D2X Gossip

2. using a higher shutter speed than the camera’s fastest certified sync speed.

I do understand the highest sync speed is defined in this way: The shortest possible exposure time where the curtain completely uncovers the whole sensor/film for a certain amount of time – this enables recording all of the strobe light.

Your CMOS is showing Julian

The D1/1H/1X and d70 all use electronic shuttering for speeds >1/250 of a second. The curtains are open for 1/250, and the imager does the rest. This is possible because CCD's can be globally switched fast enough, while CMOS is switched and read out line by line, which can not be done fast enough for effective electronic shuttering.

When using a camera with a CCD type imager, if the camera is aware that there is a strobe present, it is arbitrarily limited by the firmware to the 1/500 max sync speed that is specified for these cameras. Covering the rear two contacts on the hotshoe prevents the camera from detecting the strobe, so shutter speeds >1/500 can be used. The strobe fire pin still goes low and triggers the strobe even if the camera does not "know" there is a strobe there....

Craig,

thank you for explaining. I have to admit my little CMOS world has just proven to be kind of limited.

fast electronic shutters permitting extraordinary high strobe sync speeds, DX fisheyes, … perfect for underwater.

I get to know more and more nice things about Nikon DSLRs. If Canon continues its poor and odd lens lineup for DSLRs (except for full frame 1Ds) for a few more years (no fisheye, etc.) … opposite to the general trend I really would start considering the Nikon system.

regards,

"CMOS-Julian" :wink:

So let me see if I got this right...

The D2X has a mechanical shutter?

I understand that the CMOS needs more "write" time, but couldn't that still be controlled with an electronic shutter?

Thanks for the lesson on sensor design Craig and Jolly. I leaned something from your comments.

In practice the limiting factor is the strobe dump. Ikelite claims that their strobes take 1/250 s for a full dump. Setting shutter speeds for 1/8000 s works on the D70 (I've done it) but you are not likely to get very much light from what you expect from the strobe settings.

This is where digital and manual strobe power comes in. If you shoot like most people do in the digital era getting the correct strobe power is a trial and error process. If you don't like the result change the settings and re-shoot. You just have to keep in mind that if you don't like the exposure at f8 and 1/8000s strobes at 1/2 power increasing the strobe power isn't probably going to help. Depending upon your strobe power you might have to decrease your shutter speed with a constant flash power to increase your forecround exposure (and live with the increased background exposure). This could be very complicated to figure out but fortunately you don't have to just try it and re-shoot!

CMOS -> Greater possible frame rate, lower sync-speed

CCD -> Lower possible frame rate, possible higher sync-speed

No?

~Matt Segal

That seems wrong to me Matt.

If the write speed is faster, then the frame rate should be faster, all other things being the same. Shouldn't it?

I think my main wonder is why the D2X would have gone back to a mechanical shutter...

I just came across the invoice for my old D1X.

Date - 11/13/01

Price - $4778 body only

Accessories included a 512 Lexar 12X card - $449

Given inflation and technological improvements that D2X is a hell of a deal!

Bjorn Roslett's detailed D2X review is now online.

With an interesting shoot-out with the 1DS Mk2. Remember this is just one person's opinion.

http://www.naturfotograf.com/index2.html

Alex

Forgot to mention that the review includes comparisons with D2H and D1X

Wow!! He's done a test shooting into the sun and I reckon there are going to be some fairly increadible shots of sun rays/balls coming from the D2X (see page 3 of the review).

There is also a nice comparison between the 1DsMkII and D2X:

[*]D2X more noise at extreme ISO's

[*]D2X less light falloff with WA

[*]D2X better acuity under magnification (with the same lens used on both cameras!)

[*]1DsMkII should have better dynamic range.

Quite extraordinary really - not what I would have predicted.

If the write speed is faster, then the frame rate should be faster, all other things being the same. Shouldn't it?

I am but a young grasshopper

From http://www.wetpixel.com/modules.php?op=mod...os+canon+series

I think it's condemning if the S3's DR is matched by a conventional 8MP camera and the street price of the 1DMk2 has dropped.  It's a far better camera in every other way.  The price difference goes into a very expensive body.

 

I don't think the point is what's better for F-mount.  I think the point is why botther with a dual photosite design if it can't outperform a conventional sensor?  Fuji's sensor tech doesn't seem to be superior and it software and ergonomics are apparently substandard.  It may be the best available for F-mount for under $4000 but it seems very exposed to me.

 

That isn't quite fair. The sensor on 1DMkII has more than 1.5x larger area. If Fuji can get the same resolution and DR, then their scheme has some merit. Because the CCD has to read out in series, they'll never be able to do 8 frames per second (this is probably the main reason Nikon has gone to CMOS for their pro camera, and Canon understood this earlier and got a technology jump on Nikon) . However, they probably can make the rest of it faster with a better processing and memory.

