Which Astro Modification Should You Choose For Your Camera? 

I was quite saddened to learn of Alyn’s passing. He seemed to be a man of kind spirit and benevolence in his knowledge. I hope his book, many videos and tutorials continue to gain attention for all his hard work. We need more people like him. My sincere condolences to his family and loved ones.

Rest in dark skies Alyn, we will miss you. Your moon HDR tutorial was seriously so helpful to me, and I achieved my first decent earthshine moon photo on February 28th, 2024, with my phone using the telephoto lens. Thank you Alyn, for the progress you helped us achieve.

Rest in peace alyn we always miss u and ur videos

Rest easy Alyn and may there always be clear skies. See you on the other side 📷📸🌌☄🚀

The best explanation of the two main mods in plain English.👍

Alyn, you have had much better luck with Spencer's Camera than I. Sent Clarence a camera back in June of 2020. He modified it and sent it to me but it had a problem and I sent it back to him. After excuses for nearly a year I stopped by while passing through Utah to check on it. He said it shouldn't be much longer. That was June of 2022. It is now late October 2022 and I still haven't seen my camera and he doesn't respond to phone messages or email. I have always been cordial and positive in my communications with him. I'm out nearly $2,000 and don't know what else to do. Hope others have a better experience.

For those still around... The filter issues mentioned with the full spectrum mod, is that when using regular lenses or also when mounted to a telescope? Full spectrum sounds like the best around option, as you can play with filters to get what you want. Would probably cost a bit more since you're buying several filters too.

Been needing a video like this for so long, could never make an informed choice until now

Finally got my d750 back a month ago. I am just blown away. Being able to get grt shots from backyard in san jose,ca instead of driving 2,3,8 hrs away is a life saver for me. Inspired me to sink more $$ into go to mount. Etc. Ha ha. Big thumbs up to Spencer's.

Hello! I'd like to add my experience with my full spec modificated camera. First of all, 2 things: 1 I'm more into telescope-astrophotography (i rarely use wide angle lenses, so normally corners are okay with a coma corrector) and 2: I try to keep everything on a low budget, so if money is not a problem for you, you might prefer a proper astromodification :) About 1 year ago, i decided to buy a cheap Sony a5100 and "astromodify" it by myself. I just removed the filter and reassembled it. When i use it in my newtonian i don't find any problems, It just gets more signal compared to my unmodded sony a6000. When using it with lenses, i didn't find any issues with the autofocus. What I've noticed indeed is a "huge" chromatic aberration (since IR and UV contribute to bigger dispersion). That makes me use it almost exclusively with the newtonian (since reflectors don't produce chromatic aberrations) because I'm looking for a (hopefully cheap) IRcut clip in filter that allows me to take pics with lenses.

Thanks for sharing and clearing up the confusion I've always had concerning this topic

It is super interesting Alyn. Thanks for sharing that knowledge !

Excellent comparison and description of these modifications.

I love your content. It's so refreshing to get away from what the algorithm tells me I like. You have an amazing channel man.

Great information. A definitive video on the application and expected results of both modifications. Thank you for sharing your experience with us. Much appreciated. And by the way your book is the bomb.

Thanks Ayln, i appreciate this video. Its extremely helpful and know i have the information i need.

Thanks for your video! It was very informative.

Great video Alyn. 🙏

Great video. Spencers modified a camera for me earlier in the year. Very happy with the results.

I love you. Best explanation on utube, I don’t even know English good enough but understand everything

Enjoying your great videos. I have a Fuji X-T20 full spectrum mod done by LifePixel mainly for IR shooting. I have a Visible light + H alpha filter for the 23 & 35mm lenses and just a visible light filter for my other lenses. This enables me to use this much smaller body as the backup body when on photo trips.

