MicroHD and red filter

[gr8jab]

Hi Guys!

I'm a MicroHD owner, and really like it a lot. I was reading an article recently posted on the Sealife Facebook: MicroHD Review. A few things caught my attention, from the following excerpt:

The underwater mode produces excellent colors without a need for a red filter, even at 20 meters. Although a red filter by Sealife isn’t available yet for the camera, I tried out Intova’s red filter and was surprised to see it fit perfectly. I found that for deep dives, 20-30 meters, combining the red filter with underwater mode produced the best colors by far! However, don’t try to combine underwater mode with a red filter on shallow dives since you will get red footage.
​

1. Does Sealife plan to release a red filter, or is the built in software filter sufficient?
2. Is there a depth range for which the built-in software filter is optimized?
3. Since the filter referenced in the article fits, is this just lucky, or is there a standard size with which the MicroHD complies? Does that mean other aftermarket filters may also fit?

 

[SeaLife Cameras]

Hi!
All of our cameras use digital color correction, automatically adding the red back in the shot without need for an external filter. Using the Easy Setup Guide, you can adjust the color correction by depth - land, snorkeling (25ft or less) and diving (deeper than 25 feet). Of course depending on overall visibility and sunlight, you may need to adjust settings. The Micro HD wasn't designed to fit with any external filters, but as mentioned you won't need one - the digital color correction of the camera essentially does exactly what filters would do.
Hope that helps!
SeaLife

 

[gr8jab]

Hi!
All of our cameras use digital color correction, automatically adding the red back in the shot without need for an external filter. Using the Easy Setup Guide, you can adjust the color correction by depth - land, snorkeling (25ft or less) and diving (deeper than 25 feet). Of course depending on overall visibility and sunlight, you may need to adjust settings. The Micro HD wasn't designed to fit with any external filters, but as mentioned you won't need one - the digital color correction of the camera essentially does exactly what filters would do.
Hope that helps!
SeaLife

Hmm... that is somewhat of a generic response. I am very frustrated by such uninformed answers, usually purveyed by someone in marketing. I asked very specific questions, and received a pat on the head instead. Why do people refuse to believe that 'I don't know' is a perfectly reasonable answer. I would happily accept that, and appreciate it when people are intellectually honest enough to give it.

Please don't take me the wrong way. I love my Sealife MicroHD and SeaDragon. It think they are great products, and would buy them again. But, as an engineer, I am somewhat disappointed in your response.

So, as a retort:

I assume that there is nothing magical below 25 feet, and that 26 feet does not have the same amount of red light as 100 feet. So, therefore, I still have to assume that the color correction is not perfect for all depths. I'm wondering at what depth range it is best. I understand that such things cannot be exact, since conditions will vary. However, don't even try to imply that your color correction is perfect for all depths.

I find the statement "The Micro HD wasn't designed to fit with any external filters" absurd. I have the new macro lens. It seems that other attachments, such as filters, could use this same mechanism as the macro lens. Maybe Sealife does not plan to offer any filters, which would be totally understandable.

 

[SeaLife Cameras]

Hi gr8jab,

Please allow me to be more specific:

1. Does Sealife plan to release a red filter, or is the built in software filter sufficient?
We have no current plans to develop an underwater color correction filter at this time. We have tested lots of filters and found that our onboard software works as good or better than the best filters on the market. We are looking into adding more filter options with new models and/or firmware updates. I don’t have a specific time schedule when that would be released, but we are working on it.

2. Is there a depth range for which the built-in software filter is optimized?
You are technically correct that each depth will have more or less red and a filter or software can be optimized for a specific depth. However, we know that would not be a practical solution, so that is why we have the two ranges. The Snorkel mode filter (underwater shallow white balance) has less red/yellow added and is optimized for depths below 25ft. At 1 foot depth there may be sufficient ambient lighting and no color correction is needed, so Daylight white balance may be okay. At 25 ft, the image may be a little cooler (more blue) than compared to 15 feet but that depends on ambient lighting conditions. Keep in mind that there are many more variables than depth that will affect the amount of color-correction needed for optimal color balance (ie. time of day, cloudy vs sunny, choppy vs calm surface water conditions, water visibility, algae content, etc). The Dive mode filter (Underwater Deep) has more red/yellow added than snorkel mode and works best at depth ranges between 25ft to 80ft. That is a fairly wide range, so 26ft may result in warmer (more red) and 80ft in cooler pictures depending on ambient lighting conditions. But, in general, we found that the Underwater Deep white balance works well within that range. At a certain depth, no filter will work because all the red colors have been absorbed, so there is no way to restore the lost color. That can occur at around 50-60ft if ambient lighting conditions are not optimal. For the ultimate underwater color-correction, nothing beats external lighting. For example, the new Sea Dragon 2500 lumen UW light produces constant ambient lighting conditions, independent of depth or other ambient lighting variables mentioned above.

3. Since the filter referenced in the article fits, is this just lucky, or is there a standard size with which the Micro HD complies? Does that mean other aftermarket filters may also fit? It's true that the Intova filter fits the Micro HD lens nicely, but that is pure coincidence. We've not tested that red filter UW but I doubt it will perform better than our digital color-correction. The Micro HD has a proprietary bayonet-style lens mounting solution, which our 10X close-up lens attaches to. We would be happy to share our lens mounting mechanical design with any manufacturer that want to develop a filter for our camera.

I hope this information answers your questions. If not, please let us know and we will gladly post more specifics where we have the answer.

Best regards,
SeaLife

 

[gr8jab]

Bravo!!! Thanks for the great reply. It was very helpful.

---------- Post added May 11th, 2015 at 05:04 PM ----------

Additional question:

I'll try to be very specific, to avoid any confusion. I plan to try night photography of biofluoresence. I have a 395nm light, which is UV, but has some small amount of visible violet/blue. The 395nm light will be used INSTEAD of a white light, not in addition to it. It is claimed that additional filters are not required (as is sometimes needed when using blue light to illuminate biofluresence).

How should I configure the camera?

Thanks!

 

[SeaLife Cameras]

gr8jab,

You are most welcome.

Underwater fluorescence photography is outside of me field of expertise, but I know of no one more knowledgeable than Lynn Miner at FireDiveGear.com. Check out their website, which should answer any question you have about UW fluorescence.

Best regards,
SeaLife