This is the Heliopan Bay 6 Circular Polarizing Filter. Light rays which are reflected become polarized. Polarizing filters are used to select which light rays enter your camera lens. They can remove unwanted reflections from non-metallic surfaces such as water or glass and also saturate colors providing better contrast. The effect can be seen through the viewfinder and changed by rotating the filter. The filter factor varies according to how the filter is rotated and its orientation to the sun.

One of the "wow" factors of this filter are the index markings on the edge of the filter ring. This allows you to hold the filter up to your eye, choose a point that you like for polarization, replace the filter on the camera and simply rotate the ring to the chosen mark.

If you're out walking on a lovely day - in the mountains or at the beach - and you want to get a fabulous shot of a cloud-filled sky or make the water seem more saturated, then a polarizer is the way to go. This filter is the best way to make the clouds stand out, increase or decrease the saturation of the ocean or increase or decrease the reflection off the water. You can also use this filter when shooting into glass or windows since it will, again, either increase or decrease reflections.

If you're shooting black and white and want to simulate a threatening storm, try throwing on a #25 Red filter. The vista will take on the appearance of an imminent, ominous storm. 

Along with a UV or Skylight Filter, a polarizing filter should be a part of everyone's gear bag. It can turn a run-of-the-mill image into a stunning, creative photo by increasing color saturation.  

Heliopan has been a leader in the filter industry since 1949. They are known for their high quality and production standards. Their slim mounts facilitate using them with wider angle lenses. Heliopan offers most of their filters with either their standard hard coating or with their industry leading SH-PMC 16 layer multi-coating that transmits over 99.5% of the light striking it on to the image plane for the lowest flare and greatest color saturation.

The reputation of Schott glass is world renowned. The high production standards combined with a sturdy brass filter ring make this filter hard to beat. It has a "heft" that is impressive. It may feel heavier but the benefit is in the construction and results. Not only is the glass exceptional but so is the seal between the ring and glass. Schott Glass used in the manufacture of this filter is legendary and synonymous with the highest standards of filter production.

Makes a Blue Sky Bluer    Enhances Clouds    Eliminates Reflections    Rugged Black Brass Filter Ring    Index Marks on Filter Ring    High-Quality Schott Glass    Lifetime Warranty

Fully calibrated to indicate the axis of polarization and the convenient markings make the filters very easy to use on non reflex and non ground glass focusing cameras

With the calibrations all that is necessary is to hold the filter up to the eye and rotate it until the desired effect is seen; note the position of any number on the rim, mount the filter on the lens and rotate the mount until the selected number is in the same position as when the filter was held to the eye

The effect can be seen through the viewfinder and changed by rotating the filter

The filter factor varies according to how the filter is rotated and its orientation to the sun

Made of black anodized brass stock and have so little rim in front of the lens (5.4 mm) that they will not vignette with lenses as short as 21 mm

Heliopan filters are "dyed in the mass" and ground, polished and coated to the highest standards of the German optical industry

All Heliopan screw-in type and series size filters are mounted in precision black anodized brass rings to eliminate binding or cross threading and to ensure optimal alignment

Related Questions and Answers

Q: 1. Is a NVMe M.2 drive required, what function does it provide?

A: The Synology DiskStation DS1621+ 6-Bay NAS Enclosure does not require M.2 drives to operate, however is benefited greatly by them. Adding M.2 drives for high-IOPS system caching allows you to maximize performance and capacity efficiently.

Q: 2. I'm planning to buy this item but I just want to know first if this is compatible with D5000. If not, what camera will fit this lens?

A: The Sigma 8mm f/3.5 EX DG Circular Fisheye Autofocus Lens for Nikon AF is fully compatible with the Nikon D5000.

Q: 3. Can drives be hot swapped?

A: Yes, drives can be hot swapped in the Synology DiskStation DS1621+ 6-Bay NAS Enclosure.

Q: 4. Does the TB3 port supply power to a MacBook Pro?

A: No, it does not.

Q: 5. Im getting this from singapore, what is the basic warranty for this item? Thanks!

A: Empty enclosures carry a one year manufacturer's warranty.

Q: 6. Dose it come with a thunderbolt cable and if so what length?

A: Yes, a 1 meter cable is included.

Q: 7. Can I connect this directly to a computer via USB without using the Ethernet ports?

A: The Synology DiskStation DS1621+ 6-Bay NAS Enclosure can only connect to a computer via ethernet.

Q: 8. Can it hold 18tb and above in the box ?

A: Yes. At this time this Asustor DRIVESTOR 4 AS1104T 4-Bay NAS Enclosure BH #AS1104T • MFR #AS1104T would support 18TB and above.

Q: 9. I understand some users are having issues with the TB 3 connection dropping some drives randomly. (Note: similar problem existed with TB2 version and certain Macs, I experienced that myself). Has there been any resolution to those connectivity issues?

A: Peter,I had this problem extensively when I first bought the Thunderbay 4 enclosure. But I've since solved the problem. It now has happened only one time since then. Please bear with me while I explain how I fixed the problem. BTW no amount of searching the internet will help you. This took months of trouble shooting to figure out the solution.I have a new (2017) iMac Pro base model. I have the ThunderBay 4 enclosure and an OWC Thunderbolt 3 dock. The dock is used to add some much needed extra ports, most needed was the legacy Firewire 800 of which I have many FW800 external drives. There are two buses on the iMac Pro for the four (4) Thunderbolt ports on the back. The first two ports are on one bus, the last two are on the other bus. Being the neat freak that I am (and why I buy Apple products) I had both the TB4 enclosure and the TB3 dock connected to the last two thunderbolt ports, thus being on the same bus. You cannot do this (why, I don't know). You can check this by clicking on the About this Mac in the (black) Apple menu (top left corner) and then go to System Report. Go to Thunderbolt and you'll see Bus 1 and Bus 2, you'll see what I'm talking about.SOLUTION: You MUST have the TB4 enclosure and TB3 Dock each on it's own bus. So, connect one device to either the first two ports and the other device to one of the last two ports. Since then, I have only had a drive drop once (and that was when I had another external USB-C drive connected to the same bus as the TB4 enclosure).So I would guess this would be a problem on any Mac. Keep the TB4 Enclosure on its own bus and I'm guessing it's fine. So, at the end of the day, it's a GREAT enclosure. Compared to my other RAID drives, it's way quieter! Still some fan noise, but way more tolerable than my Sans Digital 2 bay RAID. The TB4 Enclosure sleeps and wakes with the iMac - Nice!. You do get the SoftRAID software, which is pretty nice. The only issue there is the drives do not show up in the Storage tab of the About this Mac window. So you have to do a Get Info on the drive from the Finder window to see how much storage is available on the drive.Lastly, if you do have an iMac Pro, be sure to contact tech support when you set up the drive. Apple has installed some unique security settings on the iMac Pro that need changed. OWC will be happy to walk you through the fix.Hope that helps.

Q: 10. Does Ddr Ram have to be added in equal sized pairs? So if i start with 4gigs of ram can i add one 16gig card and get optimal performance, or shd I only add either one 4 gig card, two 8gig cards or two 16gig cards?

A: If multiple RAM modules are installed inside the Synology DS1821+, both modules should be of the same speed and capacity.