On Nov 20, 2020, at 8:25 PM, Dragan Nikin via groups.io <dragannikin@...> wrote:

?

OMI is no more. They've been gone for a couple years now.?

I spoke with James last night. Apparently Plane Wave is coating amateurs mirrors now. So that's an option.?

-Dragan

Sent from my Samsung Note 10+

-------- Original message --------

From: Roger Greenwood <roger@...>

Date: 11/20/20 5:32 PM (GMT-06:00)

To: [email protected]

Subject: Re: [ObsessionUsers] Don't do what I did :)

Zambuto or OMI.

?-Roger

18" Classic AN/SC/FSA

On Nov 20, 2020, at 6:06 PM, skygazr33 via groups.io <skygazr@...> wrote:

? My 23 year old 20” F5 has always been kept in a controlled environment, but are starting to fail. ?Do you have any mirror coating companies that you could recommend?

Rick Markunas

On Nov 20, 2020, at 11:20 AM, Dragan Nikin <dragannikin@...> wrote:

?

A repost from Obsession FB group.

Sorry this will be kinda long.

Some good news I want to share. Anyone that knows me personally knows that I haven't observed regularly with my 25" or 30" in a number of years - 5 to be exact. I'll blame 'life' for this little absence. Yes, I've gotten out to observe fairly often, particularly in Ft Davis with a 48 and atop Mauna Kea with a 22, so I'm really not complaining. My scopes were in storage during this time, protected sufficiently - or so I thought. When I brought the scopes home and wanted to get them prepared for regular observing, I discovered that the primaries were covered in a 'caked on' layer of gray dust. They didn't look good at all.

Fearing the worst, a bath was in order. I pulled out the 25's mirror yesterday and proceeded to wash the mirror just as Dave does. After the initial rinse, i proceeded to use soapy water and cotton hoping to remove the film. The cotton actually turned gray - that's how bad the scum was. After numerous washings with soapy wads of cotton, the film did not come off. After far too many vulgarities, I resigned myself that it's time for a recoat and I should just dry it and move on. Well, lo and behold, as soon as I began drying the mirror, the disgusting film started to come off! What a surprise!

Now, I'll be honest. The mirror doesn't look like it just came back from the coater. But it looks great and it's definitely usable and I've bought myself atleast a few years of use! I'll need a recoat for sure but it won't be now. And that's all that matters! I'll do the 30 tonight after work and report back. I'm sure I'll have the same results.

Now, for the teaching moment. Normally, when my scope lived in its trailer, I religiously kept a 15w lightbulb underneath the mirror. For those who don't know, this helps keep the mirror warmer than ambient during storage in an enclosed container helping prevent dew from forming on the primary.

During my hiatus, the scopes lived in a relatives garage. Although the scopes were covered with plastic and blankets, that wasn't nearly enough protection. I also didn't think I needed to do the light bulb trick in a large garage so I didn't do it. BIG MISTAKE. 5 years of storage and all of the heating, cooling, dewing cycles took its toll. Never will I make this mistake again. My laziness essentially caked on 5 years of dust and whatever else in the form of airborne contaminates.

So. Please learn from my mistakes. If you're going to store your scope in anything other than a controlled environment, please use the time tested lightbulb trick. It very well could save your coatings.

I just got really lucky.....

<125836563_10224290672676461_8096491706203351079_o.jpg>

<125969171_10224290672436455_3449058360996723675_o.jpg>

<126177225_10224290671916442_9211984385989521757_o.jpg>

<126181068_10224290671676436_752145049163721168_o.jpg>

<126237410_10224290672916467_5805063476169098666_o.jpg>

<126486530_10224290673156473_7854108636239541750_o.jpg>

<126506459_10224290672196449_4929054325396449406_o.jpg>

On Nov 20, 2020, at 6:32 PM, Roger Greenwood <roger@...> wrote:

Zambuto or OMI.

