Oiii Filter For Imaging

[Mamsoth]

I've got a spare 50 pounds (pound key not working on keyboard hehe) and was thinking of getting a baader oiii filter for imaging. Im going to be using my big dob on an EQ platform to get some shortish exposures of some PN. Has anyone used this filter? Does it offer a noticeable difference over no filter?

I used to have a lumicon oiii filter for visual observation and found it didnt offer much difference over the unfiltered view. Any example images would be interesting to see or just hearing the input of anyone who has experience with the filter

Cheers

Matt

[ollypenrice]

I use a Baader CCD O111 filter on some targets for guided CCD imaging. O111 imaging is very slow and without accurate tracking I doubt it would be a good idea. Besides you would need to use other NB filters, notably Ha, to create a colour image.

You know that the CCD and visual filters are quite different?

Olly

[michael.h.f.wilkinson]

I use a Baader CCD O111 filter on some targets for guided CCD imaging. O111 imaging is very slow and without accurate tracking I doubt it would be a good idea. Besides you would need to use other NB filters, notably Ha, to create a colour image.

You know that the CCD and visual filters are quite different?

Olly

Do you know what the difference is? I wondered about the need for such a difference.

[Mamsoth]

I use a Baader CCD O111 filter on some targets for guided CCD imaging. O111 imaging is very slow and without accurate tracking I doubt it would be a good idea. Besides you would need to use other NB filters, notably Ha, to create a colour image.

You know that the CCD and visual filters are quite different?

Olly

Thats a good point olly, with my setup as it is I can't really afford significantly longer exposures, I wouldn't have minded the lack of colour as I was prepared for that but thinking realistically I should wait until I've got enough for a decent mount before acquiring any filters. I really want a G11 but I may have to wait awhile for that'n

I can't even afford the filter now anyway, the guy who was going to buy the camera that would have given me the extra money has been messing me about and has pulled out (hadn't bothered researching what he thought he was buying) so once again I am completely skint, ho hum.

I guessed there must be a difference between ccd and visual oiii but I wasn't sure exactly what that difference was.

Matt

[ollypenrice]

Do you know what the difference is? I wondered about the need for such a difference.

The visual has a wider bandpass. If you hold it up to the light you can look through it. Not so the CCD version. I can't open the Baader site at the minute to see the specs but I'm sure the difference in bandpass is huge. The narrow window in CCD filters boosts the contrast. The very aggressive filters give the most. I only have one CCD O111 but two Ha, 7 and 13 Nm. The former is more contrasty.

Olly

[michael.h.f.wilkinson]

The visual has a wider bandpass. If you hold it up to the light you can look through it. Not so the CCD version. I can't open the Baader site at the minute to see the specs but I'm sure the difference in bandpass is huge. The narrow window in CCD filters boosts the contrast. The very aggressive filters give the most. I only have one CCD O111 but two Ha, 7 and 13 Nm. The former is more contrasty.

Olly

So I would initially be better off with the visual OIII (no proper imaging set-up complete yet), which I could use for photography, until I get a specialist CCD version (i.e., it would work, but not give the same degree of contrast)

[Euan]

Also imaging filters usually include IR cut, whereas visual filters have no need for it (your eye can't see IR)

More IR in your images will result in bloated stars

[michael.h.f.wilkinson]

Also imaging filters usually include IR cut, whereas visual filters have no need for it (your eye can't see IR)

More IR in your images will result in bloated stars

I realize that. I have an IR cut filter I use with the web-cam

[valefor]

sorry to revive such an old thread but i was wondering a few things. olly why 2 ha filters? and this one sounds more stupid. but are ccd filters for ccds only or is using a dslr ok?

im just wondering about these because im thinking of diving into filter imaging. atm im using just an ed80 and a 600d. but i was thinking of buying an OIII, LRGB and a HA filter over the next few months.

thanks for any comeback

[ChrisLX200]

sorry to revive such an old thread but i was wondering a few things. olly why 2 ha filters? and this one sounds more stupid. but are ccd filters for ccds only or is using a dslr ok?

im just wondering about these because im thinking of diving into filter imaging. atm im using just an ed80 and a 600d. but i was thinking of buying an OIII, LRGB and a HA filter over the next few months.

thanks for any comeback

They won't work (well) with a DSLR because of the Bayer matrix on the colour sensor, that is why imagers prefer mono CCD cameras - then all the pixels are sensitive to the light. With your DSLR only a fraction of the incoming light will be recorded.

ChrisH

[valefor]

So aside from forking out over a grand for a half decent ccd is there a way around this?

[johnrt]

So aside from forking out over a grand for a half decent ccd is there a way around this?

If there was we'd all be doing it.

[valefor]

Not a very helpful comment. Ok let me be more specific.

Can I expose longer to compensate? Or how is everyones experience with debayering?

Or even using film? Has anyone tried using a ha or o3 filter on a film camera either b&w or colour film?

or. Is there a worth having budget ccd camera?

hope this is more specific.

