Chromatic Aberration When Shooting Lunar Eclipse?

This was manual, pretty sure it was just short of infinity on the ring.
Initially set focus (zoomed full tele) at f4,.8, then later I switched in ND1.
I'll re run this test possibly tomorrow, weather permitting (snow storm predicted), plus I have a time crunch getting the gear packed for a major symphony concert Saturday (have to fly microphones Friday and settle the aggrement with the soloist hiring me). If there's a ten minute slot in the day where I can test again, I will do another test and carefully document the focal length. But it does seem suspect because I did some shots last weekend where I definately focused on the a distant object and pulled back on zoom and the whole WA image was very soft like the f1.9 shot above.

Disturbingly, this is not reproducable in the studio. I'm concerned that Sony will find no problem either. Today it was 23ºF outside when I stepped onto the porch to run this test, which took all of a minute. The camera could not have cooled down so much that the lens stopped functioning in that short time.

I'm in a quandry about whether to send it to B&H or deal with Sony. B&H might be counting its 15 day return limit based on my first camera arrival, not the second, in which case, getting them to take it back would be difficult.

Bottom line is that I am not sure if the focus is working right. Seems fine indoors. Seems soft outdoors. (Scratching head)
 
Last edited:
Mark...
Sorry to hear this man.

That does seem odd that you can not reproduce this inside.
Yes, you definately need to do a lot more testing.

Let us know how it pans out. I would get B&H on the horn, if not, call Sony:
1-800-883-6817
Press 252 for direct dept.
 
I feel for ya Mark... This where one needs to find a Sony marketing rep to front for you with the Repair Dept., and cut through the red tape to either get this fixed or get you a new one. This doesn't do them any good either in the PR dept. so hopefully they'll be motivate to move...but you gotta get to marketing people who understand that and not some "clerk".
 
There's a an Austrian fella posting on "that other forum" about the exact same problem with his EX1. He does the zoom in, focus then back out and, if the iris is wide open, the picture gets VERY soft. If the iris is less than wide open, the picture remains sharp.
He says that it's only apparent on very distant focal points, as he could not reproduce the problem with a focus chart 15 feet away.
The guy got a replacement camera from Sony and he says it has a "massive problem with backfocus and vignetting.."
He goes on to state: "When I´m zoomed out there is no way to get a sharp image at all - no matter what I try - its always terribly blurry at f1,4 in fully wide" (I think he means f1.9).

Everyone may wish to check their EX1 backfocus at f1.9, and preferably outdoors with a distant object to zoom in and focus on.

I tested mine by zooming in on a distant tree, focusing and backing out to full wide. I noted something like f5.6, then I engaged the ND filter, which caused the iris to open to f1.9. That shot was very much out of focus, but it was odd in that NOTHING, not near nor far, was at all in focus--it was like someone put Vaseline on the lens. Very peculiar sort of bokeh, in that there's an almost 'rag texture' to the bokeh, rather than a smooth blurring of the image.

I think that a lot of us aren't noticing it because we may be using auto iris and have more than enough light to select a smaller aperture where the problem is not apparent. The camera works fine in theater situations, as I found out this weekend.

With all the talk of vignetting and how that seems to bother a lot of people, I have not heard anyone raise the issue of the more disturbing chromatic aberration. Aesthetically, I find CA to be much more distracting than vignetting that I've seen in the XDCam examples posted by various users. CA, to me, is the mark of a very poor lens, so when I see it on an expensive camera, it's troublesome. Especially when I never noticed it on the many clips that I downloaded from various XDCam owners' sites. I did see it in some footage frames posted by a user in Poland. His CA problem was as bad or worse than mine, but the discussion was about white clipping, not CA.

With the orchestra shoot, I'm seeing quite a bit of CA on things like a violinist's white cuff against the darker background of the stage floor, or the edges of music stands against lighter objects. And it's not just near the corners--it's 80% of the image area, except for a small area that is dead-center.

In reviewing some of the V1U footage of this concert, I'm not seeing CA in that footage. The XDCam footage seems to have it in spades, however. Same stage, shot from opposite corners of the balcony, so conditions should be a close match.
 
Mark,
I´m the Austrian guy you were quoting in your last post. It looks like both of our cameras seem to have the same problem with back focus.
I did some thorough systematical tests yesterday and here is what I found out: (I´m quoting myself on what I wrote in that other forum)

After more systematic test with the loaner camera this afternoon I called Sony to complain.
Well, they still do not know what´s going on with my original camera. It is still at the repair shop... I complained about the lens issue of the loaner camera. The problem now is that they do not have any more loaner cameras left they could send me - I got the very last one!!! Looks like I will have to live with it for a while.

