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-   -   AX2000 Rainbow effect in viewfinder (https://www.dvinfo.net/forum/sony-nxcam-avchd-camcorders/486805-ax2000-rainbow-effect-viewfinder.html)

Sebastian Alvarez October 29th, 2010 04:13 PM

AX2000 Rainbow effect in viewfinder
 
I just got the HDR-AX2000 and for the most part I'm happy with it, but there's something odd that I don't know if it's a design flaw or if I got a faulty unit.

When I use the viewfinder I can see this weird rainbow effect in the contours of objects, but it's not there all the time, it's like it "flashes" at certain times, every second or two. I can notice it most when I blink, although I can still see it without blinking. This problem is more noticeable when I use the guide frame, and it becomes very easy to tell around the edges of the white lines of the grid. Also, moving the camera makes this more evident, even if it's a slow panning.

This problem doesn't show at all in the LCD screen.

I googled hdr-ax2000 rainbow effect and I got nothing about this, however if I google viewfinder rainbow effect I get some results talking about this same problem, but it seems to be a problem of photo cameras exclusively.

So I'm puzzled about this. I haven't seen this problem in any viewfinder in neither consumer nor professional cameras in twenty years. I've seen poor quality viewfinders, and some that showed a bit of a rainbow effect, but it was there all the time due to the poor quality of the viewfinder, it wouldn't flash the rainbow effect. So it would seem very unlikely that a $3500 camcorder would have this, although I wouldn't put it past Sony, since they always seem to release products that are great overall but with a shortcoming here and there.

So can anybody with the AX-2000 please go outdoors tomorrow (or today if you are in a part of the world where the sun is still shining) and start panning around looking through the viewfinder to see if you can observe this problem and let me know. I would really really appreciate it, since I don't want to have to send it back for an exchange if the replacement is going to be the same.

Thanks,

Sebastian

Arkady Bolotin October 29th, 2010 05:20 PM

What you report in your post is the very well-known anomaly exhibited by many DLP-based HDTV’s and it’s called “the color wheel rainbow effect”.

This anomaly is described as flickers of red, blue and green “shadows” especially noticeable in high contrast areas of the picture or on the bright objects moving fast over a dark background. Besides, momentarily perceptible color separation can be visible during rapid eye movements.

As a matter of fact, the AX2000 EVF (as well as the viewfinder of the NX5) is build on LCoS technology (Liquid Crystal on Silicon): it contains 3 852x480 LCoS panels. The LCoS technology is a reflective technology similar to DLP projectors; but it uses liquid crystals instead of individual mirrors of DLP.

However, even with this difference, the LCoS technology suffers from the same “rainbow effect” as the DLP does.

The good news is that only small percentage of people perceives these rainbow artifacts frequently, while many others never see them at all. The bad news is that you, Sebastian, are in that small percentage, unfortunately.

Sebastian Alvarez October 29th, 2010 07:10 PM

Quote:

Originally Posted by Arkady Bolotin (Post 1583580)
What you report in your post is the very well-known anomaly exhibited by many DLP-based HDTV’s and it’s called “the color wheel rainbow effect”.

The good news is that only small percentage of people perceives these rainbow artifacts frequently, while many others never see them at all. The bad news is that you, Sebastian, are in that small percentage, unfortunately.

Interesting. What I don't understand is, how come I've never seen this effect in any viewfinder before in my life? Do they use this "LCoS technology" because it's cheaper or why? Again, it's kind of puzzling to see that they used this technology in a top of the line prosumer camera, when their cheapest prosumer, the HVR-HD1000U, which I also have, doesn't have this annoyance at all. I mean, even if a small percentage of people see this effect, you would think that Sony would use in their pro camcorders a technology that doesn't produce these RGB flashes to anybody at all.

Arkady Bolotin October 30th, 2010 08:05 AM

I believe you do not expect me answering for the Sony’s decision making policy. For my part, I can only speculate why they did this and did not that.

I assume the NX5/AX2000 EVF is built on the LCoS technology because this technology can produce higher resolution and higher contrast images than standard LCD viewfinders. Furthermore, due to high fill factors (minimal space between pixels), visible pixelation on an LCOS EVF is nonexistent. That is, the pixel structure is less visible than you get with a high resolution LCD EVF. And what’s more, LCoS-based viewfinders are less expensive to produce.

Of course, the LCoS EVF’s exhibit the “rainbow effect” which can be very distractible for some people, but the tradeoff is you get a smooth and naturalistic image, one of the best in business.

Sebastian Alvarez October 30th, 2010 08:39 AM

Quote:

Originally Posted by Arkady Bolotin (Post 1583741)
I believe you do not expect me answering for the Sony’s decision making policy. For my part, I can only speculate why they did this and did not that.

I assume the NX5/AX2000 EVF is built on the LCoS technology because this technology can produce higher resolution and higher contrast images than standard LCD viewfinders. Furthermore, due to high fill factors (minimal space between pixels), visible pixelation on an LCOS EVF is nonexistent. That is, the pixel structure is less visible than you get with a high resolution LCD EVF. And what’s more, LCoS-based viewfinders are less expensive to produce.

Of course, the LCoS EVF’s exhibit the “rainbow effect” which can be very distractible for some people, but the tradeoff is you get a smooth and naturalistic image, one of the best in business.

See, that's my problem. You say you get a smooth and naturalistic image, but since apparently I belong to that minority that can observe this problem, to me it's neither smooth nor naturalistic. It's more like "I just spent $3381 on a state of the art camcorder but I can't use the viewfinder because it flashes rainbows on edges of objects."