GREAT EXPLANATION

Having a H-alpha modified A73, and the artifact that appears when pointing at the sun can often be extremely bad- sometimes it will be flares that are not created by the lens( like you had mentioned), and sometimes it appears in a tile-like, almost mosaic, pattern, covering large portion of the frame that is really difficult to remove in post process. I fell like this is criminally overlooked. Before I decided to pull the trigger on modifying my A73, I did quite a lot of search, and all they said was custom WB will fix everything. In fact, the only source that mentioned this artifact was a reddit comment with two upvotes ( and by the time I had already had my A73 modded).

Thank you Alyn, superb explanation, I might go for an H Alpha mod one of these days

This is the perfect video. Been trying to work what mod I wanted and was getting confused by it all. Now I know. Thanks.

Thank you

I think the best solution for using a wide angle lens with narrowband filters is a full spectrum modification of a mirrorless camera and using the astro hutech filter drawer system to adapt a DSLR lens. The focus distance of the camera should be adjusted on the camera while it was modified, with the filters in place to avoid backfocus issues. Some companies offer that focus correction service. From what I know is that the stretched stars are caused by the fact that the extra sheet of flat glass between the lens and the sensor shifts the path of the light rays to about 0.3 times the thickness of the glass (depends on the glass' refractive index), and if that is not corrected by shifting the camera sensor in the body, the lens needs to be set to a narrower focus than the light rays actually are, and as the lens is not designed for that situation it can cause this abberations. It depends on the optical formular/construction of the lens how bad it will be, usually wide angle lenses suffer more from that. It's like using a tiny macro extension ring. One also possible setup would be a full spectrum modified camera with e.g. an astronomic UV/IR cut filter and the focal path adjusted to that combination. Then additionally using the astro hutech filter drawer to adapt a DSLR lens, which then should keep correct focus as it is specially designed for that, so you can quickly change the filters in the field without the need of putting the lens off. Sadly the astronomic OWB filters are only 0.6mm (instead of the 1.0 mm on the rest of all filters - I asked them about that, it's labeled wrong on their web page), so a correct focus on both usage of the cam, astro and daylight is not possible with that. They said, most users don't let their camera be focus corrected, and therefore the thinner OWB filter would cause less impact.. Front-mounting narrowband filters cause the color shift due to the band shift effect when the light rays hit the lens in an angle. The wider and the more to the image edges, the more the effect. When the filter is placed on the back of the lens, the band shift depends mainly on the aperture used. The wider, the more shift and the less contrast, but it's mostly evenly distributed across the image as the light cone does not change that much towards the image borders (except vignetting effects). There are special filters (e.g. IDAS UHS or Astronomic MaxFR) which are more pre-shifted and work better with ultra fast lenses.

I have an a7s II used solely for night videography, extra 1.5 stops of the full spectrum is super enticing!

The timing of this video is awesome alyn I’m getting my camera modded in the next couple of weeks and still in turmoil about which way to go brilliant video I have now made a decision cheers 😊

Thank you for this informative video. I took the plunge last week with my Nikon Z6ii. After a quick call to Spencer's Camera on Wednesday, I packed up my camera and shipped it off to Utah (I'm in southern California). They got my camera Friday morning, and it was on its way back to me by Friday afternoon and I got it back today! Thanks for the $30 off plus priority service promo code. Anxious to try out my camera once the clouds clear out.

Thanks alot for this one, Alyn! I was just poking around on Spencers' site this morning and the full spectrum VS more specific mods has been my debate for some time! I watched a seminar that Clarence gave some time back and he didn't mention the aberrations you point out using the full spectrum with the filters. I'm interested in both astro and 720nm IR and it's starting to sound like two different bodies may be the way for me to go.

I am so excited for my picture Alyn. I hope that you like it.

Thanks for the heads up on the Spencers's site.

