Focus Masks

[seer]

Today I am making Hartmann Focus Masks for my 76mm & 114mm Newtonians. I have a lot of them done already. Just mostly some gluing and painting to go.
I do have a Bahtinov Mask that I bought Agena AstroProducts.

[seer]

Just finished them.
I used hot glue and I spray painted them black. I would have liked flat black but all I have is semi gloss.

[seer]

I just seen something that said what I just made are Scheiner Disks and not Hartmann masks.

[seer]

This is what I originally went by.

The focus mask stuff starts at about 8:50.

[seer]

[Lady Fraktor]

A nice job Donald. Hopefully you can test them out right away

[seer]

I am hoping that the focus masks pair up nicely with my enlarged lid knobs.

[seer]

Why is the photo blocked now both here in the thread and gallery?

[Voyageur]

Why is the photo blocked now both here in the thread and gallery?

Donald, if you are referring to your photo of three focus masks, a Bahtinov and two Scheiner discs, it is showing up fine for me in the thread.

[seer]

Why is the photo blocked now both here in the thread and gallery?

Donald, if you are referring to your photo of three focus masks, a Bahtinov and two Scheiner discs, it is showing up fine for me in the thread.

It is not showing up for me whether I am logged in or not. It is blocked when I go to the gallery also but if I click on it there it opens.

[seer]

Maybe I should go ahead and make a Hartmann mask also and then do some testing and comparing.

[seer]

TA-DA!

[Don Quixote]

Ok.
I is a ignorant flatlander... :-)

What are these ones with the two holes used for.
I know the bahtinov but I am not familiar, Donald, with the other ones.

[KathyNS]

Ok.
I is a ignorant flatlander... :-)

What are these ones with the two holes used for.
I know the bahtinov but I am not familiar, Donald, with the other ones.

I use a Hartmann mask (the one with the two holes) for focusing when I am doing solar observing. A Bahtinov mask needs a point source. A Hartmann mask can focus any edge. You get a double image, and you adjust the focus until the two images merge.

[seer]

Ok.
I is a ignorant flatlander... :-)

What are these ones with the two holes used for.
I know the bahtinov but I am not familiar, Donald, with the other ones.

They are all used for focusing. I am very new to all of these. From what I am gathering some of the designs predate the others and might have been bought over from other areas of optics. Some are suppose to do a more precise job then the others. I am guessing the Bahtinov is best for stars but I wondering if one of the others might do better with the moon. These are some of the things on my to do list.

[Don Quixote]

Ok.
I is a ignorant flatlander... :-)

What are these ones with the two holes used for.
I know the bahtinov but I am not familiar, Donald, with the other ones.

I use a Hartmann mask (the one with the two holes) for focusing when I am doing solar observing. A Bahtinov mask needs a point source. A Hartmann mask can focus any edge. You get a double image, and you adjust the focus until the two images merge.

Thank you Kathy
That sounds like the split image focus on my older Nikon film camera. I like that.

[Don Quixote]

Ok.
I is a ignorant flatlander... :-)

What are these ones with the two holes used for.
I know the bahtinov but I am not familiar, Donald, with the other ones.

They are all used for focusing. I am very new to all of these. From what I am gathering some of the designs predate the others and might have been bought over from other areas of optics. Some are suppose to do a more precise job then the others. I am guessing the Bahtinov is best for stars but I wondering if one of the others might do better with the moon. These are some of the things on my to do list.

I think the Hartman, the two hole one, would be very good for the moon focusing.

[Gazbo]

Last week I made a Hartmann, from an Indian Take-away tub - (Well Washed !) plastic lid. fitted 3 nylon m4 screws through at about 120 degrees apart, to fit down the outside of the tube (ETX80). Craft hole cutter cut 2 holes on horizontal centre line, leaving about a hole's worth of material in the centre looked about right. , and sprayed the whole thing with Halfords satin black, on the outer side only. Works a treat. But then I realised, I have a Mk 1 Silhouette Cameo vinyl cutter, which cuts vinyl and card, so I grabbed an image of a Bahtinov, and a Carey, and A 3 hole Hatmann type. Loaded into the silhouette program, re-sized, to fit just inside the inner lip of those lids, and cut 2 copies of each, from cereal box card. They came out far neater than any hand- cut items. Glued the pairs, back to back, with PVA. They are presently weighted flat down on the garage bench, until dry. I have now cut the middles out of 3 further lids, with the same circle cutter, leaving enough landing, to glue the finished cards to. Then these will be fitted with screws, a la original, and sprayed again with same black stuff. I'm interested to experiment with all 4 masks, to see what works best with what. (my Mk 1 eyeball ain't what it used to be !)

If the image does show, it is simply a screendump of the various types of mask, from my Silhouette program, ready to cut. fingers crossed, will post pics if they are a success.

[seer]

Last week I made a Hartmann, from an Indian Take-away tub - (Well Washed !) plastic lid. fitted 3 nylon m4 screws through at about 120 degrees apart, to fit down the outside of the tube (ETX80). Craft hole cutter cut 2 holes on horizontal centre line, leaving about a hole's worth of material in the centre looked about right. , and sprayed the whole thing with Halfords satin black, on the outer side only. Works a treat. But then I realised, I have a Mk 1 Silhouette Cameo vinyl cutter, which cuts vinyl and card, so I grabbed an image of a Bahtinov, and a Carey, and A 3 hole Hatmann type. Loaded into the silhouette program, re-sized, to fit just inside the inner lip of those lids, and cut 2 copies of each, from cereal box card. They came out far neater than any hand- cut items. Glued the pairs, back to back, with PVA. They are presently weighted flat down on the garage bench, until dry. I have now cut the middles out of 3 further lids, with the same circle cutter, leaving enough landing, to glue the finished cards to. Then these will be fitted with screws, a la original, and sprayed again with same black stuff. I'm interested to experiment with all 4 masks, to see what works best with what. (my Mk 1 eyeball ain't what it used to be !)

If the image does show, it is simply a screendump of the various types of mask, from my Silhouette program, ready to cut. fingers crossed, will post pics if they are a success.

:thumb:
That is excellent!
I kind of feel like there is a race on with the finding of the performance results. It looks like there may be a few good nights this week for me.

[seer]

I'm reposting these photos in hopes they show up.
The 3 I made I used the cardboard box that my 10 gallon aquarium came in along with some hot glue and black spray paint.