I'm a stickler for flats. A couple recommendations: (1) Before integrating your master flat, calibrate your flats first with a master bias. (Alternatively you could use master darkflat, but a master bias is easier, more reusable, and arguable just a better option.) This can have a somewhat significant noise reduction in the final product. (2) Then when it comes to integrating the calibrated flats to make a master flat, uncheck the "Signal and Noise Evaluation" checkbox at the bottom, in addition to the settings Dylan shows in the video. (Leave this checked when integrating lights, but uncheck it when integrating flats.)

I like the tribute Alyn Wallace.

Thank you for the very kind, tasteful tribute to Alyn. I greatly enjoyed his art. He shall be missed.

Not the usual closing sentence but a tribute to a guy that gave us every month a nice overview of what is in the sky the next month, touching ... g.

On occasion, we all suddenly discover something new and wonder why that useful tidbit eluded us for so long. I started doing Flats with a DSLR and t-shirt, then switched to using an $18 tracing pad for convenience. (Temperature matching Flats with Darks/Lights isn’t necessary.) I routinely puff off dust on the objective before each session and find the Flats work well for several sessions (assuming the image train isn’t altered.) That’s just laziness on my part since Flats are so fast and easy. Great video. Love the tribute to Alyn. He was a gem and I thoroughly enjoyed his videos, especially when he shared adventures in the field. He is missed.

As others have recommended - calibrate the flats with some dark flats (same seetings, but without light) or at least bias frames, when you are using also dark frames for calibration. otherwise you substract the read noise twice. one time with the flats and one time with the darks, Taking the flat frames before the imaging sessions is tricky as the focus is important. The dust spots will change if you change the focus, so you need to take the flats with the same focus setting as your lights. For OSC (without or with only one filter) I take the flats in the morning after the session towards the bright sky with a white T-Shirt in front of the lens. If I use different filters troughout the night (that would apply also for different filters with a mono camera), I take the flats after each filter run. I have used my iPad for that, but if the exposure time is too short, it has some banding due to the flickering of the panel. I switched to a lightpanel instead, that works much easier.

OH SHIT! I didn't know about Alyn, He was great, thanks for the tribute may he rest in peace.

This is my favorite channel, make more videos, everyone else is boring

I always enjoy your no bs approach to this hobby. It's very refreshing. It was to good mention Alyn Wallace. He's a great loss to our community.

Simple, moving tribute to Alyn. 👍🏻 Noddy

Get ready for even more gradients if couple of bucks spent on a LED panel is to fancy for your flats ;) Sky and walls tend to be unevenly lit like there was a single source of light. Imagine that.

I never did flat frames for years & when I tried they never worked anyway until I found NINA, I do use an LED panel with a T shirt over the RASA & NINA does the rest it's awesome although I've never bothered using darks so got lazy there. Loved the tribute to Alyn Wallace at the end to such a shock to the community when I heard the news.

Brilliant, as always, Dylan. I appreciated your step-by-step explanation through the process. IMHO, it's important to understand that before going to something like WBPP (which, lazy me, I use now). Your tribute to Alyn Wallace was touching. Thank you for remembering him.

I really dont understand why you just have 47k subs. Definitely underrated.

It may be worth mentioning that you can also pile all your light, flat, bias and dark frames in a single folder, tell Pixinsight to 'add files' in Weighted Batch Pre Processing and press go. Iy will sort out which is which, create your master dark, flat, bias and apply all the most appropriate settings. Seems easier than your manual manipulation of the flux capacitor.

Perfect flats!!! White T shirt and the sky !! Add a elastic to prevent wrinkles on the fabric!!

Not had any notifications for new videos for months (thanks KZfaq) great video flats have always been a pain, so generally haven’t bothered, going to try again.

Excellent video Dylan. Sometimes the simplest solutions are the best. I have deep sky dad flat panels for my dual apo rig, these work very well. However, I have recently purchased a 12" RC and have been wondering about taking flats. After watching this I remembered that I have some fairly large flat white upvc panels left over from remodeling my bathroom, one of these attached to the obsy wall would be perfect for this so no need to buy anything👍

You always seem to make just the video I need right when I need it!