Hello Alyn, thank you very much for your very instructive video. Taking decision between Visible+H+ and Full spectrum modification is not easy. I would like share with you / your audience/ my experiences. I use for astrophotography Nikon Z7 Full spectrum modification. When you have full spectrum modification you face two potential issues. First is mechanic shutter and second is lens aperture mechanism on modern lenses. When you use long exposure time, both starting heat and produce infrared light which full spectrum camera recorded and produce image artefacts. Troubles with mechanical shutter you can solve with using electronical shutter (if you have it), troubles with lens aperture mechanism you can solve only with using clip in filter which "modify" your Full spectrum camera back to Visible H+ ( I personally use Astronomic UV/IR L2 filter). You can also use manual lenses which are electronicaly death... In my experience, Visible+H+ modification is much more practical for nightscape and deep sky photography with standard camera lenses. If you want to use camera with manual lenses or with astronomical telescopes full spectrum modification give you much more light (maybe + 2stops compare stock camera). BTW dedicated astro cameras like ZWO or others are full spectrum too. Finally I have on tip. If you have full spectrum camera and you are not sure how is behave your lens, take one dark frame and stretch it in PS or LR. Clear skies to everyone.

I’m also starting to explore the world of Infrared Photography along with Astro Photography so I will go the full spectrum modification route with the Canon EOS D6 camera that I just bought on eBay.

Great video! Thank you! But perhaps one small correction. With some or many unmodified cameras or a cameras modified for Ha plus visible light, one can still take IR photos with 720nm - 830nm IR filters. I've used my unmodified Pentax K-5 for IR photography for years. The caveat is that daytime exposures are generally a few seconds, so if it's a windy day your photos are going to blur. However not all cameras retain some IR light sensitivity.

I use an Optolong circular filter inside the lens adaptor(I have modified it). it works perfectly for me

I also film video under the night sky and was thinking about maybe modifying an a7s III. Thanks so much for this video!

UV/IR cut filter for the full spectrum mod.

Ive just spent the day photographing in 665 and 720nm, and am now photographing the night sky (Andromeda) on my self modded Canon 60d. Using Kolari ir filters and astronomik clip in for visible + HA. First time using it since I modded it. BTW your book is fantastic. Got the signed hard back and we'll worth it. Thanks

I have a Panasonic S5 that is full spectrum modified. I have found that I have to shoot at 24 mm with my h alpha filter to get it to not have that green cast on the edges. Also I think I noticed with having a full spectrum is sigma lenses have some sort of infrared light inside of their zoom lenses that show up on my photos as these weird purple streaks along the edge depending on what phone call length I am at. Only visible in the dark. That also includes if I just have a regular visible light filter on the end of the lens.

This is a great explanation. Clip on Filters are for Full Spectrum modifications and their downside is terrible aberrations. H Mod cameras can still shoot visible daytime light, though there maybe too much in the red channel in highlights. Fix with custom white balance.

Great video as always Alyn! I’ll probably do an H-alpha modification. Oh btw, was that a dust spot in the top left side or am I tripping 😅

Hi Alyn, well done and explained 👍. I noticed that you did not comment on the heat reduction systems offered by spencer cameras. Do you have any opinion on that? Also removal of anti-alias filter. I use both of those and like it but haven’t done any official testing comparing without. I also know the stock a7IV has a better heat dissipation system than the a7iii, so that’s another difference. Are you still in death Valley? I am there now working on a film with some people if you’re around. Thanks.

Excellent comparison, thanks! I wonder what results using a full spectrum camera might produce when shooting auroras? There are IR auroral emission lines. On the other hand, I haven’t found astro-modded cameras that much better for auroras for picking up the visible reds, as the oxygen red lines are shorter in wavelength than Ha, so stock cameras are able to pick up oxygen reds fine. Also - clip in filters will shift the focal point of any lens which, with some wide angle lenses, can introduce serious off-axis aberrations. The lens is reaching infinity focus with the lens elements actually set where they would be at some close focus position. It’s not the filter itself introducing the aberrations, but the focus shift the filter introduces, the thicker the filter the more the focus shifts. At least that’s what I’ve found in testing various clip-ins with various lenses. However, filters can introduce colour shifts off axis, as you demonstrated, even when placed in front of a lens. I find clip-ins are best reserved for just telephotos and telescopes. Clear skies! PS - I’m reading thru your book - a great work! Well done indeed!

