PST 10mm blocking filter/ Denk Spectrum 60

[Merlin66]

It's a quick and dirty lo res spectroscope assembled from "standard" parts -very cheap and easy to make, and you can use one of those ol' SLR lenses you have lying around for the imaging part...
Details on the astronomical_spectroscopy Yahoo group.

[vikeljay]

I tried to do the same thing to my BF 10 filter but could not get it unscrewed from the diagonal. I tried a rubber strap and even tried plumbers pliers but it would not budge. I hesitate to hit it on something because I don't want to break anything. Is there another way to get it unscrewed? Thanks.
Jim

[vikeljay]

I finally got it off and it fits perfectly where the BF 5 blocking filter was. Now that I have a BF 10 filter on, will I notice any difference? Will the focus be the same? Will tuning be the same? Thanks.
Jim

[marktownley]

I finally got it off and it fits perfectly where the BF 5 blocking filter was. Now that I have a BF 10 filter on, will I notice any difference? Will the focus be the same? Will tuning be the same? Thanks.
Jim

Absolutely no difference at all with a PST.

[JohnM]

I got one of those Denk/Spectrum conversions when they first came out.
I was able to talk thrm into just sending me the parts so I could do the assembly.
Visually the conversion was pretty good, but always better with the original 5mm BF.
Over the years I spent countless hours trying to get it to come to a good focus with a camera, I could never get it and finally junked the thing.
As I understand it, somewhere along the line they quit making the 10mm BF because they never worked right.
I'm going to try it with the 102mm stage 2 I'm building now and see if it will work with that size aperture.

[vikeljay]

Do you still have the parts?
Jim

[JohnM]

Are you asking me?
Anyway, no, pretty much anything I could see no use for is gone.

[vikeljay]

Has anyone gotten better results using a BF 10 on a PST as opposed to the BF 5? Everything I have read on this forum sees to suggest the BF 5 is the best way to go. Thanks.
Jim

[solarchat]

the BF5 and BF10 are the same thing just the BF10 is 10mm across and the BF5 is 5mm across. You should only see a slightly larger field of view without vignetting if anything. They function exactly the same as they are the same glass.

Either one is fine unless you are changing the the placement of the imaging device.

[marktownley]

There is absolutely no gain in putting a bf10 on a PST in it's native form. The BF5 is matched to the short focal length of a PST, bf10 is suited to longer focal length scopes.

[solarchat]

the BF5 and BF10 are the same thing just the BF10 is 10mm across and the BF5 is 5mm across. You should only see a slightly larger field of view without vignetting if anything. They function exactly the same as they are the same glass.

Either one is fine unless you are changing the the placement of the imaging device.

[vikeljay]

Anyone notice that the BF 10 is a little shorter than the BF 5. Maybe I will be able to get the full disk on my camera without having to use a barlow. Did I also read somewhere that you don't really need that other filter that screws into the black box? If I take that off, I will really be able to get focus without a barlow!
Jim

[solarchat]

Jim,

You will also lose yours or someone else looking in your scope's eyesight permanently with the slightest bad advice from other modders.

I would strongly suggest you step back a bit and try and understand all the various components before you start changing things out or removing things..,

[marktownley]

Anyone notice that the BF 10 is a little shorter than the BF 5. Maybe I will be able to get the full disk on my camera without having to use a barlow. Did I also read somewhere that you don't really need that other filter that screws into the black box? If I take that off, I will really be able to get focus without a barlow!
Jim

Like Stephen says, all those filters are there for a reason. Just get a short shoulderless nosepiece to allow your camera to reach focus.

[vikeljay]

After reading all of the post on this subject, I got the impression that I can take off the part that screws directly into the black box - is that right? I also remember reading somewhere on this forum that I can use an H-Alpha daytime filter. What does that filter do? Thanks.
Jim

[JohnM]

You seem to be missing the comments to learn about what you have first before you start changing things around.
It's advise not to be taken lightly.

[solarchat]

Im guessing this may be Apollo Lasky

[vikeljay]

Please do not take offense to this but I asked the question because I wanted it answered. I understand that any mods I make to my PST are at my own risk. Thanks.
Jim