About filters and unmodified cameras (nebulae and solar)

[Janer_2]

For starters I've got a Sky Watcher ED 80 and use an unmodded D800, I shoot from Bortle 2/3 skies mostly and haven't applied any filters so far. I have a SA 2i PRO and a HEQ-5 mount.

Nebulae filters

I've read a bit about the use of filters for capturing nebulae and the views are divided when it comes to unmodified cameras it seems. One camp say that it's useless and the other believes it can enhance the images by applying a stack of Ha captures as a layer in PS in PP. Has anyone on here actually tried using a Ha filter with a stock DSLR?

Most of these filters are quite expensive, at least the clip in ones which would be nice since it allows me to use regular lenses as well. The 2" filters are more affordable.

UHC

Commonly I see that Ha filters is the way to go first. If I understand it correctly a UHC filter will improve signal to noise ratios by blocking out artificial light - but not really enhance the nebulae otherwise?

I'm thinking that perhaps an omegon 2" UHC filter or a Explore Scientific one might be a good investment to really tone down any disturbing light sources. Only negative is I would then need a 2" one as well as one(s) that would fit my regular lenses.

H-alpha
If I apply the Ha filter to my setup, would this effectively mean that exposure times need to be increased? It seems logical since the collection of light on that specific band would be the same, only excluding all other light sources, so for it to be of any use and bring out nebulosity it would need longer exposures thus perhaps require guiding.

I haven't tested my HEQ-5 yet seeing as there's no dark skies atm so I'm not sure how long exposures I'll manage to get from it without any aids. Seeing as I've pretty much ruled out getting a clip in filter I've been looking at the cheap 2" ones like Lumicon.

I actually noticed Lumicon has lens filters as well.

H-beta

Are these mainly for observing?

OIII

Again, same as the others but different wavelengths ?

Multi bandpass

I'm not sure how much I'll part with in order to experiment with filters on my unmodded setup, besides the UHC filter perhaps, but are there any filters that combine the typical narrow Ha and OIII filters? Would this be the Optolong L-Pro? If so then maybe a 2" UHC and the Optolong would be my best bet.

Sun filters

More of a "why not" or "nice to have". It would be cool to photograph the sun although I haven't found a inexpensive filter suitable for 80mm on the page I usually buy this stuff from. Worst case I could always 3D print one and buy solar film/foil to apply. I know, inexpensive filters are frowned upon - but in this case I'd only consider getting something cheap to play with first.

Without the reducer my setup is only 600mm so I know it's not bringing me close enough to get much detail probably, but have anyone tried the cardboard cutout filters from Explore Scientific?

Sorry for the long post, I find the range of filters as a bit of a jungle to navigate through.

 

[AstroVagabond]

My only thought is take a moment and ask yourself do you see purchasing a dedicated cooled astro camera in your future.

If yes, then purchase filters and maybe a filter drawer today that will meet your needs now and in the future.

I moved from my DSLR to a dedicated cooled astro camera. I actually have two. One is an ASI294mm pro monochrome camera and one is an ASI533mc pro one shot color camera.

I have an 8 position filter wheel. I have a luminance filter, R, G, B, Ha, SII, OIII, and Optolong L-eXtreme.

You are fortunate to be able to image under Bortle 2/3 skies. So blocking skyglow is not as much an issue for you as it is for me under Bortle 7-8 skies.

I learned about LRGB and narrowband filters by purchasing Charles Bracken's Second Edition "The Deep-Sky Imaging Primer". In particular pages 67 - 70.

If you don't have that book, which is about $35, you might want to consider a purchase.

 

[Tristimulus]

Unmodded cameras:

The red, green and blue filters of the Bayer matrix limit which wavelenghts of light will hit the image sensor. Add the UV-IR block filter and the Bayer matrix is opaque to wavelenghts byond the visual 300-700 nm range.

Only 1 out of 4 pixels are sensitive to red light. The sensitivity for Ha is low. Better use a monochrome camera for Ha.

I am a fan of unmodded cameras and one shot color astro cameras. The main benefit in my case is that I can grab it all in one go. Perfect for my lousy conditions. But I miss out the fun with all those dedicated astro filters.

 

[Janer_2]

My only thought is take a moment and ask yourself do you see purchasing a dedicated cooled astro camera in your future.