Hy Alyn. Great video! I wonder if you found yet a clip in filter without aberations? I saw in this video that you are using Kolari Vision UV/IR cut + H-Alpha. Is that bad on 24mm or 35mm lenses? Or only on wider focal lenghts? Thank you in advance!

Great video, Alyn! I face currently the same issue with the full spectrum modified Sony A7III I've bought few months ago. I've tried 2 different UV/IR cut filters so far. One was Optolong and Astronomik L2. They have different thickness (L2 is thinner) and I've hoped that L2 will work better, because there will be a little less change in the optical path (shift is 1/3 of the thickness of the filter). Many lenses are designed for specific distance to the sensor (flange distance) but with the clip filter it doesn't matter how thick it is, because it affects the curvature of the lens. Yeah, the only thing that won't cause aberrations is a filter in front of the lens. I've already asked Spencer about the color cast, because I've already experienced such a thing with light pollution filter from Optolong. They haven't replied to me for over 3 weeks, but thanks to you I know the answer. Yes, it's a pity, knowing this, I would maybe decide for H-alpha mod, but I already have one Canon astro modified and wanted to try something new and versatile. No one ever mentioned these specific issues directly, any astro modification service so far. So I'm also searching for the right "Ha+visible" lens filter. I've asked Kolari about their, unfortunately they confirmed there might be also a color cast on the edges using wide lenses. It basically depends on the filter technology. Those filters based on interference can suffer from this issue, but if it would be an absorbtion filter, that would work nicely. Kolari is doing this kind of filter, but only the "visible" UV/IR, not including H-alpha. I can forward it to you by email if you want.

I found 24mm and up to work adequately with Kolari H-alpha clip in on my z7ii which I normally never use wider for wide scape Astro anyway, this is an issue with all full spectrum cameras I have heard of people getting a naked sensor conversion for cleaner corners. I had the same vignetting issue with the end of the lens H-alpha filter and returned it. I also have a Nikon d850 H-alpha from Spencer’s and I can use it if I want perfect stars, and when I want to experiment with different looks and colors I use full spectrum at night with different white balances like 470 or 550nm and manual focus Zeiss lenses to negate internal IR light leaks from lens communication, a issue with most mirrorless cameras though a clip in H-alpha illuminates it in the z7ii. I love my full spectrum but am deeply into shooting IR.

Thanks For great vid…I’m waiting on Kolari “uv/ir cut with the h-alpha pass” filter for lens to arrive for my full spectrum, it’s a clear filter hoping it doesn’t create the colour cast. It is advertised as being wide angle compatible with no colour cast and no exposure compensation factor.

Infrared photography is intriguing to me.

Supoerb explanations as always buddy, Full spectrum looks quite interesting ...I think we might need to see a new Alyn Wallace filter to solve the issue of C A :-)

Thanks for the info Alyn, was thinking of buying an optolong l enhance clip in filter, what do you think?

Thanks Alyn, very informative video as im looking to buy my first astro camera, can I ask as a beginner would it be better to use a camera with my skymax127 telescope and Skywatcher- star adventurer GTi, or to buy a good lense? Thanks for any advice from anyone who sees this 👍🏼

Hi Alyn, amazing Video Again! Question: I have a Sony A7Ra (UV / IV Filter) since 2 weeks. In another Video you told, that you fix the white balance with a greycard. I bought this one now. But... how does it work at night? Thanks and regards from Germany, CS Flo

