Orion ultrablock narrowband

[sorrimen]

Hi all

Hope this is the right place for this, but my question is whether the Orion ultrablock narrowband (light pollution filter) is the same as an ultrablock UHC. From what I can gather, they are the same but I’m trying to make sure I’m not purchasing a broadband ‘deep sky/light pollution filter’ rather than a true narrowband UHC. It’s used and in 1.25” format, just in case that has relevance.

TIA

 

[Don Pensack]

Orion's official name is "Sky Glow Ultrablock" filter.

That's confusing, because they also have a Sky Glow Broadband filter.

So everyone just refers to it as an "Ultrablock".

It is Orion's narrowband "UHC-type" filter and is comparable to other "UHC-type" filters.

Someone may just call it a "UHC" to avoid confusion with broader filters.  That's not a bad thing--good for the seller.

It will be used at powers from 10x/inch and lower, so if your low power eyepieces are 2", get a 2" filter.

A 2" filter will fit the bottom of many 1.25" adapters for a 2" focuser, and also thread on to the front of a 2" star diagonal,

so 2" is the universal size if the scope has a 2" focuser.  If the scope is 1.25" all the way through, including the focuser, then 1.25" filters are appropriate, of course.

 

[sorrimen]

Thanks for the detailed response, Don. I imagine it’s not quite as narrowband as Lumicon or astronomik but better than a much cheaper ‘UHC’? From what I understand also better than the Explore Scientific UHC which fits into the broader-band UHCs?

2” would be ideal, but I’m falling away from buy once cry once for this in particular as I’m settled on eyepieces for now (all 1.25”) and don’t want to wait on a used 2” within budget. 

[Don Pensack]

On 26/08/2022 at 13:41, sorrimen said:

Thanks for the detailed response, Don. I imagine it’s not quite as narrowband as Lumicon or astronomik but better than a much cheaper ‘UHC’? From what I understand also better than the Explore Scientific UHC which fits into the broader-band UHCs?

2” would be ideal, but I’m falling away from buy once cry once for this in particular as I’m settled on eyepieces for now (all 1.25”) and don’t want to wait on a used 2” within budget. 

To be more exact, the only issues owners of the Ultrablock filter have encountered is that the bandwidth can be slightly misplaced, clipping either the 486nm H-ß wavelength or the 501nm O-III wavelength at a much lower transmission.

My lab-tested sample had transmission % at 486 of 85.9%, at 495nm (O-III/2) of 95.4%, and at 501nm (O-III/1) of 82.8%

The bandwidth wasn't misplaced in the spectrum, as FWHM bandwidth was 482nm -508nm (26nm), plenty of room to get transmission above 90%.  That bandwidth is similar to TeleVue, Lumicon, and Astronomik.

It just wasn't a good curve.

 

A test of 8 of them here:

https://searchlight.semrock.com/?sid=a08a1af9-84ee-49d2-959d-153d7e7c0eb8#

showed H-ß transmissions from 70.3% to 97.4% and at 501nm (O-III/1) of 82.4-95.6%

That variability is why the Orion Ultrablock is not considered one of the premium filters.

Nonetheless, 2 of 8 were superb, and 4 of them had nice bandwidths, just with a bit lower transmission % than the higher priced filters.

That would only be an issue if used on a small scope of 80mm or smaller.

 

So your odds of getting a decent one look to be 75%, and a superb one of 25%, based on the 8-filter sample.

 

Last, Orion uses a different thread on their filters, so threading them into regular eyepieces can be problematic.

Know this:  At only 7g for a 1.25" filter, only 1 thread really needs to catch to hold the filter on.  So if it doesn't thread in more than a couple threads, that is really not a problem.

Internet Forums make a big deal out of that, but I've used Orion filters on and off for decades, and never had one fall off.

 

Yes, the wider UHC filters (ES, Optolong, StarGuy, Astronomik UHC-E, etc.) do not provide the contrast enhancement you want.  They're less expensive, which is why they've sold.

Here is a US-oriented listing of available nebula filters (though pretty applicable in the UK):

https://www.cloudynights.com/topic/817105-2022-nebula-filters-buyers-guide/

 

I note there are some photographic filters now that perform as credible narrowband UHC-type filters, but they are also not inexpensive.

 

 

 

[Louis D]

15 hours ago, Don Pensack said:

A test of 8 of them here:

https://searchlight.semrock.com/?sid=a08a1af9-84ee-49d2-959d-153d7e7c0eb8#

 

15 hours ago, Don Pensack said:

Yes, the wider UHC filters (ES, Optolong, StarGuy, Astronomik UHC-E, etc.) do not provide the contrast enhancement you want.  They're less expensive, which is why they've sold.

Notice that the StarGuy O-III is nearly identical to the Lumicon Comet.  Might not be a bad deal if used for comets.

I wonder if it is the same as my Zhumell O-III I picked up in 2014 for $10.  It's more of a blue-green filter than an O-III filter.  My 25 year old Lumicon O-III totally trounces it.

[NGC 1502]

I’ve had a 2” Orion Ultrablock for years and found it excellent, mainly used with my 10” Dob under typical town skies and better country skies. I always found it excellent as long as used appropriately on suitable objects.

A few weeks ago I had the chance to purchase a used 2” Lumicon UHC from a friend.  I had several sessions comparing the Lumicon and Ultrablock.  On objects like M27, M76, the Veil east and west sections, I could not detect a difference in the views.

