Do you really need a Nebula Filters to see Nebulas? Can you actually see the colour of the Nebula or is it just more cotrast but in B & W? Are they worth the money?
So far I have been trying to see Nebulas with little success. (I have a 12' dob)
I have only ever seen these 3 filters advertised for sale and that is the:
Astronomik OIII 2' by Bintel for $440
Sirius Optics 2' by Andrews for $179
Baeder 2' by York Optical for $210
Are they worth the money? does the $440 Astronomik filter provide better visuals then a $210 Baeder one? or Sirius Optics?
Hi Eardrum, go to the thread started on this forum by Asimov dated 23/09/05 which gives you a good overview of what members think of filters. this forum has lots of threads on filters. regards astroron
With a 300mm (12") Dob you should be able to spot many nebulae and with your size 'scope many of them will be very bright. Most nebulae appear green of grey thru a telescope. But the Orion neb (M42) may show traces of crimson red with a 300mm Dob at a dark site.
Nebula filters do indeed improve the visability of Nebulae but different viewers seem to have different experiences with them. These filters however don't bring out the colour in neb's they just allow the wavelengths of light that nebulae emit the most to be transmitted and block extaneous (ie non nebula) light. I personally have 2 filters. Lumicon OIII (oxygen 3) and a broad band filter (Its a lumicon filter but I can't remeber its name ). I really rate the OIII filter as it results in improvement on most emission and planetary nebulae.
The links section of this web sight will give you the details of retailers that will be able to help you with filters if you wish to purchase one but first, Find that first nebula, you wont be dissapointed.
Off the top of my newbie head, i can think of 4 nebula which i can see in my 10" dob without filters. I have little light pollution and so i am very happy with the nebula viewing.
lagoon in the milky way, tarantula near the large magellenic cloud, keyhole below the southern cross and the brightest is orion.
If you can wait up until 1am and you have clear skys, Orion is rising in the east.
Look for the saucepan and look at its handle. I suggest you take that as a reference point. I you can see the greyish clouds and are happy with that then don't bother spending heaps. If however you want to track down harder to see nebulas, go for it!. To get the lovely coloured version, well that is where long exposure imaging comes in. The eye can't see, but the camera can!
A nebula filter for me is low in priority, barlows and a really good eyepiece are next due to mars getting so big!!!
The NPB filter from DGM optics comes highly recommended and can be had for around $80 (1.25 inch) landed here in OZ. Mine's only just arrived so I can't give you any impressions, but Mike and a couple of other IISers have them and a recent US Astro mag review rated them very highly.
I used mine (DGM Optics NPB Filter) again on the weekend, in both my scope (10" dob) and hector (20" dob). I used it on the Tarantula (NGC2070) and a nice planetary NGC246 in Cetus.
On NGC2070, the filter showed wisps of nebulosity that couldn't be seen without the filter, with the tradeoff that you lose the view of the nice starfield next to the tarantula.
The view of NGC246 was substantially improved with the filter, giving more contrast and showing more detail than what could be seen without the filter. It gave an almost 3D appearance to the circular looking planetary. I'm very happy with mine, for AU$80 to my door. The 2" version is obviously more expensive, but still significantly cheaper than the upmarket alternatives (astronomik/lumicon etc).
As others have said, you don't need the filter to see the nebula, but when used, it can enhance areas that you can't see visually, as well as increase contrast to give a different view of what you could see before.
Filters will sometimes give you false colour, making things look greenish or blueish, depending on the filter.
From the look of things, it sounds like I can see nebulaes without the filters. I have defintely come across some small greyish "brush marks" in the sky but I wonder if those are nebulaes....
Iceman.... DGM NPB... what do these stand for and where can I get them for $80??? If the 1.25' is $80 I am guessing the 2' would be a whole lot cheaper as well.
What about the Sirius Optics or Baader ones that go for $180 or $210 respectively? Has anyone had any experience with these?
I will have to go for the 2' ones... only because I wear glasses and I sometimes find it hard to look into 1.25 inch eyepieces, especailly the small diameter ones like the 6.9 mm..., I almost need to look at it from an angle to see venus! Most times it really hard to see objects as it is very dim, and constant adjustment is needed to keep it in its FOV, with a dob it can be a real nightmare.
Speaking of 2'... what is the lowest 2' eyepeices thats available? The lowest I have seen is the 26mm..... I have not seen any 2' with better maginication than this....
As long as the price is relatively inexpensive, I wouldn't mind getting my hands on a 2' 6.9 mm for example....
I can vouch for the DGM NPB (narrow band pass) as well. I have very limited experience but I was amazed how well it worked from light polluted skies. It does not add colour to anything, it just dims everything except the light coming from gaseous nebulae. Well worth the $AU80 I paid for the 1.25". Ordered it from DGM optics, got it in under 10 days.
