Why using external filter?

[Swing Ninja]

Hi, this question is for people who uses underwater cases for their dslr (i.e. ikelite, meikon, etc). Is there a big advantage of using external filter (like one of these red filters https://www.google.com/webhp?source...espv=2&ie=UTF-8#safe=off&q=ikelite red filter) vs using the regular ones that directly attached to your camera?

I know that if I use an external red filter, I can easily detach it when don't need it (near the surface). Any thoughts?

 

[daz88]

if you're using an SLR why would you use a red filter anyway. Set the WB when you get down to where you'll be shooting. The red filters are pretty usless on cameras that you can set the WB on

 

[NautilusCairns]

if you're using an SLR why would you use a red filter anyway. Set the WB when you get down to where you'll be shooting. The red filters are pretty usless on cameras that you can set the WB on

These filters, the UR-Pro and Magic Filters are for use underwater in well lit shallow water so you don't use a strobe. They are really good for wide angle I believe. The filter provides colour to objects that would be beyond strobe range

The advantage of using a filter over just using WB is that you still get a vibrant blue water colour with a filter whereas post WB adjustments if shootin RAW tends to suck the blue out of the background as it restores some colour to the subject in the foreground.

I'm using information from Alex Mustard here who invented the Magic Filter, see M A G I C - F I L T E R S

I'm thinking I might try a magic filter for some shallow fisheye wreck shots. My Panny 8mm fisheye lens has a filter holder at the back but it means I'm committed to using the filter for the entire dive. For compact housings you can take the filter off during the dive.

 

[daz88]

don't belive everything you read in an ad. Never heard of setting the correct WB and it will suck the blue out of your photos.(pretty funny actually) Interesting.......

 

[Roman_66]

In simple action cameras I think you can't set up WB under water, especially if camera doesn't have display.
Why to use red filter on SLR with full operation mode under water is it really looks good sale - marketing only.
By using red filter you are not adding anything, only reduce other colors than red and push camera to increase ISO.

 

[NautilusCairns]

don't belive everything you read in an ad. Never heard of setting the correct WB and it will suck the blue out of your photos.(pretty funny actually) Interesting.......

Sorry I obviously failed to explain clearly enough that I was talking about correcting/adding colour in an image in post processing using the manual WB or WB picker of the image management software. Try it with an image shot with ambient lighting and you'll see the background blue changes to more greyish hue as colour (less blue) is added to the main subject.

You still need to set WB on the camera on a dive with a filter but you get colour penetration beyond the range of a strobe. Have a look at the link I posted earlier.

 

[Interceptor121]

A filter will give you changes in saturation and tint as well as colour temperature. In theory if you know how your filter behaves you can replicate all of those in post processing
However in practical cases it may be difficult to achieve exactly the same results without playing with colour hues and saturation at specific colour level
I have done a workshop with Mustard and for ambient light shots you can use a filter with custom white balance the results are really nice provided there is sufficient light with specific fish that is difficult to illuminate with strobes like schooling batfish or snappers or with shallow wrecks

 

[KeithG]

Hi, this question is for people who uses underwater cases for their dslr (i.e. ikelite, meikon, etc). Is there a big advantage of using external filter (like one of these red filters https://www.google.com/webhp?source...espv=2&ie=UTF-8#safe=off&q=ikelite red filter) vs using the regular ones that directly attached to your camera?

I know that if I use an external red filter, I can easily detach it when don't need it (near the surface). Any thoughts?

the the obvious answer is that you are stuck with the internal filter for the whole dive. unless it is in a flip up holder. my early amphibico video housings featured an internal flip up holder that came with a uvpro red filter. i eventually replaced the red filter with a +4 diopter and moved to an external red filter.

i only used the red filter for daytime video.

currently i never use a red filter as it takes away light. no need for it near the surface. deeper down i depend upon strobes to add any required light.

 

[spoolin01]

I realize the original question was not about the pros and cons of red filters per se, but this is a useful topic.

The question of red filter pros and cons comes up a lot and typically gets answered the way it has been here: both "you don't need the filter since you can do post production and/or manual WB" and "it's useful for restoring some color balance".

It seems to me that using a red filter provides better spectral balance to light impinging on the sensor, and that has to be a better starting point both for simple image capture and for any processing, unless ambient light levels are already so low that your camera can't take the exposure hit of slapping a filter on the front (in which case, white balancing is not a practical objective anyway). Without the red filter, your image dataset is more deficient in reds and your limits for post-processing adjustments are greater.

As a corollary, if manual white balance somehow avoided this problem, wouldn't that be saying that the RAW dataset would depend on the white balance settings? In other words, manual white balance must just be an immediate, in-camera "post-processing" activity, not a true re-balancing of the data to be captured (like the filter is).

 

[NautilusCairns]

A filter will give you changes in saturation and tint as well as colour temperature. In theory if you know how your filter behaves you can replicate all of those in post processing
However in practical cases it may be difficult to achieve exactly the same results without playing with colour hues and saturation at specific colour level
I have done a workshop with Mustard and for ambient light shots you can use a filter with custom white balance the results are really nice provided there is sufficient light with specific fish that is difficult to illuminate with strobes like schooling batfish or snappers or with shallow wrecks

Shallow wrecks caught my interest. I'm going to Kavieng in PNG in a couple of weeks and I know there are a few shallow (10 to 15 metres) plane wrecks there. May be the ideal subjects on which to try a "magic filter".