Achieving Better Astrophotography at Home

[sophiecentaur]

Here's another question for more experienced sky watchers. I have seen such impressive results from high quality astrophotography and I accept that the visual views from by garden will be vastly inferior. But there are many filters for sale and I would love to avoid buying something at great expense that will probably make not difference to what I see.
What's the point of my using filters? Is there a selection of affordable filters that are likely to actually improve what I see. I am located a fair way to the West of London and there are no street lights for several miles around our house.
As an aside, I was pleased to locate the Andromeda Galaxy with my 'good' X10 binoculars, the other night. Later in the week, I got a view of it through my 8" Dobsonian. It looked much the same, actually; the central blob was, to my eyes, much the same angular size in the eyepiece. The fuzz round the outside was more of less lost against what I thought was a pretty clear sky. You are going to tell me that's par for the course and that I will have to spend much longer on a very cold clear night etc. etc.??
I was still humbled by the thought that the light I was seeing (and identifying) was launched 2.5 million years ago!

 

[davenn]

hey mate

top of the list for optical viewing is the O-III (O3 Oxygen - II filter) this really enhances the planetary nebulae in particular
http://www.telescope.com/catalog/en...&subCategoryId=48&ensembleId=27&type=ensemble

there are other filters for astro imaging eg the Ha filter which really enhances nebulae
but these need to be used for either a dedicated astro imaging CCD camera or a DSLR camera that has been
modified to take out the standard filters.
The standard filters in a DSLR camera will negate any additional filters placed in front ... hence the need to modifyDave

 

[sophiecentaur]

Hi there.
Thanks for that opinion. A bit pricey for me at the mo, though. I have been spending money on this hobby like water and (unfortunately) I am actually seeing improvements since a new set of eyepieces, finder etc. etc.. That's the slippery slope ain't it? Money really does make a difference (unlike with silly priced Audio HiFi).
I was really hoping you'd be recommending something for 10GBP. Some hopes!
SWMBO is very understanding in these matters - bless 'er - but I don't want to be taking the mick. Haha.
My main problem is that she likes to take a bath late and the bathroom blind is not that opaque. It's literally the only local source of light pollution. So I have to wait till late for ideal conditions. I could paint the window black, I suppose.

 

[davenn]

That's the slippery slope ain't it? Money really does make a difference (unlike with silly priced Audio HiFi).

yes and yes

I was really hoping you'd be recommending something for 10GBP. Some hopes!

sorry to dash your hopes. Astronomy really is one of the few areas where increasing price really does = increasing quality
To a great extent, it's much like that in photography as well.
All these various filters are quite good, designed with very narrow passbands and notches in the right places of the spectrum for observing specific objects
That is some are more suited for planetary nebulae than for emission or reflection nebulae.
There isn't really one that does everything

My main problem is that she likes to take a bath late and the bathroom blind is not that opaque.

haha, that reminds me of a long time ago ... back in the '80's when I used to travel to my mate's family home ( he and brother were still living with mum and dad)
My mate, Dave, had an Edmund Scientific 8" Newtonian scope which was on a tracking mount. We used to do hours and hours of astrophotography with his or my 35mm SLR film camera connected to the scope ( years before CCD astro cams or any digital cam). He and I would share the work of doing the guiding to make sure tracking errors were accounted for.
His scope was set up in a shed with a removable roof in the back yard and next door there was a gal who periodically liked to get ready for bed without pulling the curtains... leave the rest to your imagination
cheers
Dave

 

[Chronos]

I don't have much love for filters. The bang for the buck just isn't there unless you are a seasoned AP'er with imaging goals. For visual use, they are mostly just photon eaters and rarely beneficial for anything aside from solar or lunar views.

 

[glappkaeft]

I disagree, a H-beta, OIII or UHC filter can work wonders on some nebula.

 

[sophiecentaur]

I'm glad to read that there are differences of opinion here. I tend to err on the stingy side when it come to buying bolt ons but, in the case of a fave hobby, I can sometimes go completely the opposite way.
Electronic imagers are very 'literal' with what they see and you can't fool them. The brain / eye combination can dredge stuff up out of nowhere - but not always correctly, as with the canals of Mars.
More opinions please. They will be gratefully received.