Once I started using NINA's flat wizard, taking flats was such a no-brainer that I don't have an excuse to not do it. I do use a light panel with a couple of pieces of paper between the telescope and the panel to both dim it and to disperse the light a bit more and that works great. I will never not take flats again.

Nice work Dylan!! Alyn will be missed 😢

The only thing that help me best were taking sky diffused flats with dyi cover during the imaging session. Basically put a diffused sheet cover over the objective at the beginning, middle and end of the session to cover the entire light pollution dome. Don't change any camera settings and take ten each. No need for any other calibration frames or gradient apps. Daystar sells diffused glass covers for solar imaging that can be used for night imaging too but are expensive. So sad about Wallace.....Rest In Peace Kool Guy.

I recently upgraded from the ASI585 to the SV405cc (with the IMX294 sensor) so I had to actually learn how to do my flats and darkflats properly. During the day my rig sits behind me so I can just point the scope at my PC screen with an empty Notepad open, and shoot away, but I do have to throw something over the screen, or the scope, otherwise NINA makes my exposures too short, and the SV405 doesn't play well with flats below about 2 seconds. Which is also why I have to use darkflats instead of those really short bias frames. But yea, the Flat Wizard in Nina is great.

dang never woulda thought you of all ppl didnt use many flats thats so neat and odd lmao gotta love the hobby so many ways to do thigns

Even easier would be to use NINA's Twilight Sky flats exposure instruction. I do it at sunset and completes in about 4 mins for a set of 7 filters (30 flats/filter)

I just use my tablet screen as flat panel. It is feature that is built into my live stacking app - so camera connected to android tablet for EAA and when I just use same tablet screen to create flat surface - so I can do it at night on demand. The app has built in feature to make white screen during flats collection so it makes it super easy (at least as long as the tablet larger than the scope aperture. Though it works well for EAA and works at night

The number of rubber bands that I've flung off the roof while trying to put a tshirt over the scope is... around 3

I was honestly expecting a sarcastic Taylor Swift reference when you said blank space…. 😂

Some cameras are more difficult to capture good flats. The asi294 (both color and mono) require longer exposure flats due to noise of low exposure times. So if you have to do a 3 second flat, your light source needs to be super dim, but not too super dim... that requires a good source you have a lot of control over.

Dylan, thanks for the info. I initially shot all of my flats at the sky with a T-shirt but eventually I started having that nagging OCD voice telling me "how can they be uniform, what if the color of the sky is off today". These were things I could logically explain away to myself, but I eventually found myself giving into voices. I think folks should know even if you have a larger SCT (i use an Edge HD 11") you can buy an LED tracing panel for less than $20 American that will fit your scope. Not only that NINA Flatwizard even has a "point to zenith" button (just make sure you have tracking turned off!). My big question is this "do you actually use that workflow for calibrating? Or do you let WBPP handle it and you are showing us basically what WBPP does effectively? BTW as a Plano, TX guy I appreciate your support of one of my favorite locals ( guitar and T-shirt!)

You can be even lazier than the flow you use. Just point PixInsight's WBPP at the flats/flat darks and it works it all out.

Thank you.

26000 ADU is my target for flats. set in the histogram mean target section. Flats of course dont need to be cooled as you indicated, just the long exposure darks.

Order up and send one of those Science Toys over this way, please. I can't find the proper link. 😉 Great tribute to Alyn Wallace.

Flats are so easy to do it should be part of every photograph session. You can even cheat, if using the same telescope setup, and use a previously made flat frame (but new dust motes will not be removed).

I have to comment on the light panel. Especially if anyone travels to a dark site: get the light panel. They are cheap, consistent and can be powered by your ASI Air if you use one. I think the one for my C8 was $15. Here is my real comment: If you are going to the trouble to stay up late, travel to dark skies, spend the money on a good camera, you might as well commit to taking the light frames. Just like the video showed, they are easy to do.