?-Roger

18" Classic AN/SC/FSA

On Nov 20, 2020, at 6:06 PM, skygazr33 via <skygazr@...> wrote:

? My 23 year old 20” F5 has always been kept in a controlled environment, but are starting to fail. ?Do you have any mirror coating companies that you could recommend?

Rick Markunas

On Nov 20, 2020, at 11:20 AM, Dragan Nikin <dragannikin@...> wrote:

?

A repost from Obsession FB group.

Sorry this will be kinda long.

Some good news I want to share. Anyone that knows me personally knows that I haven't observed regularly with my 25" or 30" in a number of years - 5 to be exact. I'll blame 'life' for this little absence. Yes, I've gotten out to observe fairly often, particularly in Ft Davis with a 48 and atop Mauna Kea with a 22, so I'm really not complaining. My scopes were in storage during this time, protected sufficiently - or so I thought. When I brought the scopes home and wanted to get them prepared for regular observing, I discovered that the primaries were covered in a 'caked on' layer of gray dust. They didn't look good at all.

Fearing the worst, a bath was in order. I pulled out the 25's mirror yesterday and proceeded to wash the mirror just as Dave does. After the initial rinse, i proceeded to use soapy water and cotton hoping to remove the film. The cotton actually turned gray - that's how bad the scum was. After numerous washings with soapy wads of cotton, the film did not come off. After far too many vulgarities, I resigned myself that it's time for a recoat and I should just dry it and move on. Well, lo and behold, as soon as I began drying the mirror, the disgusting film started to come off! What a surprise!

Now, I'll be honest. The mirror doesn't look like it just came back from the coater. But it looks great and it's definitely usable and I've bought myself atleast a few years of use! I'll need a recoat for sure but it won't be now. And that's all that matters! I'll do the 30 tonight after work and report back. I'm sure I'll have the same results.

Now, for the teaching moment. Normally, when my scope lived in its trailer, I religiously kept a 15w lightbulb underneath the mirror. For those who don't know, this helps keep the mirror warmer than ambient during storage in an enclosed container helping prevent dew from forming on the primary.

During my hiatus, the scopes lived in a relatives garage. Although the scopes were covered with plastic and blankets, that wasn't nearly enough protection. I also didn't think I needed to do the light bulb trick in a large garage so I didn't do it. BIG MISTAKE. 5 years of storage and all of the heating, cooling, dewing cycles took its toll. Never will I make this mistake again. My laziness essentially caked on 5 years of dust and whatever else in the form of airborne contaminates.

So. Please learn from my mistakes. If you're going to store your scope in anything other than a controlled environment, please use the time tested lightbulb trick. It very well could save your coatings.

I just got really lucky.....

<125836563_10224290672676461_8096491706203351079_o.jpg>

<125969171_10224290672436455_3449058360996723675_o.jpg>

<126177225_10224290671916442_9211984385989521757_o.jpg>

<126181068_10224290671676436_752145049163721168_o.jpg>

<126237410_10224290672916467_5805063476169098666_o.jpg>

<126486530_10224290673156473_7854108636239541750_o.jpg>

<126506459_10224290672196449_4929054325396449406_o.jpg>

? My 23 year old 20” F5 has always been kept in a controlled environment, but are starting to fail. ?Do you have any mirror coating companies that you could recommend?

Rick Markunas

On Nov 20, 2020, at 11:20 AM, Dragan Nikin <dragannikin@...> wrote:

?

A repost from Obsession FB group.

Sorry this will be kinda long.

Some good news I want to share. Anyone that knows me personally knows that I haven't observed regularly with my 25" or 30" in a number of years - 5 to be exact. I'll blame 'life' for this little absence. Yes, I've gotten out to observe fairly often, particularly in Ft Davis with a 48 and atop Mauna Kea with a 22, so I'm really not complaining. My scopes were in storage during this time, protected sufficiently - or so I thought. When I brought the scopes home and wanted to get them prepared for regular observing, I discovered that the primaries were covered in a 'caked on' layer of gray dust. They didn't look good at all.