Looks like a job for Haida Rear Lens Filter Holder for Sony and other camera models that most have never heard of! I do not have a modified camera but for my passion for MW panos I use the "Clear Night" filter in the rear and use the Alyn Wallace "Starglow" filter up front in a filter holder so as to adjust for the horizon with most times doing a 200 + degree pano say on a beach with dunes left and right it has to be pulled up. With new LED lights "Clear Night" murges the many colors but keeps glow lower to the ground and LED blue glow white. And one other weird thing, you should never use a polarizer on a wide angle lens like 10/12/16 or 20mm for the dark center and the 90 degree rule, if you forget to take the "Clear Night" filter out when exploring a site capturing with your 12-24mm or 14mm you will get a very good baby blue sky with perfect white clouds with no dark center area and even point at the sun and get the same blue sky no 90 degree rule and you can also use the other rear filters for the milky waterfalls/rivers with no 90 degree rule. So instead of those clip in filters maybe a filter for each mods for daytime. Just weird a filter behind the lens is better than in front. Also MANY DO NOT KNOW of the A7's Mod I and Mod II's on camera apps the www.playmemoriescameraapps.com/portal/ that make those models keepers. The main app is the "Digital Filter" + "Upgrade" I use on my A7Rii but on my A7s I captured a vertical MW over a lit runway and many cities/towns. You get a raw or jpeg output but get to adjust horizon and many more before sending to SD card - You can control foreground setting and get the dark sky without any glow or color of lights, it takes awhile to figure but no need for Physical Filters ever.

I believe optolong started making thinner clip in filters to reduce the distortion in the edges of wide angle lens photos.

Which specific clip in filters have you tried? I def noticed what you describe with an astronomik l3 sony clip filter on a wide angles. Used to have an stc nightscape clip which had other issues/halos and color cast

Great video Alyn, on the note of filters to use with a full spectrum, I used to own both a mk1 A7s and A7r full spectrum modded cameras and had bought a DEO-Tech OWL filter adapter (canon EF-Sony fitment). This enabled me to use 'drop-in' 2" inch filters (48mm and 52mm) which are more popular for deepsky telescope astrophotography such a Optolong L-PRO filter or Astronomik H-alpha filters (there are hundreds to choose from). I found that the drop-in filters worked better than clip-in or screw-on front filters. Only problem was you couldn't use native sony lenses (only canon ef, Nikon etc). It's worth a look especially if you have any canon ef lenses kicking around to test. I only changed back to Canon from the Sony A7s and A7r because the star eater problem became a big problem beyong 30sec images especially on the Mk1 sony bodies. Went back to Canon with a Ra due to less to carry around until I decide whether to get a modded R6 or R5 from Spencers. Cheers Simon

Perfect timing with this video as I’ve been contemplating a full spectrum conversation. You’ve given me a lot to rethink. I’m curious if you tried any astro with the full spectrum camera and the OEM hot mirror filter. Is there a noticeable difference compared to pre-conversion. I’d like to explore infrared, while keeping my options open for astro. Thanks again!

Maybe size up on the thread on filter, extending past the vignette?

Get one of each. Lol. I have the Canon EOS 60Da and the EOS Ra. I have some older EOS Cameras and I’m thinking to get one a full mod. I have plenty of other cameras for daytime photos.

Hi Alyn , I have a Astro modified Sony a7r, also a full spectrum. What about the Astronomik Clip-Filter System for Astro? Do you know much about them?. Great videos by the way, really enjoy them. Thanks

Thanks for this video, I thought finally my questions would be answered but I still am hung up... If I have a dedicated astro camera (6dmkII) I'm still lost on what the downsides are to going full spectrum if I am not planning to use it in the daylight? I don't fully understand why one would filter back to H+Alpha, either... I'll admit I am very tempted to get into the IR filters and play in that realm eventually but not enough so to paint myself into a corner by choosing to go full spectrum when I should go H+Alpha. (I May never actually get around to it, either...but having the option is nice). Help?

Hi Alan, I have a camera that is infrared converted, is that totally different to these conversions you talk about here and is a infrared conversion still good for astro?

