finderscope bahtinov

[bottletopburly]

Is it possible to make a bahtinov mask to fit a standard sw finderscope just looked on the bahtinov generator those are fine lines too cut ,has anyone made one before 

[DHEB]

As you point out, it can be very difficult to make a classical Bahtinov mask for a small telescope. There are alternatives though, such as a Hartmann mask, or a "Y" mask. Search the internet for "focusing mask" and you will find plenty of ideas. Good luck!

[bottletopburly]

cheers a hartman mask looks so much more simpler to make 

[Pompey Monkey]

Just focus it until the stars look small. PHD will work fine. In fact, It might even work a little better with slightly defocused stars. I am certainly at, or very close to, my mounts physical accuracy limit (.6" rms) with just a rough focus of my 200 mm fl guide scope with a QHY5guide camera  

[Gina]

Yes, PHD does work better with slightly defocussed stars.

[ronin]

Would have thought that really you are not too bothered by them being pin-sharp, you just want to find them. If small points or small dots/disks seems irrelevant. Also once a mask is on the finder you have to focus it on a bright star, then remove it and start locating objects and with you looking through it there is - I would say - a 100% chance that you will adjust the focus at least a little, people do that with eyepieces and focusers. In which case the original focus set up is lost.

If you to use the finder as a guide scope then there may be a use for one, but if the finder is for visual I would doubt it. As a visual you set the finder to correspond to your eyes which is likely not best focus for a sensor/imaging.

[Pompey Monkey]

On 5/15/2016 at 08:09, bottletopburly said:

 

 

11 hours ago, Pompey Monkey said:

Just focus it until the stars look small. PHD will work fine. In fact, It might even work a little better with slightly defocused stars. I am certainly at, or very close to, my mounts physical accuracy limit (.6" rms) with just a rough focus of my 200 mm fl guide scope with a QHY5guide camera  

 

On 5/15/2016 at 08:09, bottletopburly said:

Is it possible to make a bahtinov mask to fit a standard sw finderscope just looked on the bahtinov generator those are fine lines too cut ,has anyone made one before 

Sorry! I just assumed that it was for a finder-guider! My bad