[MossyRocks]

Wait a minute, I checked many review video on YouTube and found that, the intensifer only works at night time to cut haze from artificial lighting, I don't see any similar filter for day time use to enhance contrast and color, does such thing exist ?

Yes all of those light pollution filters or filters that do a good impression of one are to solve the light pollution problem at night and won't solve haze issues during the day a polarizer would be your best bet there. The red intensifier will make fall colors better or that is one of its other claims but few use it for that because you can just tweak the saturation on a digital file and not have to buy one.

[Wasp]

Even though UV doesn't matter, I am old fashioned. My lenses need protection.

[lotech]

Even though UV doesn't matter, I am old fashioned. My lenses need protection.

I am too insisted to have them on to protect the lens, but some cheap ones added a layer of reflection and ruin the image.

---------- Post added 01-05-20 at 05:44 AM ----------

Yes all of those light pollution filters or filters that do a good impression of one are to solve the light pollution problem at night and won't solve haze issues during the day a polarizer would be your best bet there. The red intensifier will make fall colors better or that is one of its other claims but few use it for that because you can just tweak the saturation on a digital file and not have to buy one.

Yes physical filters are replaced with digital in many use, but I still want to try out those intensifier if the price is right, just need some real review from users to see how exactly it performs.

[BigDave]

the best filter would be a mild red blocking filter at about the wave length of the “spike” in the blue sensitivity in the red range,

Please note, the graph does not show the Red portion of the spectrum (which would be about 650 and up to about 700/720nm), It does not show the Green or Yellow either, only the deepest Blue portions and UV. The filter to block Red would be a Cyan filter, which would allow Blue to pass.

[Lowell Goudge]

Please note, the graph does not show the Red portion of the spectrum (which would be about 650 and up to about 700/720nm), It does not show the Green or Yellow either, only the deepest Blue portions and UV. The filter to block Red would be a Cyan filter, which would allow Blue to pass.

Look at the graph in your post #3

Does UV matter in digital ? - PentaxForums.com

It shows exactly that.

[BigDave]

Yes, Lowell, I realized that after stating, which is why I continued with the suggestion for the Cyan filter. But good catch!

[steamloco76]

My fifteen years as a working photojournalist, who had to cover rural high school sports in bad to terrible lighting, taught me a few things about UV and clear protection filters. In normal use, all of my lenses used during the film era had a multicoated UV filter mounted. These filters saved the filter threads of several lenses from impact damage, though the filters themselves were ruined. However, I quickly discovered that when shooting any lens wide open the extra piece of glass caused sharpness losses. Two lenses in particular went from acceptable sharpness to unusable, my Tokina AT-X Pro 80-200/2.8 AF and a Pentax SMC 85/1.8. I did all my own printing and began to make notes as to which shots had the filter on and which had it off as an experiment. The extra glass from the Tiffen MC filters really ruined the results. To a lesser extent, the SMC-A 50/1.7 I used for basketball suffered a small sharpness loss.

Today, I have a drawerful of MC UV filters for my lenses which generally go unused. I use lens hoods religiously and don’t run around working directly from a camera bag that often so I’d rather not add glass to the optical equation. Now, I do use filters when I’m photographing steam locomotives. You never know when some oily steam, a few cinders or other debris will hit your lens. In that case, sacrificing a tiny bit of sharpness for front element safety is well worth it.

[Lowell Goudge]

Yes, Lowell, I realized that after stating, which is why I continued with the suggestion for the Cyan filter. But good catch!

Actually I disagree, since red is already more sensitive, it wouldn’t hurt to cut the red, and lessen the reaction of the blue channel to the red, I am looking to cut the response of the cyan where it is not wanted, although boosting cyan where it is wanted might have the same overall benefit

[BigDave]

Um... a cyan filter cuts Red light, thereby reducing sensitivity to Red, it is Red's compliiment in the spectrum/color wheel. Cyan will also let both Green and Blue Pass, so no real effect on the sensitivity of these portions of the spectrum.
Regards,