Re: [tec-scopes] Re: Using a LPF with the dedicated TEC140 FF


Sep 3, 2010

 


----------------------------

#18885 Sep 3, 2010

I use the TEC140 with dedicated FF that has, as its output, a T-ring that

attaches to my Canon DSLR. This is the setup directly from Yuri.



I also have a 2" light pollution filter, with standard threads that I would

like to be able to use. I do not seem to see a way of inserting the filter

into the optical path. Does anyone know if this can be done, and if so, how

or where?



Gedas,

gallery at gedas.me



Light travels faster than sound..

This is why some people appear bright until you hear them speak.



----------------------------

#18886 Sep 3, 2010

If there is nothing like this available, perhaps have a adapter machined so that it can accept the 2" filter on the inside opposite of the t-threads.  

From: Gedas w8bya@...>To: tec-scopes@yahoogroups.comSent: Fri, September 3, 2010 12:32:57 PMSubject: [tec-scopes] Using a LPF with the dedicated TEC140 FF

I use the TEC140 with dedicated FF that has, as its output, a T-ring that attaches to my Canon DSLR.  This is the setup directly from Yuri.

I also have a 2" light pollution filter, with standard threads that I would like to be able to use.  I do not seem to see a way of inserting the filter into the optical path.  Does anyone know if this can be done, and if so, how or where?

Gedas,gallery at gedas.me

Light travels faster than sound..This is why some people appear bright until you hear them speak.



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----------------------------

#18887 Sep 3, 2010

Do you plan to insert the filter between the FF and camera? In that case you need to us a different spacer (not the stock one) to compenstate for the filter, filter holder and effect of the glass on the optical path.



If you put the filter between the OTA and FF then you don't have to get a different spacer made but may get vignetting.



Hutech makes a 2 piece holder that one can put any 2" standard filter in, which has 2" SCT threads on both the camera and OTA side, if SCT threads will mate with your other components.



Drew S.

--- In tec-scopes@yahoogroups.com, Tim Khan timkhan@...> wrote:

>

> If there is nothing like this available, perhaps have a adapter machined so that

> it can accept the 2" filter on the inside opposite of the t-threads..

>

>

---------------

> From: Gedas w8bya@...>

> To: tec-scopes@yahoogroups.com

> Sent: Fri, September 3, 2010 12:32:57 PM

> Subject: [tec-scopes] Using a LPF with the dedicated TEC140 FF

>

> I use the TEC140 with dedicated FF that has, as its output, a T-ring that

> attaches to my Canon DSLR.. This is the setup directly from Yuri.

>

> I also have a 2" light pollution filter, with standard threads that I would

> like to be able to use.. I do not seem to see a way of inserting the filter

> into the optical path.. Does anyone know if this can be done, and if so, how

> or where?

>

> Gedas,

> gallery at gedas.me

>

> Light travels faster than sound..

> This is why some people appear bright until you hear them speak.

>

>

>

---------------

>

> Yahoo! Groups Links

>



----------------------------

#18888 Sep 3, 2010

Hi Drew. I really like the rigid T-ring output from the FF and did not want

to disturb that. And, as you mention, that location would upset the

critical FF to camera distance. I had completely forgot how critical that

is before I started wondering about this so I'm glad you reminded me. I do

not want to put it before the FF as this would for sure vignette like crazy.

To try out the LPF I took the FF off and used a standard 2" nose into the

drawtube to try some before and after shots. The vignetting was horrible.

Made me appreciate the larger 3.5" size of the FT focuser and drawtube.

Having the dedicated FF and large drawtube is so sweet. I guess there

really is no way to do this, at least with a small 2" filter. I need to see

if larger sizes are available for possible placement before the FF. Thank

you.



Gedas,

gallery at gedas.me



Light travels faster than sound..

This is why some people appear bright until you hear them speak.







----- Original Message -----

From: "ancient.sull" ancient.sull@...>

To: tec-scopes@yahoogroups.com>

Sent: Friday, September 03, 2010 4:13 PM

Subject: [tec-scopes] Re: Using a LPF with the dedicated TEC140 FF





Do you plan to insert the filter between the FF and camera? In that case you

need to us a different spacer (not the stock one) to compenstate for the

filter, filter holder and effect of the glass on the optical path.



If you put the filter between the OTA and FF then you don't have to get a

different spacer made but may get vignetting.



Hutech makes a 2 piece holder that one can put any 2" standard filter in,

which has 2" SCT threads on both the camera and OTA side, if SCT threads

will mate with your other components.



Drew S.