Short answer, yes probably. I've been looking at them for two reasons really, better results and I'd like to avoid having my DSLR hanging outside in various conditions.

If yes, then purchase filters and maybe a filter drawer today that will meet your needs now and in the future.

I moved from my DSLR to a dedicated cooled astro camera. I actually have two. One is an ASI294mm pro monochrome camera and one is an ASI533mc pro one shot color camera.

I have been looking at ZWO's, both the ASI 533 series and ASI 183 series, leaned towards the color cameras just to save myself needing any filters and the added work. How do you find the difference between them?

I have an 8 position filter wheel. I have a luminance filter, R, G, B, Ha, SII, OIII, and Optolong L-eXtreme.

You are fortunate to be able to image under Bortle 2/3 skies. So blocking skyglow is not as much an issue for you as it is for me under Bortle 7-8 skies.

That's true, it wouldn't be a necessity as such, but if a filter could noticeably reduce the effect of artificial light even for me I would be considering it. I reckon it could come in handy for really wide field shots with a foreground. Whenever I gear up in my own backyard there are street lamps and houses in near proximity, so it probably would help a bit.

I learned about LRGB and narrowband filters by purchasing Charles Bracken's Second Edition "The Deep-Sky Imaging Primer". In particular pages 67 - 70.

If you don't have that book, which is about $35, you might want to consider a purchase.

I have a list of things I want in the future, mostly this comes down to a dedicated astro camera, a guide camera and possibly the polemaster. Adding these would set me back more than I could prioritize for the time being, and I do realise I'm kind of jumping the gun as I haven't tested my HEQ-5 setup yet. But I'm planning ahead, and all of these aids seem like a necessity at some point. I have to admit that I have only looked into esteemed brands like ZWO and QHY though. There might be good/cheaper options out there.

 

[Janer_2]

I've been looking at dedicated cameras and guiding for some time now. With it comes a lot extra bits and bobs that are either needed or can simplify the operation. This is the list of gear that I've narrowed it down to for now, leaving a dedicated camera out for now due to cost since I'd prefer a mono with filters rather than getting a color camera and not getting the results I want:





Guide camera - As cheap as it gets I reckon, undecided on whether I'll go mono or color, but I reckon the color one will do in my case.

Adapter - I intend to use my 50mm finder scope (came with my ED80) as a guide scope.

USB Direct - This will let me control the mount from PC bypassing the HC.

USB Control HUB - Powered USB HUB to connect the guide camera, mount, DSLR and one dew heater (do I need a heater for the reducer as well?). Simplifies everything and I only need one cable to go to my laptop.

Solar filter - Just a cheap one to be able to get some solar shots.



So, if I decide to get these additions to my mount I should be able to control most of the process via my computer, except from focusing is that right? If I choose to still use my intervalometer I could also attach a second dew heater if need be.

 

[G Dickson]

Probably doesn't matter much, but a mono guide camera will be slightly more sensitive than a colour. Also if you are imaging with a laptop then you could run NINA or similar software with polar alignment routines and avoid another purchase - you mentioned a polemaster in an earlier post.

 

[Janer_2]

Probably doesn't matter much, but a mono guide camera will be slightly more sensitive than a colour. Also if you are imaging with a laptop then you could run NINA or similar software with polar alignment routines and avoid another purchase - you mentioned a polemaster in an earlier post.

--
Gilmour

Yes, I've tossed the idea of adding a polemaster or the likes of it. Spent most of the weekend evenings watching setup guides and realised it would be obsolete, which really just gives me another reason for getting a guide setup.

Tbh the only reason I'm hesitating is that I have to keep my laptop connected. Mostly I have to shoot during winter and biting cold. So keeping a window open isn't very tempting. I've read that the Asiair only works with CCD cameras and the wifi hotspot is a lot slower than USB.

 

[andresch]

Tbh the only reason I'm hesitating is that I have to keep my laptop connected. Mostly I have to shoot during winter and biting cold. So keeping a window open isn't very tempting. I've read that the Asiair only works with CCD cameras and the wifi hotspot is a lot slower than USB.

That was my thinking exactly, I did not want to leave a laptop outside. I went with the Asiair instead. There are quite a few Nikon and Canon DSLR/DSLM cameras compatible wit the Aisiair. You are correct tough, the WiFi is not great... But you can connect it trough Ethernet.
I would consider the Asiair as a good option. Around the same price as the pegasus box with the same features but with built in RPi. The software is easy to use, everything included. But you limit yourself to mainly ZWO products, that's the caveat...

