139 replies to this topic

[craig]

I've edited this post after reading the link davichin has provided. It appears in that article that diffraction is a function of f-stop rather than physical aperture. I'm looking for a detailed explanation of that. Meanwhile I've deleted what appears to be contradicted by davichin's article. The rest is consistent with it, though frankly his article is far more informative that what I have to say. It's a worthwhile read.

For a given aperture, diffraction will limit the maximum lines/mm that a lens can achieve and the total resolution of that lens will be no better than that limit over the surface of the frame. For an ideal lens at small apertures, a 35mm full frame system has roughly 4 times the total resolution of 4/3 because of it's larger coverage. Lenses are not ideal but they aren't so bad that smaller formats can overcome such a huge handicap.

In order for a 4/3 macro lens to break even considering its sensor size, it would have to offer double the lines/mm over its surface and I'd love to see a test that showed that (along with an explanation for why everyone else sucks so bad). Even if it were that capable, the smaller still offers inferior sensor performance due to its pixel pitch and inferior DOF/resolution compromises compared to the larger sensor. The Oly 50mm macro lens may be the sharpest lens ever tested in terms of lines/mm but that has to be taken in context of its vastly smaller image circle.

As sensors improve and lens performance increasingly limits total resolution, the only way to increase the total resolution of the system is to use a larger sensor. We can argue forever where we are on that progression and the fact is that no one really knows for sure. The logic, though, is inescapable.

[davichin]

For those with time:

http://www.uned.es/p...0outresolve.pdf

from the table on page 15 we can see that FF holds the diffraction 1 step better aprox than DX which is not too much advantage for me.

[craig]

I found the answer here: http://www.cambridge...photography.htm

Since the physical size of the lens aperture is larger for telephoto lenses (f/22 is a larger aperture at 200 mm than at 50 mm), why doesn't the size of the airy disk vary with focal length? This is because the distance to the focal plane also increases with focal length, and so the airy disk diverges more over this greater distance. As a result, the two effects of physical aperture size and focal length cancel out. Therefore the size of the airy disk only depends on the f-stop, which describes both focal length and aperture size.

So what Herb said was exactly correct: the reason 4/3 is more sensitive to diffraction is entirely due to the smaller photosites required for equivalent resolution.

[PRC]

http://www.uned.es/p...0outresolve.pdf

Ah - bedtime reading, my head hurts .

Thanks for the links David & Herbko.

And today's thrill here at work is my second of two days with our tame professor of math ( who does the really ugly bits in our software ) - I hate math - can I go diving now?

Edit

Just found out our tame prof. is a bit of a camera buff - I may be on to a bit of sport today after all.....

End Edit

Paul C

Edited by PRC, 14 May 2008 - 11:14 PM.

[diverdon]

Purported Nikon D3H samples revealed?
http://www.electroni...amples.revealed

Follow the link to the story if you want to use the links embedded in the story.

A video from an alleged insider shows sample images from the as-of-yet unannounced Nikon D3H, which illustrate the overall scale of precision the camera could provide. With an advertised boosted ISO rating of 51,200 (25 to 12,800 native), it would indicate that Nikon is making great strides in reducing sensor noise. The video claims that the photographs were shot with a second generation prototype under various lighting conditions.

The video is not the first to surface from the individual, identified on YouTube as Lilkiwiguy87, who has also posted videos with specifications of both the unofficial D3H and D3X, as well as a sneak preview of the cameras’ chassis designs. The sneak preview alludes that he is one of several worldwide to test the cameras, which may not see release this year.

The alleged leaks follow Nikon’s unveiling of the standard D3 in August of 2007, which offered users a large upgrade from the company’s flagship D2/H/X platform. An upgraded firmware was also unveiled, citing a maximum pixel size of 24.4 megapixels, which was not authenticated by Nikon.

Edited by diverdon, 22 May 2008 - 04:25 AM.

[loftus]

Here's the same guys D3x.
Hmmm, I'm a little sceptical.
http://www.youtube.c...feature=related

[diverdon]

Hmmm, I'm a little sceptical.

Loftus, you are probably correct to be skeptical. Only 17MP and not released till July 2009? I much prefer the 24MP with release to come in May 2008 rumor. And 24bit color depth? I hate to be a troglodyte, but what would you need more than 16 bit color depth for? And what would you do with it if you had it?

I apologize to the board for not vetting the source before posting.

[davichin]

A new D700 rumour: mobile phone pics of a publicity leaflet from factory: D700, 12.1 mpx, great viewfinder, same grip as the D300´s MBD10:











more:

http://www.fredmiran...um/topic/657828

[diverdon]

http://www.kenrockwe.../nikon/d700.htm

Ken Rockwell has some more info on the D-700. Now lets here something on the D3x.

[loftus]

Pray, pray, pray this fits in a D300 Subal Housing. Could be a huge Christmas (even though I'm Jewish), D300, D700 and a shiny new Subal D300 housing. Taking donations!

[NWDiver]

So Aquatica was going to make housing upgrade for D200 owners to the D300. Did that ever happen? Could it be too much to hope for that D200 owners can upgrade to the D700 without buying a whole new housing????