[ChrisLX200]

Not a very helpful comment. Ok let me be more specific.

Can I expose longer to compensate? Or how is everyones experience with debayering?

Or even using film? Has anyone tried using a ha or o3 filter on a film camera either b&w or colour film?

or. Is there a worth having budget ccd camera?

hope this is more specific.

No, a longer exposure would just accumulate background noise while adding not much signal.

If you want ot see the best that can be achieved with film just look at old ('80's) astronomy books. I certainly would not want to go back there!

There are 'budget' cameras to be had (but who's budget - yours or mine?). An Atik 314 would be a fine starting point.

The answer you received previously may have been succinct but no less accurate for being that.

ChrisH

[valefor]

Thanks chris. The atik mite be in my budget. Tbh im a little despondent atm because ive recently saved hard and brought a 600d only to find its not able to be used with filters and therefore unable to get a full image. Basicly the value of a 314 wasted.

But thanks for your advice

[ChrisLX200]

Thanks chris. The atik mite be in my budget. Tbh im a little despondent atm because ive recently saved hard and brought a 600d only to find its not able to be used with filters and therefore unable to get a full image. Basicly the value of a 314 wasted.

But thanks for your advice

I'm not much better off having bought a 70D at the beginning of the year with the intention of getting into astrophotography. It's a very nice camera but not the best choice. I may well sell it if I can get enough money back. If the 70D were my only camera I wouldn't mind but I already had a little Sony RX100 which is all I need for general use. This hobby is a money pit and no mistake.

ChrisH

[johnrt]

Not a very helpful comment. Ok let me be more specific.

Can I expose longer to compensate? Or how is everyones experience with debayering?

Or even using film? Has anyone tried using a ha or o3 filter on a film camera either b&w or colour film?

or. Is there a worth having budget ccd camera?

hope this is more specific.

I think you missed my point. Let me explain, if you want to do full narrowband imaging then you need a mono CCD. OIII and SII are very diffuse and weak in signal in all but a couple of very bright planetary nebula, even with a good sensitive mono CCD exposure times of 30 minutes are the norm to get enough signal, stacked up to make many hours of exposure per filter.

There aren't any quick easy shortcuts I'm afraid. The place to start is with an Atik 314 but beware the chip size is tiny compared to what you are used to with a dslr.

[swag72]

You can do Ha imaging with a DSLR, but it's going to be seriously hard work if not almost impossible on an unmodded camera. You can buy Ha clip in filters from Astronomiks and they just clip into the barrel of the camera, in front of the sensor.

I used one briefly before I decided that a mono CCD was the way forward. Nonetheless, I achieved some results.

https://www.flickr.com/photos/swag72/5866369691/

https://www.flickr.com/photos/swag72/6130069050/

https://www.flickr.com/photos/swag72/6155271603/

I've not seen any images that stick in my mind with a DSLR and an OIII filter. I would say that they are not out there for good reason - Save your pennies and get a CCD.

[ollypenrice]

I had two Ha filters by accident, really. I realized that the 13Nm Astronomik was not as good as the 7 Baader so I bought the Baader. Then I went for the monstrously expensive Astrodon 3Nm. This has the highest contrast of all but is hard work because it needs a bright star, usually out of shot, to be focused.

Don't discount Ha with a modded DSLR. It is slow and the resolution is not too good but Ha is a wonderful thing to add as a layer. But if your camera is fairly blind to Ha then it will be just as blind with a filter.

One simple Ps trick to find lurking Ha signal in any colour image is incredibly simple. Go Image, Adjustments, Selective Colour, and move the top slider in reds to the left. If the signal is there, this will find it.

Olly

[valefor]

Thanks for all the advice guys. Il be saving for a ccd for a bit so il muddle thru for now.

John i think your rite but im guna save longer and get a bigger chip ccd.

Swag those pics are great. While im saving il still be taking lots of shots with my 600d.

Olly thanks for the tips. I think i mite just leave the filters till i get a ccd. Looking forward to learning about them when the time comes.

Thanks again guys

[valefor]

Actually one more thing. Is there any filters that are worth having with an unmodified dslr

[Aenima]

Was looking for info on a decent OIII filter for imaging and found this thread - the title says oiii for imaging, but seems mostly related to DSLR so i thought i'd post my own results using a DSLR for narrowband. As a rough idea to anyone thinking of doing it.

 

Here is a Ha + OIII bi-colour image of the VEIL NEBULA

taken with an ED80 and a modded 350D (filter removed, not mono though) using astronomik 12nm h-alpha clip, and a cheap skywatcher visual OIII 2" filter. 

 

and a h-alpha only mosaic of the north america nebula - 2 panes, with just the red channel extracted, using ED80/350D astronomik ha clip. 

 

and a mix of OSC RGB data from the 350D and a h-alpha stacked and layered as luminosity in photoshop to add contrast and improve detail. Rosette and Bubble nebula.