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Contax ND

Strange thing about the vignette is that it is most visible when the image is shrunk. This is apparently a technology issue that I do not yet understand. It happened on a few shots I made that sunny day, so I am guessing there was no obstruction. I will try some shots with the filter and firmware 1.07 and then without the filter to see if the results are the same. I will post hopefully by Monday.=20
 
I just received the Jan 2003 issue of Shutterbug today. It has a article mentioned that at Photokina, there was a hot topic talking about light fall of for wide-angle lens in digital photography. It is due to "angular view of incidence" which affect digital chips more that silver particles in traditional films. It said that there are more details on the Dec 2002 issue. I will see if I can find out more.
 
Diane, what kind of a polarizer? Is it slim, or regular? If it is regular, it will almost certainly vignette at 24mm either with chrome film, or digital. You won't notice it with bw or colour negative because they have wider exposure latitude.
 
I am told by DJ that it is not thin. I guess that explains why the problem at 24mm. Glad to know and thanks for your help.
 
Diane, slim filters have only one mounting thread. If yours have two, that's the reason for the vignette.
 
Returning to Marc’s problem with the moiré pattern in RAW files – anybody know what is going wrong? I thought that the “optical uncolored crystalline lowpass filter eliminates false color producing frequencies that often affect image quality” prevented this problem. I know that aliasing is usually dealt with by optical means (a filter like this), software correction or dithering the CCD. I presumed that Contax were only using the filter, so there should not be moiré patterns in ANY file mode, because the filter blurs light to prevent the recording of frequencies beyond the Nyquist frequency and the filter is in front of the CCD. The quote above is from the Kyocera website and I’d say that the word “eliminates” is pretty decisive.

Marc, perhaps your filter is defective and you only notice it in RAW because there is no processing that disguises it? Then again, I may have completely misunderstood the issue!
 
Here's a view of normal and real thin filters. The real thin has no threads at all on the front - it comes with a slip-on cover.

67517.jpg


You see, Irakly, I overcame my scratched & dirty lens paranoia long enough to take this straight flash photo (no compensation). The full frame showed more of the cushion.

DJ
 
Philip, Irakly noticed the problem with his camera before I did with mine. It must be something in the software conversion...Again with the crappy, slow software. However, I get zero Moire' shooting in tiff, but hate the color space when shooting in tiff

I going to shoot a models' portfolio this Sunday, and plan on using the ND for some of the shots (along with the Contax 645 and Kodak 645C ProBack).
I'm interested in whether I can shoot ISO 25 with my smallest (600 watt) Profoto generator dialed to its' lowest output, and use the 85 and 50 at as wide an aperature as possible. The small buffer will be a problem with any fast moving fashion sequence. But maybe a few portraits and detail shots will be possible.

Here is another interesting note concerning the tiny ND buffer: The new Kodak 14 meg has 256 megs of memory which buffers 8 shots before loading to the card. You will be able to send the camera to a special
tech center that will alter the hardware and increase the memory to 512 meg, boosting the buffer to 18 shots before downloading to the CF card. I just discovered that Nikon also offers the same service for the D1-X to boost the 9 shot buffer to 18 shots !!!!

Now, the question is, can the ND ever be upgraded like that? Nikon charges $240. to increase the memory (and upgrade the firmware to better work with PS 7 Adobe RGB color space).

I'd be more than willing to pay for a good increase of buffer capability in the ND, and it would be nice if they altered the tiff colorspace to Adobe RGB with the next round of firmware while they were at it.

A further comparitive note about service responsiveness...I just sent my Kodak ProBack Plus to Kodak because computer wasn't recognizing that the camera was connected., making it impossible to shoot directly to the screen during studio shoots. It shipped to them on Friday last week (delivered Monday), and I got the unit back in perfect working order on Weds. !!! And they completly cleaned the sensor and IR filter while they were at it, and sent me their test shot print out, and a color test pattern to help me calibrate color space on my computer screen.

Here's another question for ND cult members:
Has anyone used just a plain old Manual/Automatic on-camera flash with their ND? The Contax TTL system seems to have difficulty reading off the sensor (it was designed for film), and produces weird results occassionally. Nikon SB-28s had the same problem, and Nikon was quick to offer the SB28 DX as a solution. Since Contax will be either slow to offer a solution, if at all, I wonder if a regular
auto flash would work better? I also wonder if the relatively slow sync speed of the ND is due to the limits of the flashes they have, or the camera itself?
 
White Balance - do you guys & girls set white balance for each type of light using the one touch preset, use the auto setting or the degrees K settings?

If you are taking a reflected light reading, I've had good results with white A4 typing paper, but it's a hassle to carry round. Anyone got any other ideas?
 
Marc,

What kind of weird results have you gotten? Also, what setting do you have custom function 19 set to?

I haven't used flash extensively, but the stuff I've shot so far with my old TLA-280 looks alright, including a few "people" shots I took today while visiting a tolerant friend. I shot Aperture Preferred and the 280 in TTL Auto, and I have custom function 19 set to 0.

I did notice some extreme aperture control at close-up distances, like the camera wouldn't go below f/11 even when set wide-open. This went away very quickly as I increased the distance, and certainly did the required job, as witnessed by that close-up of the two filters above.

BTW, the ND can x-synch at 1/250th, same as all other high-end focal plane shutter cameras.

DJ
 
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