--- In tec-scopes@yahoogroups.com, Tim Khan timkhan@...> wrote:

>

> If there is nothing like this available, perhaps have a adapter machined

> so that

> it can accept the 2" filter on the inside opposite of the t-threads.

>

>

---------------

> From: Gedas w8bya@...>

> To: tec-scopes@yahoogroups.com

> Sent: Fri, September 3, 2010 12:32:57 PM

> Subject: [tec-scopes] Using a LPF with the dedicated TEC140 FF

>

> I use the TEC140 with dedicated FF that has, as its output, a T-ring that

> attaches to my Canon DSLR. This is the setup directly from Yuri.

>

> I also have a 2" light pollution filter, with standard threads that I

> would

> like to be able to use. I do not seem to see a way of inserting the filter

> into the optical path. Does anyone know if this can be done, and if so,

> how

> or where?

>

> Gedas,

> gallery at gedas.me

>

> Light travels faster than sound..

> This is why some people appear bright until you hear them speak.

>

>

>

---------------

>

> Yahoo! Groups Links

>









---------------



Yahoo! Groups Links







----------------------------

#18889 Sep 3, 2010

I'd recommend forgetting the LPS filter, taking good flats and using GradientXterminator.



Drew S.

--- In tec-scopes@yahoogroups.com, "Gedas" w8bya@...> wrote:

>

> Hi Drew. I really like the rigid T-ring output from the FF and did not want

> to disturb that. And, as you mention, that location would upset the

> critical FF to camera distance. I had completely forgot how critical that

> is before I started wondering about this so I'm glad you reminded me. I do

> not want to put it before the FF as this would for sure vignette like crazy.

> To try out the LPF I took the FF off and used a standard 2" nose into the

> drawtube to try some before and after shots. The vignetting was horrible.

> Made me appreciate the larger 3.5" size of the FT focuser and drawtube.

> Having the dedicated FF and large drawtube is so sweet. I guess there

> really is no way to do this, at least with a small 2" filter. I need to see

> if larger sizes are available for possible placement before the FF. Thank

> you.

>

> Gedas,

> gallery at gedas.me

>

> Light travels faster than sound..

> This is why some people appear bright until you hear them speak.

>

>

>

>

> ----- Original Message -----

> From: "ancient.sull" ancient.sull@...>

> To: tec-scopes@yahoogroups.com>

> Sent: Friday, September 03, 2010 4:13 PM

> Subject: [tec-scopes] Re: Using a LPF with the dedicated TEC140 FF

>

>

> Do you plan to insert the filter between the FF and camera? In that case you

> need to us a different spacer (not the stock one) to compenstate for the

> filter, filter holder and effect of the glass on the optical path.

>

> If you put the filter between the OTA and FF then you don't have to get a

> different spacer made but may get vignetting.

>

> Hutech makes a 2 piece holder that one can put any 2" standard filter in,

> which has 2" SCT threads on both the camera and OTA side, if SCT threads

> will mate with your other components.

>

> Drew S.

>

> --- In tec-scopes@yahoogroups.com, Tim Khan timkhan@> wrote:

> >

> > If there is nothing like this available, perhaps have a adapter machined

> > so that

> > it can accept the 2" filter on the inside opposite of the t-threads.

> >

> >

---------------

> > From: Gedas w8bya@>

> > To: tec-scopes@yahoogroups.com

> > Sent: Fri, September 3, 2010 12:32:57 PM

> > Subject: [tec-scopes] Using a LPF with the dedicated TEC140 FF

> >

> > I use the TEC140 with dedicated FF that has, as its output, a T-ring that

> > attaches to my Canon DSLR. This is the setup directly from Yuri.

> >

> > I also have a 2" light pollution filter, with standard threads that I

> > would

> > like to be able to use. I do not seem to see a way of inserting the filter

> > into the optical path. Does anyone know if this can be done, and if so,

> > how

> > or where?

> >

> > Gedas,

> > gallery at gedas.me

> >

> > Light travels faster than sound..

> > This is why some people appear bright until you hear them speak.

> >

> >

> >

---------------

> >

> > Yahoo! Groups Links

> >

>

>

>

>

---------------

>

> Yahoo! Groups Links

>



----------------------------

#18890 Sep 4, 2010

The Astro-Physics 35mm adapters for their 4" and 2.7"FF's are threaded to take 48mm filters----at least that's true of the standard model #67RT, and these also fit the TEC FF. AP offers a wider model for the Canon EOS (#67LEOS), but doesn't mention 48mm filter capability in their text, however a version specifically designed for their 160FF does mention 48mm capability. (The AP160 FF does not use the Pentax-based mounting system like all other AP and TEC FF's).



