Xena filter image quality and colour rendition

Discuss older Nikon-based Kodak digital SLRs, including DCS 100, DCS 200, NC2000, DCS 400/600/700-series, etc. Ask questions, post general comments, anecdotes, reviews and user tips.
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atlas
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Xena filter image quality and colour rendition

Post by atlas » Wed Mar 18, 2020 7:40 pm

Hello again friends,

I didn't see a topic on the matter and I was hoping someone could answer.
Is there a substantial difference in the images from the "normal" models of the 500, 600 and 700 series and their "x" (Xena filter) counterparts?
How do you describe the differences and which do you prefer?

Stan Disbrow
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Re: Xena filter image quality and colour rendition

Post by Stan Disbrow » Sat Mar 21, 2020 6:49 pm

Hi,

Sorry for the delay. This site sees so little use these days that I rarely check in.

Yes, there is a difference. The normal sensors use RGB dyes in the CFA. The Xena sensors use CYM. In other words a single layer of color for each filter in the CFA as opposed to two colors per. This gives you less light subtraction for the CFA and allows more light to reach the photosites. It is a compromise between normal color sensors and monochrome ones (no CFA at all).

What I found was that all the images had a yellow cast to them which was difficult, at best, to correct. This, until Kodak took care of it in their PhotoDesk software. It was worse with the 620x than the 720x as well. And, the 720x was cleaner than the 620x. You know, always improvements.

For a long, long time I used a 720x as my high ISO unit and a 760c as my normal unit. I also had a hi-res version in the Pro Back Plus on a Contax 645. These days, I just use a Nikon Df for just about everything. The Df gives me the 16 MP of the Pro Back with lower noise and higher ISO than the 720x.

Missing is the Kodachrome color of the 760c, so there is one reason to keep the 760c. But, this does not apply to the x models. Nor to the 520/620 non-x,as in -c, models. The Kodachrome dyes were on the 60 series (460, 560, 660, 760) and the Pro Back. Those dyes lost even more light than the standard (520c, 620c) ones. But, nice color in good light.

The 720x and the Pro Back wound up sold off. I kept the 760c as my secondary camera plus it offers the use of the Chimney FInder along with several focusing screens. I have need for a wide-field microscope and the 760c with the Chimney Finder on a copy stand and one of my old manual focus lenses plus an extension tube makes for a decent set-up. What I call my 'macroscope'.

I also kept a 520 for use on my Leica Stereo Zoom 5 microscope (it has a Canon mount) and a 660m for true monochrome use. Of course both of those use the same batteries, chargers and power adapters as the 760c.

What I used the 620x and 720x was: Night auto racing and professional bowling. Both places with not the best light and no flash ever allowed. They worked, and were the only things that did back in The Day. The yellow cast was better than no photos at all. And, as I mentioned, Kodak managed to fix that fairly well in their own software.

Stan
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Professional Electronics Development Engineer

atlas
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Re: Xena filter image quality and colour rendition

Post by atlas » Fri Mar 27, 2020 2:39 am

Thanks for the reply and the information Stan, a few more questions about your experience:

I take it the yellow cast didn't offer anything in the way of aesthetic value similar to the D1's red shift due to its NTSC colour space?

So the APS-H series of cameras used a different RGB filter than the APS-C versions even of the same generation?

Do you have some sample images from the 760 and the 645C?
Several images I've seen from the Pro Back appeared to have more pastel-like colours like the 14n rather than the deep and rich ones expected from a Kodak CCD; of course, that could very well be the artists post processing manipulation.

What's the deal with the forum?
Are people not getting into the older cameras like they were or is it just that the forum itself isn't attracting an audience?

Stan Disbrow
Posts:579
Joined:Fri May 20, 2005 7:33 pm
Location:Raleigh, NC USA

Re: Xena filter image quality and colour rendition

Post by Stan Disbrow » Fri Mar 27, 2020 1:10 pm

Hi,

The yellow cast was pretty much just annoying. In Photoshop, I could get it out and then not like some other colors in the shot. That wasn't bad using it for night auto racing. Those folks were happy with any pictures taken. If I got the car color close to right, they were happy. For my wife's pro bowling shots that tendency wasn't so good. Fixing the yellow tended to mess up skin tones. Fortunately, I didn't have to put up with it for long with the 620x before Kodak fixed things with their PhotoDesk. And, the 720x was a lot better all the way around.

Yes, the APS-H cameras were very much like Kodachrome as was the 645 Pro Back Plus. They were the same CCD fabrication, so all that was different was the physical size and resulting increase in MP.

The other Kodak CCDs tended to be more Kodacolor, so they give a different look.

The forum is pretty much dead these days. Most of these cameras have gone from still being used to sitting on shelves as collector's items. There is one guy on Digital Photography Review in the Kodak SLR forum who drags his stuff out and shoots with it and posts there. No one here posts much any more.

I still use my 760c mostly with a macro lens and the chimney finder to shoot failed electronics boards as a wide-angle microscope. My Leica scope goes down to 5x and that is too tight often times. So, I am probably the only one to ever call a 200mm macro lens 'wide angle'. :P I also still have a Kodak 520c on the Leica scope.

