW conversion. With MF – unless you make big board-room or mural-sized prints – you probably already have enough data for high IQ without needing a mono sensor.
I keep images meant for BW conversion in RGB, making an initial choice between Default and Custom BW layer in PS (usually not a big difference), and then re-do the conversion of tones with the color sliders at later points in post processing.
Just my two cents,
Kirk
One of the most useful features of larger sensors is that one can use the color sliders to shift tones at advantageous points in the BW conversion. With MF – unless you make big board-room or mural-sized prints – you probably already have enough data for high IQ without needing a mono sensor.
I keep images meant for BW conversion in RGB, making an initial choice between Default and Custom BW layer in PS (usually not a big difference), and then re-do the conversion of tones with the color sliders at later points in post processing.
Just my two cents,
Kirk
Last edited:
aztwang
Member
I have emailed a bit with Dan. He had some useful info. Here's a portion of an email he sent me...He's got a sense of humor as well...
"From me...So I'm curious what is your method in removing the bayer array? Do any scratches occur when doing this? Also after a process
like this I would assume an image capture would be over exposed based on settings originally meant for color .
Fom Dan..Hi Don,
I have seen some experimenters who use sharpened wooden sticks or abrasives to scrape away the Color Filter Array (CFA), but that is like doing self-brain surgery with a power drill. It just doesn't work well. We have semiconductor fabrication equipment to remove the CFA - that's why it is expensive and why others are unlikely to follow. If I were to even slightly touch the sensor surface with my finger, it would leave a defect that could be seen later.
Sensitivity changes with frequency of light. You also lose the microlenses which increase sensitivity, but in general:
- Ultraviolet sensitivity goes up by 6x
- Visible sensitivity goes up by 2x
- IR sensitivity goes up until 800nm when the CFA becomes transparent. After 800nm, there is a net loss in sensitivity because of the microlens loss."
I agree, Dan knows his stuff!
This is an interesting discussion. I was tempted several times by a Leica Monochrome in the past (and have seen stunning results from friends and colleagues with both the older as well as the new CMOS sensor based model of this Leica camera), but in the end it always comes down to risk / reward structure etc. For *me* (granted, this is a very personal decision) investing in the X1D as a truly portable medium format camera with plenty of pixel to spare, and a solid workflow de-saturating colors in Phocus followed by a Nik Silver Effex conversion completely cured my desire to have a dedicated monochrome model - for now. I've attached a picture from last week below ("Carmen" - staged by Es Devlin @ the Seebuehne Bregenz in Austria). A dedicated XF backpack might be on an entirely different scale (I have no experience with it), but I can't see making that financial jump anytime soon. Your personal mileage may vary, but the resolution and monochrome conversion of the 50 MPixel MF Bayer-Sensor files are plenty for me and my printing style.
P.S.: Just noticed I can't add the photo. I'll post this note and try to add the picture in a different browser. Stay tuned.
P.S.: Just noticed I can't add the photo. I'll post this note and try to add the picture in a different browser. Stay tuned.
Hmmm...I'm really struggling to the add the picture. Tried 3 Browser Version (Edge, Chrome, old IE11) and limited myself to 2400pixel / < 1MB, but it does not seem to take. One last attempt:
I guess I should really provide context now to size the stage. Mind you, the file size limitations and max pixel size won't due the picture justice.
iiiNelson
Well-known member
Adding thebpicture to your gallery or a site link Flickr and linking the forum compliant link code is the easiest way to attach a picture but I see yours on the last message.
Not conclusive evidence of anything, but I elected to do a side-by-side comparison of the monochrome P45+ and my own color P45+ several years back. My conclusion was the mono sensor was a tad cleaner, and showed a tad more resolution, like maybe 25% (???) more, but *speaking for myself* I didn't feel the advantage was significant enough to warrant the added price for a dedicated mono back. Today, if I regularly shot MF landscape and specialized in doing it in B&W, I would possibly consider a 100MP conversion -- but I'm neither 
Here is a pair of the comparisons for your review, draw your own conclusions. Note too, this was C1 6 IIRC, and the B&W conversion tool in C1 as well as the de-bayering algorithms have only gotten better since. Note there seems to be a slight exposure bump to the mono image -- at the time, we had the two cameras side-by-side and shot them at the same exposure settings at the same time. At this time the P45+ mono had just been released, so I suspect the exposure difference is probably due to the native profile in C1 at the time for each cam at that time. And of course best viewed on a calibrated monitor...