😢 Can't believe Alyn Wallace passed away. RIP Alyn.

The more light pollution you get, the less you can get away without flats. The dust motes visible in your flats would wreck my images if I didn't use flats. In fact, if a flat comes out wrong and I notice too late (ie: after the rig was disassembled) then I'm screwed, I have to mostly drop that data. From Bortle 9 the overall brightness of the image makes the artifacts those dust motes create leak all over and mess with gradient reduction and everything else down the pipeline. I've tried sky flats, and they are tricky to get right, especially if doing narrowband where exposures get long and makes the whole process tkae quite a few minutes. Sky brightness changes very fast around dusk and dawn, and with long flat exposures by the time you got your 20 flats the sky may be twice as bright or more, meaning your flats are always either over or under exposed. Long story long, a flat panel is quite handy, and it doesn't need to be an expensive EL panel. I use a dirt cheap LED tracing board, and it does the trick just fine.

Nice tribute to Alyn Wallace at the end. What a tragic loss.

Needing over 3s flats exposure for my 294mc pro( to ensure a linear response ) makes flats difficult , I haven't found anything that can dim the panel sufficiently without the light becoming uneven . Rest In Space Alyn .

Crikey, no wonder you didn't bother before - so many manual operations, what a nightmare! My situation isn't really comparable (one-shot colour, different kit & subjects) but Siril scripting seems so much simpler.

Why the face fungus, Too many late night's? I went to Texas for the eclipse! And what a Fantastic eclipse! Oh what a trip! Oh and I stayed with my mate Tom Pickett (Pickett's Balls, I sent you a photo of it.)

Luv ya', Dylan. But I'd never do flats this way. A good flat panel (e.g., Spike-A, Optec, or PrimaLuce) with USB-controllable intensity in order to shoot flats for all 7 filters at the same, fixed duration (usu. 4s for me), and a set of flat darks is the only thing that has ever worked for me. The quality of my data jumped significantly when I figured all this out. It only took me five years.

I also use a wall haha, but I move the telescope because the vignetting remains persistent but any dark patches on the wall are smeared out

10 min exposures for the final pic, wow!

I have noticed this theme in all your videos. But why don’t you use WBPP?

Hi Dylan, I am curious why the gain needs to be the same as your lights. If you are looking for the desired illumination level as configured in the imaging software I think the only influence gain has is determining the exposure length to get that level. From my experience lowering the gain makes it easier to get reasonable exposure lengths if the light level are high but gives the same calibration outcomes.

I laughed when I saw you having a sneaky game of Fortnite - I've been playing it with my sons. It's fun!

I'm lousy at taking flats and I use a light panel with an assortment of gels to dim down the brightness. I'm wondering if N.I.N.A can be used in conjunction with the light panel to help me take better flats?

"Flat Frames are easy" *Clicks several strange ImageIntegration settings* I kid. Flat Wizard is great :)

If you truly want to be lazy with a Sony 571 you really don’t need darks. Flats though, yeah, ya need those.

Me slowly making a big dob workshop "Yes, this costs more, this must be better" :^)

Why not just use WBPP. It will create your master flats and master darks for you, then calibrate your images with them. Much easier in my opinion.

so if you point at the sky for flats wont clouds crossing your lens view be a problem ? up till now i just hold a piece of white A4 paper over the lens while facing up

So this has to be done every time or just once?

Another great Video mate. Classy Tribute to Alyn🥲

Wait so I can just take flats from the inside of the dome? I thought you need a flat, evenly illuminated surface?

So this whole time you were not using flats?

With this dust i do thee mote you.

Flats have vastly improved my images.....they were dog shit before 😂

I wouldn’t say taking flats is easy.

LOL! a quick ALT-TAB. Nothing to see here!

Life is meaningless indeed..

Look after your mental health.

This is where AI could really help, "hay G, image M16 / does everything" more time for other hobbies...

complete novice here, lookin at whats easy? 🫣