 

[Schneibster]

My experience with filters for visual is that you need to have really good dark adaptation (an hour or more with as near as possible zero light) for your eyes to be sensitive enough for them to make a big difference. I own a UHC, an Hβ, and a couple others. Also note that they are by far most effective for nebulae; they don't do much for galaxies (but that said, they can make the nebulae in the Triangulum galaxy stand out nicely, which is quite kewl). Some people report interesting results with some filters when viewing planets; I've tried it and wasn't impressed, but your mileage may vary.

 

[davenn]

My experience with filters for visual is that you need to have really good dark adaptation (an hour or more with as near as possible zero light) for your eyes to be sensitive enough for them to make a big difference.

dark adaption helps with everything and the longer the better

Also note that they are by far most effective for nebulae; they don't do much for galaxies

yes as I noted earlier ... that's what they are designed forDave

 

[Drakkith]

If you want a filter that may help you out while observing galaxies, they make "light pollution filters" that may work for you. Take a look at this article: http://www.prairieastronomyclub.org.../useful-filters-for-viewing-deep-sky-objects/

 

[sophiecentaur]

If you want a filter that may help you out while observing galaxies, they make "light pollution filters" that may work for you. Take a look at this article: http://www.prairieastronomyclub.org.../useful-filters-for-viewing-deep-sky-objects/

I may go for something like that. That link makes good reading - thanks.

 

[Chronos]

The pictures in the link exaggerate the plusses of filters for visual use, which I believe are negligible. They caveat their praise under the context of 'experienced' observers. I would argue filters are among the worst bang for the buck of any visual deep sky accessory. An eyepiece upgrade would be my preference. But, then again I am old.

 

[davenn]

The pictures in the link exaggerate the plusses of filters for visual use, which I believe are negligible. They caveat their praise under the context of 'experienced' observers. I would argue filters are among the worst bang for the buck of any visual deep sky accessory. An eyepiece upgrade would be my preference. But, then again I am old.

that's pretty harsh

definitely not of negligible value ... my Lumicon UHC filter gets a lot of use and works reasonably well. gives much better contrast between sky and nebulaDave

 

[sophiecentaur]

The pictures in the link exaggerate the plusses of filters for visual use, which I believe are negligible. They caveat their praise under the context of 'experienced' observers. I would argue filters are among the worst bang for the buck of any visual deep sky accessory. An eyepiece upgrade would be my preference. But, then again I am old.

We're really into Bang per Buck considerations and financial priorities, here. My choice of new eyepieces was a really good one and they do enhance the experience a lot. Also the right angle finder scope has preserved my neck joints (I am old too!) A DIY solar filter, with plastic sheet mounted in a round baking tin, with a hole cut in it, has also made a difference to views of the Sun. Unfortunately, I missed 'that transit' and also the massive sunspot that was there a few weeks ago but I live in hopes. Of course, I will probably never see those interesting views of the bubbling solar porridge, which is a disappointment but a high end narrow band filter would be a bit over the top.
The new 13% Moon filter will come in handy tonight (I hope). Looking at the full Moon without it was giving me unpleasant feelings of blindness in my right eye when I look away from the EP.

 

[Chronos]

My experience with filters is admittedly thin. My enthusiasm was sharply diminished following some early disappointments with Hb and OIII. Of course my 'big' scope then was an 8" f10 SC, so that could be a factor. It appears most DSO filter praise originates from veteran observers with light buckets. On a side note, I agree a RA finder scope is a veritable godsend on a Newt, or almost any other sizable scope. It used to puzzle me why these are not offered as a standard option on most scopes.

 

[davenn]

Unfortunately, I missed 'that transit' and also the massive sunspot that was there a few weeks ago but I live in hopes.

if your solar filter is ready to use ... there's a big spot group visible at the moment. Will still be for a couple of days till it rotates off the disk faceD

 

[sophiecentaur]

if your solar filter is ready to use ... there's a big spot group visible at the moment. Will still be for a couple of days till it rotates off the disk faceD

I took a look at the Sun today (filter plus eyeball, only) and I couldn't see anything significant. I may be lucky with the cloud cover tomorrow and dig out the Scope.

