Vignette problem

[Piotr Wozniacki]

Tom, if I say "probably" is because while you're generally right that most lenses exhibit this to some extent, whether it's acceptable or not depends on the intensity - please don't compare a "Pro" camera lens with the cheap compact point 'n' shoot digi-still cameras :)

I can assure you my V1E doesn't exhibit a brightness fall-off like we see on these grabs posted here to show the EX1's vignetting problem. But then it only has chips half the size of those on the EX1, while the lense sizes are of 62/77 ratio... Now, I know the maths behind it is not that simple, but it clearly does suggest something!

I'm sure that at the early concept design stages, the well established 82mm lens size must have been considered. Why the Sony engineers decided on the 77mm beats me but I guess it was not for engineering reasons at all.

[Tom Hardwick]

Piotr, when you say, ''that most lens exhibit this to some extent'' the fact is that unless they have a mechanical stop that prohibits the two widest apertures being used (it has been done) then all lenses - regardless of cost - vignette when used at wide apertures. It's just the laws of optics. Hassleblad sell various ND centre-grads to counteract this.

I'm pretty sure your V1 doesn't have this 'mechanical vignetting' as seen on these EX1 samples, but it sure does vignette the image at all focal lengths when you're using wide apertures.

And a small correction. The chips in the EX1 are 30.72 mm2 whereas the V1 uses 8.17 mm2 chips - so your V1's are just over a quarter the surface area of the EX1's.

tom.

[Martin Mayer]

Has anybody had any acknowledgement from either Sony themselves (OK: unlikely) or a Sony dealer yet that there is actually a problem?

The longer this goes on without such an acknowledgement, the greater the damage to sales from them being "in denial" will be.

[Piotr Wozniacki]

Tom, I was comparing the linear chip sizes and linear lens sizes; you're of course right as to the surface difference.

And one more thing: in order to counteract the inherent deep DOF and any possible diffraction softness, I'm almost exclusively shooting with apertures of 4 and wider; yet I've never seen such a noticeable fall-off on the V1E.

[Serena Steuart]

Yes, the relationship you are speaking of is the cosine squared law, so the edges of the image must be less bright than the centre. The greater the angle the greater the fall off, so wide angle lenses have noticeable fall off. I'd be very glad to see somebody do a quantitative test. Not hard to measure the gradient from centre to edge. Then we could determine whether the gradient follows the usual law or if something unusual is happening. I'd do it if I had received a camera, but I haven't. All these frame grabs of curtains and carpets tell me nothing except that someone needs to take a systematic look to see if there is or is not a problem. So far we have 15 pages of chicken little speculations.

[Paul Cook]

Originally Posted by Serena Steuart

All these frame grabs of curtains and carpets tell me nothing except that someone needs to take a systematic look to see if there is or is not a problem. So far we have 15 pages of chicken little speculations.

See I don’t really understand your thinking on this. Clearly you know way more about photography science than many on this forum (myself included) but do you really need a degree in math to see that the image is unsatisfactory?

Also given this issue only seems to be effecting certain cameras...doesn’t that all but prove it IS a problem and not a gradient following the usual law in which case ALL EX1's would exhibit the same ‘issue’?

[Eric Pascarelli]

Removed by user

[Paul Joy]

Originally Posted by Serena Steuart

All these frame grabs of curtains and carpets tell me nothing except that someone needs to take a systematic look to see if there is or is not a problem. So far we have 15 pages of chicken little speculations.

Sorry, but I value real world tests more than any chart or mathematical calculations about the performance of the cameras. Many of us have used this camera and experienced this fault first hand so the results posted so far are much more than "chicken little speculations", they are the result of actual tests using the camera.

[Paul Joy]

Originally Posted by Paul Cook

Also given this issue only seems to be effecting certain cameras...doesn’t that all but prove it IS a problem and not a gradient following the usual law in which case ALL EX1's would exhibit the same ‘issue’?

I'm actually getting to the point where I'd be more surprised to see footage posted showing the 10 - 25mm zoom range without this problem. It's quite easy to produce material with the camera not showing this issue, you just have to avoid the 10 - 25mm zoom range or shoot subjects where the effect is not apparent.

