IQ2 Series, Extended Black Calibration

[JoeKitchen]

I noticed the other day that my IQ260 has two black calibration modes, normal and extended.  (Or at least it had these modes while attached to the XF body; I know the menu changes and I did not check to see if it is present when attached to the Arca.) 

I have not been able to find any info on this other then it can help with shadow noise. 

Anyone know what this does or how effective it is?   

[voidshatter]

Tried it before but didn't find it useful. Solution for long exposure = get an IMX161 / IMX211 / IMX411 instead!

[JoeKitchen]

Tried it before but didn't find it useful. Solution for long exposure = get an IMX161 / IMX211 / IMX411 instead!

If only it was that simple. 

Remember, I do shoot architecture with wide angle tech camera lenses, and I'll be damned if I correct the perspective in post.  We will need to wait and see on the IMX411. 

[voidshatter]

If only it was that simple. 

Remember, I do shoot architecture with wide angle tech camera lenses, and I'll be damned if I correct the perspective in post.  We will need to wait and see on the IMX411.

So you have tried the IMX211 and found evidence that the color cast is severe enough to force you stick with the 60MP Dalsa? Could you share some examples of failed LCC please? (Of course, I mean a side-by-side comparison between the 60MP Dalsa and the IMX211, at the same time/place, same scene, same lens etc.)

[JoeKitchen]

Come on Yunli, you know as well as I do that lighting conditions have nothing to do with lens cast.  It is a function of shift and aperture only. 

I have reviewed images captured with the IQ3 100 and the lens cast with the Rodie 32mm is worse then with my SK 35mm on my IQ260 at the same amount of shift. 

Plus, most other architectural photographers I have spoken to about this agree with this as well.  For some, resolution trumps color, but for me, color color and color are what is important. 

If the IMX411 truly has better acute angle response, as you said in another thread, then I would consider that. 

[alatreille]

As many have said...

CMOS
Fullsize chip
50-60mpix.

Most AP's on tech cameras would be happy.

[Paul2660]

Not to be-little the color cast issue on the 100, however unless Yuni re-did his testing (I have only the first stuff) things have changed drastically on the 100 and color cast correction.

No doubt before correction it can be harsh, but the latest C1 LCC corrections are impressive.  I am not a Architecture photographer, however in a lot of my work, I shift and nothing in my work is harder to correct than a blue sky with color cast.  All I can say is the process is vastly improved with the latest versions of C1, enough so that I would still use the 100 on a tech camera now.

But I also realize it's a very independent issue.  I have the 35XL and have used it on both the 160 and 260 and on those backs it's a dream lens, being symmetrical, and I often was able to get to 10mm of shift.  After that the lens I have just lost too much details with smearing.  The 32 Rodenstock can get to 15mm, but for landscape work it's plagued by classic retrofocus distortion (things towards the edge get elongated and flattened) and there is no correction I know of for that.  Color cast is lessened a bit by the CF which balances out the exposure, but on the 50MP and 100mp backs I agree it can get problematic.  For some reason I see it still worse on the 50MP back. 

It will be interesting to see when the new chips arrive as to how well movements can be handled.  I can state that with the Sony A7RII and the BIS design, I did not see any relief of color cast in my testing with the M2 and a few of my lenses, still quite red.  However with the Canon lenses much better since the lens is moved back much further from the sensor due to the need for a mirror box on Canon DSLR cameras.

Paul Caldwell

[voidshatter]

Come on Yunli, you know as well as I do that lighting conditions have nothing to do with lens cast.  It is a function of shift and aperture only. 

I have reviewed images captured with the IQ3 100 and the lens cast with the Rodie 32mm is worse then with my SK 35mm on my IQ260 at the same amount of shift. 

Plus, most other architectural photographers I have spoken to about this agree with this as well.  For some, resolution trumps color, but for me, color color and color are what is important. 

If the IMX411 truly has better acute angle response, as you said in another thread, then I would consider that.

No offense here! I just wanted to see some examples of professional architecture shots to illustrate the color cast and crosstalk issues in real-world applications where money is earned! Since you shoot with an SK35 (instead of a 32HR) I can totally understand that the current CMOS backs are not an option for you. If you already own a 32HR then your opinion might change a bit?

Regarding keystone correction, I think my previous test already showed that it could be a viable option in the future. Maybe 150MP with keystone correction can produce more details than 60MP technical cameras with shift?

I was only told by the Sony sensor engineer that the color cast could improve for the IMX411 but I'd take it with a grain of salt.

Not to be-little the color cast issue on the 100, however unless Yuni re-did his testing (I have only the first stuff) things have changed drastically on the 100 and color cast correction.

No doubt before correction it can be harsh, but the latest C1 LCC corrections are impressive.  I am not a Architecture photographer, however in a lot of my work, I shift and nothing in my work is harder to correct than a blue sky with color cast.  All I can say is the process is vastly improved with the latest versions of C1, enough so that I would still use the 100 on a tech camera now.

But I also realize it's a very independent issue.  I have the 35XL and have used it on both the 160 and 260 and on those backs it's a dream lens, being symmetrical, and I often was able to get to 10mm of shift.  After that the lens I have just lost too much details with smearing.  The 32 Rodenstock can get to 15mm, but for landscape work it's plagued by classic retrofocus distortion (things towards the edge get elongated and flattened) and there is no correction I know of for that.  Color cast is lessened a bit by the CF which balances out the exposure, but on the 50MP and 100mp backs I agree it can get problematic.  For some reason I see it still worse on the 50MP back. 

It will be interesting to see when the new chips arrive as to how well movements can be handled.  I can state that with the Sony A7RII and the BIS design, I did not see any relief of color cast in my testing with the M2 and a few of my lenses, still quite red.  However with the Canon lenses much better since the lens is moved back much further from the sensor due to the need for a mirror box on Canon DSLR cameras.

Paul Caldwell

If you can't observe improvement of color cast with the A7R-II then the future doesn't look very bright for technical cameras. 150MP with keystone correction beats 60MP technical cameras most likely (I guess).

[JoeKitchen]

No offense here! I just wanted to see some examples of professional architecture shots to illustrate the color cast and crosstalk issues in real-world applications where money is earned! Since you shoot with an SK35 (instead of a 32HR) I can totally understand that the current CMOS backs are not an option for you. If you already own a 32HR then your opinion might change a bit?

Regarding keystone correction, I think my previous test already showed that it could be a viable option in the future. Maybe 150MP with keystone correction can produce more details than 60MP technical cameras with shift?

Eventually I may get the Rodie 32mm.  The damn thing is just too big

With the keystone corrections, it is not a loss of resolution I am worried about, but the proportions of the building are different and less accurate with correcting in post.  I have done this test and ti becomes very obvious when composing one-points. 

Not to mention, you typically need to shoot wider and crop.  Plus, when on location with a client, it's harder for them to visualize what the image will look like after correcting it in post.