What I found out during my tests today:

- Zoom in with ND off - aperture wide open at f1.9 - focus near infinity mark - zoom out - image is o.k. and sharp (did not test this before without ND)

- Zoom in with ND ON - aperture wide open at f1.9 - focus near infinity mark -zoom out - image is extremely blurry

- Zoom in with ND ON - aperture set to f5.6 or higher - focus near infinity mark -zoom out - image is o.k.

It looks like that the ND filter is the only cause for the blurriness?? I bet my camera is not the only one with this issue - you can easily try for yourself... Looking through some older footage I shot with my original camera, I guess it might have the same problem (I did not do this zoom test during the 2 days I had it before I sent it back to Sony for repair.)
I´ve retried the suggestion to improve the infinity focus by fully rolling it all the way back to 0.8 - and guess what - to the contrary what I said yesterday - it works! So whenever I want to shoot a wide landscape with ND-filter ON I have to manually set the focus to 0.8 instead of the traditional method of zooming in, focusing and zooming out. So if I want to shoot a zoom from something far away and end in a wide shot, I have to pull the focus during the zoom!! How sick is that? Thats a phenomenon I just cant explain.
The vignetting issue is also visible in real world situations - like when filming a blue sky - so no need to shoot another living room wall ;-)

Sorry for my ramblings and thanks for letting me vent ;-)

cu,
Gerald

There is at least another fellow who has the same problem we have. Its clearly related to the ND filter. If you send it in for repairs the guys at Sony are probably checking it indoors with the ND OFF - and then of course they can not see any problem. In the meantime I could reproduce the issue inside as well - but only with ND ON!!

regards,
Gerald
 
Sounds like there's a problem in your camera where the ND filter is affecting your backfocus.

Probably a defect, because the camera should compensate for the ND filter being there.

Maybe both of you should try a backfocus adjustment with the ND filter already engaged, and then see if the problem reverses and there are backfocus issues with the ND off.
 
Gerald,
Thanks for sharing your findings about different ND settings with regard to various apertures. As I was reading, something occured to me:
Perhaps the problem is in the ND filter MATERIAL itself. At wide apertures some texture in the filter may be confusing the servo focus mechanism, while at smaller apertures, it may ignore the filter's texture. That could explain the 'celluloid' look I was getting, particularly in the bokeh of these soft images. They don't look purely out of focus with the smooth bokeh that one typically associates with a focus issue--the bokeh is somewhat textured, like looking though a textured piece of plastic. Then I thought: ND filter is like a piece of plastic in between the lens and the image sensor block.

That you are able to get clear images at wide open aperture WITHOUT the ND filter is indeed telling. I'll experiment with that this week, using a high shutter speed to make up for the light in hope of getting to f1.9 without ND filter. If I can replicate the same results as your tests, then this data may be useful to Sony.

Does your lens seem to produce large amounts of chromatic abberation as well, particularlly at full tele? Mine was really driving me nuts with all the closeups I shot at a concert Saturday night. Even in not so contrasting edges, one can see red and blue fringes. I don't recall seeing that on my first EX1 (which bit the dust after five hours of use and had to be sent back for exchange), nor on any of the footage I downloaded from various EX1 web sites/blogs.

Matthew77,
I performed a backfocus adjustment last week, after discovering the soft wide angle footage problem. It made no difference to the problem.

No ND filter used in the studio tests... that's the key. No wonder I could not reproduce the problem in-studio. The ND filter must be part of the problem.


DeeZiD,
I did an experiment in the studio just now, with bright lighting and ND1 and was able to reproduce Gerald's exact results. Then I tried the BF adjustment in the service menu with ND1 switched on. You are correct--it does seem to improve the backfocus with ND on. Not sure what happens with ND2, but I will have to try more in sunlit conditions. I was also using the LCD with the expanded focus feature to analyze the sharpness of the picture. The difference between ND off and ND on is very noticeable on the LCD with focus assist enabled. And it was apparent that the BF adjustment while ND1 was on made a definate improvment. Prior to that, I had to dial focus back to .8, as Gerald was observing, to attain focus on wide shots. This explains why this problem did not appear in the theater last Saturday.

The whole notion of backfocus shifting with ND filters is disturbing though. It's as if the camera were jumping through many hoops to make the optics perform 'better' than they're supposed to. One wonders at what price of longevity and reliability this may be coming from.
 