I mean the really interesting question would be. Can I compensate the downside of a not-astromodified camera by shooting e.g. 10 times more frames and stack them? Would the result be the same or even better? Mostly only one e.g. 120s frame provides a nice milkyway picture. So why not to should 10x120s with a not-astromodified camera, when result are the same. Of course an astromnod. camera will always winn when comparing same total exposure times, but in case someone has no money for a 2nd astromod. camera, this could be a good compromise. What do you think?

There is a green noise removal tool in siril . Works pretty well

After consideration for a while now, after watching this, I finally decided to Astro-mod my Sony A7rii. My plan is to do the mod, and replace the A7rii with a newer camera. But looking at the spencer's website, I see the A7rii is NOT RECOMMENDED for modification due to some IR light feedback/interference. Uhg. Now not sure what to do.

Do we need a clips-in filter after removing IR cut filter to have a H-Alpha Visible Astromod camera? or just removing IR cut filter is enough? I have a Canon 6D and I've removed its IR cut filter (it has a cyan color). I don't know whether I need a clips-in filter or not. thank you.

I have 2 full spectrum Sonys, an A7r and an A6000. I went full spectrum because I could do it myself and so bought the old, cheap cameras and modified away. A big difference is I use them for deep sky so the issues of a wide lens doesn’t affect me. They work amazing but I must always use a filter, even if it’s just a UV/IR. If I had to pay for my mods, I likely would have done the HA mod but I don’t regret full spectrum for my use.

Informative video, thanks! I was wondering if you also had aberrations with the 12nm Astronomik h-alpha clip in filter on your ha modded cam.

I reeeeallly want to modify my canon 5Div but I’m nervous about sending it out. Ugh should I just modify one of my less expensive cameras? I’ve got a canon t2i, canon 5dii (1 dead pixel), canon 5Div (mint condition) and a Sony a7iv (I don’t really want to modify the Sony though lol) What route would you suggest?

In the year since you made this video, have you happened to come across a Visible + H-Alpha solution for the full spectrum camera? Either on-lens or clip-in?

Did they moved sensor after deleting the filters, to compensate changed focal distance? I've read about that modifications in tg chat about astrophotography, and they're too suffered from huge aberrations after modification sony a7 III. But when they've moved sensor a little to compensate, aberrations gone.

How to shift sensor up front for infinite focus? I see in A7s three brass spacers which removal could shift distance by 0.4mm, do I need to leave them?

We want to see ghost hunting RU-vid channel 🙋‍♂😂 Love the comparison. Nice vid!

have you tried using those Light Pollution filter like the Kase Clip in natural light filter? I found they also produce horrible aberration effects at the corner like what you show with your fukk spectrum mod with filter.

Hi Alyn would you be able to recommend someone in the UK to modify a Sony camera.

Hi Alyn - the green vignetting: Didn't you try to get rid off those by flat calibration (like the astro people use to do)? I can't think of why this shouldn't work.

Hi can you tell me who modifiy cannon cameras in the uk please

Full spectrum is really meant for DSOs, not wide field.

Very helpful video, I had a Canon EOS R Astro modified (H Alpha) after watching this video. What filter would you recommend to use for normal photography so I don’t have to set a custom white balance?

@AlynWallace Do you have the Heat Reduction System from Spencers installed in any of your Sony A7 Astro Mod cameras and if yes do you recommend it?

I had my D810 Nikon Full Spectrum modified. Hardly used it that much since I got my 2 Sony cameras and lenses. I unfortunately bought the wrong Sony's for astromods. Apparently Sony did something different with the A7R series cameras. If you go to get them modified they will have a light leak. At least that's what Spencer's told me in Utah. Other non-R models don't have that problem.

Is astrogear a reliable way to buy astro modded dslrs?

Hi Alyn, have you ever consider to try broadband filters with full spectrum camera ?

