Lumicon oiii filters - important information

[Dave In Vermont]

Here, for comparative purposes, is the transmission-graph for the Astronomik OIII visual filter one:

 

 

Zip ------------------------------------>

Dave

[John]

Here are a number of O-III filters band pass graphs bought together for comparison:

 

[Dave In Vermont]

Lordy, John - where on Earth (or anywhere!) did you find THIS?! Or did YOU create this work of ART+++!?

I Stand Amazed!

Dave a Filter-Nut (deferring)

[Racey]

Well, I'm wondering whether I dodged a bullet or not. What do you think @John or @Dave In Vermont ?

This was the Filter report included in our February purchase...

It's not exactly the same as the one posted by Dave given it also shows passes at the 420nm mark. But then again so did some on the graph you posted John. What do you think chaps ? 

 

[YKSE]

3 hours ago, Dave In Vermont said:

Lordy, John - where on Earth (or anywhere!) did you find THIS?! Or did YOU create this work of ART+++!?

I Stand Amazed!

Dave a Filter-Nut (deferring)

I think it's Jim Thompson's measurement done in 2000 As seen on the graph. You can find many of these graphs here:

http://www.karmalimbo.com/aro/pics/filters/

The one linked by John is namned O3a.jpg

I posted a question on CN about reading these graphs, Jim gave his comments in the end of the thread.

https://www.cloudynights.com/topic/512332-ranking-of-uhc-filters-by-this-chart/?hl=%2Bfilter+%2Branking#entry6787299

23 minutes ago, Racey said:

Well, I'm wondering whether I dodged a bullet or not. What do you think @John or @Dave In Vermont ?

This was the Filter report included in our February purchase...

It's not exactly the same as the one posted by Dave given it also shows passes at the 420nm mark. But then again so did some on the graph you posted John. What do you think chaps ? 

 

The FWHM for your filter is around 12nm (50% transmission is about from 492nm to 504nm), a very good narrow range, transmission for OIII lines (496nm and 501nm, however, is a bit lower (around 90%) than we usually than top Lunimicon OIII.

[John]

57 minutes ago, Racey said:

Well, I'm wondering whether I dodged a bullet or not. What do you think @John or @Dave In Vermont ?

This was the Filter report included in our February purchase...

It's not exactly the same as the one posted by Dave given it also shows passes at the 420nm mark. But then again so did some on the graph you posted John. What do you think chaps ? 

 

My initial reaction (sorry to have to say this) is that this looks more like the chart for a lower cost O-III

The peak of the O-III lines should be at 90% plus and the top of the curve should be flatter - the flatter top, with sharper cut off edges high up the pass % scale gives better contrast as I understand it.

The chart you have posted looks more like the one for Skywatcher O-III filters, which work, but are not to the traditional Lumicon quality IMHO.

 

 

[Racey]

@John Thanks John. I appreciate the candour. That's pretty much what Susie and I thought. 

I'm sanguine as we managed to get it for $99, so it may be annoying, but it wasn't as costly as some might be finding...

Which might you recommend if we wanted to ensure we got a top quality one ? Astronomik?

[Scooot]

I bought my 2" o111 in 2014 but they exchanged it in March 2016 because of a fault with its fitting, ( there's a thread about it on here somewhere.) This is the one I received back. I presume it's still the older version?

[Dave In Vermont]

Scooot -

I can't tell much from it's box, the time-line of March, 2016 is prior to Lumicon going under, so your's should be fine.

I have made a Pdf. of an excellent article available on the net: ASTRONOMICAL FILTERS SPECTRAL TRANSMISSION. This has a great many transmission-graphs for many types of filters from many different sources. So grab a copy and add it to your files:

ASTRONOMICAL FILTERS SPECTRAL TRANSMISSION.pdf

So what are you waiting for? Give yourself a crash-course in Filter-Spectra, and bore your friends' to tears!  

Well off to check in on CN. See if they've finished building the scaffold for the hanging of Lumicon.....