The only difference I found was the thread issue mentioned above. The Ultrablock was not completely compatible with some eyepieces but the Lumicon has no issues like that.

I think it’s likely that my Ultrablock was one of the better ones, it’s now found a home with a local friend.

Ed.

[Don Pensack]

7 hours ago, Louis D said:

 

Notice that the StarGuy O-III is nearly identical to the Lumicon Comet.  Might not be a bad deal if used for comets.

I wonder if it is the same as my Zhumell O-III I picked up in 2014 for $10.  It's more of a blue-green filter than an O-III filter.  My 25 year old Lumicon O-III totally trounces it.

If the O-III extends upward far enough to capture the 511nm and 514nm C2 lines, it could be a decent comet filter.

The Starguy was (it's no longer made) identical to the Optolong.

Not all the 18-28nm wide O-III filters (all too wide for O-III use) extend upwards far enough to catch those lines.

Edited August 28, 2022 by Don Pensack

[Zeta Reticulan]

The Astronomik UHC-E passes one of the Swan bands I believe. 

[Louis D]

40 minutes ago, Zeta Reticulan said:

The Astronomik UHC-E passes one of the Swan bands I believe. 

According to the SearchLight data Don pointed to, The Astronomik UHC-E (the blue line) passes both Carbon lines (olive green) quite well along with a particular Orion SkyGlow from Japan (olive green) and one from Korea (magenta).  However, other SkyGlow versions don't, so it's pretty hit or miss on Carbon lines for them.

[sorrimen]

Really enjoying reading this discussion. Once I think I know a lot of what there is to know, an entirely new topic comes up and reminds me that I'm a serious amateur. Loving all this information!

[Zeta Reticulan]

3 hours ago, Louis D said:

According to the SearchLight data Don pointed to, The Astronomik UHC-E (the blue line) passes both Carbon lines (olive green) quite well along with a particular Orion SkyGlow from Japan (olive green) and one from Korea (magenta).  However, other SkyGlow versions don't, so it's pretty hit or miss on Carbon lines for them.

Interesting. My SkyGlow is Korean. I also have the UHC-E.

Although I now have a dedicated comet filter.

I've even seen a comet with it lol.

[Guest]

I have been running both the Orion narrowband and their OIII filters recently and they are pretty decent and bringing out nebula. I have both 1.25 and 2 inch models, i have not had the chance to use the 1.25s yet, but based on what i have seen with the 2 inch i have no reason to expect that they won't be good enough for me. 

Edited August 30, 2022 by Mike Q

[bosun21]

I have and use the Astronomik UHC(not E) and OIII. I have found both of them to be great filters. They were both recommended to me and I’m glad I bought them, although they aren’t cheap.

[TheLookingGlass]

On 26/08/2022 at 12:14, sorrimen said:

Hi all

Hope this is the right place for this, but my question is whether the Orion ultrablock narrowband (light pollution filter) is the same as an ultrablock UHC. From what I can gather, they are the same but I’m trying to make sure I’m not purchasing a broadband ‘deep sky/light pollution filter’ rather than a true narrowband UHC. It’s used and in 1.25” format, just in case that has relevance.

TIA

 

I've owned about 6 of these over the years. They are "hit and miss" filters. Some were good, while others, not so good. My last one wasn't very good and I know this because I compared it directly with a really good Lumicon UHC on the Lagoon nebula and a few others. In the Lumicon UHC on the Lagoon, the three parts of the nebula was mottled and bright, while in the Orion Ultrablock, the three parts were half as bright without any mottling.

I don't think I would chance getting another Ultrablock, but will be getting a DGM NPB filter instead. We compared the DGM NPB to the Lumicon UHC and it was a tie between the two. I highly recommend the DGM NPB !!!

Clear skies!

Edited September 5, 2022 by TheLookingGlass

[sorrimen]

Okay filter is received. This is very likely a stupid question, but is there any way to tell if it’s a dud other than spectroscopy? I.e. should I be expecting a mirror-like effect when I look through, because it’s more like a blue filter when looking through. 

edit: having said that, even if you could tell I would need to have looked through other filters to distinguish them! Will test it out in the field instead!

Edited September 5, 2022 by sorrimen

[Stu]

9 minutes ago, sorrimen said:

Okay filter is received. This is very likely a stupid question, but is there any way to tell if it’s a dud other than spectroscopy? I.e. should I be expecting a mirror-like effect when I look through, because it’s more like a blue filter when looking through. 

edit: having said that, even if you could tell I would need to have looked through other filters to distinguish them! Will test it out in the field instead!

I suspect a field test is the best option, just don’t judge it on one session as you need good transparency to really tell. I assume you’ve got nothing to compare with?

[sorrimen]

1 hour ago, Stu said:

I suspect a field test is the best option, just don’t judge it on one session as you need good transparency to really tell. I assume you’ve got nothing to compare with?

Yeah this is my first use of any filter. Hopefully even the poor examples still provide some contrast benefits.

[NGC 1502]

10 hours ago, sorrimen said:should I be expecting a mirror-like effect when I look through, because it’s more like a blue filter when looking through. 

 

The Ultrablock I used to own and the Lumicon I now own both look mirror like.  The only way to find out if it’s good is to use it. As already mentioned it will likely take several sessions to find out what you need to know.

Every type of similar filter, even the bargain basement ones I’ve owned have been worth having, all showed better views that with no filter at all.  It’s a better, a bit better, a lot better story.