Interesting. Thank you. So if you're a landscape photographer who wants to include the Milky Way in your (night) landscapes, you should go for the Hydrogen-alpha (astro) mod, right?. But what if you want to put your camera on a telescope and do deep space astrophotography, nebulae and so on? Which mod is better then?

Does an H-alpha mod make sense on an APS-C sensor?

Great timing as I am looking to get and astro-modified camera, most likely a Sony as all my camera lenses are Sony.

Nico Carver recommended use of the Kolari UV/IR with HA pass, which is what I've been using. My modded camera is a Canon 2000D, so APS-C. I did not see that Kolari had a clip-in filter for mine, so I use a 77mm front mount since most of my lenses are that size, but they seemed to have an abundance of clip-in filters for Sony. I also have not used my filter on a wide angle lens yet, because I use that camera primarily for DSO. My mod is recent, so I haven't had a chance to experiment much with it, but I like the results I've gotten using that filter, but my images have been with telephoto lenses. I haven't noticed any aberrations in the corners. As for color results, the only thing I can tell you with certainty (since I'm colorblind) is that I can definitely see more red in my images. Since you liked the other Kolari filter you mentioned in your video, you may like this one as well. The front mount filter that I bought was $125 USD. I didn't notice how much the clip-in filters were running.

I've been using the STC Astro Multispectra clip filter in my full spectrum A7RIII and have not noticed any problems in the corners I've also been doing a lot of IR shooting during the middle of the day, no way I'm up for sunrise after taking astro shots the night before

I have a Sony A7rii full spectrum camera that I use for infrared photography. Lots of fun but what I have found is that any focal length wider than 24mm, the edges are not sharp. It's not the filter you're using, it's the full spectrum conversion. Not sure why it does this but it keeps me from using anything wider than 24mm.

Thank you, Alyn. Well, I just bought the H+Alpha and hot mirror filters from Spencers last week and they are arriving tomorrow. It would be nice to get discounts with your code. I'm worried about the performance of the H+Alpha filter as you mentioned. I got my Nikon D810 modified to full spectrum three years ago with Spencers. The quality of work was excellent. It took a while, though so make sure you are okay to part ways with your camera. I mainly use the camera for deep-space imaging and it works great. I was planning to start using it for Milkyway and infrared imaging. I say that the D810 is an excellent DSLR to be Astro modified. I might send my Z6 II in the future for modification once I get another Z body (Z9 or Z8) and my Z7 II as a backup.

What about DSO? you mention filming and wide angles, but most modifications are done for Nebula shooting. Those are for 100mm+. Which one would you recommend then? FS or HA mod?

Regarding the Full Spectrum aberration, are you sure this is not rather a tilt issue? Maybe the sensor is tilted on your gear...

I hardly doubt you will find a filter to fix that issues with the full spectrum body. Its physics. Thats why serious IR mod companys don't recommend full spectrum for astro.

Hi Alyn, I have just bought a 40D astro modded (h-Alpha) and want to use it for astro and normal use, are you saying I only use the custom white balance for normal (terrestial images) and AWB for astro images.. I always shoot in raw.

Do you notice any red or purple in greys with the astro mod camera, even with a custom WB? I'm using an OWB filter in my modded camera and I'm happier with the colours I get in daylight.

I had lifepixel do visible + h alpha mod on my A7C. Shipped back to me in Aus and it wouldn't focus to infinity with wide angle lens.. so went back to them and was fixed. Worse thing about a7c is no plug in intervalometer works 😢

Concerning the green vignette with the screw-on filter: Was that only an issue at 14mm, or is that something you noticed with your 24mm lens? I am expecting my full-spectrum camera in the mail tomorrow, and I often use a 28mm lens for astro. Also, when you used the full-spectrum without any filters, were there any issues with the sky portion of the image to be aware of? Thanks.

Have you tried an oversize filter? Say using a 90mm filter stepped down to a 77mm thread?