Dave

 

 

[jetstream]

6 hours ago, YKSE said:

I think it's Jim Thompson's measurement done in 2000 As seen on the graph. You can find many of these graphs here:

http://www.karmalimbo.com/aro/pics/filters/

The one linked by John is namned O3a.jpg

I posted a question on CN about reading these graphs, Jim gave his comments in the end of the thread.

https://www.cloudynights.com/topic/512332-ranking-of-uhc-filters-by-this-chart/?hl=%2Bfilter+%2Branking#entry6787299

The FWHM for your filter is around 12nm (50% transmission is about from 492nm to 504nm), a very good narrow range, transmission for OIII lines (496nm and 501nm, however, is a bit lower (around 90%) than we usually than top Lunimicon OIII.

This is the shape of the preferred Lumicon OIII

[jetstream]

4 hours ago, Scooot said:

I bought my 2" o111 in 2014 but they exchanged it in March 2016 because of a fault with its fitting, ( there's a thread about it on here somewhere.) This is the one I received back. I presume it's still the older version?

So you exchanged your OIII for an Hb?

[Dave In Vermont]

21 minutes ago, jetstream said:

So you exchanged your OIII for an Hb?

I wasn't going to say a word!

But I gave the benefit of the doubt a photo of the wrong box was taken. These things happen!

By the by - Lumicon is smoldering along nicely over in the flames of....er....in CN!

<koff!>

Dave

[John]

5 hours ago, Racey said:

@John Thanks John. I appreciate the candour. That's pretty much what Susie and I thought. 

I'm sanguine as we managed to get it for $99, so it may be annoying, but it wasn't as costly as some might be finding...

Which might you recommend if we wanted to ensure we got a top quality one ? Astronomik?

I'd try and get either one of the good Lumicons (because when they are good, they are really good) or an Astronomik.

The Lumicons in 2" were usually around £200+ new I seem to recall so $99 is one of those "if it seems to good to be true ..." deals I fear

[Racey]

2 minutes ago, John said:

I'd try and get either one of the good Lumicons (because when they are good, they are really good) or an Astronomik.

The Lumicons in 2" were usually around £200+ new I seem to recall so $99 is one of those "if it seems to good to be true ..." deals I fear

It was a 1.25" direct from Lumicon. They are still charging $200 for the 2". 

Neither @Mrs Racey nor I are gullible enough to be taken in by a "too good to be true" deal John. This was bought directly from Lumicon with everything we read giving assurances that the new owners were maintaining everything as it had been prior to their purchase. 

I've taken what we  are referring to as our "Lumicon Comet Filter"  out of our filter wheel this afternoon, and it will be replaced with an Astronomik Oiii as you suggest. Thanks for the recommendation...

[John]

12 minutes ago, Racey said:

It was a 1.25" direct from Lumicon. They are still charging $200 for the 2". 

Neither @Mrs Racey nor I are gullible enough to be taken in by a "too good to be true" deal John. This was bought directly from Lumicon with everything we read giving assurances that the new owners were maintaining everything as it had been prior to their purchase. 

I've taken what we  are referring to as our "Lumicon Comet Filter"  out of our filter wheel this afternoon, and it will be replaced with an Astronomik Oiii as you suggest. Thanks for the recommendation...

I can understand your strong annoyance Simon. I didn't realise it was a 1.25" filter. Reading what has been going on here (including the Cloudynights posts) is very dissapointing. I don't know how the new owners of the Lumicon brand think they can get away with pushing out a 2nd rate product - they should know that highly active forums such as SGL and CN with knowlegeable members will see straight through this sort of thing and ring alarm bells, as is now happening.

They have also undermined what was a notable name in astro equipment

I hope you get prompt redress from the supplier and can find a good replacement.

 

[Mark at Beaufort]

This is an interesting thread and I hope that Lumicon has not 'shot itself in the foot'.

I bought Lumicon UHC and O-III filters which were produced in Livermore CA 94550 so the original - photo below showing the O-III. Its ironic that my Son now lives in Livermore CA with the same zip code.

At the same time I also bought an Astronomik O-III filter which I have to say I preferred. I have now sold the Lumicon although I kept the Lumicon UHC. My main O-III remains an Astronomik.

My only conclusion if you have any doubt about the new Lumicon filter I would simply buy an Astronomik - well that is my opinion.

