2" or 1.25" Solar Continuum Filter

[Starry Jack]

My Debbie gave me a Solar Continuum filter and Photo Solar Film for Christmas.

Do I need the 1.25" or 2" filter? I can utilize either format, but don't want to vignette in white light imaging.

-152mm f6.5 refractor
-80mm f7.5 ED refractor
-ASI174 camera

Thanks,
Jack

[DeepSolar64]

I have the 1.25" Baader 540nm continuum filter. It works well for me. Most of my eyepieces are 1.25" so a matching filter made sense.

[marktownley]

I have the 1.25" version with exactly same reasoning as James.

[Montana]

The 1.25" fits nicely on the nose of your camera so why spend more

Alexandra

[SimonM]

Do I need the 1.25" or 2" filter? I can utilize either format, but don't want to vignette in white light imaging.
-ASI174 camera

You didn't say if this was ASI174MM or ASI174MC or ASI174MM Mini:

1. ASI174MM Mini accepts 1.25" filters on the front;
2. ASI174MM/MC both accept 1.25" filters on the 1.25" nose-piece;
3. ASI174MM/MC both come with a T2-1.25" adapter and two T2 extenders.

Using the T2-1.25" adapter puts the filter closer to the camera so is preferable to using the 1.25" nose-piece. What is included in the box may vary with each camera e.g. my ASI294MC has a removable 11mm T2 extender which may be fixed. If in doubt, you can draw out the light path and show the filter location e.g knowing that a 1.25" Baader filter has a 2mm thickness, a clear path of 27mm (45mm for 2" filters), its position, and the positionand diagonal size of the sensor.

I had the same issue with a 1.25" UV/IR cut filter - either to use a 1.25" version (as above) or try to put a 2" version in-line with M48 extension tubes. The latter isn't a good idea because the filter glass is in contact with the threads of the next adapter and the filter threads are not as deep as the threads on an extension tube so cannot accept as big a load.

A 2" filter can also be placed under a 1.25"-2" EP adapter, but the adapter usually has depth for an eyepiece and one 1.25" filter - two may require a focus ring collar to increase the depth. This also requires additional back-focus (which you might not have). The only time a 2" filter is useful is if you already have it e.g. the Baader Herschel Wedge may include additional 2" ND filters - so one ND filter can be placed under a 1.25"-2" EP adapter.

So the 1.25" filter is (on the whole) more flexible and costs less - what's not to like?

Simon

[Starry Jack]

Thanks, all!
I"m convinced!

Sadly my first spin was less than enthralling, but I'll keep at it. I have the Baader Photo Solar film (3.8) and the Solar Continuum.

I'll bet tomorrow it will pop into amazing! I did see the one larger and 3 smaller sunspots.

Oh and of course, my camera dropped out of the focuser and found a hole in the observatory floor so I had to fish it out of the dirt.

2020...what a year! LOL

Jack

[DeepSolar64]

The 1.25" fits nicely on the nose of your camera so why spend more

Alexandra

Ditto!!

[DeepSolar64]

Thanks, all!
I"m convinced!

Sadly my first spin was less than enthralling, but I'll keep at it. I have the Baader Photo Solar film (3.8) and the Solar Continuum.

I'll bet tomorrow it will pop into amazing! I did see the one larger and 3 smaller sunspots.

Oh and of course, my camera dropped out of the focuser and found a hole in the observatory floor so I had to fish it out of the dirt.

2020...what a year! LOL

Jack

I hope dirt did not get onto the CMOS sensor.

[Starry Jack]

camera is alllllll clean

[DeepSolar64]

camera is alllllll clean

Good on that!!