31mm Filters Fitted

[Starwiz]

I found that a nervy job - my hands aren't exactly the right size for this sort of work.  21 tiny screws, so I had visions of the screwdriver slipping and getting scratches across these rather expensive pieces of glass. 

I just hope I've got them all the right way around now! ?

[symmetal]

Yes, it's a fiddly job. Do you have the early versions of the ZWO 31mm filters which required the filter masks being fitted as well, for best results. The later ZWO 31mm filters can be used without the masks as the edge 'blackening' was much better and covered the filter bevel too. Unless you have a large sensor which benefits from the 31mm unmounted over the 1.25" mounted it doesn't matter using the masks, and the 'belt and braces' approach is not a bad thing. 

On several of my ZWO filters there was no apparent difference in the reflectivity of the two sides despite using the 'test' of viewing objects close to the filter surface so I assumed in that case there was no difference in which way round they were mounted.

I'm assuming you're using ZWO filters. If not most of what I've written is  not relevant to you. 

Alan

[Starwiz]

2 hours ago, symmetal said:

Yes, it's a fiddly job. Do you have the early versions of the ZWO 31mm filters which required the filter masks being fitted as well, for best results. The later ZWO 31mm filters can be used without the masks as the edge 'blackening' was much better and covered the filter bevel too. Unless you have a large sensor which benefits from the 31mm unmounted over the 1.25" mounted it doesn't matter using the masks, and the 'belt and braces' approach is not a bad thing. 

On several of my ZWO filters there was no apparent difference in the reflectivity of the two sides despite using the 'test' of viewing objects close to the filter surface so I assumed in that case there was no difference in which way round they were mounted.

I'm assuming you're using ZWO filters. If not most of what I've written is  not relevant to you. 

Alan

Thanks Alan,

Yes, ZWO filters and the latest ones so they have the blackened edges.

The screws didn't come with separate washers, just the masks, so I had to fit these anyway as they acted as the washers.

I'll be using my new ASI1600mm-Pro with my SW200p (F5) so it should be fine.

I'm looking forward to getting started.  My tripod and some other bits and pieces should arrive in Malta later this week along with the rest of our stuff.

John

[symmetal]

Interesting that they don't supply the fibre washers anymore John, so it seems they expect you to fit the masks anyway and so reduce the area advantage the 31mm filters have.

Alan

[Starwiz]

16 minutes ago, symmetal said:

Interesting that they don't supply the fibre washers anymore John, so it seems they expect you to fit the masks anyway and so reduce the area advantage the 31mm filters have.

Alan

If I'd known that at the start, I'd have bought the mounted filters and saved a bit of money.  Still, I suppose it gives me the option to source some washers at a later date if I ever need to increase the filter area.

John

[symmetal]

The masks do give you 1mm extra filter width compared to the 1.25" mounted. If you want to use washers to give you about 2mm extra filter width over the mounted ones them M2 fibre washers fit nicely. They are a bit more 'grippy' than nylon washers. 

The 1600 camera just manages with the 1.25" mounted filters so leaving yours with the masks on will be fine. 

Alan

[Starwiz]

31 minutes ago, symmetal said:

The masks do give you 1mm extra filter width compared to the 1.25" mounted. If you want to use washers to give you about 2mm extra filter width over the mounted ones them M2 fibre washers fit nicely. They are a bit more 'grippy' than nylon washers. 

The 1600 camera just manages with the 1.25" mounted filters so leaving yours with the masks on will be fine. 

Alan

Thanks Alan.

John