Anti-light pollution filters used to be a specialty item that was both hard and expensive to procure, limiting them mostly to hardcore astrophotography enthusiasts with deep pockets desiring the best clarity in their astro shots. They've since gotten somewhat popular in the recent years, with many brands releasing their own take on these filters. New to the game is Hoya's Starscape filter, which purports to be able to reduce the glare of artificial city lighting, such as sodium and mercury vapour lamps, whilst keeping image colours natural and pleasing with improved contrast in the night sky, while keeping colour casts to a minimum.

Main Features (quoted from Hoya's product page):

• Reduces yellowish and greenish color cast from artificial city lights
• Natural color reproduction and improved contrast overall
• Compatible with wide and super-wide angle lenses
• Low profile frame

I received my 77mm copy from Cathay Photo Singapore, who provided me with a sample of the new Starscape filter for this review. As with the other reviews on my blog, I will be as forthcoming as I can with my opinions and thoughts of the product, even though I've been given a copy for my review.

Packaging and Form Factor

The filter came packaged in a familiar clear plastic padded case, which is typical of most of Hoya's circular filter lineup. Since this is a circular screw-on filter, there are many sizes to choose from depending on the diameter of your lens (49mm to 82mm diameters). Sadly, Hoya does not offer these filters in 100mm square formats - which would be a far better solution for adaptability and modularity between lenses of different front diameters, and would remove the need for purchasing multiple filters of different sizes or using step-down adapter rings, which may cause vignettes.

However, this also removes the need for buying a dedicated filter kit, which will be pricier compared to just purchasing a single screw-on filter. If you happen to only use lenses of a certain diameter, or do not mind carrying adapter rings, the Hoya Starscape is certainly a far simpler (and arguably cheaper) solution.

77mm Hoya Starscape in plastic case

Hoya Starscape mounted onto a camera lens

Price Comparisons

As with other filters designed for a specific and niche scenario, light pollution filters can be pricey, especially for photographers who do not photograph night scenes or indulge in astrophotography on a regular basis. The prices here are also for the 77mm circular variant of each manufacturer's night filter.

For a name-brand such as Hoya, the Starscape filter is priced the cheapest out of the commonly-available night filters here in Singapore, which does give it a leg up over the competition on price. Coupled with the Made-in-Japan assurance of quality in contrast to its more expensive Chinese siblings, the Hoya is indeed a compelling option for those who want to try their hand at some astrophotography or improve their night-time photography without a heavy investment on what would be a filter that is arguably won't be used as often as a neutral density filter.

Image Quality Comparisons

A light pollution filter works by cutting out certain frequencies of yellow light that is normally emitted from sodium and mercury vapour street lamps and similar sources of light, thus reducing or eliminating heavy light pollution from artificial light sources, which are plentiful in a busy city like Singapore. Ideally, the filter should help in reducing light pollution and flare caused by strong yellowish light sources, which become prominent as it gets dark. This should net a positive result by improving contrast on night scenes and especially on night skies.

For the review images in this comparison, I used a Sony a7rii with the Zeiss 16-35mm wide-angle zoom lens, along with a 72mm step down ring to mount my 77mm Hoya Starscape filter onto the lens. All images were exported to JPEG from Capture One with minimal processing (highlight recovery and lens profile corrections), without tweaking white balance and colour cast.

In the above and below image comparisons, the yellow cast that is typical of city lighting has been greatly reduced when the Hoya Starscape filter is used. This also has a side effect of shifting the white balance towards the cooler tones. Depending on your preference, you can choose to further correct the white balance if the filter is too cool for your liking, but I found that the filter generally produces a natural rendition that can be quite pleasing. 

Since the filter does cut out on certain frequencies of light in order to remove the colour cast caused by artificial lighting, it can also help light sources that are normally overwhelmed by city lighting to become more apparent, thus revealing additional colours that may be obscured by the cast. Because of that, the filter will slightly increase exposure time as it cuts down around 0.5 stops of light.

White Balance Matching

By selecting a neutral spot on both images as a base to match white balances, any residual colour cast created by the filter will be revealed. I used the white balance picker on the outer white facade of the apartments in the foreground for the comparison images below and found that the filter corrects very well to give a neutral result that is close to the corrected image taken without filters.

Looking at the street lamps in both images, it is clear that the Hoya Starscape does its job by eliminating the yellow cast, although the filtration does make the resulting effect on the lighting more orange-magenta.

Compared with Haida Clear Night

In contrast to the Haida Clear Night filter that I own, the Hoya does not exhibit such a strong blue-magenta cast and is actually quite neutral. Even though the Haida's colour cast can be corrected in post, the fact that Hoya produces such a neutral and pleasing result out-of-the-box makes it very straightforward for processing or for a usable result without processing work.

Concluding Remarks and Recommendations

The Hoya Starscape filter fares well in real-world testing, especially when compared to its more expensive counterparts like Haida or Nisi. Despite being a newcomer in this specialised field of light pollution filtration, the Hoya offers excellent value-for-money in terms of quality output and neutral results, which helps in cutting down time spent in post-processing. It is hard to find anything to fault this filter with, although I do wish that it does in 100mm and 150mm filter sizes, even though that would definitely add to the cost.

This filter is available for S$118 at Cathay Photo Singapore, and can be bought through Cathay's online and physical stores.

Sample Image Gallery

Central Fire Station - Sony a7rii, Zeiss 16-35mm, Hoya Starscape

Esplanade Bridge - Sony a7rii, Zeiss 16-35mm, Hoya Starscape
Cityscape from Funan Roof Garden - Sony a7rii, Zeiss 16-35mm, Hoya Starscape

Queenstown Estate - Panorama with Sony a7rii, Zeiss 16-35mm, Hoya Starscape

Queenstown Estate - Sony a7rii, Zeiss 16-35mm, Hoya Starscape
(C)Jon Chiang Photography 2019

Clarke Quay - Nikon D850, Nikkor 70-200mm VRII, Hoya Starscape