 

[davenn]

I took a look at the Sun today (filter plus eyeball, only) and I couldn't see anything significant.

really ? a huge spot group...

cheers
Dave

 

[davenn]

that was for yesterday, they have rotated a bit more towards the west limb now

 

[sophiecentaur]

I took a look at the Sun today (filter plus eyeball, only) and I couldn't see anything significant. I may be lucky with the cloud cover tomorrow and dig out the Scope.

I must remember to clean my glasses tomorrow!

 

[sophiecentaur]

What sort of filter were you using, btw?

 

[davenn]

What sort of filter were you using, btw?

this one for the telephoto lens

http://www.bintel.com.au/Accessories/Solar-Filters/Orion-Solar-Filter----br--90mm-Refractor/1014/productview.aspx

and its BIG brother for the telescope

http://www.bintel.com.au/Accessories/Solar-Filters/Orion-Solar-Filter---br--9-25--SCT/1028/productview.aspx

there are still the rare times where I happen to be away from home without either of the above filters
and I have resorted to my old mylar filter ( survival blanket x 3 layers) it gives quite a blue image compared to the
orange of the commercial filtersDave

 

[sophiecentaur]

That picture has a lot of subtle detail but the view through my filter at a magnification that fills the visual field is pretty well a uniform yellow. Should I consider some additional EP filter to reveal that? I see the prices of the best Etalon filters are a joke for the amateur enthusiast.

 

[sophiecentaur]

@Dave: There was some blue sky today and I looked at the Sun 'properly' That sunspot group was very visible but not as sharp as your photo. I guess that 'seeing' problems are common during the day - especially hot and muggy days, which is what we are having at the moment.

 

[davenn]

That picture has a lot of subtle detail but the view through my filter at a magnification that fills the visual field is pretty well a uniform yellow.

were you referring to those lighter markings near the limb to the right of the spot group ?
They are called plage, they are only really seen when they are near the limb where there is a better contrast between the background and the plage. They get washed out in the brightness of the background when in the central region.
Plage are active regions that haven't formed sunspots. They can become more active and produce spots, or conversely, active spot regions can decay and leave just plage visible.

The better detail within the spot groups only comes with a good scope. My 9" scope will do that but my 500mm lens on the camera just doesn't quite get thereDave

 

[davenn]

then if you have a really big scope you can start getting this sort of detail
including the granularisation. That I would like to be able to do haha

 

[sophiecentaur]

then if you have a really big scope you can start getting this sort of detail
including the granularisation. That I would like to be able to do haha

Yikes!

 

[lomidrevo]

Hello stargazers, I'd like to revive the topic about nebula filters, more particularly I am interested in UHC filters for observing planetary nebulas. I have read lot of discussions, reviews and opinions on this topic over internet, but it would be very interesting to get some feedback from PF "stargazing" community :)

I wonder whether:
1) do you use any UHC filter (or other narrowband filter) for nebula observations? If yes, which one?
2) what are your light-pollution conditions at your place?
3) what telescope aperture do yo have?
4) what would be your subjective comparison of the view with or without the filter

On my side:
1) So far I would probably buy something like Orion Ultrablock, nothing more expensive like Lumicon UHC
2) According to light pollution map, my place is class 4 in Bortle scale.
3) I've got 8" dobsonian
4) never tried one...

Sorry if this post looks like questionnaire, but I thought it could be interesting for all stargazers, not only me :)

Thanks for your replies

 

[sophiecentaur]

, I'd like to revive the topic about nebula filters,

From what I have read, I would think that most seasoned visual astronomers will have tried many different kinds of nebula filter (probably a drawer full of discarded ones) and spent a lot of money. 'The one you just ordered' will always be the answer to the maiden's prayer - maybe until you actually look through it - but ambient conditions differ from site to site, especially in town.
I reckon the only filters that really do what they are supposed to are the narrow band ones which are (necessarily) only for long exposure astrophotogtraphs.

 

[Drakkith]

I have a light pollution filter that I sometimes use. It seems to help somewhat, depending on local conditions. But it's not a significant difference. You'll probably get the best results if you're looking at emissions nebulas through somewhat narrowband filters since you can block out most of the light except for the emission bands you want to see. Unfortunately I don't have any narrowband filters designed for visual use, I only have them for my camera.