Fearing the worst, a bath was in order. I pulled out the 25's mirror yesterday and proceeded to wash the mirror just as Dave does. After the initial rinse, i proceeded to use soapy water and cotton hoping to remove the film. The cotton actually turned gray - that's how bad the scum was. After numerous washings with soapy wads of cotton, the film did not come off. After far too many vulgarities, I resigned myself that it's time for a recoat and I should just dry it and move on. Well, lo and behold, as soon as I began drying the mirror, the disgusting film started to come off! What a surprise!

Now, I'll be honest. The mirror doesn't look like it just came back from the coater. But it looks great and it's definitely usable and I've bought myself atleast a few years of use! I'll need a recoat for sure but it won't be now. And that's all that matters! I'll do the 30 tonight after work and report back. I'm sure I'll have the same results.

Now, for the teaching moment. Normally, when my scope lived in its trailer, I religiously kept a 15w lightbulb underneath the mirror. For those who don't know, this helps keep the mirror warmer than ambient during storage in an enclosed container helping prevent dew from forming on the primary.

During my hiatus, the scopes lived in a relatives garage. Although the scopes were covered with plastic and blankets, that wasn't nearly enough protection. I also didn't think I needed to do the light bulb trick in a large garage so I didn't do it. BIG MISTAKE. 5 years of storage and all of the heating, cooling, dewing cycles took its toll. Never will I make this mistake again. My laziness essentially caked on 5 years of dust and whatever else in the form of airborne contaminates.

So. Please learn from my mistakes. If you're going to store your scope in anything other than a controlled environment, please use the time tested lightbulb trick. It very well could save your coatings.

I just got really lucky.....

<125836563_10224290672676461_8096491706203351079_o.jpg>

<125969171_10224290672436455_3449058360996723675_o.jpg>

<126177225_10224290671916442_9211984385989521757_o.jpg>

<126181068_10224290671676436_752145049163721168_o.jpg>

<126237410_10224290672916467_5805063476169098666_o.jpg>

<126486530_10224290673156473_7854108636239541750_o.jpg>

<126506459_10224290672196449_4929054325396449406_o.jpg>

On Nov 20, 2020, at 3:06 PM, skygazr33 via groups.io <skygazr@...> wrote:

?My 23 year old 20” F5 has always been kept in a controlled environment, but are starting to fail. ?Do you have any mirror coating companies that you could recommend?

Rick Markunas

On Nov 20, 2020, at 11:20 AM, Dragan Nikin <dragannikin@...> wrote:

?

A repost from Obsession FB group.

Sorry this will be kinda long.

Some good news I want to share. Anyone that knows me personally knows that I haven't observed regularly with my 25" or 30" in a number of years - 5 to be exact. I'll blame 'life' for this little absence. Yes, I've gotten out to observe fairly often, particularly in Ft Davis with a 48 and atop Mauna Kea with a 22, so I'm really not complaining. My scopes were in storage during this time, protected sufficiently - or so I thought. When I brought the scopes home and wanted to get them prepared for regular observing, I discovered that the primaries were covered in a 'caked on' layer of gray dust. They didn't look good at all.

Fearing the worst, a bath was in order. I pulled out the 25's mirror yesterday and proceeded to wash the mirror just as Dave does. After the initial rinse, i proceeded to use soapy water and cotton hoping to remove the film. The cotton actually turned gray - that's how bad the scum was. After numerous washings with soapy wads of cotton, the film did not come off. After far too many vulgarities, I resigned myself that it's time for a recoat and I should just dry it and move on. Well, lo and behold, as soon as I began drying the mirror, the disgusting film started to come off! What a surprise!

Now, I'll be honest. The mirror doesn't look like it just came back from the coater. But it looks great and it's definitely usable and I've bought myself atleast a few years of use! I'll need a recoat for sure but it won't be now. And that's all that matters! I'll do the 30 tonight after work and report back. I'm sure I'll have the same results.