Reference image in color:
100% crops from,
Color back:
Color Back converted to mono:
Mono back:
Cheers,
Here is a pair of the comparisons for your review, draw your own conclusions. Note too, this was C1 6 IIRC, and the B&W conversion tool in C1 as well as the de-bayering algorithms have only gotten better since. Note there seems to be a slight exposure bump to the mono image -- at the time, we had the two cameras side-by-side and shot them at the same exposure settings at the same time. At this time the P45+ mono had just been released, so I suspect the exposure difference is probably due to the native profile in C1 at the time for each cam at that time. And of course best viewed on a calibrated monitor...
Reference image in color:
100% crops from,
Color back:
Color Back converted to mono:
Mono back:
Cheers,
I use an maxmax converted camera for about one year now. Specific I use a full spectrum modified black and white Canon 5Ds.
Paired with good lenses and flawless filter, you are able to achieve an outstanding quality (especial while taking IR pictures).
When it comes to the digital development you should keep in mind that your program of Choice still see the "true monochrome" picture as normal Colour Picture.
I don't know if Phase One spend Capture One a true Monochrome process for the Achromatic backs, but I can confirm that you will lose some potential informations while processing an image, taken with a modified camera (See here http://chromasoft.blogspot.ch/2013/12/accuraw-monochrome-and-true-monochrome.html)
For large prints I use AccuRaw Monochrome and create a .dng for the further editing. In this case you get rid of the colour cast too (green; the filter stack is only removed 95%).
To show you the look of the converted image I uploaded an image I took earlier this year. It is a single frame taken in Infrared (uncoated IR filter 820nm) with an Hasselblad CFE IF 40mm @f4.0. Standard sharping applied and contrast adjusted. You may need to download the images, Microsoft OneDrive is awful for pictures.
https://1drv.ms/f/s!AnQjmF7qULqhhnAcyNlR6rAYxvhi
(1x .jpg, 1x .cr2 OOC, 1x .dng AccuRaw converted)
From my experience this conversion is great, but limited to cameras with live view. To get the full potential of a modified camera you rely need to set your focus perfect.
Best regards
Pascal
Paired with good lenses and flawless filter, you are able to achieve an outstanding quality (especial while taking IR pictures).
When it comes to the digital development you should keep in mind that your program of Choice still see the "true monochrome" picture as normal Colour Picture.
I don't know if Phase One spend Capture One a true Monochrome process for the Achromatic backs, but I can confirm that you will lose some potential informations while processing an image, taken with a modified camera (See here http://chromasoft.blogspot.ch/2013/12/accuraw-monochrome-and-true-monochrome.html)
For large prints I use AccuRaw Monochrome and create a .dng for the further editing. In this case you get rid of the colour cast too (green; the filter stack is only removed 95%).
To show you the look of the converted image I uploaded an image I took earlier this year. It is a single frame taken in Infrared (uncoated IR filter 820nm) with an Hasselblad CFE IF 40mm @f4.0. Standard sharping applied and contrast adjusted. You may need to download the images, Microsoft OneDrive is awful for pictures.
https://1drv.ms/f/s!AnQjmF7qULqhhnAcyNlR6rAYxvhi
(1x .jpg, 1x .cr2 OOC, 1x .dng AccuRaw converted)
From my experience this conversion is great, but limited to cameras with live view. To get the full potential of a modified camera you rely need to set your focus perfect.
Best regards
Pascal
Recently used an IQ260 Achromatic DB and yes, C1 DOES use a true Monochrome process and profile for this Achromatic DB from what I can see. At 60MP this DB is excellent, but I still prefer my IQ3100 images over this back, probably due to its increased DR not to mention a 67% increase in MP from 60 to 100. I can only imagine the quality that will come from the yet to be delivered IQ3100 Achromatic DB.