Megapixel vs Quality

[petermmc]

A DX format D300 and a FF format D700 have similar mexapixel counts (around 12 and a bit million). One of the reasons you may consider purchasing a D700 might be that the pixels are bigger allowing more detail and light and other stuff. When you use a dx lens on a D700 you only get to use a patch of pixels in the middle which I would estimate to be about 8 megapixels worth (could be 6). My maths maybe wrong and my megapixel counts may be a bit out but the question that follows is what I am getting at:

What is the difference in quality between two pictures - one taken on a standard D300 and the other taken on a D700 using DX cropping? To make this more real, if I were to enlarge to say A3, would I notice much difference using my trusty 17-55 2.8 tank?

The reason I ask this question is that if I go to FF one day, would I have to sell all my DX lenses or could the larger pixel size of the ff off set the fewer pixels that I can utilise using dx lenses? That has also turned into another question. At the back of my mind is the fact that Nikon will inevitably introduce a higher megapixel D700 kind of camera maybe 24 megapixel that would give DX users a much higher resolution when cropped for DX. The extra cash paid for this camera would be offset by the savings in not purchasing a whole raft of new lenses. The reason I say it is inevitable is that my local camera dealer said it would definitely happen this year and he never knowing lies

I wonder if it would be possible for the next ff d700 range of camera to have a higher density of pixels just in the dx range that could be turned on when the dx format is required. This would mean that the top of the range dx (currently d300) and the bottom of the range ff (currently d700) would merge into the same camera providing both ranges of users with a great machine and many future possibilities.

[Grev]

I think the FX area is 864mm2 and the DX area is 384mm2.

Therefore the DX crop on the D700 is only 5mp or so.

Knowing this, you can use some DX lenses on FX bodies, like the 17-55mm can be used from 28mm onwards (the extreme borders are fuzzy though) and the AFS 35mm f1.8 can be used (quite acceptable corner sharpness) provided you don't mind a little 'arty' vignetting at the corners.

I tried other DX lenses, don't use them is what I say.

[ljxphotography]

I shoot DX crop on my D3 a lot when im trying to get more reach shooting motor sport, I am hard pressed to see a difference a FF and a DX crop image, and I dont think you are going to see much difference in an A3 print.

I print A3 from my D2hs 4.1 mp and the results look pretty good.

there aint much point shooting with a FF body and using DX lenses, thats not what you get a FF body for.

Mick

[gstark]

I am hard pressed to see a difference a FF and a DX crop image,

If they're both shot on the same camera - A D3 or a D700, then I'd be very surprised if you could see any differences - they should, in effect, be the same image.

But the D300 shoots at a higher resolution, and if resolution is what you're after, then one should be looking at either the D300 or the D3X.

What is the difference in quality between two pictures - one taken on a standard D300 and the other taken on a D700 using DX cropping? To make this more real, if I were to enlarge to say A3, would I notice much difference using my trusty 17-55 2.8 tank?

From those two cameras, yes, I would expect to notice a difference.

The reason I ask this question is that if I go to FF one day, would I have to sell all my DX lenses or could the larger pixel size of the ff off set the fewer pixels that I can utilise using dx lenses?

I would not be looking at DX lenses were I looking to go FF. There's more to FF than just the pixels.

I wonder if it would be possible for the next ff d700 range of camera to have a higher density of pixels just in the dx range that could be turned on when the dx format is required.

In just the Crop sensor portion? That would be an interesting way to move the technology.

The D3X already has a higher pixel density, which is roughly equivalent to the density of the D300. I would expect to see this technology downsized into a D700 variant before the end of the year.

[aim54x]

Slightly off topic...but i would take the D700 or D3 with their FAT pixels and not worry about the DX...you should be able to get decent prices for your DX glass.

[ATJ]

FX format: 4,256 x 2,832 [L], 3,184 x 2,120 [M], 2,128 x 1,416 [S]; DX format: 2,784 x 1,848 [L], 2,080 x 1,384 [M], 1,392 x 920 [S]

2,784 x 1,848 = 5,144,832 = 5.1MP

[Glen]

Peter, I think this is being looked at from the wrong end. If you use DX lens on a FX camera you are using all of their image area. Most lens are at their optimum in the centre and quality wanes towards the edge. So the 5mp you do get may only have 4mp at the quality you desire. By comparison using a FX lens on DX uses the best quality section of the lens.

This post would have been more useful before you bought your DX lens, but in reality, for the money you are paying, I think you will be asking too much from your DX lens. I think Cameron and Grev have it right, sell the DX glass and buy FX glass, even if s/h, you are sure to get a better result. A DX 17-55 still gets a good price s/h. Otherwise you will have a $5k combination which provides 5mp pictures from the centre of the imageviewer which aren't even perfect edge to edge, doesn't seem like good value?

[petermmc]

Thanks all, as usual, great feedback and all food for thought. I think I would wait until a newer version of the d700 comes around before I moved to ff. Meanwhile I may get ready by selling my dx glass and concentrate on less but better ff glass.

[Grev]

Get the AFS 35mm f1.8 no matter what. It's a great lens.

[chasem]

Using megapixels as a quality guide is a sale pitch. my 4mp D2H take far better photos than any 12mp Point and shoot that i have used!