Does the Vectorscope Have Adjustable Gain?

[Peter Moretti]

I've been trying to find out if the built-in vectorscope on the 300/5 has adjustable gain? And if so from what level to what level and how is the adjustment made?

If this vectorscope has some adjustability, it is a very valuable addition to the camera, as a good portable vectorscope costs a few grand.

Thanks much!

[Michael Reichmann]

Peter,

The vectorscope can be set to either Normal or Spot mode and to 1X or 5X magnification.

Michael

[Peter Moretti]

Michael,

Thank you very much for the info.

While it sounds good, it kind of sucks by quite a bit. DSC Labs charts specifically require x2 gain to properly calibrate a camera. If the XF's had x2 gain, that would save the need for an external vectorscope. It would be a feature worth paying a grand or so premium for.


P.S. Although, I wonder if 1X gain is the same as x2 gain? Perhaps it doesn't mean * 1 because any number * 1 is that number. Or is 1X gain no gain at all?

[Chris Hurd]

Quite right -- there's no way to know what the "x" is until it's properly compared. So we're looking for someone with an XF and a decent standalone VS/WFM like a Leader.

[Peter Moretti]

Chris,

If this is (or can be made to be via a firmware upgrade) a viable on-location vectorscope and waveform monitor w/ the appropriate gain for shooting DSC Labs calibration charts, then that goes a considerable way to justifying the price of the XF's.

[Martin Koch]

Does this mean it's not possible to adjust the XF300/305 using the built in vectorscope and a DSC Labs calibration chart? It only fails because of the 5x gain and there's no 2x gain? Everything else is there. Targets in the vectorsope, color matrix settings ...

Please say this is not true! I've ordered a testchart. Now I read this.

[Uli Mors]

Hi Martin,

yes , thats right. Unfortunately most "simple" Vectorscopes (in TV Logics or Sony 9" / 7" LCDs) do neither have a x2 Gain...

I have no idea why the dont throw in a simple 2x in it - DSC is quite well known for their testcharts...

br

ULI

[Martin Koch]

Thanks a lot Uli.
I'll wait for my test chart, look what the XF300 vectorscope says and then ask Canon support for tipps and tricks on how to reach the targets with 1x or 5x gain.

Are there test chart available where the targets are reached with 1x gain?

[Uli Mors]

No.

There is a good explanation on the DSC website saying its not possible to print the necessary colour saturation + contrast.

Thats why DSC goes "the trick" to print just the "half" saturation and compensate this via 2x gain in the vectorsopce (faking a 100% saturation).

of course you could use 1x gain and find out where the DSC targets should be, but for this the resolution of the XF vectorscope is probably too bad.

I am trying to find out if software vectorscopes (like BlackmagicDesign) have an adjustable gain, information is difficult to get.

uli

[Martin Koch]

Thanks again, that's very helpful. I'll post more when I have the chart in a few weeks.

The vectorscope of Final Cut Pro X also doesn't offer 2x gain but a scale of 100% and 133%.
The $16000 C300 also has 1x an 5x.
I really don't get it.

[Juan Diaz]

Assuming you're on a Mac, have you tried Divergent Media's Scopebox?

ScopeBox

As of version 2.1 they added a zoom control to the vectorscope that allows you to get 2x zoom. According to their documentation, they added this feature specifically for use with DSC charts.

I've used it with the component inputs on an AJA Kona LHe card and it seems to work well. Though I'd be curious to know what other people's experiences are with it.

Juan

[Martin Koch]

Thanks, Scopebox looks like an interesting and affordable option. I downloaded the trial and will test it as soon as I have my chart.

[Uli Mors]

Hi Martin,

did you find out more?

UIi

[Martin Koch]

Uli, thanks for your interest. Yes I did and sorry, the long delay was caused because the first DSC Labs chart which I ordered from a company in Germany never arrived.

This time I ordered the smallest and cheapest DSC Labs chart - the postcard sized Camette Pocket -directly from the DSC Lab website. This chart also has spectral accurate white on the back for proper white balancing.

It arrived today and here are my quick findings:

In the first attachment you can see the vector scope of the XF300 set to Alan Roberts BBC_VIDEO Custom Profile. The traces head in the right direction but without 2x vectorscope gain there’s no chance to reliable judge or tweak anything.

The vector scope of the trial version of ScopeBox, shown in the second attachment reveals the truth.

I see now that a 2x vectorscope gain setting in the XF series would be extremely helpful and I would love to tweak the color matrix live on the camera. It would be accurate enough for me. As it is now I would need some HDMI capture device to use ScopeBox live.

I already contacted Canon customer support about this. Should be really, really easy to add a 2x multiplier in the firmware.

A question to the pros: After proper white balancing and setting the correct exposure are the matrix settings in the camera menu the correct and only way to align the traces to their boxes?

[Uli Mors]

Yes, thats exactly what I encountered a while ago - most VS do not offer the necessary 2x GAIN.

I wonder if some software VS like the Blackmagic Designs Ultrascopes do offer 2x Gain...

?

Let us know what Canon says.

br

ULI