When *NOT* to use a Circ Polariser Filter

[Calxoddity]

Hi from dank and miserable Wellington (just thought I'd mention that to get it off my chest...).

I discovered last week that my love of using the circ polarising filter has its limits.

On my drive down to Canberra I stopped at Lake George to take some pikkies looking back across the lake to the wind farms on the eastern shore. The resulting shots were really nice - great light, stark colour contrasts, nice feeling of isolation etc. I got a little excited and then thought "this is too good to waste - I'm gonna take a series of shots for a pano."

Pano planning went well - 21 overlapping shots at 70mm in portrait mode, for a majestic 135 degree sweep of Lake George.

Took the pikkies home and proceeded to stitch them together. O Noes! I left the circ polariser on, and now the different blue depth of sky across the arc of the pano has been chopped into little pieces in the pano stitching. I now have slivers, kites and other odd patches of different blues dangling in the sky across the middle section of the pano. Despite all efforts to fix, no joy so far - the hue/saturation differences are too stark.

Moral of the story - if you're gonna do a big pano, take the circ polariser off before you start...

(I'm considering replacing the sky altogether, but that somehow feels like cheating).

Regards,
Calx

[mercho]

Yeah I found that out that Hard way a while a go too!

Because as your panning, your changing the angle in which the light is being being filtered resulting in some funky results when stitching lol

My CPL is constantly attached to my 17-40, hence i don't do panos that often :o

[arthurking83]

With a note in mind to announce my lack of pano experience, and with all of my experience coming form the use of a UWA(10-20mm siggy) only...

generally I find that when attempting such a wide FOV, if the conditions aren't so bad and the difference in hues are so huge, you should be able to process the differences out. ie. lighten the darker areas and darken the light areas to get to a reasonable middle ground.

ofd course time of day is imperative to do this properly.. but even that is not the only limitation/clause! Location(from the equator) may have a large impact and time of year too.
I find that during mid autumn to mid spring(approx) you can get better results more often than say during daylight savings time(approx).
I have no exact scientific proof, just my observations over the past few years in doing it more and more.

One more thing: if you shoot during the day at at midday)or when the sun is directly overhead, there should be no issue doing a full 360° pano as the polarised light will be the same at any direction you look(ie. 90° to the angle of the sun)

.. but who shoots at midday huh? :p

I also use GND's to balance the sky as much as possible too... but you're right it is easier to do a pano without a CPL.

[rellik666]

Thanks for the tip......but can we see?

Roo

[Kym]

Maybe a bit of research would have helped...

http://www.ausphotography.net.au/forum/showthread.php?p=320293


5: remove filters, especially polarisers

:D

[mudman]

(I'm considering replacing the sky altogether, but that somehow feels like cheating).
Calx
it's only cheating if you are caught. so tell anyone.
cheers

[stoogest]

Also learned that one the hard way. It's a pretty big club, so don't feel alone ;)

[darylcheshire]

My Sony DSC-WX1 has an automatic pano mode where it takes 6 or so photos in succession as you swing around.
My latest attempt was with the camera pressed against the window of a moving train.

Came out weird, all chopped up. It expects you to be swing around in an arc.

Might try with my 5D MkII from a moving train and then process in PS.

Daryl

[Briancd]

Here is my first lesson in why not to use a CP filter on a pano. As you can see there is a dramatic difference between the left and right side of the sky.

[Calxoddity]

Hi again,
Sorry, I'd love to post the image, but it's 17,600 x 2600, and it's on my Mac at home. I'll be back home in around 36 hours, so if I can trim it to show the offending section, I'll post it on Saturday night.

And yes, I should have rtfm (or rtff in this case).

Brian - imagine your pano with the deep blue only in the middle, with blue boxes and stripes in the deep blue...

[Calxoddity]

Hi yet again...

Here's 2 photos to show the detail:

Photo 1 is a standard single shot, showing how the sky looked
Photo 2 is the pano - sorry if it's a bit squashy, but you can see the sky effect.

[Flash Hit]

Any post processing to whatever the camera has captured is "CHEATING". We all CHEAT! The amount of cheating depends on what your client or yourself require in the finished product and if the cheating has worked and all are happy with the end result, then you have the "PERFECT" shot! Those who are better at PP may be considered a "Better Photographer" than those who are not so gifted at PP.
I make the above statements with TIC.

[arthurking83]

Technically speaking.. capturing 11 images and stitching them into a single panorama image is as much cheating as it would be to overlay another sky into the panorama itself.

To me that process sounds too complicated!

I'd be inclined to use the clone/heal tool in PS to smooth out the graduation of blues in the sky into a single looking graduation of colour. Of course I say that, having never done it myself, but I have corrected for such differences in a single image myself(sometimes successfully, other times not very!)

[Dylan & Marianne]

one wonders what the context aware button can do in CS5 lol.
anyway, I learned the hard way too - not so much of an issue with clouds in the sky though
brian , your example wasn't too bad at all ! that looked like a natural progression of light to shade from a light source on the left - I've seeen and done far worse hehe - if that's the worst you got, you've gotta have pearls for trash!

[bricat]

AS dtoh said. The sun could be in that corner. I didn't find it too bad. cheers