~Matt Segal

Here is Bjorn's quote on shooting sunbursts that Anthony mentions:

"So, let's investigate various aspects of the image rendition of D2X. First out , the issue of "blooming", which can result from massive overexpoure of the imager, typically when you shoot into the sun...

I consider the "blooming" issue to be largely non-existant with the D2X, while on D70 at least it could be a nasty issue unless you followed the practice of stopping the lens down and setting the exposure to the lean side. This welcomed trait of D2X implies you can include bright spots of light into your images without fear of getting image anomalies."

This is not the whole issue of shooting sunbursts UW, but this does sound VERY encouraging.

Alex

Wow, look at the vignetting comparison shots! Score one for Nikon on the sensor-lens combination.

Still reading the review.

Cheers

James

Bjorn Roslett's detailed D2X review is now online.  

And my thoughts of "the switch" have been consigned to the status of fever dreams.

Now, which of those credit card's has the biggest reserve

On a related note: A big warehouse of B&H's burned today. Sure hope they didn't have any 2x's in there...

http://abclocal.go.com/wabc/news/wabc_0224...yyardfire.html#

[*]D2X better acuity under magnification (with the same lens used on both cameras!)

Yeah, but I'm not so thrilled with his methodology here and don't consider the data he presented as conclusive. He also presented evidence of significant color fringing.

Regarding his noise data, he only compared it objectively to the D70 which is no noise champion. Why not compare it to its clear competitors, the 1D* Mk2's? You'd see the difference.

It does look as though the D2x is a superb camera. Yeah!

Yeah, but I'm not so thrilled with his methodology here and don't consider the data he presented as conclusive

Would be nice to see some other scenes - or better still another tester conducting a similar test. I'm not really sure how the methodology could be improved. It might have been instructive to also include a test with the Canon 300 2.8L, so that we could compare it to the other two shots and partially control for the Nikon lens on a Canon body.

He also presented evidence of significant color fringing.

Was that more a function of the lens or the camera?

Regarding his noise data, he only compared it objectively to the D70 which is no noise champion. Why not compare it to its clear competitors, the 1D* Mk2's? You'd see the difference.

Absolutely agree, but I think it is fairly clear that the 1DsMk2 exhibits significantly lower noise levels at high ISOs. I would be interested in seeing an objective comparison at ISO 100 though.

Yeah, but I'm not so thrilled with his methodology here and don't consider the data he presented as conclusive

Would be nice to see some other scenes - or better still another tester conducting a similar test. I'm not really sure how the methodology could be improved. It might have been instructive to also include a test with the Canon 300 2.8L, so that we could compare it to the other two shots and partially control for the Nikon lens on a Canon body.

It couldn't be worst. Almost anything else would be an improvement. You can show that a 35mm shot has the same resolution as a medium format shot if you put a 50mm lens on both and shot the same subject from the same distance.

Cut and paste from Thom Hogan addressing this issue:

"Read Bjorn's commentary VERY carefully. There are two situations that have to be addressed when discussing how a camera resolves, and Bjorn has dealt with both of them. In one case, there's the issue of what happens when you take a picture with a photo from a fixed position with the same focal length (instead of a barn, imagine a polar bear that can't be approached any closer and both the D2x and 1Ds photographer having 600mm lenses--that's what the barn test is all about). In the other case, both photographers frame the same angle of view, which requires one to use either a different focal length or a move. In Bjorn's case, he chose to move because the impact of a different focus distance on the same lens is less than that of using different lenses.

 

His thought behind his methodology is correct. Since I wasn't there, I can't vouch for whether he dotted every i and crossed every t in implementing it, but the logic is correct. If you can't follow that, I would humbly suggest that you study it some more, because Bjorn's choices were made after considering optical issues."

Cheers

James

Cut and paste from Thom Hogan addressing this issue:

 

"Read Bjorn's commentary VERY carefully. There are two situations that have to be addressed when discussing how a camera resolves, and Bjorn has dealt with both of them. In one case, there's the issue of what happens when you take a picture with a photo from a fixed position with the same focal length (instead of a barn, imagine a polar bear that can't be approached any closer and both the D2x and 1Ds photographer having 600mm lenses--that's what the barn test is all about). In the other case, both photographers frame the same angle of view, which requires one to use either a different focal length or a move. In Bjorn's case, he chose to move because the impact of a different focus distance on the same lens is less than that of using different lenses.

 

His thought behind his methodology is correct. Since I wasn't there, I can't vouch for whether he dotted every i and crossed every t in implementing it, but the logic is correct. If you can't follow that, I would humbly suggest that you study it some more, because Bjorn's choices were made after considering optical issues."

 

Cheers

James

and what do you think James....

I think Thom is full of it on this one.