Now, for the teaching moment. Normally, when my scope lived in its trailer, I religiously kept a 15w lightbulb underneath the mirror. For those who don't know, this helps keep the mirror warmer than ambient during storage in an enclosed container helping prevent dew from forming on the primary.

During my hiatus, the scopes lived in a relatives garage. Although the scopes were covered with plastic and blankets, that wasn't nearly enough protection. I also didn't think I needed to do the light bulb trick in a large garage so I didn't do it. BIG MISTAKE. 5 years of storage and all of the heating, cooling, dewing cycles took its toll. Never will I make this mistake again. My laziness essentially caked on 5 years of dust and whatever else in the form of airborne contaminates.

So. Please learn from my mistakes. If you're going to store your scope in anything other than a controlled environment, please use the time tested lightbulb trick. It very well could save your coatings.

I just got really lucky.....

<125836563_10224290672676461_8096491706203351079_o.jpg>

<125969171_10224290672436455_3449058360996723675_o.jpg>

<126177225_10224290671916442_9211984385989521757_o.jpg>

<126181068_10224290671676436_752145049163721168_o.jpg>

<126237410_10224290672916467_5805063476169098666_o.jpg>

<126486530_10224290673156473_7854108636239541750_o.jpg>

<126506459_10224290672196449_4929054325396449406_o.jpg>

On Nov 20, 2020, at 6:06 PM, skygazr33 via groups.io <skygazr@...> wrote:

? My 23 year old 20” F5 has always been kept in a controlled environment, but are starting to fail. ?Do you have any mirror coating companies that you could recommend?

Rick Markunas

On Nov 20, 2020, at 11:20 AM, Dragan Nikin <dragannikin@...> wrote:

?

A repost from Obsession FB group.

Sorry this will be kinda long.

Some good news I want to share. Anyone that knows me personally knows that I haven't observed regularly with my 25" or 30" in a number of years - 5 to be exact. I'll blame 'life' for this little absence. Yes, I've gotten out to observe fairly often, particularly in Ft Davis with a 48 and atop Mauna Kea with a 22, so I'm really not complaining. My scopes were in storage during this time, protected sufficiently - or so I thought. When I brought the scopes home and wanted to get them prepared for regular observing, I discovered that the primaries were covered in a 'caked on' layer of gray dust. They didn't look good at all.

Fearing the worst, a bath was in order. I pulled out the 25's mirror yesterday and proceeded to wash the mirror just as Dave does. After the initial rinse, i proceeded to use soapy water and cotton hoping to remove the film. The cotton actually turned gray - that's how bad the scum was. After numerous washings with soapy wads of cotton, the film did not come off. After far too many vulgarities, I resigned myself that it's time for a recoat and I should just dry it and move on. Well, lo and behold, as soon as I began drying the mirror, the disgusting film started to come off! What a surprise!

Now, I'll be honest. The mirror doesn't look like it just came back from the coater. But it looks great and it's definitely usable and I've bought myself atleast a few years of use! I'll need a recoat for sure but it won't be now. And that's all that matters! I'll do the 30 tonight after work and report back. I'm sure I'll have the same results.

Now, for the teaching moment. Normally, when my scope lived in its trailer, I religiously kept a 15w lightbulb underneath the mirror. For those who don't know, this helps keep the mirror warmer than ambient during storage in an enclosed container helping prevent dew from forming on the primary.

During my hiatus, the scopes lived in a relatives garage. Although the scopes were covered with plastic and blankets, that wasn't nearly enough protection. I also didn't think I needed to do the light bulb trick in a large garage so I didn't do it. BIG MISTAKE. 5 years of storage and all of the heating, cooling, dewing cycles took its toll. Never will I make this mistake again. My laziness essentially caked on 5 years of dust and whatever else in the form of airborne contaminates.

