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-   -   PMW-300 and Fujinon XS chromatic aberrations (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/521983-pmw-300-fujinon-xs-chromatic-aberrations.html)

Meng Li March 3rd, 2014 01:47 AM

PMW-300 and Fujinon XS chromatic aberrations
4 Attachment(s)
Sorry for double posting but I thought it would be better to post it here. Admins can feel free to delete the same post in the other forum.

So I have been running around the entire city taking some places of views in the last few days. When I started reviewing the footages I have noticed that there are some chromatic aberrations in the picture, especially the not focused area, and thin objects (focused) in the wide angle. The new firmware I have updated seemed to have not solved any problems of it for 3rd party lenses.

My lens is Fujinon XS17x5.5BRM. Generally it gives a high pic quality and I am quite satisfied with it, but this problem is kinda bothering me a bit.

I have read an article here:
[opendtv] Update: Lens Performance on Small Imagers - opendtv - FreeLists

and it says that both XS and HS lenses have such problem, with XS a bit more severe. Also it says this:


-The XS series lens exhibited strong aberration at wider angles.
-The VCL lens did not have strong monochromatic aberrations at any focal length (squares staid square) and no apparent chromatic aberration when focussed or not.
So should I stay with the Fujinon when taking wide angle shots with better resolution and sharpness, or switch back to stock lens? Also, is there any way to clean this colour aberration in the post processing stage, like using some filters? Thanks.
Oh yeah and if there is any settings in the camera menu that can correct it, I am very appreciated if anyone can instruct me to tune it up.

The pictures are attached here. In my previously posted test footage you can also see a bit of it.

PS: By thinking about lenses of this level, Canon lenses like KS21ex5.7IRSE may have a better effect. Has anyone used such lenses before? Should I drop Fujinon and exchange for a Canon instead?

Christopher Young March 3rd, 2014 05:50 AM

Re: PMW-300 and Fujinon XS chromatic aberrations
2 Attachment(s)
Sad to say I have had bad experiences with both the XS17x5.5 and the XSs18x5.5 1/2" lenses. Both these lenses suffering from poor to bad CA depending on conditions.

I have had similar experiences with a variety of Canon lenses including the HJ series in both 21 and 22 x on a Sony PDW-800 (2/3rd "). In fact the worst lens CA I have experienced was on Canon's HJ4.3 wide angle. All these lenses and the camera have had the latest firmware with the ALAC compensation firmware upgraded and checked and the issue still raises its head every now and again. What can I say, neither Sony nor Canon have any answers.

All of the above lenses were well and truly beaten with regards to CA by the standard VCL glass which is designed specifically for the PMW series.

On a recent history doco I had a few shots where the problem was quite severe. In post I have ended up using Red Giants Magic Bullet Suite which has a CA correction tool as part of its toolset. It's not a 100% solution but in most case you can dial the CA errors down to a pretty negligible level. Once the doco series was finished and viewed by many nobody and I mean nobody including some pretty knowledgably camera guys and editors picked the fixed shots. On that basis I guess the Magic Bullet was quite 'magic'.

I have one lens amongst my kit which is an 18x7.6 SD Fujinon Digi lens and it kills all of the above lenses when it comes to lack of CA problems so go figure.

Check the attached JPGs they will give you some idea of what Magic Bullet can achieve. By no means perfect but way better than being stuck with some shots that have bad CA.

Chris Young
CYV Productions

Meng Li March 3rd, 2014 08:56 PM

Re: PMW-300 and Fujinon XS chromatic aberrations
Thanks for the information Chris, and the effect of those pictures is quite fantastic. It uses the algorithm to move the colours back together. Costly, though. So according to you, it's generally unavoidable to have aberration with those lenses, do you bear with it since it has lots of other benefits, or you just give it up and use other lenses? Is the aberration problem acceptable in final productions by people and clients?
My feel is that, if the pictures are still, then people would be more likely noticing it, but in moving scenes people generally don't care.

Mark OConnell March 4th, 2014 02:12 PM

Re: PMW-300 and Fujinon XS chromatic aberrations
Effect> Color Correction> Change to Color in After Effects can be effective for cleaning up CA. You often need to use several iterations of it though.

Christopher Young March 4th, 2014 05:40 PM

Re: PMW-300 and Fujinon XS chromatic aberrations
CA has always been with us. It just wasn't such a problem in SD days. ALAC 2 on Sony cameras is an improvement over the original ALAC. Personally I think the CAC system on the Panasonics works better. It was designed in from the get-go whereas ALAC was a retro-fix.

The best lenses I have seen for lack of CA have been the lenses specifically built for a model of camera. Such as the Sony EX camera range.

It appears that it is something we have to live with and if it becomes obvious fix. The Red Bullet plug in is great as I can fix it on the timeline as I edit. No need to go to AE or external workflows that really slow down the process. As you can see from the pix there are three color controls you just dial up or down numerically and you can see the results in real time.

