Let's Talk Telescope: Orion's UltraBlock UHC Filter
Evaluating Orion UltraBlock Narrowband Filter: A Notable Choice for Effective Blocking
Take a deep dive into the wonderful world of celestial observation with Orion's UltraBlock UHC filter. Perfect for beginners graced with a tight budget, this bad boy is a must-have for your telescope arsenal. But hold yer horses, pardner! Before we start gushin' 'bout this filter's marvelous capabilities, let's dish the deets on what it does and what to expect when yer wranglin' with it.
Many greenhorns have unrealistic expectations or slap these filters on the wrong objects, only to be left disheartened. However, when utilised correctly, the Orion UltraBlock UHC is a downright joy to use and transforms your viewing experience on planetary and emission nebulae, regardless of the quality of your skies.
This little gem screws on to your eyepiece using the built-in threads, making it compatible with all yer telescopes. If your baby's got a 2" focuser, most 2" to 1.25" adapters allow you to use the 2" UltraBlock filter with 1.25" eyepieces, and if yer adapter ain't up to par, there's plenty of cheap options out there that are filter-friendly.
What's a UHC Filter and How It Works
Telescope filters work by rejecting light from wavelengths you don't want and letting through the ones you do. This is achieved with a specially tinted piece of glass for color filters or complex multi-coatings for nebula filters. For color filters, it's simple as apple pie: a blue filter only passes blue light, a purple filter passes only red and blue light, and so on. For nebula filters, it's a tad more complicated. Most nebula filters only pass narrow wavelengths around the hydrogen-alpha, hydrogen-beta, and oxygen-III lines that nebulae strongly emit, enhancing contrast and visibility of nebulae details. They're ionized and lit up by nearby stars, emitting specific melliferous colors. So the filter only passes the light at the wavelengths around those colors: hydrogen beta and oxygen III in the blue-green range and hydrogen-alpha in the deep red.
Naturally, only passing these specific wavelengths results in a dimmer image. So you ain't gonna see anything brighter than the unfiltered view, and stars and galaxies will be dimmed severely. But for planetary and emission nebulae, the restriction helps make the background pitch-black, boosting contrast and revealing hidden gems.
A UHC (ultra high contrast) filter like the UltraBlock has a narrower bandpass than a broadband nebula filter, and thus the contrast effect is more pronounced. In simpler terms, you get a blacker sky to better observe those glorious nebulae.
Neighbula filters don't completely eliminate light pollution's effects on nebulae, but they sure do help. Light pollution reduction is still possible even under a dark sky simply due to these filters' contrast-boosting properties.
Many folks seem to like the effect the UltraBlock has on the Moon and planets, but I'm still struggle to understand why. I've never ventured into using the UltraBlock for this task, but if I had to guess, I'd say it's due to the color shifting that folks find distracting.
Performance
The Orion Nebula becomes significantly more pronounced with the UltraBlock, even under suburban skies. With a 6" Newtonian, the UltraBlock makes the difference between seeing the Lagoon Nebula or not, as with the Veil Nebula. Using a larger telescope of at least 12" aperture with the UltraBlock unlocks the Horsehead Nebula with some effort – an H-beta filter might still be your best bet for this task.
Planetary nebulae are improved in contrast with the UltraBlock, but not as much as with a dedicated oxygen-III filter. However, spotting small, low-power planetary nebulae is still far easier with the UltraBlock than without.
Compared to pricier filters, the UltraBlock UHC's principal disadvantage is the overall light transmission. I've found the difference to be somewhere around a half to a third of a magnitude. However, the UltraBlock holds its own, providing equally sharp images and excellent faint detail at a fraction of the cost.
Final Call
While I personally use a more expensive filter, there's little tangible gain of a more expensive filter over the UltraBlock. It's hard to beat this bad boy's performance at its price point. If you're just dipping your toes into the filter world, let the UltraBlock be your first conquest.
- The Orion UltraBlock UHC filter is beneficial for beginners with limited budgets, improving the viewing experience on planetary and emission nebulae, regardless of the quality of the skies.
- This filter works by rejecting unwanted light wavelengths and allowing the passage of desired ones, using a specially tinted piece of glass or complex multi-coatings for nebula filters.
- When used correctly, the Orion UltraBlock UHC transforms the viewing of planetary and emission nebulae, making the background pitch-black and boosting contrast to reveal hidden details.
- While light pollution isn't completely eliminated with nebula filters, the Orion UltraBlock still helps improve contrast and visibility even under Suburban skies.
- Many find the UltraBlock's effect on the Moon and planets appealing, but its color-shifting properties might be the reason for this response, as the UltraBlock is more effective in improving contrast and detail in planetary and emission nebulae.
