light pollution filters?...

[palatine]

my heads mashed..... whats the best filter to get for taking images on an unmodded canon 550d?....

i  live in a heavily polluted area

i've searched and cant make head nor tail.

thanks

[jambouk]

The two which seem to filter out most LP are the CLS and the IDAS ones. I'll try and find links.

What scope etc are you using? 1.25" or 2" or fancy an EOS clip so you can use it to do widefield too with a standard DSLR lens (not all fit though so need to do some research).

James

[jambouk]

Can't remember which is best out of these two for what you want, ask FLO:

http://www.firstlightoptics.com/light-pollution-reduction/idas-d1-light-pollution-suppression-filter.html

http://www.firstlightoptics.com/light-pollution-reduction/idas-p2-light-pollution-suppression-filter.html

[jambouk]

And the CLS filter:

http://www.astronomik.com/en/visual-filters/cls-filter.html

I think the CLS CCD one is for cameras which have been astro modified, but again do some research.

James

[LukeSkywatcher]

Since there is no mention of a scope, i assume you are looking for a LPF to attach directly to your camera. 

Cant help there i'm afraid. If there is a scope involved, then i do like my Skywatcher LPF. Cheap as chips @ about £30-40.

[FunkyKoval35]

Hi Palatine.

My advice: If you live in heavily light polluted area do not waste your money on LP filter. Those filters are not "magic solution" for LP sky - they works, but only with moderate/low LP.  Collect money and go for CCD camera + Ha filter.

Adam.

[palatine]

The two which seem to filter out most LP are the CLS and the IDAS ones. I'll try and find links.

What scope etc are you using? 1.25" or 2" or fancy an EOS clip so you can use it to do widefield too with a standard DSLR lens (not all fit though so need to do some research).

James

i have a 250 flex tube goto dob and also a SW adventurer that I intend to use for wide field and also with a 80mm travel scope. All connecting to my in modded canon 550d. So I guess the "click" filter is the way to go but.... CLS? Ha? DLS-CCD?

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[jambouk]

Do you have a tracking mount for any of these scopes?

If not, and you primarily want to use the filter for imaging through a scope, i would go as cheap as possible as you won't get any of the benefits of the expensive ones as your exposures will be limited to a fraction of a second anyway. If you are doing dslr planetary video, the LP shouldn't pose too much of a problem.

If you have a tracking mount then you need to decide.

If you are unmodified i don't think you need CLs-CCD.

James

[jambouk]

Getting an Ha filter for an unmodified canon is a very expensive and VERY time consuming way to get data. Add in a manual mount, and that is a sure way to get sectioned.

Even if you have a tracking mount, an Ha filter on an unmodded dalr is pretty pointless as the filters inside the dslr filter out about 70% of Ha wavelength light and stop it ever reaching the sensor... If it were a modded camera that would be a different kettle of fish.

James

[palatine]

The skywatcher star adventurer is a mini tracking mount but the dob is obviously Limited...

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[LukeSkywatcher]

Hi Palatine.

My advice: If you live in heavily light polluted area do not waste your money on LP filter. Those filters are not "magic solution" for LP sky - they works, but only with moderate/low LP.  Collect money and go for CCD camera + Ha filter.

Adam.

I tend to agree. If you live within a stones throw of a major city centre (Warrington is big and bright enough), then a LPF probably wont improve things much. 

[jambouk]

Ab, nust seen the GOTO but... Alt-az i guess rather than equatorial. So your exposures are limited to 5-20 seconds.

I'd get the £20 light pollution filter and give that a go. If it helps but you want to progress you can sell it for £10 and get the £150 filter instead.

James

[palatine]

Ok. So basically..... I'm wasting my time with lp filters on my scope and wide field attempts?...

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[palatine]

Ab, nust seen the GOTO but... Alt-az i guess rather than equatorial. So your exposures are limited to 5-20 seconds.

I'd get the £20 light pollution filter and give that a go. If it helps but you want to progress you can sell it for £10 and get the £150 filter instead.

