Friday, October 30, 2015

VHT Nebula Filters From DGM Optics

The VHT Nebula Filters from DGM Optics - First impressions

Just a short Post, for now.

You can see the full line of (1.25") nebula filters available, from DGM Optics Here Of course, they are also available for 2" eyepieces.

As I mentioned in my previous Post: The pair of Garrett Optical 100mm binoculars were in need of some nebula filters...More specifically, the pair of (stock) 1.25" eyepieces needed filters. And, I wasn't 100% sure which types I would go with, this time around. These binoculars are much larger than any pair I've used before.

I was originally thinking: A pair of (1.25") GCE's (again)... Unless, (I thought to myself) after consulting Dan: He might suggest something different this time? Perhaps NPB's? I was anxious to find out.
Well, I did ask Dan (of DGM Optics [via e-mail]) and he recommended The VHT's. And it made a lot of sense to me. Here's a Link to the Info page, for the various filters.

Here is the transmission curve, from Omega Optical, the manufacturer: 

Also, from Omega Optical's Site regarding The VHT's:

"An excellent Nebula filter for smaller scopes (4-6 inches aperture) where light gathering and throughput are at a premium. It is also quite effective with larger scopes."

I have been very intrigued, with the measured spectral information shown here on DGM's page. The white graph on the lower right is of GCE Filter.
I also can't help wondering exactly what the measured spectral results would be, for my actual filters. That would be neat.

I haven't had many nights of good seeing, in which to thoroughly test them - But so far, the VHT's have been able to boost the contrast, on the few nebulae that I've tried them on.

And, finally, for astrophotographers - Here are some examples of how these filters help when imaging.
You'll see links to some Reviews of DGM nebula filters Here.

I plan to post a short Review of these filters here, in the near future.

Clear skies!