Last edited:
hi,
the ND is definitely the key for our problem :-(
Regarding the CA - its there, maybe a little less at my camera from what I can tell. I can mainly see it at high contrast areas of the picture and then its not limited to full tele. As the camera is pretty useless for me as long as it does not work properly - I did not shoot too many real life situations yet to judge the CA issue correctly. I will let you know when my original camera returns from repair. In the meantime I do my jobs with my old cameras...

cu,
Gerald
 
The CA problem is variable and dependant on shooting conditions, particularly zoom percentage and how far from the center of the lens' image circle the contrasting edge is located.

I find that it doesn't take extreme contrast to bring out the problem. On other cameras I've used, it would take bright sky against black power lines to show a problem near the edge of the picture.

I was under the impression that this camera employed CA suppression/compensation technology in DSP or whatever, to eliminate it--the online footage that sold me on the EX1 had none at all and that was with bright sunlight coming through an open door to a trade show floor, and mercury vapour lights, which are hell on most any lens. That EX1 footage impressed me. Then I read that they may have CA compensation, so I figured that's how they get that quality out of a relatively cheap lens. However, there are rare times when my EX1 will produce pictures free of CA, and I think it depends on the zoom level, maybe aperture too. About 70% tele and it's quite clean. Full wide and there's some CA. Full tele and it's downright 'consumer cam' looking.

Quantifying the CA could be done with a resolution chart perhaps and controlled lighting where we can set known f-stop values and measure the number of pixels width for the chromatic mis-convergence. If we know this is happening on all EX1s, then there is probably little that can be done service-wise. If some cameras have it and others don't, then the cause for the difference needs to be identified and Sony made aware of the cause.

In the meantime, it's a mixed bag with ours. It can look wonderful at times, and other times it looks downright awful. I had intended to purchase four units this month to get us out of the HDV level and it's capture workflow time issues, but these glitches need to be worked out before we buy any more cameras. This whole lens issue caught me by surprise. Really, I was focussing on making sure the audio section wasn't dumbed down like our other two cameras, and, because our other Sony cams were optically terrific, it never occured to me that there could be a first time for Sony to err in the optics. The Fujinon name gave me peace of mind--too much peace of mind, as it may turn out.
 
Matthew77,
I performed a backfocus adjustment last week, after discovering the soft wide angle footage problem. It made no difference to the problem.

No ND filter used in the studio tests... that's the key. No wonder I could not reproduce the problem in-studio. The ND filter must be part of the problem.
Click to expand...


Basspig,

What I'm suggesting you try is a backfocus adjustment with the ND filter engaged. Then see if the problem exists in reverse - see if backfocus is good with the ND on and bad with it off. That will be a good clue.

I see that you did that - but did you check that the backfocus got worse with ND off afterward?

I suspect there's an ND filter backfocus compensation built into the lens that is not functioning on your camera. Might also be creating your CA issues, as that is electronically compensated as well.
 
Last edited:
I rechecked the backfocus without ND1 after backfocus adjusting with ND1. Now both modes seem to backfocus sharply. Not sure HOW sharp, as I'm only testing on the LCD at the moment, but the backfocus seems to have improved on ND1, possibly at no expense of ND off.

I'm not convinced there IS any CA compensation, but if there is, adjusting the Flare adjustments in the service menu has ZERO affect on the picture except for adding a greenish cast to the blacks at extreme settings. The CA visible around the light fixtures in the studio remained unchanged on the monitor that the camera was connected to. Is the flare adjustment even related to CA compensation at all? Maybe it's unrelated.
 
basspig said:
I rechecked the backfocus without ND1 after backfocus adjusting with ND1. Now both modes seem to backfocus sharply. Not sure HOW sharp, as I'm only testing on the LCD at the moment, but the backfocus seems to have improved on ND1, possibly at no expense of ND off.

I'm not convinced there IS any CA compensation, but if there is, adjusting the Flare adjustments in the service menu has ZERO affect on the picture except for adding a greenish cast to the blacks at extreme settings. The CA visible around the light fixtures in the studio remained unchanged on the monitor that the camera was connected to. Is the flare adjustment even related to CA compensation at all? Maybe it's unrelated.
Click to expand...

Thanks to your suggestion - I did the same procedure. The backfocus really improved, but it is still far from being perfect. Did it solve your problem completely? I would say that on my camera it improved about 50%, but it´s still far from delivering a usable picture.
Cr*p!!

cu,
Gerald
 
I just repeated my test outdoors today, with the backfocus calibrated to ND1 from a couple of nights ago.

What I found was that picture with no ND filter was soft at wide angle.
Picture with ND1 was a little sharper.
Picture with ND2 was soft again.

None of the pictures were sharp. So Backfocus adjustment with ND1 just seems to compromise between all settings with no particular image being sharp.

This may suggest that there is a compensation circuit that adjusts backfocus for ND filter settings.