The 520c has one Canon 28-105 macro zoom lens should I want to drag it out of the lab for some fresh air. But, I tend to use my old Nikon D1H, also with a 28-105 macro zoom, for that. I prefer the D1H output over the 520c. The 760c has a 24-85 macro zoom and a SB28d flash, making it a viable standalone unit. My main camera is a Nikon Df. It essentially replaced the Pro Back and the 760c and the 720x in one unit. The 760c was my main camera from 2003 to 2018. Now it is my secondary.

I have lots of manual focus prime Nikkors covering every focal length from 24mm to 500mm. I also have auto focus prime Nikkors from 20mm to 300mm with a hole in the bag at 135mm. Most are old AF or AFD. A real hodgepodge. I began with a FE in 1979 and so the lenses came about over decades, so all of the various eras are represented. The Df works with them all. My Pre-AI ones were converted to AI back when Nikon offered new aperture rings, and that was to work with an FA I bought in 1983. Later I got an F4, hence the AF lenses.

I mostly use the manual focus lenses with the Df. So much so I might eBay off most of my AF lenses due to disuse.

I just decided to make a move to a Pentax 645D. I decided to not go 36 MP or larger with the Nikon system as I think most of my lenses won't perform so well above 24 MP. Not an issue with the Df, of course. I need more pixels for a semi-professional project so I decided to go for a generation old medium format and a couple lenses. Those Pentax lenses can be used on the FujiFilm mirrorless medium format if I decide to go that way later on. We'll see how that part plays out, but meantime I have something new to play with. ;)

And, it is a Kodak CCD sensor. 40MP. A KAF-44000. 44x33mm. Supposed to have the Porta look. Well, Kodak has always done well making their CCDs look like their films. :)

So, now I have the Df for most shooting and returned to medium format (well, as soon as the stuff arrives. I bought it from Roberts two days ago) for higher resolution.

And, the final piece is a 660m for when I want to shoot real monochrome rather than make it up later from a color shot. The 6 MP there is like having 18 MP from a color sensor. Nice. One day I am likely to grab a used Df and modify it to monochrome, but for years now (and likely years to come) the 660m will fill the bill.

Stan
Amateur Photographer
Professional Electronics Development Engineer

atlas
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Joined:Thu Sep 28, 2017 7:32 pm
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Location:Central Florida

Re: Xena filter image quality and colour rendition

Post by atlas » Fri Mar 27, 2020 1:50 pm

Do you think the KAF-40000 of the 645D has the "Portra-look?"
What lenses do you intend to use with it?

Any reason why you prefer the D1H over the 520?

So after correction, the Xena variants have about the same rendition as the Bayer units?

I'd still enjoy to see some of the photos you've gotten out of these, particularly 760 and the Kodak 645 back.

Stan Disbrow
Posts:579
Joined:Fri May 20, 2005 7:33 pm
Location:Raleigh, NC USA

Re: Xena filter image quality and colour rendition

Post by Stan Disbrow » Fri Mar 27, 2020 3:11 pm

Hi,

Yes, after correction in PD, the Xena images look quite close to their RGB CFA counterparts. The 2 MP ones.

The images from the D1H are quite a bit smoother and cleaner than the 520c ones. This probably because the Sony sensor in the D1H is a 10 MP CCD where they ganged four photosites under each CFA filter to gain improvements in signal to noise ratio. The original D1 had this as well, but the D1H sported improvements in the silicon and it shows.

They gained enough SNR improvement that they could gang the photosites in pairs to produce the D1X. That led to rectangular instead of square pixels and resulting oddities in the images sometimes. It wasn't until the D200 and D80 that Sony improved the silicon enough to single the photosites up.

I worked for Sony Ericsson at the time all this went on, so I had all the inside info. :)

I really ought to scare up a Nikon adapter for my Leica scope and pass the 520c on to some collector while it still functions.... ;)

I don't have the Pentax 645D yet. The Porta look is something I have been told by a couple of pros who use the 645D and Z along with film bodies. I have no reason to doubt them, though.

I bought three lenses to begin with. An FA 45-85, an FA 80-160, An A 300, and both the 1.4x and 2x A teleconverters. We will see how they work, and I have a list of other A lenses to watch for. I am told that many of the Pentax lenses work well on the FujiFilm GFX 100 and also work well with a tilt/shift adapter. So, even if I decided later on to get a 50s or a 100, these lenses would still be useful.

As far as images go, this farm I live on is internet free. So, I use a cellular bridge. That costs quite a bit, so I am bandwidth limited.

Stan
Amateur Photographer
Professional Electronics Development Engineer

atlas
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Joined:Thu Sep 28, 2017 7:32 pm
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Location:Central Florida

Re: Xena filter image quality and colour rendition

Post by atlas » Fri Mar 27, 2020 4:14 pm

The D1 series used Sony sensors?
I don't recall reading that.
Wouldn't it have been better to use larger photosites in order to avoid losses around the well boundaries?

That's a shame; if you get the chance to share some images, let me know.

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