Visual vs. CCD/Astrophotography Filters

[employee2-4601]

Hi Folks,

Been melting my brain lately looking at all the weird and wonderful scope filters available and I noticed quite a number that are advertised as for CCD only. Can anyone tell me what the difference is between these and visual filters? I appreciate the human eye is not as sensitive as a CCD or DSLR camera, so are these filters useless for normal visual observation?

[Physopto]

Visual filters do not need to filter out infra red as we cannot see that wavelength of light. CCD filters do need to as the CCD is sensitive to these wavelengths.

Derek

[employee2-4601]

That being the case, would you be able to use them for standard visual observing as opposed to AP?

[Physopto]

I have never tried. So cannot say for certain. I see no reason why not. I only use LRGB and narrow band filters for my ccd. So do not own any visual filters bar an old moon filter. That hasn't seen an outing in several years. I think the main point will be a small difference in initial cost in buying. I would ask someone who uses DOBs possibly. I have heard that they use OIII filters on some targets to bring out details difficult to see otherwise.

Derek

[John]

Filter intended for imaging seem, from the band pass charts I've looked at, to have lower peak transmission than visual filters of the same class.

 

[employee2-4601]

28 minutes ago, John said:

Filter intended for imaging seem, from the band pass charts I've looked at, to have lower peak transmission than visual filters of the same class.

 

Does that mean that imaging filters block more of a particular band than visual filters?

[Physopto]

You need to go to Astronomiks website and have a good look at the graphs of transmitted light. Compare them to each other yourself and you will get a far better understanding than us trying to explain it to you. 

Derek