Chris Young
CYV Productions

Meng Li March 4th, 2014 11:47 PM

Re: PMW-300 and Fujinon XS chromatic aberrations
So as you said, CA problem has just floated out during the HD era, how about 4K? That could mean that the lenses we are using are much worse for 4K than we think, other than those stock lenses tuned by the body manufacturers themselves? Beside that, will 3rd party like Fujinon make their 4k ENG lenses later or should we just turn to things like F55 (with money not being a problem) and use DSLR lenses instead? I have several Canon L series lenses, though it would be completely manual...

Alister Chapman March 14th, 2014 11:03 AM

Re: PMW-300 and Fujinon XS chromatic aberrations
CA and resolution go hand in hand.

As light passes through a glass lens the different wavelengths that result in the different colours we see are diffracted and bet by different amounts. So the point behind the lens where the light comes into sharp focus will be different for red light to blue light.

The larger the pixels on your sensor the less of an issue this will be. Lets say for example that on an SD sensor with big pixels, when the blue light is brought to best focus the red light is out of focus by 1/2 a pixel width. All you will see is the very slightest red tint to edges as a small bit of out of focus red spills on to the adjacent pixel. Now consider what happens if you increase the resolution of the sensor. If you go from SD to HD the pixels become around half the size. So now that out of focus red light will completely fill the adjacent pixels so the CA becomes more noticeable.

In addition as you increase the resolution of the lens you need to make the focus of the light "tighter". This has the effect of making the difference between the focus points of the red and blue light more distinct, there is less blurring of each colour, so less bleed of one colour into the other and as a result more CA as the focus point for each wavelength becomes more distinct.

This is why SD lenses very often show less CA than HD lenses. Lens manufacturers will use exotic types of glass to try to combat CA. Some types of glass have a negative index so blue may focus closer than red and then other types of glass may have a positive index so red may focus closer than blue. By mixing positive and negative glass elements you can cancel out some of the colour shift but this is very difficult to get right across all focal lengths in zoom lenses so some CA almost always remains. The exotic glass used in some of the lens elements can be incredibly expensive to produce and is one of the reasons why good lenses don't come cheap.

Rather than trying to eliminate every last bit of CA optically the other approach is to electronically reduce the CA by either shifting the R G B channels in the camera or reducing the saturation around high contrast edges. This is what ALAC or CAC does. It's easier to get a better result from these systems when the lens is precisely matched to the camera and I think this is why the CA correction on the Sony kit lenses tends to be more effective than that of the 3rd party lenses.

Meng Li March 15th, 2014 03:23 AM

Re: PMW-300 and Fujinon XS chromatic aberrations
Thanks very much Alister for your detailed explanation. I have been looking for a lens that supports ALAC. I have found a list that supports it in some other post but all of them are 2/3" lenses. Is there a list of 1/2" lenses that support them?

Christopher Young March 15th, 2014 05:06 AM

Re: PMW-300 and Fujinon XS chromatic aberrations
Check with Fujinon because if my mind isn't failing me I seem to remember one of the Fujinon techs telling me that quite a few of the later Fuji lenses could be firmware upgraded with ALAC. Now whether this covered some of the 1/2" glass I don't know but maybe worth a follow up.

Also have you got PMW-300 Firmware Version 1.12 on board as that does specifically cover an ALAC upgrade. Foe what lenses who knows! See here:

Sony of Canada: E-Support

Chris Young
CYV Productions

Meng Li March 16th, 2014 02:09 PM

Re: PMW-300 and Fujinon XS chromatic aberrations
Yes Chris, I have already upgraded the firmware of my 300 to latest and the XS lens still doesn't support it. From other posts I have seen a list of lenses that supports ALAC here:

HJ14ex4.3B IRSE / IASE
HJ17ex7.6B IRSE A / IASE A
HJ21ex7.5B IASE A
HJ22ex7.6B IRSE A / IASE A
HJ18ex28B IASE A
HJ40ex10B IASD-V
HJ40ex14B IASD-V
KJ20x8.5B KRSD

All of these are 2/3" lenses. By observing the model of these lenses I found that all of these Fujinon lenses are of Premier (HA) and Selected (ZA) models. XA lenses as the low end, are not supported. According to this predicate I would assume that HS and HSs lenses actually do support the latest ALAC functions, especially with the update. Can anyone confirm this?
According to this link: http://www.tvtechnology.com/multifor...bad-rap/259538
EX3 only supports ALAC of stock lens, but the article also says that the Fujinon lenses would be supported by other models in the near future, which is very likely to be PMW-300. That's probably why Chris got poor results out from EX3. Can anyone try out the PMW-300?

Paul Cronin May 10th, 2014 06:31 AM

Re: PMW-300 and Fujinon XS chromatic aberrations
This is of interest to me since I am looking for a wide lens to match with the PMW-300. Options are Canon KH10x3.6 an Fujinon XS13x3.3. Has anyone tried the KH10x3.3?

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