[Viz'art]

The conversion package is available as part # 20057-R and even includes a repaint of the owner's D200 to the new black paint finish at no extra charge but the shipping.

As for the D700, well let's just see one for starter, thses who know us know that if it possible we will make it happen, but the camera will need more than just battery pack compatibillity <_<

[knewton]

The conversion package is available as part # 20057-R and even includes a repaint of the owner's D200 to the new black paint finish at no extra charge but the shipping.

As for the D700, well let's just see one for starter, thses who know us know that if it possible we will make it happen, but the camera will need more than just battery pack compatibillity <_<

Hey Jean,

I seem to recall hearing that Aquatica was going to work on a D3 conversion for the D2X housings--is that a myth or reality? would it even fit?

[Viz'art]

It was close but no cigar, the D3 suffer from aerocephalis, meaning inflated head, that full frame prism made the top just a whee bit to snug and the control location was quite different. so no go on that one, but not for lack of trying.

[Undertow]

the d700, if real, wont fit in any D200 or D300 housings - the AF module & viewfinder prism will have to be inflated as per D2x-D3 like Jean said.

I'm quite surprised they would introduce a camera that would compete directly with their D3 so soon, thought we'd see D3x & D90 first. flyers do look pretty convincing though.

[gobiodon]

I'm quite surprised they would introduce a camera that would compete directly with their D3 so soon, thought we'd see D3x & D90 first. flyers do look pretty convincing though.

There is a big market pressure. Sony is coming with a full-frame model, canon will also upgrade the 5D soon.

[Alex_Mustard]

The 'D10' finder may have to be taller than the one on a D300. :glare: The eyepiece center may be a tad higher. :glare: The fit of a 'D10' in a D300 housing may thus not be 100%.

Still a damn good point!

[diverdon]

Nikon unveils D700 full-frame digital SLR
Monday, June 30, 2008 | by Rob Galbraith

http://www.robgalbra...cid=7-9311-9483

their are also lots of official pictures of the D700 on Robs site.

Nikon has filled in the gap between its midrange and pro digital SLRs. The D700, announced today and slated to ship in late July 2008, looks like a D300, acts like a D3 and promises to be as big a hit as each of them. Nikon has taken the full-frame 12.05 million image pixel CMOS sensor from the D3, placed it inside a body that is similar to the D300, weaved in capabilities from both and put a U.S. price tag of US$2999.95 on the result.

Nikon D700 feature summary

If you own a D3 and a D300, then you have in two separate bodies most of the key bits and pieces that comprise the D700. Its main features include:

* A weather-sealed magnesium alloy body with popup flash that at a glance looks very much like the D300, though putting the D300 and D700 side-by-side reveals that:

o The D700 is taller, sports an FX badge on its front and has a larger and more sculpted viewfinder bubble (plus various other small styling differences)
o It has a round D3-style eyepiece opening rather than the rectangular type of the D300
o The multicontroller on the back is pulled directly from the D3
o The CF slot door slides rather than swings open
o The INFO function has its own button
o The caps on the 10-pin remote and PC sync ports are a different design than either the D3 or D300

Open in new window
Fraternal Twins: The Nikon D300 and D700, side-by-side. Click to enlarge (Photos courtesy Nikon)
Put more simply, handling the D700 is like handling a slightly bigger D300 with a larger viewfinder and better multicontroller. Make that much better: Nikon has really nailed the usability of the multicontroller with the D3, and it's great to see that the same component is on the D700.

Edited by diverdon, 01 July 2008 - 04:27 AM.

[Alex_Mustard]

Good info, Don.

[diverdon]

It looks like DPReview has some info up also.

http://www.dpreview....views/nikond700

The introduction of Nikon's new D700 may been one of the worst kept secrets in an industry with more leaks than the Titanic, but it was still something of a surprise coming so hot on the heels of the D3 and D300. Essentially a D3 shrunk down and squeezed into a body roughly the same size as a D300, the D700 is Nikon's first 'compact' professional SLR, and seems designed to go head-to-head with whatever Canon has up its inscrutable sleeve to replace the EOS 5D.

The imaging side of the D700 is pretty much the same as the D3; it shares the acclaimed 12.1MP full frame ('FX') sensor and has the same processing engine, so we would presume output to be almost identical. The main differences (aside from being considerably smaller) are physical; there's a different shutter (good for 150,000 exposures rather than 300,000 on the D3), different viewfinder prism (with 95% coverage) and a slower burst rate. You also lose the rear LCD info panel (there's no room for it) and one of the D3's two CF card slots, but you do get a couple of extra features to soften the blow slightly; most notably a self-cleaning sensor and a built-in flash. We'll look a little more in-depth at the differences between the D3 and D700 in a moment.

The D700 joins the D3 as a fully-fledged 'professional' model; it has the same tank-like build quality (though we're sure the pop-up flash will cause a few raised eyebrows), and gets you the full pro service from Nikon. And the pricing (around $2999) reflects this; anyone hoping for an 'affordable' semi-pro full frame Nikon SLR will have to wait until the cost of producing such large sensors falls considerably.

Edited by diverdon, 01 July 2008 - 04:55 AM.