James

Will do. Cheers everyone

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[Andy Mitchell]

Depends on the "flavour" of light pollution. If its broadband white light pollution narrowband is indeed the only solution. It is however a very expensive solution as you will need a mono CCD camera, expensive tracking mount, narrowband filters etc. You can spend a couple of grand on a mono camera and still be left thinking you have a small sensor compared to your DSLR.

If on the other hand your mostly suffering from things like low pressure sodium street lamps (orange), a CLS filter will help. I had good improvements with both cheap neodymium ones (a sort of poor mans CLS)  and a much more expensive UHC filter, right up until the council decided to replace the LPS street lamps with white ones (CFL on my road).

I suspect the trick is to take some long exposures and see what colour the sky glow is to get an idea what the problem is where you are.

[jambouk]

I think you should experiment, but not at the cost of £150.

Get a cheap one and see how you get on.

Does anyone near you have an expensive one you could try? Are you in an astronomical society? I'd happily lend you my CLS EOS clip filter but someone else has robbed [i mean is borrowing] it

I don't want to appear to be discouraging, but certainly don't want you to waste money.

I think you are limited by your exposure duration which is a hinderance in a heavily light polluted sky; if you could get to a dark site and get 200 x 10 second exposures of say M42 then you'd end up with a nice image. You need to try a similar attempt at home with a cheap LP filter - if the results are promising but still LP is causing you trouble, try the next filter up.

James

[palatine]

http://www.firstlightoptics.com/light-pollution-reduction/baader-neodymium-filter.html

Are these better than the cheaper ones?.....

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[jambouk]

That is a very good point about the colour of the LP; mine is still very yellow luckily.

You can find the graphs for most filters online, so can see how the compare in terms of blocking unwanted wavelengths, and transmissing others. The neo filters have a good reputation, but going back to the LP colour issue, they don't work the same for everyone.

If you are determined to buy something, make sure you check astrobuysell and ebay as you might get one for half the price of the new cost, and should still be able to sell it in if it doesn't suit with minimal loss of money.

James

[jambouk]

In fact, i might have one of those neo filters at home. I'm not back until tomorrow so i will have a look and if so i can post it to you and you can give it a go.

What size were you looking at? 1.25" or 2"? How do you attach the dalr to the Newtonian?

James

[palatine]

To the newt I fit it directly off the camera adapter to the 2" focus tube adapter as it's the only way to get focus in prime mode...

Thank you for your very kind offer.

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[Andy Mitchell]

Probably not worth spending the extra for the Baader if you just want to take a punt without first knowing what the right solution is.

If I recall correctly my 2" neodymium one is a skywatcher light polution filter, the 1.25" was some even cheaper one like ostara. I've also got a redhancer (marumi) camera lens filter thats made out of the same sort of glass. They all helped with the orange glow of LPS and were a lot cheaper than the Baader

http://www.firstlightoptics.com/light-pollution-reduction/skywatcher-light-pollution-filter.html

And speaking of sticking filters onto camera lenses, widefield with just a camera lense can be a lot of fun.

[jambouk]

So are you screwing a 2" adapter (2" diameter) like this onto the front of the DSLR? Does it have a thread on the inside at the telescope end?

http://i00.i.aliimg.com/wsphoto/v0/2051884230_2/2-To-T2-M42-0-75-2-inch-DSLR-Prime-Nose-Adapter-For-Telescope-Aluminum-ED.jpg

Do you have a 1.25" version of this nose piece too in case the filter I've got is a 1.25" version?

James

[jambouk]

I found an email which suggests Bernard at Modern Astronomy sent me a 2" neo filter last year, so hopefully it is still at home unless I've lent it / given it to someone else.

James

[palatine]

Does this clarify how I'm doing it?

I still have the 1.25" nosepiece also but as I said. I struggle to get prime focus with it.

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[jambouk]

No. What is on the inside of the the bit I have lighlighted in yellow at the telescope end? Is it threaded? What is the internal diameter of the that bit at the telescope end? How does that bit attach to your telescope?

James