OT: Need help deciphering a statement in a digicam user manual

[DougK]

OK, I know there's folks hanging around here who are a lot more proficient with digital camera technology than I am, so here goes.

On page 74 of my Nikon Coolpix 8700 manual, there is an interesting statement next to the black-and-white menu option:

Black-and-white images require same amount of memory as color images, but show a higher level of detail.

Why would this be? If you're in black-and-white mode, is it treating every photosite on the sensor as a pixel instead of the photosite averaging which occurs using the Bayesian GRGB matrix on the sensor? If so, that means you're getting higher resolution images in B&W than you can in color, which would make this camera a great B&W shooter for me. I couldn't find any information on Nikon's website.

Any help appreciated and thanks in advance.

 

[rover]

Written by the marketing department for sure.

 

[Doug]

I think the only way to get higher resolution is by getting more pixels. So, in B&W mode, if the camera is serving you up a pic with more pixels than in color, you then know that it's reporting each photosite as a pixel, and you have your answer. 🙂 If it's not doing this, and I'm guessing it isn't, the statement is puzzling. If each group of photosites is reporting one grey-scale pixel, it should require only 1/3 the memory of a color image. Probably it's giving you the same three color layers but with zero saturation; that would take the same memory as a color image, but I don't see where this would produce more detail.

 

[DougK]

That's what had me puzzled as well. I can't imagine that the camera is intelligent enough to make the switch between pixels and photosites, so there must be another explanation. It's entirely possible that the statement actually refers to how the camera applies sharpening, noise reduction, etc. to the image, but as written it's just unclear.

Gotta love those tech writers 🙂

 

[pvdhaar]

The statement could basically be correct. Each pixel in colour photography is obtained by interpolating from a number of adjacent photo-sites (typically in the ratio of one Red to one Blue to two Green). This interpolation is a form of weighed averaging. The best way possible is to use the luminance value of each individual site, but to obtain the colour ratio of that pixel by averaging values from neighbouring photosites.

For black and white photography, the luminance value of each photo-site can be used straight away, and averaging is not required.

Whether that's actually done in the mentioned camera is of course anyones guess.. It's certainly possible if you use RAW and have good postprocessing..

Conclusion is that in colour photography you can have the same luminance resolution as in B&W, but that the colour resolution is lower than that. This may not be as bad as it sounds, as the human eye is so much worse at seeing colours than at seeing brightness..

 

[DougK]

Thanks Peter, that makes sense. I'm about ready to call Nikon tech support and ask them what they meant.

 

[ch1]

The statement could basically be correct. Each pixel in colour photography is obtained by interpolating from a number of adjacent photo-sites (typically in the ratio of one Red to one Blue to two Green). This interpolation is a form of weighed averaging. The best way possible is to use the luminance value of each individual site, but to obtain the colour ratio of that pixel by averaging values from neighbouring photosites.

For black and white photography, the luminance value of each photo-site can be used straight away, and averaging is not required.

Whether that's actually done in the mentioned camera is of course anyones guess.. It's certainly possible if you use RAW and have good postprocessing..

Conclusion is that in colour photography you can have the same luminance resolution as in B&W, but that the colour resolution is lower than that. This may not be as bad as it sounds, as the human eye is so much worse at seeing colours than at seeing brightness..

But would there be a difference between Color and B&W if one was shooting in RAW (NEF) mode? I thought there was no pixel interpolation in RAW mode? 😕

 

[DougK]

RAW mode just means it's not preprocessing the image (sharpening, contrast, white-balance) and compressing it into a JPEG format for you. The pixel interpolation still happens to generate the actual image pixels because of the Bayesian matrix over the photosites (if I understand all this stuff correctly) which is where the statement in the manual becomes highly confusing.

T-Max is so much easier to understand 🙂