Watch this clip, the natural vignetting at each extreme does look like a fairly normal gradient, but the top left corner showing at 10 - 25mm (around 3 seconds in) is an entirely different thing.

http://www.dvinfo.net/conf/attachmen...2&d=1195761898

[Piotr Wozniacki]

With all due respect to Serena and Tom, I also think no scientific methods are needed to see there is a serious problem. I agree that any lense will show vignetting with aperture open wider than the camera is designed for (hence the "mechanical stops" Tom is mentioning), but it doesn't change the simple fact that within the normal (i.e. allowed) aperture openings and zoom/focus range, a camera must not show corner vignetting or brightness fall-off as apparent as have been shown in this thread.

I'm not bashing the EX1; in fact I am myself in a very difficult situation as I not only have ordered one, but paid for it in full almost a month ago, having been attracted by its undisputable virtues and advantages! What's more, I also purchased the newest and fastest (and most expensive) Sony Vaio laptop with ExpressCard reader and BluRay drive, to provide for the EX1 workflow... To loyal customers like myself and many others, Sony owes an explanation of the vignetting problem nature and possible remedies, as well as its impact on delivery time.

Luckily enough, I didn't sell my old good V1E and EX1- incompatible accessories for less than they're worth...

[Paul Joy]

As a comparison, the clip linked to below shows my XH-A1 set up in the same way as the EX1.

Sony EX1: http://www.dvinfo.net/conf/attachmen...2&d=1195761898

Canon XH-A1: http://www.olikai.com/forum_images/xha1zoom.mov

You can see that both have a natural vignetting at the extreme zoom range, but the canon does not suffer from anything like the same problem elsewhere.

[Steven Thomas]

Originally Posted by Serena Steuart

All these frame grabs of curtains and carpets tell me nothing except that someone needs to take a systematic look to see if there is or is not a problem. So far we have 15 pages of chicken little speculations.

Please do us a favor AND DO NOT DERAIL this thread with your perceptions.
It's a KNOWN problem (even pointed out by Adam Wilt with the pre-production EX1). Sony "IS" working on it. It's not normal vignetting.
It's mainly seen between 10-25mm focal range. NO it's not seen at wide open where ONE would expect it to be the worse.

In fact, Sony HAS been following this thread

[Steven Thomas]

Here's a message posted at Mr Phillip Blooms's blog:
>>
" Phil from Glasgow
Phil I went to the IOV show last month (UK
video show) and Sony's demo camera suffered
this vignetting very badly on the left of
screen, I have tried many times to log onto
DVINFO to pass on this info with no joy.
Sony told me it was a faulty image
stabilizer (IS) and a known bug that would
be fixed by the time these cameras went to
production. Looking at some of the chaps on
DVINFO Sony have not cured this problem and
we are still seeing this IS problem. I am
due to receive this camera on Friday and
will be pretty P***ed off if I also get this
problem. Sony have delayed this camera in my
opinion to overcome this problem, it's a
shambles.
Wednesday, November 28, 2007 - 09:30 PM "
<<

Sorry for the long quote, there was no easy way of linking just this section from the page:
http://web.mac.com/philip.bloom/Phil.../28_Day_1.html

[Steven Thomas]

Here's an email I received this morning from my Sony dealer:

>>
"
Here’s this morning’s info.

Sony is working on figuring out the vignetting issue. The problem has been reported by a number of customers, but only a few of those who have already received their cameras. They have an engineer on his way to Japan to figure out what the problem is. For instance, was this only a certain series of serial numbers, or a wider issue, what is the cause, and how to resolve it?
"
<<

[Dave Elston]

It may not be worth much, but heres a theory...

Steady-Shot OIS is an opto-mechanical correction of the image before it lands on the imagers (unlike cheaper 'digital IS' which centre-crops the image)then it is possible the problem units are suffering from an OIS that is mis-positioned such that (regardless of being ON or OFF) it is passing a wider FOV to the imagers than it should - hence the vignetting.

Maybe I'll catch the next flight to Japan and take my screwdriver set with me ;0)

At least Sony are fezzing up and admit they are working on a solution. Lets hope it's not a complete re-design to fix ( EX2 anyone? ).

Cheers,
Dave.