Call AP to check on 48mm filter threads on the #67LEOS, or perhaps Roland may also chime in here.



---John

--- In tec-scopes@yahoogroups.com, "Gedas" w8bya@...> wrote:

>

> I use the TEC140 with dedicated FF that has, as its output, a T-ring that

> attaches to my Canon DSLR. This is the setup directly from Yuri.

>

> I also have a 2" light pollution filter, with standard threads that I would

> like to be able to use. I do not seem to see a way of inserting the filter

> into the optical path. Does anyone know if this can be done, and if so, how

> or where?

>

> Gedas,

> gallery at gedas.me

>

> Light travels faster than sound..

> This is why some people appear bright until you hear them speak.

>



----------------------------

#18891 Sep 4, 2010

Hi John, thanks very much for passing that along. Will see if Roland and/or

Yuri can add to this before we make some calls. There may be hope yet esp

since I already have the filter. Just want to try it out to see if it has

any value in my imaging.



Gedas,

gallery at gedas.me



Light travels faster than sound..

This is why some people appear bright until you hear them speak.







----- Original Message -----

From: "John Boudreau" jeboud@...>

To: tec-scopes@yahoogroups.com>

Sent: Saturday, September 04, 2010 7:44 AM

Subject: [tec-scopes] Re: Using a LPF with the dedicated TEC140 FF





> The Astro-Physics 35mm adapters for their 4" and 2.7"FF's are threaded to

> take 48mm filters----at least that's true of the standard model #67RT, and

> these also fit the TEC FF. AP offers a wider model for the Canon EOS

> (#67LEOS), but doesn't mention 48mm filter capability in their text,

> however a version specifically designed for their 160FF does mention 48mm

> capability. (The AP160 FF does not use the Pentax-based mounting system

> like all other AP and TEC FF's).

>

> Call AP to check on 48mm filter threads on the #67LEOS, or perhaps Roland

> may also chime in here.

>

> ---John

>

> --- In tec-scopes@yahoogroups.com, "Gedas" w8bya@...> wrote:

>>

>> I use the TEC140 with dedicated FF that has, as its output, a T-ring that

>> attaches to my Canon DSLR. This is the setup directly from Yuri.

>>

>> I also have a 2" light pollution filter, with standard threads that I

>> would

>> like to be able to use. I do not seem to see a way of inserting the

>> filter

>> into the optical path. Does anyone know if this can be done, and if so,

>> how

>> or where?

>>

>> Gedas,

>> gallery at gedas.me

>>

>> Light travels faster than sound..

>> This is why some people appear bright until you hear them speak.

>>

>

>

>

>

---------------

>

> Yahoo! Groups Links

>

>

>







----------------------------

#18893 Sep 4, 2010

The funnel like piece (by Astro-Physics) which connects my EOS to my field flattener canaccept a filter??



----------------------------

#18894 Sep 4, 2010

The original adapter with a T-thread (67RT---) could take a 48mm filter. The newer Canon model (67RLEOS) has a larger ID. It's threaded (for reflections), but I don't if its compatible with a particular filter thread.

Kurt

--- In tec-scopes@yahoogroups.com, Mike C mike@...> wrote:

>

> The funnel like piece (by Astro-Physics) which connects my EOS to my field

> flattener can

> accept a filter??

>



----------------------------

#18895 Sep 4, 2010

Just went and checked my 67RLEOS. It does indeed take a 48mm threaded filter, as does the 67RT---. It just maintains this thread all the way to the bayonet, whereas the 67RT--- reduces to a smaller I.D.

Kurt

--- In tec-scopes@yahoogroups.com, "mihalco" mihalco@...> wrote:

>

> The original adapter with a T-thread (67RT---) could take a 48mm filter. The newer Canon model (67RLEOS) has a larger ID. It's threaded (for reflections), but I don't if its compatible with a particular filter thread.

> Kurt

>

> --- In tec-scopes@yahoogroups.com, Mike C mike@> wrote:

> >

> > The funnel like piece (by Astro-Physics) which connects my EOS to my field

> > flattener can

> > accept a filter??

> >

>



----------------------------

#18896 Sep 4, 2010

Whoa!!! I had no idea, excellent, thanks for checking, Kurt.

Mike Clemens



Just went and checked my 67RLEOS. It does indeed take a 48mm threaded filter, as does the 67RT---. It just maintains this thread all the way to the bayonet, whereas the 67RT--- reduces to a smaller I.D.

Kurt


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