So. Please learn from my mistakes. If you're going to store your scope in anything other than a controlled environment, please use the time tested lightbulb trick. It very well could save your coatings.

I just got really lucky.....

<125836563_10224290672676461_8096491706203351079_o.jpg>

<125969171_10224290672436455_3449058360996723675_o.jpg>

<126177225_10224290671916442_9211984385989521757_o.jpg>

<126181068_10224290671676436_752145049163721168_o.jpg>

<126237410_10224290672916467_5805063476169098666_o.jpg>

<126486530_10224290673156473_7854108636239541750_o.jpg>

<126506459_10224290672196449_4929054325396449406_o.jpg>

On Nov 20, 2020, at 11:20 AM, Dragan Nikin <dragannikin@...> wrote:

?

A repost from Obsession FB group.

Sorry this will be kinda long.

Some good news I want to share. Anyone that knows me personally knows that I haven't observed regularly with my 25" or 30" in a number of years - 5 to be exact. I'll blame 'life' for this little absence. Yes, I've gotten out to observe fairly often, particularly in Ft Davis with a 48 and atop Mauna Kea with a 22, so I'm really not complaining. My scopes were in storage during this time, protected sufficiently - or so I thought. When I brought the scopes home and wanted to get them prepared for regular observing, I discovered that the primaries were covered in a 'caked on' layer of gray dust. They didn't look good at all.

Fearing the worst, a bath was in order. I pulled out the 25's mirror yesterday and proceeded to wash the mirror just as Dave does. After the initial rinse, i proceeded to use soapy water and cotton hoping to remove the film. The cotton actually turned gray - that's how bad the scum was. After numerous washings with soapy wads of cotton, the film did not come off. After far too many vulgarities, I resigned myself that it's time for a recoat and I should just dry it and move on. Well, lo and behold, as soon as I began drying the mirror, the disgusting film started to come off! What a surprise!

Now, I'll be honest. The mirror doesn't look like it just came back from the coater. But it looks great and it's definitely usable and I've bought myself atleast a few years of use! I'll need a recoat for sure but it won't be now. And that's all that matters! I'll do the 30 tonight after work and report back. I'm sure I'll have the same results.

Now, for the teaching moment. Normally, when my scope lived in its trailer, I religiously kept a 15w lightbulb underneath the mirror. For those who don't know, this helps keep the mirror warmer than ambient during storage in an enclosed container helping prevent dew from forming on the primary.

During my hiatus, the scopes lived in a relatives garage. Although the scopes were covered with plastic and blankets, that wasn't nearly enough protection. I also didn't think I needed to do the light bulb trick in a large garage so I didn't do it. BIG MISTAKE. 5 years of storage and all of the heating, cooling, dewing cycles took its toll. Never will I make this mistake again. My laziness essentially caked on 5 years of dust and whatever else in the form of airborne contaminates.

So. Please learn from my mistakes. If you're going to store your scope in anything other than a controlled environment, please use the time tested lightbulb trick. It very well could save your coatings.

I just got really lucky.....

<125836563_10224290672676461_8096491706203351079_o.jpg>

<125969171_10224290672436455_3449058360996723675_o.jpg>

<126177225_10224290671916442_9211984385989521757_o.jpg>

<126181068_10224290671676436_752145049163721168_o.jpg>

<126237410_10224290672916467_5805063476169098666_o.jpg>

<126486530_10224290673156473_7854108636239541750_o.jpg>

<126506459_10224290672196449_4929054325396449406_o.jpg>

On Nov 7, 2020, at 11:05 AM, Roger Greenwood via groups.io <roger@...> wrote:

?

I will definitely try this with my 28" Classic!!

