Green filter #58 vs solar continuum

[Piero]

As it seems a bit unclear how the two filters compare, I finally decided to get a SC filter and do the comparison myself!  Looking at the spectrum of the two filters, my bet is that the SC should show a bit more contrast as it is more a line filter than the generic green filter #58. (Please note that the SC is not a line filter.) The nice thing is that I will be able to fit these two filters on the barrel of my vixens so that I won't need to swap the filter between eyepieces every time.

Delivery from FLO should be within a week hopefully. Weather permitting, a report will come soon.  

 

p.s. Nice to see it's sunny today when they forecast rain all day. I wish the best to all imagers and observers who have the chance to catch / see the transit of Mercury on the Sun today. Looking forward to reading reports and seeing images!  

[Fozzie]

Should be an interesting comparison Piero, I've just picked up a SC and have found it to be beneficial, especially on full disk views over the OIII filter which was my usual option..

Have to say it is very green, but after a while the greenness does fade to the minds eye and turns almost greeny yellow..

Looking forward to your report!

Ta

Fozzie

[John]

I'm looking forward to your findings as well Piero

Unfortunately, due to cloud and light rain, my Lunt Hershel Wedge is unlikely to see action viewing the Mercury transit though .....

 

[Piero]

Thanks Gentlemen!  

I hope the expected delivery time from FLO is a large over estimation! (Available - Delivery 7-10 working days)  Really curious to see myself!

@Fozzie May I ask you what OIII filter did you use? I tried a few times my Astronomik UHC and OIII, and to be honest I MUCH prefer the views without filter rather than using one of those for solar observation. It seems the Lumicon OIII is quite praised among members for solar observation though.. I wonder whether these findings are down to preference or the different band lines between the two filters are actually the reason for so much difference...  ... My Orion green filter #58 (made in Japan) works well to my eye. There is a substantial difference between the views without filter and with that GF filter even at very high powers (180x). I hope this SC will outperform of course. I would have probably bought another green filter anyway, so at this point, it seems reasonable ( )  to get a proper SC filter!  

[Fozzie]

You can sir..

I've had both the "optics" branded skywatcher offering and now I've an Astronomik Oiii.. I actually found both to be quite usefull, however the astronomic is sharper than the skywatcher offering.

The SC to my eye is again marginally better..  Interesting I found the Astronomik UHC to be absolutely terrible, so much so I'm slightly worried about it's deep sky performance, as I've not had the chance to try it out!

I've noticed that with the SC when you first start observing it is VERY pea green, however it mellows a fair bit and after a while of useage..

I guess, and it's been said before, that were different in how we see things though our kit, some like some dislike the same things.. It's great fun finding it all out though!

ta

Fozzie

[jetstream]

5 hours ago, Fozzie said:

Should be an interesting comparison Piero, I've just picked up a SC and have found it to be beneficial, especially on full disk views over the OIII filter which was my usual option..

Have to say it is very green, but after a while the greenness does fade to the minds eye and turns almost greeny yellow..

Looking forward to your report!

Ta

Fozzie

Well there are 2 of us now lol! After viewing with the SC a bit the sun turns yellow to my eyes...

Edited May 9, 2016 by jetstream

[LukeSkywatcher]

13 minutes ago, jetstream said:

Well there are 2 of us now lol! After viewing with the SC a bit the sun turns yellow to my eyes...

It does also in my eye(s). You really get used to the funky green of the SC and dont notice it........even after maybe a 30 min session. The power of the human brain kicks in and tricks you into thinking the view is either yellow or even as if you are observing in white light.

[Piero]

The Baader solar continuum filter (SCF) arrived only today as it was not in stock. I had a chance to try it in the last 30 minutes and do some preliminary comparison between this filter and my Japanese Orion Green #58 filter (GF58).

The image is greener with the SCF than the GF58. To be honest, I started with the SCF and I only noticed this after replacing it with the GF58. The latter shows the Sun more like with a pale green/blue-green tint in comparison with the SCF. As far as contrast concerns, which is what all of us are interested in , there is an increase in contrast with the SCF. This is not huge, but is noticeable. I tested this with my 9mm and 5mm Vixen SLV twins. Granulation was possibly the feature which was more evident with the SCF than the GF58, but also the "eyelashes" on the penumbra region and faculae were a bit crisper with the SCF. All these features were not impossible to spot with the GF58, but they were just a bit less defined and clear. Right now it is quite windy outside (15km/h N), and although I am not an expert, I found that my GF58 shows granulation nicely when the wind is almost absent. The SCF showed somehow the same if not a bit more granulation now, in presence of wind, compared to the GF58, in absence of wind. I guess this is due to the tighter passing band that this filter has compared to the GF58. To me, the same seems valid for the internal lines on the penumbra region ("eyelashes"). Unfortunately due to the wind, I could not try 100x and 180x successfully, but considering my previous observations at these magnifications with the GF58, I would suspect the SCF will just outperform the former. So, how much can I quantify this improvement..? It is not huge, but is there. It is definitely not as near as the improvement one would get between filterless view and SCF/GF58. To my eye and under these medium quality seeing, if filterless is 0 and SCF is 1 a GF58 would sit at .75 . I know that the GF58 shows better views under good/excellent seeing. Hopefully the SCF will improve proportionally.

So, if one does not own any of these filters, I would recommend an SCF. It is better between the two and if the GF58 is bought, you will wonder about the improvement achieved with the SCF. If one already has a GF58 and only has little interest in solar observation, then I would not buy the SCT and just continue using the GF58 as this still does a good job to me at least. 

Overall, I am happy I bought it

Hope this helps.

Piero

[spaceboy]

Interesting comparison Piero. I went from a #11 & #12 stack to #58 to SC and felt the improvements were significantly incremental each time. Apparently some of our friends the other side of the pond consider a stack of #58 & OIII to be a nearer comparison to the views of the SC filter. What I have found though is a contrast booster filter makes faculae more apparent than the SC filter does. This said though apparently you can use various different filters on the sun to improve various features as you would on the planets. I think a #47 has also been mentioned at one time for improving the faculae.

In my personal experience, just as with night time observing, seeing can make all the difference. I have had moments with the SC filter in place where the solar surface has apparently dimmed. In truth it hasn't darkened at all but due to a patch of good seeing the surface detail has become so contrasted the granulation gives the impression in the eye that the sun has darkened because there is so much more detail apparent over the usually mild surface details. Again, as with night time observing those clear and calm spells in seeing are fleeting and few and far between.

[David Smith]

I am currently considering the Baader SC filter so this thread has proven very interesting.

Visually I am just using a #56 filter but have read recommendations for #21, #23, #25 filters to boost contrast in specific phenomena. Photographically I have seen both the #58 (for general use) and #80B (for "Polar Faculae") recommended. I cannot vouch for any of these recommendations as I have not tried any other than the #56.

 

[Steve Ward]

If you have an OIII or UHC in your box of Astro-trinkets then I would try them first , I use an OIII imaging-wise as a contrast/detail booster ... 

[michael.h.f.wilkinson]

Interesting comparison. The SC filter is indeed a more ideal band-pass filter than the GF58.  There are of course many factors that can influence perceived contrast apart from the spectral  shape of the pass band. Optical quality might be equally important. I must say I almost always use the SC filter for white light.

[laudropb]

I use the SC filter in conjunction with the Lunt Herschel wedge and I am very happy with it. I also have tried a polarising filter, but the SC gives much better contrast. I do not have any coloured filters so can not pass comment on how good they are, but I think I will stick to my SC anyway.