I will have to go for the 2' ones... only because I wear glasses and I sometimes find it hard to look into 1.25 inch eyepieces, especailly the small diameter ones like the 6.9 mm.
I think you have the impression that 2 inch format eyepieces automatically come with longer eye relief. This isnt the case.
Examples of 1.25" eyepieces with long eye relief:
Pentax XL and XW, Vixen lanthanium, Televue radian, ED2 eyepieces, Synta LER.
Eyepieces in 2 inch format are usually longer focal length, which normally means longer eye relief but its not always the case.
The Meade UWA eyepieces have quite short eye relief.
I have an impression that 2' eyepieces are (if everything remains constant) better than the 1.25' eyepieces.
hence a Widewview 15mm 2' will look better than a wideview 15 mm 1.25'.
When ever I look through my 2' compared to my 1.25' the view appears alot brighter, the 1.25 ones just looks dimmer.
I am currently thinking of which barlow to get... a 2' one or a 1.25'.
Lately I 've been having lots of cloud, so have not been able to see much. I do want to see Davidpretorius' nebula before I make a decision on going for the filters.
Judging from your responses, the DGM ones look like the ones to go for. For both its price and its quality
The brightness difference is not due to barrel size but focal length. Lower magnification (longer focal length) gives a brighter the image because more light is illuminating the same apparent field (image plane).
You only need the 2" format for EPs with longer focal lengths and wide apparent fields of view. The 2" allows for a larger field stop needed by longer focal length wide view eyepieces (approx FL>23mm, AFOV=70deg). Otherwise it makes no diff. It's like putting a larger diameter dew shield on your scope, or a bigger chrome pipe on the end of your exhaust pipe. Might look more impressive but does nothing for the performance.
The 1.25" format is more versatile, with cheaper accessories (filters, barlows etc). If you ever decide to get into binoviewing then you'll almost certainly want 1.25" EPs.
What about the Sirius Optics or Baader ones that go for $180 or $210 respectively? Has anyone had any experience with these?
A review of 20 or so filters in the August issue of Astronomy put the DGM NBP well ahead of all others tested, including those you mention. The second highest rated was Orion's nebula filter. But it's worth keeping mind that this is just one (experienced) reviewer's subjective evaluation.
Eye relief is important for me as I wear eye glasses so I am thinking anything above 15mm eye relief for my next eye peice.
Focal length determines the brightness, can you get a high magnification eye peice with high focal length? or are they negatively correlated?
Its hard to find the focal length of eye peices as the online shops like Bintel and Andrews don't give such information.
I am considering the one below....
<TABLE cellPadding=1 border=0><TBODY><TR><TD class=ProductDescription vAlign=top>Meade 5000 06.7mm (1.25") </TD></TR><TR><TD class=desc vAlign=top>The new six and seven element Series 5000 Ultra Wide Angle eyepieces deliver extremely high resolution, contrast and full-field sharpness over an astounding 82° apparent field-of-view.
Is this good? It has 15mm eye relief, but it doesn't say the FL so i am not sure as to how bright the image will be....
and the price is like 1/3 of my scope?!?!?!? Is it worth it to spend so much on an eyepeice?
Is there a cheaper alternative I can get which offer similar results?
I am about to get a list of as many eyepieces that will be there at snake valley and who will allow me to look at and review from my noobie status.
List the ones you are looking at, the details like eye relief you are looking for and i will do my best to check it out at what is a great opportunity to review lots of great equipment.
After reading treads and calling up shops for advice... it seems that there are different eyepieces that will work well with different telescopes. Some eyepieces that will work well with the SCT will not work well with the dob and so on.
I spoke to someone at Bintell and as I ask them what they thought of a 4 x powermate and a number of 2' eyepeices (26mm, 30mm, 40mm etc...), and he said that I would not be happy with the image. He said that for a powermate to work, i would need to get high quality eyepieces.
Guys, any thoughts on this?
My original thought process was to get a powermate x 4 and then get some cheaper 2' eyepieces. To save cost overall. Instead of getting many wide view 1'25 eyepieces which will cost me more than the scope at the end.
Now it looks like that is not even going to work... I'm so confuse as to what eyepieces I should get now.......
Davidpretorius I wouldn't even know which eyepieces to list for you now... it seems that different eyepeices work well with different scopes.
Visual use a 2X barlow is nice, IMHO forget the 4X unless you want to do imaging. I purchased a 2" 30mm EP recently to see what all the fuss was about. Perhaps it's an aquired thing to get used to or something because I just didn't like the views. Sold it. I like my 1.25" 24mm ultima best for wide view low mag viewing.
Perhaps if I looked thru a high end 2" my opinion would change. My experience on this subject is limited.
Are they worth the money? 
). I really rate the OIII filter as it results in improvement on most emission and planetary nebulae.
