How to fit a LP filter with a SW reducer/flattener

[martin_h]

Ok, well I tested it all last night, with mixed results, the flattener works to the edges, so the spacing is ok, but the imaging train is not square to the lens, and also the Skywatcher LP filter I purchased (which started all of this off) doesnt do much for the LP around here! So at the moment it was a waste of time - ho hum

[Merlin66]

What is the thread size at the front of the SW reducer??

Surely a better way would be to have a "special" adaptor machined that allowed 48mm filters to be fitted inside and screwed onto the SW focus tube (55mm?) on one side and into the reducer (tbd?) on the other.

I had some adaptors made up for the PST mods etc and they were only around 35gbp.....

[martin_h]

Drawtube side is 56mm, camera side is 48mm

[Sp@ce_d]

I've decided to try Flo's adapter and ordered a Baader H-alpha 7nm with it. Last night I had first light with the 1000D since removing the internal filter at the weekend. What a difference! So feeling a bit impatient to try narrowband.. just watch the clouds roll back now..

Martin at FLO is asking Atik about adapters & the feasibility of fitting a FW to the front of the Reducer

[martin_h]

Martin at FLO is asking Atik about adapters & the feasibility of fitting a FW to the front of the Reducer

Yes you can, but if you want an LP filter in the train you will have to use the nose piece...my problem!!

The spacing between rear of reducer and front of CCD is exactly 40mm, chip face to front of CCD is 15mm 40+15=55 dead on! so no room for anything else.

[Sp@ce_d]

Looks like it's going to have be a custom adapter to get anything to screw upto the focus tube.

I recieved my FLO adapter & must say it's a nice fitting piece of engineering. Shame they don't do one in reverse with a female thread. Grub screws seem to tighten up ok so fingers crossed for some clear nights soon.

[idigitize]

After lots of googling this subject, this thread keeps popping up. I know it's 3+ yrs old, but wondered if there was any better solutions over the flo adapter and slightly wobbly train.

As mentioned in this thread, surely ed80 - ff - m48 - dslr is a common setup and a lps filter a common want.

As a non canon user the clip in filter is not an option, and the hutech lps with a flo adapter is best part of £200.

Simon (spikey) be really keen to know how the filter works for you as my light pollution for anything vaguely East is Crewe, wistaston area and the street lights on Marshfiled bank to Nantwich area for anything, west, north and South.

Sorry for bringing such an old thread up if there is a newer one around.

[Earl]

As far as I am aware there is no solution for DSLR's as the Reducer is designed to fit direct to the Focuser via thread and the camera t adapter for correct spacing.

A custom adapter whcih will thread into the reducer and attach to the drawtube but provide a filter thread also is whats needed and shoud not be to difficult to make either if you know a good engineer.

[Spikey]

After lots of googling this subject, this thread keeps popping up. I know it's 3+ yrs old, but wondered if there was any better solutions over the flo adapter and slightly wobbly train.

As mentioned in this thread, surely ed80 - ff - m48 - dslr is a common setup and a lps filter a common want.

As a non canon user the clip in filter is not an option, and the hutech lps with a flo adapter is best part of £200.

Simon (spikey) be really keen to know how the filter works for you as my light pollution for anything vaguely East is Crewe, wistaston area and the street lights on Marshfiled bank to Nantwich area for anything, west, north and South.

Sorry for bringing such an old thread up if there is a newer one around.

Haha no worries, I even forgot I'd started it !

I eventually changed the focusser for a steeltrack and ended up also using CCD's instead of DSLR's but I did get it to work.

I do have some comparison pics taken with the SW filter in place via a DSLR which I'll pop into this thread again (the last ones disappeared when the links were changed when the forum software was updated). My garden backs over towards the railway line and the Alex football ground direction so the LP is pretty bad from all the light they generate. The SW filter does a pretty good job for how much it cost. I use it on the QHY8 now and it's fine. 

[Sp@ce_d]

After lots of googling this subject, this thread keeps popping up. I know it's 3+ yrs old, but wondered if there was any better solutions over the flo adapter and slightly wobbly train.

As mentioned in this thread, surely ed80 - ff - m48 - dslr is a common setup and a lps filter a common want.

As a non canon user the clip in filter is not an option, and the hutech lps with a flo adapter is best part of £200.

Simon (spikey) be really keen to know how the filter works for you as my light pollution for anything vaguely East is Crewe, wistaston area and the street lights on Marshfiled bank to Nantwich area for anything, west, north and South.

Sorry for bringing such an old thread up if there is a newer one around.

I got over the "wobbly train" by using one of these http://www.firstlightoptics.com/adaptors/baader-click-lock-2956256-m56-celestron-skywatcher.html

That the FLO adapter & eventually swapping the SW LP filter for a P2 worked very well.

Sent from my iPhone using Tapatalk

[Rico]

I got over the "wobbly train" by using one of these http://www.firstlightoptics.com/adaptors/baader-click-lock-2956256-m56-celestron-skywatcher.html

That the FLO adapter & eventually swapping the SW LP filter for a P2 worked very well.

