Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Uv/Ir cut filter

  • Please log in to reply
7 replies to this topic

#1 GKA

GKA

    Sputnik

  • -----
  • topic starter
  • Posts: 27
  • Joined: 03 Jan 2019

Posted 19 November 2019 - 03:11 AM

Hi, i have an unmodified can on EOS 1000D and Wonder if i could or should use an external filter on bright targets As the SUN, Moon and perhaps Jupiter.
I already have the Uv/Ir cut filter, so it will be No extra expence for me.
I have tried to Google the subject, but feel i haven't found out much.

Will i benefit from it, or will it make things worse.
I'm currently using a cheap achromat, a skywatcher startravel 120 F5
All the best.

Edited by GKA, 19 November 2019 - 03:12 AM.


#2 Tapio

Tapio

    Vanguard

  • -----
  • Posts: 2,237
  • Joined: 24 Sep 2006
  • Loc: Tampere, Finland

Posted 19 November 2019 - 03:21 AM

With lens scope it's useful to have to make smaller stars and maybe it will help some with moon and other targets (doesn't really matter how bright target is).

If you have it try using in.



#3 GKA

GKA

    Sputnik

  • -----
  • topic starter
  • Posts: 27
  • Joined: 03 Jan 2019

Posted 19 November 2019 - 04:28 AM

I will try it out once the Weather clears up, but looks like it will take some time 😊.
MODERATOR...
I put this in the wrong forum, it was supposed to be in the DSLR forum, any chance to move it?
All the best.

#4 bortle2

bortle2

    Vostok 1

  • -----
  • Posts: 116
  • Joined: 18 Sep 2019

Posted 19 November 2019 - 04:47 AM

Hi, i have an unmodified can on EOS 1000D and Wonder if i could or should use an external filter on bright targets As the SUN, Moon and perhaps Jupiter.
I already have the Uv/Ir cut filter, so it will be No extra expence for me.
I have tried to Google the subject, but feel i haven't found out much.

Will i benefit from it, or will it make things worse.
I'm currently using a cheap achromat, a skywatcher startravel 120 F5
All the best.

As to the intended purpose of the UV/Ir filter: you already have multiple levels of protection -- IR protection glass over the sensor (cuts IR), Bayer filter (cuts both IR and UV), microlens array over the sensor and the two lenses in your SW 120/5 (cut UV). Whatever IR/UV there remains shouldn't affect your images. Adding an extra filter is adding two more glass/air surfaces, always a potential to cause extra reflections and lowered contrast.

 

Since you're shooting bright targets (e.g. the Moon), what you can really benefit from image quality-wise is "stopping down" your telescope by making a simple round diaphragm from cardboard and putting it in front of the objective; doublets (vs. high-end APOs) respond to that very nicely.

 

All that said, dimming your image means lengthening exposure, which at some point might become detrimental to the IQ even when shooting bright targets. I suggest you try various combinations and see what works for your setup. Good luck with that.



#5 GKA

GKA

    Sputnik

  • -----
  • topic starter
  • Posts: 27
  • Joined: 03 Jan 2019

Posted 19 November 2019 - 06:55 AM

Thank you for a great reply, I'm very much a newbie on this, the reason i asked was that since my scope i a fast achro (F5) with some CA i thought that an extra might help, and I already had it laying around. 😊
So much to learn, but this is a great place to do Just that.
Thank you All for your input. 👍😀

#6 PDB

PDB

    Explorer 1

  • -----
  • Posts: 84
  • Joined: 18 Nov 2016

Posted 19 November 2019 - 08:23 AM

If you want to shoot the Sun the UV/IR filter wont be enough. (unless you want to fry your sensor or get eye damage while looking through the viewfinder.)

You need proper protection with a SOLAR filter (eg Baader AstroSolar or similar) in front of the scope.

 

Paul


  • havasman and alstarjoey like this

#7 GKA

GKA

    Sputnik

  • -----
  • topic starter
  • Posts: 27
  • Joined: 03 Jan 2019

Posted 19 November 2019 - 10:52 AM

I do have both baader film and Herschel wedge and a uv / ir cut filter in front of it. 👍
That was part of the reason i asked, because it is supposed to (i was told, but i could have misunderstood) clear up some atmospheric distorsion, espesially on refractors, and maybe even more on cheap ones like mine.

Edited by GKA, 19 November 2019 - 11:16 AM.


#8 t-ara-fan

t-ara-fan

    Viking 1

  • -----
  • Posts: 806
  • Joined: 20 Sep 2017
  • Loc: 50° 13' N

Posted 19 November 2019 - 09:59 PM

An IR-PASS filter sharpens the image of the sun (with sun filter) and moon. This is because red light refracts less than blue. And IR less than red. So the effects of bad seeing are reduced.

The moon is for the most part monochrome, so this works well. Isn't as good for planets that have colors.

Edited by t-ara-fan, 19 November 2019 - 10:00 PM.



CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics