Lacerta solar wedge (2"/M54) for white light observing

[Victor Boesen]

This thread will consist of my impressions of the 2" (M54) Lacerta solar wedge with the Brewster angle prism. This includes observing through it, build quality and other aspects I find important

Build quality
I received the bare prism so the final verdict may vary for different units/combinations of accessories, but I'll try to focus on the wedge only.

The metal construction of the wedge feels very solid, and the large heatsinks on the rear end of the wedge don't feel too large, nor too small to the point where they would essentially be unnecessary. The angle of the Herschel prism itself can be adjusted with screws on the side of the wedge, and these don't seem to go loose or move the slightest when shaking the wedge.

The wedge clearly shows its infamous "Brewster angle" which I will eventually add a comment on later in the post.

I went for Baader equipment for the threads, for which I purchased an M54 to 2" clicklock clamp and an M48 to 2" nosepiece with safety kerfs*.
Furthermore I also use a 2" to 1.25" eyepiece adapter in which I have a Baader ND3.0 filter permanently mounted.

The entire wedge with the chosen accessories is quite large compared to a regular night time 2" diagonal!

The entire body including accessories ends up being quite large, but the feeling is very sturdy!

*The nosepiece is quite short, but I haven't had any problems with it and it feels secure in the focuser of my telescope.

Observing with the prism
The prism was used together with a 4 inch F7 apochromatic refractor and Explore Scientific 82 degree eyepieces.

I have only done a small amount of white light observing before including brief looks in SCT's, Cat's and my own Evostar 72ED with Baader white light film. It has never really caught my interest properly, but after getting hooked on solar with a Daystar Quark I couldn't help it, when an offer on a Lacerta wedge came up. After I had overcome the fear of pointing my 4" apo towards the sun, verifying the prism was in place together with the ND3.0 filter, I immediately noticed how bright the view was by just looking at the glass of the eyepiece and not through it!

You may notice my eyepiece is not all the way into the focuser. This is because the polarizing filter would otherwise hit the ND3.0 filter in the 2"-1.25" adapter. This is not a problem without the polarizing filter.

I placed a variable polarizing filter in the eyepiece and rotated the 2" to 1.25" adapter by simply loosening the clicklock slightly until the view was comfortable. This rotating mechanism works surprisingly well. Focusing on the solar limb I noticed a small active region in the center of the disk, which looked like a small colony of islands consisting of small umbras with faint gray penumbras. Limb darkening was also visible and some faculae towards the edge of the limb. I added a 2" OIII filter to the ND3.0 filter (acting as a solar continuum filter) and this reduced the brightness noticeably and faculae across the disk became visible. Adjusting the brightness with the polarizing filter in my 14mm eyepiece (51X) I could begin to see more faculae and granulation was also visible.

Two small sunspots visible on the 8th of July 2021 together with faculae just below the left sunspot

I found that low magnifications made it easier to observer the low contrast faculae, which I assume is due to a larger exit pupil. This meant I preferred keeping the magnification at around 50-80X, although I have yet to observer larger sunspots, so that might change my preference. I do see a zoom eyepiece coming in handy for white light, but funds are currently limited

I really enjoy the wedge and the view is very sharp with granulation, faculae and small sunspots easily observable at low magnifications. I really like being able to rotate the 2"-1.25" adapter to dim/brighten the view, and my OIII filter helps a bunch. Can't see myself observing without it, but I still think a 2" solar continuum filter is quite pricey for a single filter which may not perform much better than my OIII filter. I look forward to observer larger sunspots as I just barely missed AR2835

Final notes

The thing I'm most skeptical about is the open bottom of the wedge. I know this cools the prism a lot more efficient, but I have a slight OCD towards dust and speckles on optical equipment Another thing about the open bottom is the risk of burning yourself. I haven't done this yet, but I usually grab the diagonal, when nudging my scope to follow a target, and I could definitely see myself sticking my fingers too far into the prism housing at some point.
Together with the heat sink on the back, however, the prism stays nice and cool when observing with my 4" refractor. I even have difficulty feeling the slightest heat from the heat sink, which I find very reassuring!

Need a lighter? The Lacerta wedge got you covered!

The Brewster angle of the prims means that this might not be for everyone. If you're living far north/south - no problem! But, due to the angle of the prism you can risk having the need to observe with the eyepiece pointing towards the ground. Not only can this be uncomfortable, you would likely also need a taller tripod/mount. This feature is something that should not be overlooked since it can result in some uncomfortable yoga positions at the eyepiece.

If you're not looking into getting special adapters or not good with/don't want to worry about thread dimensions and adapters the naked Lacerta wedge body might not me for you. Instead I'd get the complete "set" which includes all the necessary adapters, or you can get something like the Lunt or more pricey yet highly coveted Baader wedge.

As the final note I'd like you to take my opinion with a grain of salt. As I briefly mentioned, I have never been a keen white light solar observer, and I can't compare the Lacerta wedge to any other wedges out there. I can only say that I'm very satisfied with mine, and I'm a huge fan of the build quality and ability to use this wedge in many other scopes of larger apertures due to its great dispersion of heat. I am definitely not disappointed with my purchase and I must confess I really like white light observing as well as H-alpha since the granulation and faculae are quite interesting features to observe together with sunspots of course!

Thanks for reading!

Victor

[johninderby]

Actually the open bottom is no problem heat wise. No heat escapes out the bottom and even when accidentally sticking a finger inside nothing happened. Maybe if you held your finger inside for a while? 🤔

You don’t have to worry about dust or dirt getting on the back of the prism as the rear surface of the prism isn’t a part of the light path you look through. 

You might want to read this review.

https://fullerscopes.blogspot.com/2019/02/lacerta-lac2s-2-50mm-herschel-prism.html

https://fullerscopes.blogspot.com/2019/02/lacerta-lacs2-brewster-angle-herschel.html

Edited July 8, 2021 by johninderby

[Rusted]

Thanks for the excellent review. I find myself in general agreement.
I have had a Lacerta 2" wedge for quite a while and used it on my 7" f/12 iStar refractor.
Now occasionally on my 6" f/10.
The heat sink gets hot with these larger apertures.
Optical quality seems fine.

The Brewster Angle is insignificant if you have a camera attached.
Not so good visually in high summer with high solar altitudes.

The Lacerta rotating adapter system is valuable for a polarizing filter and works really well.
The downside is the available, internal depth for multiple filters. The Solar Continuum plus polarizing plus ND. 
The downside is the darkness when you forget to turn the polarizer to match your brightness needs.
You can find yourself winding up the gain in SharpCap until you realise your error.
[Probably an age related error when WL isn't a major interest.]

The open bottom is valuable for centring the sun. I often tilt the prism so I can see inside when first setting up.
The inside of the heat sink gets quite a tan after many hours of tracking the sun.
But then many black anodized surfaces do.

[Victor Boesen]

17 minutes ago, johninderby said:

Actually the open bottom is no problem heat wise. No heat escapes out the bottom and even when accidentally sticking a finger inside nothing happened. Maybe if you held your finger inside for a while? 🤔

You don’t have to worry about dust or dirt getting on the back of the prism as the rear surface of the prism isn’t a part of the light path you look through. 

Haven't had my finger in there yet So perhaps I would feel it in time before things get too serious, but I think it'd be too stupid to even try it out "for fun"😅 I'm aware the backside of the prism doesn't really mattere as far as performance and dust goes, dust and fine surfaces aren't my thing anyways. Good thing I don't wear glasses!

[johninderby]

I have the stock rotator on the top with the ND3 and variable polarising 2” filters screwed to the bottom and a ZWO T2 to 1.25” filter adaptor screwed into the bottom of the T2 adaptor for the continuum filter.

Edited July 8, 2021 by johninderby

[Victor Boesen]

11 minutes ago, Rusted said:

I have had a Lacerta 2" wedge for quite a while and used it on my 7" f/12 iStar refractor.
Now occasionally on my 6" f/10.

Would love to have a look through such apertures! Must be quite a view under good seeing

[Victor Boesen]

1 minute ago, johninderby said:

I have the stock rotator on the top with the ND3 and variable polarising 2” filters screwed to the bottom and a ZWO T2 to 1.25” filter adaptor screwed into the bottom of the T2 adaptor. 

That's quite a long optical length! I could imagine you'd have trouble reaching focus in some telescopes? It's a really nice solution for keeping filters permanently in the wedge though;)

[johninderby]

1 hour ago, Victor Boesen said:

That's quite a long optical length! I could imagine you'd have trouble reaching focus in some telescopes? It's a really nice solution for keeping filters permanently in the wedge though;)

Fortunately in my Tecnosky 125 infocus travel is no problem even with the 2” extender still mounted on the focuser. Wish more scopes would come with a removable focuser extension for those using a wedge or binoviewer. 

Edited July 8, 2021 by johninderby

[Rusted]

Here is the Lacerta 2" wedge on my 7" f/12 with the 6" f/8 [H-alpha.]
Together on my home made mounting in my home made two storey observatory. A couple of years ago.

Larger instruments need very steady seeing to maximise their usefulness.
My Vixen 90mm f/11 with Lunt 1.25" wedge can give the illusion of a sharper image.
Until I need far more reach [power] to make a small detail visible. 

Yesterday there were a few small spots on a disturbed area in the far NW. AR12840[?]
So I used the 2" Lacerta, ASI174 and 2x Barlow on my 6" f/10 to show it.
The seeing was poor so 3m of focal length wasn't going to be razor sharp.
The curvature of the solar limb shows the scale of the image.
The 7" is waiting to be remounted on a home made cross-axis. under a new dome.

Edited July 8, 2021 by Rusted
added image

[Stu]

Great report @Victor Boesen, glad you are pleased with the wedge. I must say I do love white light observing. The contrast, sharpness and fine detail visible can be amazing when conditions allow. Don’t rule out (I know you haven’t) using higher powers. When conditions allow, there is plenty to be seen at x150 or even x200, bringing out the detail in large ARs and the granulation.

Somewhere in my garage I have an old 6” f10 scope which I intend to use for both Ha and white light solar observing when I get around to it.

[Victor Boesen]

54 minutes ago, Stu said:

Somewhere in my garage I have an old 6” f10 scope which I intend to use for both Ha and white light solar observing when I get around to it.

Thanks Stu! Wow 6" will be nice Will you be using it with a quark for H-alpha or the PST mod?

[Stu]

7 minutes ago, Victor Boesen said:

Thanks Stu! Wow 6" will be nice Will you be using it with a quark for H-alpha or the PST mod?

The intention is to use it as a big PST primarily, but I would like to be able to pop the Wedge in it too to see what it’s like. It was a somewhat irrational eBay purchase a while back, no idea how good it is optically but hopefully will be ok.

[Victor Boesen]

1 hour ago, Stu said:

The intention is to use it as a big PST primarily, but I would like to be able to pop the Wedge in it too to see what it’s like. It was a somewhat irrational eBay purchase a while back, no idea how good it is optically but hopefully will be ok.

Sounds interesting! Look forward seeing more about it in the future. Perhaps in the following summer days?

[Victor Boesen]

Reaching focus with the Skywatcher Evostar 72ED and the 2" Lacerta wedge

A couple days ago I began to worry I wouldn't be able to reach focus with my Evostar 72ED and a quick experiment confirmed that I couldn't reach focus and I needed inward focus. I then remembered I had purchased an M54 to M48 adapter a while ago for my OVL field flattener to be mounted directly onto the focuser tube of the Evostar. I replaced my baader click lock with the adapter and it threaded perfectly in the thread of the Lacerta wedge.

With my eyepiece that requires the least outward focus I'm then left with 0.55mm of spare inwards travel subtracting the 5mm optical length of the adapter. Call that a close call

This is by no means an ideal solution to this, but since I'm mostly going to use the wedge with my 102mm F7 refractor I'm not in a rush buying adapters to decrease the optical path length of the wedge/system. I figured I'd share this solution as some may find it good to know that this specific adapter can be useful with the Lacerta wedge.

Victor

Edited July 15, 2021 by Victor Boesen

[johninderby]

Infocus travel is a headache with a wedge with many scopes. Wish all scopes had a removable focuser extension for when you need more infocus.

 

[Rusted]

My focuser extension is called a hacksaw. 

[johninderby]

Been there with a couple of scopes. 🙄

[Victor Boesen]

4 minutes ago, johninderby said:

Wish all scopes had a removable focuser extension for when you need more infocus.

 

That would be great! But I guess I really can't ask for more in a scope I got for 269£

4 minutes ago, Rusted said:

My focuser extension is called a hacksaw. 

Don't even make me consider

[Highburymark]

Great report Victor. I had the 1.25” Lacerta wedge and thought it was excellent. If you have access to any Plossls or orthos you might find them slightly sharper than widefield eyepieces, although some widefields do work well. 

[Victor Boesen]

46 minutes ago, Highburymark said:

If you have access to any Plossls or orthos you might find them slightly sharper than widefield eyepieces

Thanks Mark! I find my ES 82 degrees work quite well but haven't tried anything else so can't tell for sure I consider buying a Baader Hyperion zoom with the 2.25X Barlow for white light and some night time observing, and my impression is that it's highly coveted among white light- and H-alpha observers and for binoviewers.

And who knows, perhaps I can get a pair of them in the future and stick them in a binoviewer

[Gemineyes]

I wish to thank Victor for his SUPER idea with the Baader M54i click lock! I recently got a Lacerta LAC-2s, and first tests were SUPERB!!

I have a ZWO M54 (12.5mm extra spacing) and M54-M48 insert ring coming later in the week. This will effectively give me more spacing for use in the wedge. I can then rotate the collar to tune brightness as well. I plan to use my spare Baader 2" ND3.0 for now but may remove the Lacerta ND3.0 out of the housing and put into a new empty cell. I find the Lac2S has more travel for me right now, compared to the Baader Wedge I have also,  so I can easily accommodate 12.5-15mm and still have more in-focus travel in most of my scopes. NICE. See below why, but sometimes I stack an additional filter with achromats. 

 

My scope test was with my Stellarvue 90mm BVT APO (f/7, 630mm f.l.) - mounted on a Skywatcher AZ5 on a Oberwerk TR3 Maple tripod - SUPER setup for general solar/lunar! Anyway, I was using my Baader wedge this past weekend, at about the same time, and just got the LAC-2s yesterday. It was overcast until lunchtime, and then wow! What a view! I used my insert in the C-L adapter with an APM 15mm UFF (65 degree, 42X in this scope)...

 

Granulation and plage REALLY pop in the Brewster wedge! I think - more work to do, but think - there's more detail in the Lac2s versus the Baader due to the more complete polarization. WOW! Just awesome. 

 

I plan to use this with several APOs (80/90/TMB105), and my ST120 (which does amazingly well with a SA filter behind the polarizer in the wedges I have) and my TSO 152RFT, which also is AMAZING on Sol, at least in the Baader wedge. (with exceedingly low chromatic levels - read: faint sliver of blue/mauve, off axis, and nearly none on-axis). 

More to come! 

 

Darren H

Edmonton, AB Canada

 

[Gemineyes]

Okay: Update....

I have added a TS Optics M54 (15mm) extension tube, which has an open aperture of 51mm. This allows with my Baader Clicklock (M54i like Victor's) to have extra clearance in the Wedge housing. Allows up to 3 for sure, and possibly 4 x2" stacked filters. Not that I will do THAT, but it is possible. I will be using the ND3.0->2"Polarizer->2" Baader SA for my ST120 and TSO 152RFT (Achromats), and the ND3.0->2"Polarizer in my Apos. I can opt for using my 8nm 34mm D-line filter in line as it is a bit thicker, but have not checked fit yet on that (8mm thick housing) - gives an image similar to Ca-K, but Yellow (in D-line Na/He light) 

Here's my first run on Sol using only the Baader M54 on it... worked amazingly well before I got the extra kit for it!

Visual setup was a Stellarvue SV90BVT f/7 APO, using the Lacerta Brewster Wedge, Baader ND3.0+Hoya L-Pol filter, with a TS Optics UWAN 13mm EP (48.5X):

I am thinking that this solar continuum system works on par, or IMO slightly better (by a hair) than my Baader Herschel Wedge. VERY close, but I just feel that it is has a bit more contrast - certainly both do, but the Plage and depth of granulation seems just a bit more prominent. Just when I thought I'd hit a wall, this unit comes along! LOL. 

 

Darren

[Gemineyes]

I have several wedges, the most recent one as of last week is the new Lacerta 2s Brewster angle version. Just got it, as mentioned above. 

 

I'm going to add hopefully some useful physics and math - However, the math is pretty easy. It is easiest to use OD (optical density) addition and subtraction for these types of calculations as they are logarithmic:

OD = -log(T);

where OD is the optical density, and T is the transmission.

So, if I have 10% T, or 0.10 T, I have OD=1.0, and the larger the OD, the dimmer the image. Ideally, one should be in the OD5.0 regime for safe visual use. One can employ an additional ND filter after the ND3.0 (in leu of a polarizer) to reach safe levels, and I'll discuss this later below. There are some significant differences between a "standard" Herschel Wedge and the Lactera Brewster Window type of solar filter. We will start by discussing the differences between the way these two reflect light:

 

https://rmico.com/re...-light-tutorial

 

Has an excellent succinct coverage of this topic. Especially the reflection/polarization "depth"; I include the picture of the graph here for illustration (will be relevant in a moment):

As can be seen in this graphs, we get a noticeable difference in the S-polarization off the surface. at 45 degrees, there is a difference as well, but only PARTIALLY - thus when using a polarizing filter, we cannot totally cross-polarize to nearly null out the light. this is why standard (Baader/Lunt/APM etc.) Herschel wedges have a narrower range of brightness control, and also why they have a lower reflective transmission (OD ~1.35-1.40, or 4.5% approx.) off the wedge's surface. (not including the OD3.0 post-filter)

 

A Brewster Wedge or plate, being at the Brewster angle, effectively nulls out one polarization, and reflects the other - also, at this angle, the S-pol light is reflected better, and hence why a Brewster Solar wedge (like the Lacerta units) pass closer to 8.5%, or OD ~1.07. (again, sans ND3.0 post-filter).

 

Given the above, this explains why the Lacerta Brewster Wedge has a much wider brightness range; one can go from VERY bright (WAY too much/unsafe for visual!!) to below what might be available for a standard Herschel Wedge system. Okay - now... can one just employ a ND filter after the Wedge/Plate + ND3.0? Absolutely! so long as you keep in mind you want to be in the OD ~4.9-5.5 range, all safe and good. (so, this is approximately achieved in a Herschel wedge (OD~4.3 to 4.4 with post filter) using a ND0.6 (25%T filter, like a standard one) or a ND0.9 will give in the OD5.3 regime. For a Lacerta Brewster Wedge (OD~4.07), you need a ND0.9 (12.5% T) minimum to be in the regime closest to, say a Baader AS film level for visual. 

 

BTW, a polarizing filter (single) gives an ND(effective) of 0.35, or ~45%T. Stacked in line for max transmission, two are about ND0.4, or 39% (approx.). One could co-rotate a preset dual polarizing filter in lieu of a single if one wished to use that on a Wedge, but I find I prefer a single myself. 

 

One final note: most currently available polarizers are circular/elliptically polarized units; in the "old days", say pre-2000 for sure, polarizers were exclusively linear. In general, I prefer LINEAR polarizers with wedges since the polarity passing is mostly linear, esp. on a Lacerta Brewster Wedge. I get better nulling depth and control without any chromatic shifts (I have seen some of this when using other filters, also in-line, like a Baader SA filter on an achromat with a wedge) nearer the nulling minima, with circular polarizing filter models. (acting like wave-plates) I also find that using polarizers in general with both wedges and AS-film equipped scopes shows better detail overall - in the wedge case it is both a brightness/contrast optimization for the conditions, and some solar magnetic details, being polarized magnetically, also polarize light coming off the continuum - same also in the AS-film case. In both cases these cut light haze MUCH better, too. 

 

Anyway, I hope that this addition to the topic was useful and informative. More set up and testing work to be done on the Lacerta, as I just got it. I will be adding a ZWO M54 (2mm M54-M48 adapter ring for internal ND3.0 mounting); essentially an adapter ring for the OD3.0 filter internally, and I have currently installed a M54i Baader click lock to be used in lieu of the stock LAC-2s setup, with a TS Optics 15mm M54 extension tube w/51mm clear aperture for 2" FILTER CLEARANCE. I'll post some info later on this here and in another separate post shortly once I get the finalized configured system up and running next week. 

 

CS, and safe solar! 

Darren

 

Edited July 19 by Gemineyes

[Paz]

Very interesting updates on the Lacerta wedge. I've used a 1.25" lacerta wedge for along time and more recently got a 2" Baader Wedge (mk2).

I have not seen so far pinned down either being better than the other outright but as said above the brewster angle gives huge adjustment in brightness and for some lower contrast features, like limb darkening and faculae, being able to get a dim image brings out more detail (if you are able to get a good blackout around your eyes). I have found the lack of dimming range on the Baader a bit annoying having gotten so used to the Lacerta.

The 90 degree angle on the Baader is useful for eyepiece access but it's only an advantage when I am not using an observing chair. With a chair it makes no difference.

I have a perspex plate screwed to the bottom of my Lacerta wedge to stop bugs getting into my scope. I have wondered if the open bottom robs contrast by allowing light in but holding a hand over it doesn't seem to make a difference for solar (but the open bottom did make a difference when using the wedge to observe Venus with the nd3 taken out).

Something I am looking out for in comparing them is if either does a better job of keeping heat and heat currents out of the scope, I don't have enough observations to go on yet to conclude either way on this.

One other comment is that the Baader is a bit delicate whereas the Lacerta is built like a tank. If you were to be hit by a meteor whilst observing with the Lacerta I think you can rest easy knowing that your wedge will be be found sitting at the bottom of the crater unmarked.

[Gemineyes]

Hi Paz! thanks for the kind comments, and I have to second that build comment!

I think that the Lacerta units are VERY well made! I have the older (Mark I - I think?) Baader wedge - similar optically with the 23 degree prism. Mine has the older baffle set up where the rear of the wedge's window waste heat hits a flat black aluminum baffle, and the wedge has a rear opening to allow radiative cooling for the unit. It gets warm as well, but only a bit, even when using it with my 152mm RFT scope. 

My Lac-2 prism/window housing is pretty much sealed insofar as bug and flies are concerned. I would think the heat would repel them anyway 😉

From what I see with mine, the Brewster Window looks to be around maybe 10-12mm thick, and has a housing around it to hold the window at the correct angle. there ARE some set screws which likely allow one to manually adjust the angle over a small range, but mine is fine, so I won't be doing anything with it! I suppose a small ant, or something like it, COULD crawl into the scope via the underside, but I'd have had this happen years ago on the Baader MK I Wedge, and never have seen this yet. The opening in the Lac-2s is larger, but mine seems fine - I MAY look into making a cover as I think it would be nice to have something to cover it for general protection when not using it.... I usually lay it on a clean MF cloth for now, but I just got it. 

Lacerta should have included a case with the unit - APM does on their wedge (have that too), and it would have been nice. 

Do you know of a way to contact Lacerta? I tried the website email links (hate social media platforms for contacting!) and both bounce back as undeliverable - both Linz and Vienna. Very odd. I had a few technical queries I was curious about mostly, and no joy so far. If you know whether they filter outside of the EU, that would explain it. Only issue so far with them is the lack of contacting options - I know that I could phone, but I don't have a plan to Europe,  and my cell would cost lots! And, if the answering person was non-English speaking, even worse. 

_________________________________

 

Getting back to the techno-chat portion, I was amazed how well this wedge worked the past two days with upper level forest fire smoke haze we just got plagued with form fires in NE British Columbia and Northern Alberta and Saskatchewan. WOW - almost like a sunset though haze, but overhead! I could still make out significant plage and granulation details, even in my ST120 I tried it out on today - I was using my 90mm Apo, but wanted to give this a go with the fast f/5 achromat! Did superbly, BTW. I am running the ST120 with a TS Optics focuser, which gives me more than the previous stock focuser's in-focus distance (good for wedges and so on! lol), and on the wedge, I had several EPs in use, but mainly my Baader Mk III Zoom with the following configuration: Wedge>>ND3->Polarizer->SA filter->Zoom EP. The EP had the filters stacked on it, and my extension tube had JUST enough to allow this. Once my TS Optics 15mm Tube comes in tomorrow (Sunday or Monday, TBD), I'll be putting the ND3.0 on it and only need 1-2 filters dep. on scope, so way more internal clearance for many EPs and visual configurations . 

So even with heavy haze aloft, the Achromat was able to pull in (with setting the brightness optimally) pretty deep plage to the eastern limb edge into ~35%-40%  in the disk center. Like a sort of "river of plage". NICE! While the SA (semi-Apo) filter does not fully curtail CA in the ST120 on solar, it is pretty good - leaves a pale "straw" color to Sol, much less yellow than those glass filters some use, and looks nice, actually - I do have some filtering which cuts CA better and balances the tint on Sol to pretty neutral, but I can't fit that stack in until I finish the mods. Even so, today with the haze, it'd have had a tint regardless of the scope used; CA is a thin medium-faint blue ring off axis and zero tint on, with a very pale yellow inside disk off axis (eye placement oblique to view).

The SA filter also has integrated NIR cut profile, to at least 2um and should be fine in the wedge for this and my 152 f/5.9RFT on solar. My other Apos are all 4.1" or smaller, so not needed there, anyway. 

 

CS and good views! 

 

Darren