Sent from my iPhone using Tapatalk

Glad this thread was revived as I'm looking to add a filter to my setup (ed80 +flattener +DSLR). I'm not yet prepared to get a clip filter as a CCD will eventually be in the works. How does the Baader click-lock solve the issue?

[Sp@ce_d]

Glad this thread was revived as I'm looking to add a filter to my setup (ed80 +flattener +DSLR). I'm not yet prepared to get a clip filter as a CCD will eventually be in the works. How does the Baader click-lock solve the issue?

It replaces the dodgy SW screws with a nice tight even fitting compression joint holding the Flo adapter ( http://www.firstlightoptics.com/adaptors/flo-adapter-for-skywatcher-focal-reducers.html) in which you place a 2" filter.

[Rico]

So the filter goes on the FLO adapter and the FLO adapter goes into the Baader Click Lock? 

i.e. :

DSLR->M48 EOS Adapter-> Reducer -> FLO adapter + Filters-> Baader Click Lock -> Focuser?

I presume it made not difference having the filter so far from the sensor and before the reducer?

[Rico]

Theres also a Baader protective t-ring. The filter fits within and still goes between the reducer and the dslr. Comes out a little bit cheaper ... but you're then restricted to baader filters and the inability to to combine filters (not sure if this ever done in AP). 

http://www.baader-planetarium.uk.com/en/pdf/ProtectiveT_Ring_CanonEOS_e.pdf

[idigitize]

All sounds good, and I know your getting a nice baader click lock, but it does seem to involve investing £60 just to attach a filter.

I was told it was an expensive hobby

[Spikey]

My SW LP filter just screwed into the front of the FLO adapter.

[Rico]

All sounds good, and I know your getting a nice baader click lock, but it does seem to involve investing £60 just to attach a filter.

I was told it was an expensive hobby

All this bad weather is wreaking havoc on my bank account! 

If i can then use the same filters for any future CCD, than I imagine £60 might not be that much. It would save having to buy a whole new set in the future. Now i need to do some research on filters for CCDs! And make sure that 2" filters are future proof.

[Earl]

I may of come up with a solution.

As a M48 adapter is used to connect a dslr to the reducer, there will be a M48 thread on the inside of this adpter.

If a M48 filter can be threaded into this and the filter reveresed in its fitting, (if it needs to be reversed im not sure) this will provide a LPF inside the DSLR Adapter.

I only have a T adapter myself and the T-Cell LPF i have is to chunky to fit inside the adapter so i can t test it myself.

I have picked up a M48 DSLR adapter and SW LPF filter to experiment with

[russellhq]

I sketched this up when I had the same issue. Maybe it might be of some use?

Cost to get fabricated may be less than the £85 for the click lock and FLO adapter.

[Sp@ce_d]

There were 2 reasons why I did it the way I've suggested.

1. Using the click lock removes the flexure you get from the original screw type fitting. I've used a click lock on other makes of scopes because of this too.

2. The adapter T-ring is designed to give you exactly the right spacing for DSLR sensor to flattener. If you place a filter in there it changes that. Now it may or may not be that noticeable but for me I could see it at the edges.

Sent from my iPhone using Tapatalk

[Earl]

There were 2 reasons why I did it the way I've suggested.

1. Using the click lock removes the flexure you get from the original screw type fitting. I've used a click lock on other makes of scopes because of this too.

2. The adapter T-ring is designed to give you exactly the right spacing for DSLR sensor to flattener. If you place a filter in there it changes that. Now it may or may not be that noticeable but for me I could see it at the edges.

Sent from my iPhone using Tapatalk

If the filter fits in the adapter all you need to do is add a .5mm spacer between the reducer and adapter to compensate

[russellhq]

There were 2 reasons why I did it the way I've suggested.

1. Using the click lock removes the flexure you get from the original screw type fitting. I've used a click lock on other makes of scopes because of this too.

2. The adapter T-ring is designed to give you exactly the right spacing for DSLR sensor to flattener. If you place a filter in there it changes that. Now it may or may not be that noticeable but for me I could see it at the edges.

Sent from my iPhone using Tapatalk

I also ended up getting the Click Lock as I already had the FLO adapter. The Click Lock works really well and it makes it a lot easier to rotate the camera compared to screwing the camera directly to the focuser tube.

[Earl]

I have the filter and eos adapter now, with the way the adapter is made it wont work, but it most definantly would if it was made a touch different and the reducer locked the glass of the filter in place

[prusling]

Theres also a Baader protective t-ring. The filter fits within and still goes between the reducer and the dslr. Comes out a little bit cheaper ... but you're then restricted to baader filters and the inability to to combine filters (not sure if this ever done in AP). 

http://www.baader-planetarium.uk.com/en/pdf/ProtectiveT_Ring_CanonEOS_e.pdf

A review on the FLO site says that the restriction is to filters of 6mm width or less.  Does anyone have experience of using this with a 2" SW LP filter which seems to fall within that?