Infrared Gear CPL headache

lucien

Hall of Famer
Hi, it's my first time out with a cpl. And nothing turned out right. Am I supposed to focus first then turn the ring for the desired effect or turn the ring then focus? It's not the lens, It's me or the cpl. Are cpl's created equally?

I have some samples straight out of the camera, only converted to jpeg.

Fire away : )

and thanks,
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lucien

Hall of Famer
Thank you, So I should only buy cpl's with a dot? Any brands off the top of your head. Hoya? Andoer? I'm sorta new. What if there is no Dot. Like the one I have : (
 
As far as I remember, all CPLs have a white dot on the outer ring which turns. For the purpose of turning the dot towards the sun to get the best results.

B+W and Hoya are good brands. There are others but I don’t have experience with them. I have had good results with the ICE brand ND filters sold on Amazon. So their CPLs may be good also.
 

lucien

Hall of Famer
This is why I never took to using a CPL except with a mirrorless camera where you can see the effect. I did not even know about this dot on the filter...
You can see the difference through the viewfinder, the image gets, more defined with water, sky or glass. But my images didn't focus at all or what I saw wasn't what came out. I'll go with the Dot, focus then fire method
 

lucien

Hall of Famer
I have something to add about the set up, I don't think it should factor though. This lens really flare's. I shot these at -2 ev raw and still this happened
 
Your exposure is 1/200th, F4, and ISO100. The CPL filter on average subtracts 1ev, the same as 1 F-Stop. That is compensated for when using TTL meter.
Bright sun. as shown- I would have expected 1/200th at F8.
Are you sure that you did not have the compensation set to +2ev?
Or have the camera set to manual exposure?

The images are overexposed. The exposure of the images looks wrong, at least going by the EXIF data.
The CPL can be used to darken the blue sky, the Dot is helpful. For getting rid of reflections off of surfaces in the scene, the dot is not as helpful and viewing the image through the finder of an SLR, mirrorless, or second filter is best. The latter setup- for masochists using polarizing filters on RF cameras. I use a matched pair.
 

lucien

Hall of Famer
ok that is excellent. What would the proper settings look like f stop and shutter wise,? I agree but how do you explain, out of focus issues? The shutter speed? This lens has no vr
 
Most of the images look in focus to me- you shot at 40mm and F4. That is not a lot of depth of field. A saturated image loses details. Between narrow DOF and details lost to saturation, that will give an overall soft look.

I would try again with the correct exposure, set the lens to F8 and give another try.
 

Petrochemist

Veteran
Location
N Essex, UK
Name
Mike
With a CPL, you always turn the dot on the ring towards the sun. Then compose and focus. And no, not all CPLs are created equally.
That depends what you're trying to do with the CPL!
Adjust the CPL after focusing to get the effect you want. Sometimes refocusing may be needed, with subsequent tweaking of the polariser. If photographing through glass AF might originally focus on your reflection.

Effects from polarisers can be darkened skies (cloud contrast), increased reflections from water, killing reflections, or more exotic uses like viewing stress in clear plastic using polarised light & a polariser on the lens...
Here's an example of the last case (with no sunlight involved)
41468699545_98477c9206_b.jpg
stressed stencil by Mike Kanssen, on Flickr

I don't see many signs of infra red in your images (or mine above) but as it's posted under IR Gear I ought to point out most polarisers are fairly transparent to IR. I've actually used crossed polarisers to get an Ir filter when I'd found I'd left my IR filters behind, the effect is similar to a 720nm filter:
50746448723_bd704e8c07_b.jpg
PK 28mm vari ND by Mike Kanssen, on Flickr

Finally here's a shot simply using sunglasses as a polariser to boost reflections:
5169851979_5ce9769e47_b.jpg
Roadside pond, NZ by Mike Kanssen, on Flickr
 
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