One filter to rule them all?

[Neotox]

Hey! Been reading around on net and trying to get a grip on all the filters around. What im looking for is actually ONE filter (as they are so damn expensive...) to buy, but wich is the best alround filter for a Canon APS-C 800D camera? 

Optolong, Astronomik, diffrent versions...UHC, CLS, L-ehance, L-pro etc...

Anyone have any experience?

[smashing]

Depends what you want to image and why you want to use them i.e. light pollution etc etc 

I've got an IDAS D2 for general light pollution duties and broadband targets due to the LED lights around my house and currently have a L-extreme on order for a bit more focused nebula narrow band work with my DSLR....not tried it out yet mind you.

 

[SteveNickolls]

Really depends on what your imaging interest(s) are and other factors such as your local light pollution and whether using a modified or unmodified DSLR etc. I've found a clip-in 12nm Ha filter from Astronomik to have given my hobby a great boost when imaging with a modified Canon 700D and lenses (see my galleries). I've found the 12nm version allows me to manually focus objects (it's made more difficult with narrower filters) for imaging sessions and produces pleasing images of nebulae.

Good luck on whatever you do proceed with.

Cheers,
Steve

[Neotox]

Thanks for the input (gonna check out you pics), im going to use it on a Unmodded Canon 800D. Mainly for DSO nebulas etc, to be able to get more detail. I mean is there more value in actually buying one expensive filter instead of  a CLS for a 1/3 of the price of the expensive ones.

[Space Oddities]

Well it depends what you want to photograph!

I'd say there are 5 kinds of filters to consider for a color camera:

1. Light pollution filters (L-Pro, IDAS LPS...)

They remove some of the light pollution (usually, older kinds of street lamps, that emit light in a specific wavelength). These filters are broadband, so they only remove some of the light.

The overall effects are light: contrast will increase slightly, some of the light pollution will be reduced.

 

2. CLS/CLS-CCD filters (many brands, they're all named CLS or CLS-CCD)

These filters are stronger than standard light pollution filter. They basically cut off the middle of the spectrum completely. They are mostly meant for visual use, but there are some "CLS-CCD" versions that also cut off the infrared. This is what you need if you have an unfiltered camera.

 

3. UHC filters

UHC filters are similar to CLS filters; but they let a bit more light on both side. They're initially meant for visual use only. They will filter less light pollution, and provide less contrast than CLS filters. Also, they generally don't cut off the infrared, but I think Baader makes a UHC-S filter that reduces or filters out the IR.

 

4. Dual/Tri/Quad narrowband filters (L-eNhance, L-eXtreme, STC Duo, IDAS NB1/2/3...)

These dual-narrowband filters are even more restrictive than UHC and CLS filters. They're designed for photographing emission nebulae, and have narrow 2 bandpass usually centered around OIII and Ha wavelengths. 

Here you have many brands and filters, they're quite popular these days. Depending on what brand you get, you'll have a more or less narrow bandpass. Check out this thread for more info!

You can also find some higher end models, that have 3 or 4 peaks, like the Triad filters from OPT. But they're very, very pricey!

5. Narrowband filters

Narrowband filters only filter a specific wavelength, like Ha or OIII or SII only. They're more or less narrow, and better suited to mono cameras. But it's still possible to use for example an Ha filter, with a DSLR, and use it as a red channel to create an HaRGB image.

 

Conclusion

There isn't really 1 filter to rule them all... it really depends what you want to photograph and your light pollution.

• For emission nebulae, emitting in 2-3 very specific wavelengths, duo narrowband filters are a good match to a color camera (or standard narrowband filters for a mono one). However, they are too restrictive for targets that emit in all wavelengths.
• For other targets emitting in all wavelengths (galaxies, reflection nebulae), other filters can help to various degrees: light pollution filters are the weakest, CLS-CCD the strongest, UHC in between).

Things to keep in mind:

• These filters cut light, and the more they cut, the longer you need to expose
• You'll always be limited by the filter placed on the sensor of your DSLR. A standard DSLR is meant to be used in daylight, and filters UV and infrared light. Sometimes, they also drastically reduce the transmission of wavelength 656nm, which is the wavelength of hydrogen alpha, that is very common in deep sky objects. In other words, your DSLR might be filtering the light you're trying to photograph. That's why people "mod" their cameras, by removing that UV/IR filter, to unlock the full potential of the sensor.
• If your camera is modded or unlocked, always use a filter that gets rid of infrared light (> 700nm). Digital sensors can see IR light, and it can mess with your image ultimately
• Some filters like CLS-CCD can mess with your color balance, it can be hard to correct in post

Hope that helps  

 

Edited January 14, 2021 by Space Oddities

[Neotox]

Wow, thank you very much for that post really helpfull!

[Space Oddities]

 

Also a couple videos with interesting examples and real world comparisons   Charts are nice, but nothing beats a real image!