Now, if I would have been born with an eye anomaly such as being colorblind or anything else that doesn't allow me to see TV sets and other viewfinders properly, then I wouldn't be so upset about it, but if it's known that a small percentage of people can observe this problem in this display technology, then why does Sony use it instead of using some other technology that maybe doesn't look so crisp, but that doesn't display any anomaly for anybody?

Arkady Bolotin October 30th, 2010 09:28 AM

In the perfect world a manufacturer would have to care about each and every customer’s opinion and needs. But unfortunately we do not leave in that perfect world.

So, some people always will be an injured party of every new technology and innovation.

Bob Hart October 31st, 2010 02:46 AM

Sebastian.


Consider yourself as having a rare gift. You would probably make one hell of a baseball or cricket player in another life if you do not already excell in bat/ball sports.

One small question. It is not a joke comment and hopefully not interpreted as stupid. Do you use both eyes when operating the camera, one for situation and one for the viewfinder?

Cristian Adrian Olariu October 31st, 2010 08:26 AM

My advice is to ask a friend or more to see if they notice same as you do. Maybe your camera really has a problem. Then check another AX2000 or NX5 for the same problem.

Sebastian Alvarez October 31st, 2010 10:05 AM

Quote:

Originally Posted by Bob Hart (Post 1583811)
Consider yourself as having a rare gift. You would probably make one hell of a baseball or cricket player in another life if you do not already excell in bat/ball sports.

One small question. It is not a joke comment and hopefully not interpreted as stupid. Do you use both eyes when operating the camera, one for situation and one for the viewfinder?

Bob, how would this problem relate to being a good baseball or cricket player? I don't understand. In any case, more than a gift it's a curse.

Normally I close my left eye when I look through the viewfinder, although I have tried opening the other eye and the problem is still there.

Sebastian Alvarez October 31st, 2010 10:08 AM

Quote:

Originally Posted by Cristian Adrian Olariu (Post 1583850)
My advice is to ask a friend or more to see if they notice same as you do. Maybe your camera really has a problem. Then check another AX2000 or NX5 for the same problem.

I wish I could see another AX2000 for this problem, but the only way to do that would be to request a replacement from the dealer, and judging by what Arkady said, it's because of the type of display that I'm seeing this problem, so exchanging it would mean being without it for two weeks and in the end it would be the same.

Bob Hart October 31st, 2010 10:59 AM

Sebastian.


My comment makes two assumptions, probably wrong.

One is that your eyesight has the ability to see fast or momentary things most of us can't. - Perhaps analagous to faster shutter speeds which can freeze motion and make moving objects discernable.

The late legendary batsman Don Bradman also "the little master" batsman Sachin Tendulkar, apparently share such a gift.

As for the using of the second eye question, I was wondering if eye movements themselves would make the viewfinder artifact less or more more apparent. I speculated on whether using or closing the left eye might have an effect on being able to see the artifact through affecting the movements of the right eye.


Out of all this, I should be so lucky. I am short-sighted and partially colour blind. Sometimes I am a bit too clever for my own good. This might have been one of those times.


Cristian's suggestion of trying another camera of the same type makes good sense.

Sebastian Alvarez October 31st, 2010 11:58 AM

I just asked my girlfriend to go outside with me and the camera to test this and she also sees it. So either she's in the same minority that sees this problem, or the viewfinder really has a problem. I'll keep doing some more research on this, but let me ask this in case anyone knows: is there a chance that the viewfinder is not calibrated properly in factory and therefore exhibits this issue? Or is this, without a doubt, simply a side effect of the technology used for it? Because again, I had never seen this problem in any viewfinder of any camcorder I ever had or looked through before in my entire life, consumer or professional.

Dave Blackhurst October 31st, 2010 02:14 PM

Sebastian -
It's a well known and rather more pedestrian (common) effect with the particular technology they are using in the viewfinders - I see it in my CX550V VF (curent model), it's been widely reported in the latest SLT (Sony's new Alpha) EVF.

I'm going to guess that the technology allows for higher numbers of pixels in the tiny display, and so was regarded as "superior" (or maybe it was just cheaper).

I too particularly notice the RBG artifacts with the gridlines on, and it has to do with my eye moving, as some have noted. It was a little strange the first time I saw it, but haven't given it a thought beyond that!

Sebastian Alvarez October 31st, 2010 02:28 PM

To me it's just really upsetting that a company like Sony designs a professional camcorder with a price tag of $3500 and they don't put a decent viewfinder in it. I can't even remember how many camcorders I've had in my hands during my life, and never before have I seen this problem.

Bob Hart October 31st, 2010 10:40 PM

Sebastian.


Your second person's observations and the comments in this thread pretty much nails it.

Sony perhaps should have upfront made it plain that the particular design has a characteristic, which if observed, is "normal" in an easily found disclaimer statement in the promotional flyers,

It is a bit like "rolling shutter" and CMOS sensors. The consumer becomes the crash-test dummy owner of a product which cannot be returned because it is performing to specification.

At the price points, people will accept that consumer-prosumer gear will not perform at the level of a Panavision Genesis. However people also like to be able to make informed decisions.

Sites like dvinfo.net become defacto points of disclosure and many thanks to Chris and the team for that. Unfortunately, it can only be after a buyer of a product has already been nipped.

We should therefore be appreciative that you have informed the rest of this community via this forum.


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