Side note: a photographer friend of mine thought the idea of backfocus changing because an ND filter was in front of the imager to be ludicrous. He didn't see why backfocus should be affected by changing light levels.


I've found some contact info for Sony Broadcast service dept, but the question is whether they will really work to solve this problem. I wish to avoid being without my camera for six months, only to get back the camera with the same problem.
 
That bad news!
There's been a couple users that have bought a camera with this issue.
Have you asked at the "other" forum how they handled getting it fixed or replaced?

Your camera friend is right, I can't image how a ND filter would change the focal point. The idea of an "ideal" ND filter itself is to cut light of all wavelengths equally.
I can't imagine why a focal point would be affected.

But having said that, it does seem to appear there's something unique going on
with the ND and backfocus on the EX1. Either that, or it's a weird coincidence that it behaved different after you ran the BF calibration with the ND1 filter on...
Strange.

Well, the good news and bad news is they all certainly do not do this. Mines dead on. I alway zoom in on my target and pull out wide. The bad news is there have been a few cameras that have this issue.... Call Sony. They are real cool to talk to. They will help you out getting it fixed.
 
Jeez i really feel for u guys with cam probs its just thee most annoying thing known to the universe (most probably) i hope you guys get it resolved soon enough so you can all get back to filming what ya love!
 
Stevet, I don't have posting privilages in 'that other forum'. This is the only forum where I have posted details about the lens issue.

Sony's lens is so full of high-handed tech manipulations that who knows what's going on in there--stuff that seems unconnected, logically, is somehow connected and interactive.

I am convinced the CA problem is not normal either. I don't remember seeing this on the first camera. CA is something that is visually annoying--my eye goes right to it, and whenever I spot it, I lose focus on the content of the video. On my EX1, it is particularly nasty, even when compared to my V1Us, both of them. I was hoping to be rid of CA, once and for all, with the EX1. Now it seems that I may just have a bum camera, second in a row.

In trying to contact Sony, I am looking at the link their site provided:
http://esupport.sony.com/US/perl/contact-relation.pl?

...however, this appears to be for consumer stuff. I wanted to contact their customer relations, but it's only for news media folks.

Then there's their Teaneck NJ service facility, however, hearing that it's better to contact their marketing people and gain their support, I'm reluctant to just FAX Teaneck and get an uncaring service tech who's only concerned with when 5 o'clock rolls in. But it looks like that's the best option at the moment.
 
lawriejaffa said:
Jeez i really feel for u guys with cam probs its just thee most annoying thing known to the universe (most probably) i hope you guys get it resolved soon enough so you can all get back to filming what ya love!
Click to expand...

There is one thing more annoying, and that would be property taxes on primary domiciles. Your home is your refuge, until the tax man taketh away. Anyway, I digress...

Frankly, this is the first time I've had a video camera that two in a row, wasn't working right. I've owned many Sony's, dating back to the modest TRV900, and including the VX2000 and HVR-V1U. All cameras have been reliable and had no optical issues. This business with the EX1 and vignetting and backfocus and CA issues is disturbing. It tends to make one wonder if there's a design issue that can't be fixed 100%. I'm sitting on purchase orders for 3 more EX1's until this is resolved to my satisfaction.

The kicker here is that we are getting into the busy season now, and losing the camera for even a day or two is going to cost us significant business.
 
An Objective Test for CA?

An Objective Test for CA?

I was thinking that there must be a way we can participate in a standard test for CA, to determine what's the norm for the EX1, however, there are several factors which must be controlled in order for the test to be valid.

My first thought would be to shoot some sort of black and white chart, with bars or blocks of grey and black on white background.

Line this chart up and shoot like a resolution chart. Move camera 12' away and zoom in and shoot. Then move camera to 2.7' and zoom full wide and shoot the chart. Observe the amount of CA. Perhaps measure it in number of pixels wide each color fringe is.

Whatd'ya all think? Perhaps I can come up with a chart pattern and make a PDF file that anyone can download and print and shoot.


UPDATE: The choice of Matrix gamma type affects the appearance of CA. I was flipping between picture profiles and the edge of a ceiling fluorescent light would show a blue fringe when I selected a certain profile. After toggling each parameter, I narrowed it down to Cinema as the matrix type. The other three do not produce visible CA in the LCD display. Something about Cinema Matrix seems to bring it out strong enough to see on the LCD panel.

Any standard test we do should probably used PP OFF to avoid introducing a huge number of uncontrolled variables.

Going to experiment with this further and see if I can figure out the connection between Cinema matrix and chromatic abberation.
 
Last edited:
You must log in or register to reply here.
Back
Top