 

[glappkaeft]

I wonder whether:
1) do you use any UHC filter (or other narrowband filter) for nebula observations? If yes, which one?
2) what are your light-pollution conditions at your place?
3) what telescope aperture do yo have?
4) what would be your subjective comparison of the view with or without the filter

1. I used pretty much all of the visual narrow-band nebula filters. Which one works the best depends on what wavelengths the nebula emits, overall UHC and OIII are the best but if the nebula is mostly emitting H-alpha and H-Beta a OIII filter.
2. It was pretty good (similar to your I expect or slightly better especially at some star parties at darker locations) but then I moved and mostly stopped doing astronomy.
3. I have used nebula filter in telescopes from 9 to 60 cm. Most of it was with our astronomy clubs F/4 45 cm Newton and 38 cm Dobson.
4. That is one of those question that depends on a myriad of variables. Sometimes better, sometimes worse. Almost always different. Magnification and exit pupil might change the result. So will the nebula surface brightness and if there are variations in which emissions dominate in different parts of the nebula. For instance the Dumbell nebula can look very different depending on which filter you use (and different from using no filter).

 

[lomidrevo]

From what I have read, I would think that most seasoned visual astronomers will have tried many different kinds of nebula filter (probably a drawer full of discarded ones) and spent a lot of money.

yes I agree, it is quite easy to give in temptation when you are enthusiastic amateur :) It is almost one year since I am reconsidering the purchase of the filter because I really don't want to spend my money for something what I would keep unused in a drawer. Maybe I reconsider too much ...

 

[lomidrevo]

I have a light pollution filter that I sometimes use. It seems to help somewhat, depending on local conditions. But it's not a significant difference. You'll probably get the best results if you're looking at emissions nebulas through somewhat narrowband filters since you can block out most of the light except for the emission bands you want to see. Unfortunately I don't have any narrowband filters designed for visual use, I only have them for my camera.

Initially I was thinking about this category of broadband filters (LPR). They are not so expensive and theoretically they could be used for more deep-sky objects. But looking at the transmission graphs, majority of them seems too broad, maybe not that helpful in a suburb area.
I agree, it seems that narrowband filter should be more efficient for emission nebulas (planetary nebulas and HII regions are of my interest)

 

[lomidrevo]

1. I used pretty much all of the visual narrow-band nebula filters. Which one works the best depends on what wavelengths the nebula emits, overall UHC and OIII are the best but if the nebula is mostly emitting H-alpha and H-Beta a OIII filter.
2. It was pretty good (similar to your I expect or slightly better especially at some star parties at darker locations) but then I moved and mostly stopped doing astronomy.
3. I have used nebula filter in telescopes from 9 to 60 cm. Most of it was with our astronomy clubs F/4 45 cm Newton and 38 cm Dobson.
4. That is one of those question that depends on a myriad of variables. Sometimes better, sometimes worse. Almost always different. Magnification and exit pupil might change the result. So will the nebula surface brightness and if there are variations in which emissions dominate in different parts of the nebula. For instance the Dumbell nebula can look very different depending on which filter you use (and different from using no filter).

Oh, that doesn't sounds good you had to stop doing astronomy, is the light pollution so bad at your current place?

Honestly, I am bit afraid to jump directly to OIII filter, isn't it too much specialized? On the other hand, it could better suppress the light pollution... I found this link useful when comparing UHC and OIII filters - the guy was doing test with 4 types of filters on some popular nebulas.

Regarding the emission lines, it seems there are two groups of UHC filters. All of them transmit Hβ and OIII lines, but regarding Hα, some of the filters block the near-red band (eg. Orion Ultrablock) and some of them transmit it, including Hα (Astronomik UHC), comparison here. Do you have experience with both types?

EDIT: sorry, Lumicon UHC is blocking Hα line

 

[Andy Resnick]

1) do you use any UHC filter (or other narrowband filter) for nebula observations? If yes, which one?
2) what are your light-pollution conditions at your place?
3) what telescope aperture do yo have?
4) what would be your subjective comparison of the view with or without the filter

For me:

1) No.
2) Awful: urban conditions.
3) 5.5" refractor (400mm/2.8 telephoto lens)
4) N/A.