[iPeace]

As reported earlier here, these arrived end of April from TS. Entirely unburdened by knowledge of filters, I guess I will just have to see what the O-III does for me over time...

[GavStar]

12 minutes ago, iPeace said:

As reported earlier here, these arrived end of April from TS. Entirely unburdened by knowledge of filters, I guess I will just have to see what the O-III does for me over time...

The Oiii looks good to me! I used my new 'old' one last night on the Veil Nebula and it gave great views. I'm very happy with it.

[scarp15]

The filter stats for my Lumicon 2" OIII filter, which have received use for several years are

486mm Hydrogen Beta N/A

496mm Oxygen III      96.3

501mm Oxygen III      97.0

656mm Hydrogen Beta  N/A 

      

 

 

[Scooot]

8 hours ago, jetstream said:

So you exchanged your OIII for an Hb?

Nope, it was meant to be an OIII, so I guess I've been tricked, or diddled, maybe a genuine mistake. Today is the first time I've looked at the box, and I don't use it very much. Unless of course it's just the box that's wrong?

Ps

i'm not at home to look at the moment but I think from memory the filter itself is marked as oxygen III, so I reckon it's just been sent back in the wrong box. I only have two filters and the other is an astronomic Uhc.

another edit. Thanks for pointing it out Gerry, I had no idea it was HB filter box until you mentioned it, not even when it was staring me in the face this morning  I hope I at least have the right filter.

[Dave In Vermont]

In that the representative of 'Lumicon-in-name-only' over in CN stated people can send their filters to them and they'd scan it's transmission-details and send a report to the sender. Absolutely free. Notably absent was any indication of how you'd get the thing back - or what you'd get back. Maybe a cucumber-sandwich on rye with horseradish & carpenter-ants?

I'm not recommending that you do such.

The mess is getting deeper in my opinion. Dark-days for a filter-nut.....

Dave

[John]

I sincerely hope that the Lumicon brand regains it's status quickly though products that deserve that name.

I used my Lumicon O-III filter (around 3-4 years old) tonight to show my astro society buddies the Veil Nebula with my ED120 refractor and they were bowled over by the views, as was I in all honesty. The contrast enhancement was really impressive (the nebula was practically invisible without a filter even with 12" scopes from the observing location tonight) and stars still looked plentiful and star-like. Worth the price for those views alone IMHO

 

[Racey]

4 hours ago, John said:

I sincerely hope that the Lumicon brand regains it's status quickly though products that deserve that name.

I used my Lumicon O-III filter (around 3-4 years old) tonight to show my astro society buddies the Veil Nebula with my ED120 refractor and they were bowled over by the views, as was I in all honesty. The contrast enhancement was really impressive (the nebula was practically invisible without a filter even with 12" scopes from the observing location tonight) and stars still looked plentiful and star-like. Worth the price for those views alone IMHO

 

It was reviews and reports like this that encouraged @Mrs Racey and me to go to the trouble that we did and fork out what we did for a supposedly premium filter.

Thus far, on the few occasions we have used the Lumicon Oiii filter without the sort of amazing results you describe John we naturally blamed ourselves for perhaps not pointing the scope correctly or we thought conditions weren't as good as required. 

Now we truly understand what this graph shows and the alteration to manufacturing quality made by the new owners we perhaps have a better understanding of why we don't get the sort of wow factor and results you and your group did. 

For me, such sneaky unpublicised changes to a tried and tested product, while maintaining premium pricing means a reputation is tarnished for a good while...

An offer of a free test and graph isn't going to placate me when it appears I paid a premium price for what you and others correctly described as a "run of the mill" Oiii. 

$100 is a bit rich for what turns out to be only a Comet Tail or an alternative to a polariser on our White Light Solar Wedge set up...

[John]

I can only agree with you Simon. I've had some recent data from a reliable source in the USA that the Astronomik O-III is now, with the demise (hopefully temporary) of the previously high Lumicon standards, the best quality option. Apparently Astronomik have actually improved the performance of their O-III over the past couple of years so it should do even better than the one that I used to own a few years back , and that was a really effective filter.

 

 

[Racey]

@John we'll be able to let you know Sir in a few days. We placed an order for an Astronomik one yesterday...