 

[Janer_2]

Tbh the only reason I'm hesitating is that I have to keep my laptop connected. Mostly I have to shoot during winter and biting cold. So keeping a window open isn't very tempting. I've read that the Asiair only works with CCD cameras and the wifi hotspot is a lot slower than USB.

That was my thinking exactly, I did not want to leave a laptop outside. I went with the Asiair instead. There are quite a few Nikon and Canon DSLR/DSLM cameras compatible wit the Aisiair. You are correct tough, the WiFi is not great... But you can connect it trough Ethernet.
I would consider the Asiair as a good option. Around the same price as the pegasus box with the same features but with built in RPi. The software is easy to use, everything included. But you limit yourself to mainly ZWO products, that's the caveat...

It seems to be out of stock everywhere atm, not surprising all things considered. I'm mainly looking at ZWO for now anyways, mostly because the slightly cheaper brands can be hard to find any good reviews for. Also the website I'm looking at, which is convenient considering import/VAT and a site I trust, don't have too many alternatives spec wise.

Mostly that is regarding the camera for imaging, I pretty much decided to stick with my stock D800 until I can justify getting a cooled mono camera - in stead of getting a cooled/uncooled MC camera and not being satisfied. There really should be a side by side test of DSLR vs MC vs MM, maybe I've just not found it yet.

 

[G Dickson]

I found going from my DSLRs (6dmkii and R6) to a cooled one shot color camera a huge step up. But I should point out that I image under class 1 skies so don't have to deal with cutting through light pollution.

 

[Janer_2]

I found going from my DSLRs (6dmkii and R6) to a cooled one shot color camera a huge step up. But I should point out that I image under class 1 skies so don't have to deal with cutting through light pollution.

 

[danny006]

You can get great images with a OSC camera too. I recommend using a duo narrowband filter like the L-eXtreme or Antlia ALP-T for emission nebulae and supernova remnants, even in dark skies. For galaxies you can't use these filters. With these filters you can image in heavy light pollution. Take a look at this comparison .

For polar alignment you can use Sharpcap pro which is very easy to use and you can use your guidescope.

A modded dslr captures a lot more Ha red color and many nebulae have this red color. I would go for a cooled astrocam. Because of the cooling you can make your darks and biases at any time you like and you can reuse them. You also get less noise at lower temperatures.

--
http://alexalpha.wix.com/alex-birdpictures

 

[AstroVagabond]

I've read that the Asiair only works with CCD cameras and the wifi hotspot is a lot slower than USB.

The ASIAir and ASIAir+ will not work with non-ZWO products. Having said that, the ZWO product line is robust and many astronomical imagers who view my YouTube channel are always encouraging me to move to the ASIAir+.

I own both the ASI294MM Pro monochrome camera and the ASI533MC Pro one shot color camera. Great products for sure.

Having started with a Canon 6D DSLR where I then moved to a cooled astro camera I'm biased about the importance of using cooled cameras. However many great images are produced using DSLRs.

Right now I prefer to stay with an open system approach as I may want to use non-ZWO products with my next scope where the focal length will let me image galaxies.

Based upon personal conversations and the comments I get from my viewers they are highly satisfied with the ASIAir+ and how easy it makes their imaging efforts.

As to the QHY Polemaster, I own one. Since I'm a traveler I use it to rough in my polar alignment and then refine that alignment using N.I.N.A. Three Point Polar Alignment plugin. The sites I travel to allow me to see Polaris.

While this is a work in progress here is an early iteration of one panel of a two panel mosaic of the Cygnus Loop captured with my ASI294MM and a Ha and OIII 3nm filter.







I have much more work to do in PixInsight before this two panel mosaic image is complete.

~ Bill

 

[Janer_2]

Thanks again for the replies, and awesome photos Bill! One of the many objects I would love to shoot myself some day.

I'm currently waitin on my latest order which contains some bits to turn my finder scope into a guide scope as well as a ZWO ASI 120mm color camera and a Baader 80mm solar filter.

I figured that should keep me entertained for a while until I jump onto a dedicated camera sometime in the next year or so. I'm determined to get a cooled camera at some point, preferrably mono - but cost might play a part so I've decided to hold off on making a purchase.