-Roger

18" Classic AN/SC/FSA

On Nov 7, 2020, at 9:06 AM, Frédéric Ruciak via groups.io <frederic.ruciak@...> wrote:

?Hi everyone,
hope you do well,
yesterday night, having a chance to observe Mars with my classic 15, on a rather stable night, I had a very interesting experience.
At first with full aperture, I had a very luminous image dancing a little bit on the edge with very luminous diffraction rays (rather large due to the planet being rather large too).
I tried to close the aperture with a mask letting only a circular aperture decentered to be completely free on any obstruction. As you can imagine the diameter is around 6 inches (15-20%)/2. The scope became a 6 inches f 9 more or less 0% obstruction.
I was observing with a ethos 8mm at x250 well beyond the theoritical ~300 limit for a 6 inches scope. The image became much darker (4 times less light incoming) but much easier to observe because of no diffraction rays at all and I have been able to spot more details and some very luminous spot at the pole of Mars most probably the very last remnant of the polar cap. I never had this kind of improvement before especially when observing planets like Jupiter or Saturn, I always preferred the full aperture view.
Any comments of similar experience?
Clear skies, Frédéric

On Nov 7, 2020, at 11:05 AM, Roger Greenwood via groups.io <roger@...> wrote:

?

I will definitely try this with my 28" Classic!!

-Roger

18" Classic AN/SC/FSA

On Nov 7, 2020, at 9:06 AM, Frédéric Ruciak via groups.io <frederic.ruciak@...> wrote:

?Hi everyone,
hope you do well,
yesterday night, having a chance to observe Mars with my classic 15, on a rather stable night, I had a very interesting experience.
At first with full aperture, I had a very luminous image dancing a little bit on the edge with very luminous diffraction rays (rather large due to the planet being rather large too).
I tried to close the aperture with a mask letting only a circular aperture decentered to be completely free on any obstruction. As you can imagine the diameter is around 6 inches (15-20%)/2. The scope became a 6 inches f 9 more or less 0% obstruction.
I was observing with a ethos 8mm at x250 well beyond the theoritical ~300 limit for a 6 inches scope. The image became much darker (4 times less light incoming) but much easier to observe because of no diffraction rays at all and I have been able to spot more details and some very luminous spot at the pole of Mars most probably the very last remnant of the polar cap. I never had this kind of improvement before especially when observing planets like Jupiter or Saturn, I always preferred the full aperture view.
Any comments of similar experience?
Clear skies, Frédéric

On Nov 7, 2020, at 9:06 AM, Frédéric Ruciak via groups.io <frederic.ruciak@...> wrote:

?Hi everyone,
hope you do well,
yesterday night, having a chance to observe Mars with my classic 15, on a rather stable night, I had a very interesting experience.
At first with full aperture, I had a very luminous image dancing a little bit on the edge with very luminous diffraction rays (rather large due to the planet being rather large too).
I tried to close the aperture with a mask letting only a circular aperture decentered to be completely free on any obstruction. As you can imagine the diameter is around 6 inches (15-20%)/2. The scope became a 6 inches f 9 more or less 0% obstruction.
I was observing with a ethos 8mm at x250 well beyond the theoritical ~300 limit for a 6 inches scope. The image became much darker (4 times less light incoming) but much easier to observe because of no diffraction rays at all and I have been able to spot more details and some very luminous spot at the pole of Mars most probably the very last remnant of the polar cap. I never had this kind of improvement before especially when observing planets like Jupiter or Saturn, I always preferred the full aperture view.
Any comments of similar experience?
Clear skies, Frédéric

On Oct 27, 2020, at 7:46 PM, Michael Barsotti <Barsottimm@...> wrote:

?Dave,

You will get a more accurate alignment if you use a illuminated reticle eye piece in your you main focuser. ?The finder will get you near your target but not precisely centered on it. ?Your alignment needs to be centered on the main focus tube not on the finder scope. ?Using this method, my go to accuracy of my ServoCAT has been excellent and if my target is not in the FOV, a nearby search will usually find it. ?I have considered replacing my 9 x 50 RACI with something bigger, but if I can get near my target, when I use my 13mm Ethos i now have a finder that is using my 15” mirror, in your case a 20” mirror, and not 50 or 80mm mirror.

Mike