The best Astrophotography channel on KZread

Thanks for this video. It is a clear answer to a question I asked on one of your other videos.

Hi Cuiv, thanks for the information. I found your videos are very educational and helpful. What you said makes sense for the dust particles on the filter or sensor window, because their distance to the sensor doesn't change. But how about the dust particles on the primary mirrow/lens?

Excellent explanation as usual! Really going to help a lot of people here. Pronounced: Vin-yet-ing

@CuivTheLazyGeek

4 жыл бұрын

Thank you! And understood on vignetting pronunciation :D

@larryfine4719

Жыл бұрын

I was wondering this just recently. I'm a native English speaker and have always pronounced it "vin-yet-ing" but in typical English style it is spelt differently. I doubted myself there for a while!

Cuiv - I love the beard. You look like Obi-Won Kenobi!! Badass!

@CuivTheLazyGeek

Жыл бұрын

Haha thanks! The wife wasn't such a big fan lol

Informative. Thanks.

yes yr channel have great help on my astro

@CuivTheLazyGeek

4 жыл бұрын

Glad it is helpful! Clear Skies!

My first AP season is now finished at 60 deg north and I have roughly 4 months before the skies are yet dark again for AP. I have plenty of time now to go back an watch your videos in chronological order! 😄 And I learn something from all of them. This was particular helpful, and while I am waiting for dark (and clear) skies, I can make flats for my old imaging sessions! I have also had my Canon 60D modified and just received the Optlong l-enhance filter. So very excited for next season, and on top of my priority list for september/october is the full Veil nebula. So any tips for this nebula with a Canon 60Da and a Canon 300mm f4.0 is very much welcome! 😄 I have two shooting locations, Bortle 3 & 5. Would you use the l-enhance in Bortle 3 skies? And again thanks for this very useful and well explained videos!

@CuivTheLazyGeek

3 жыл бұрын

Oh man, Bortle 3 and 5 are like paradise... I'd probably still use the L-eNhance on the Veil, as it will control star bloating, and reveal the nebulosity much more vs stars, regardless of Bortle zone. You'll have a lot of fun!

Useful video. If only I didn't have to disassemble every night or rotate things for framing, I could be lazy :(.

@CuivTheLazyGeek

4 жыл бұрын

Yeah, not disassembling and not rotating makes everything so much easier! Before I had my roof balcony, I used to take my equipment inside, but I took great care to keep the OTA and tubes + camera as is... Still, it is indeed quite painful.

thanks for answering my doubt！

@CuivTheLazyGeek

4 жыл бұрын

My pleasure :)

This is a useful guide. For the likes of the Takahashi Mewlon 250CRS, it has an electronic focuser on the secondary which “resets” whenever the battery/DC power is taken in & out.

@CuivTheLazyGeek

4 жыл бұрын

Oh right, the 250CRS actually moves the secondary! I had forgotten about that (although it is the same in the end as moving the primary mirror). So if it resets, you need to get back to best focus manually each time? That sounds painful.... But then the optical qualities of the Mewlon make it worth it!

@AnakChan

4 жыл бұрын

Luckily I can disconnect the battery & the focus position stays (until I put the batteries in again in which case it’ll reset). So I’ll have to take my flats after the light subs.

@CuivTheLazyGeek

4 жыл бұрын

@@AnakChan Good that there's a workaround!! Glad to hear it.

When i said it , they laughed !! When CUIV says it , its law .... ignorance is bliss, Good Job Cuiv, again, for clearing the air..

@CuivTheLazyGeek

4 жыл бұрын

Hahaha, well, I can (and do) make mistakes, so I hope what I say is not taken as law! Thanks for the feedback!

@BrokenPik

4 жыл бұрын

@@CuivTheLazyGeek smart and humble . rare qualities these days ...

I’m using a SCT and I was wondering « Do I have to take flats at the exact same focus than the pictures because during the night, the focus is changing a little bit? ». I have the answer! Thanks a lot for explanation. Clear skies. JM

@CuivTheLazyGeek

4 жыл бұрын

Excellent to hear that JM :) It is a very, very common question, and so I thought it was important to set it to rest, at least on my channel! Thanks for watching and Clear Skies!

Hey Cuiv, very good video as usual and i would like the idea to NOT taking Flats after every session; but the moderator of Astro Pixel Processor says "Another important bit is to have the focus to be exactly the same as when you took the lights, this is because any dust can be corrected for as well, but those need to be exactly the same in both lights and flats, so the exact same focus." What do you think about this?

@CuivTheLazyGeek

4 жыл бұрын

Hey Didi! I actually have an upcoming video about when to retake flats, so that should hopefully help! It is surprising that the APP mod would say that - as I explain in the video (and I did all the maths to convince myself, although it's mostly simple trigonometry), the shadow of the dust motes depends on focal ratio (e.g. incoming light angle), size of dust mote, and distance from filter to sensor. It does not depend on focus, except if the focus has changed the focal ratio very significantly (and that would imply a system where a mirror is moved to achieve focus, and a very large change of focus). If focus point affected dust mote shadows, then it would also affect vignetting caused by filters or other elements in the light path (rendering a filter vignetting calculator - which exists - useless)! It does not... Not sure what else to say here...

The real problem with flats are the DSLR camera in my case (I think the mirror movement does it) Dust on the sensor moves or change from a shot to another, expecially on targets at zenith, and, if you do the meridian flip... after the stacking and calibration ouch disaster!!

Hi, and thank you very much for your great videos. I recently have a SCT C11 XLT, and I use a Nikon D610 with f6.3 reducer to do Deep-Sky. On the C11 I have the EAF. If I focus on an object, I have a numerical value of the focus with EAF. Obviously, during the night the EAF changes the focus, even if only slightly. If I do the Flats the next morning, I can use the numerical value of the first focus without quality problems on the Flats? I think I understand this from your video. Thank you very much for your reply and many greetings from Venice. Karl-Heinz

@CuivTheLazyGeek

3 жыл бұрын

So small changes in focus don't really matter - so you don't need to adjust your focus in the morning, although setting it up to what it was at first is fine as well.

@khmphotoart3491

3 жыл бұрын

@@CuivTheLazyGeek Many, many thanks, Ciao

Hey Cuiv and thanks again for another great tutorial! Ok, so now I know that focus doesn't really matter for flat frames... awesome! Nonetheless, as dust spots will probably move between 2 imaging sessions, I tend to think I still have to shoot flat frames after every single session, and therefore can't build a Flat frames library... Am I totally wrong? What do you think about this?

@CuivTheLazyGeek

4 жыл бұрын

Thanks for the feedback! Well, you are absolutely right - but I tend to think/hope that dust motes tend to stay in place quite well (greasiness for stuff like pollen, electrostatic for others), so I don't really bother. My philosophy is: build a flat library. If one day you see it doesn't work for last night's session, just take some more flats and use those for that session and further sessions... Up to now it's been fairly successful!

@alexgti9345

4 жыл бұрын

Cuiv, The Lazy Geek Thanks for the additional information ... and somehow I agree with this lazy geek way of thinking ! 😂 I do tend to clean up every lens before a session so I guess I am messing with the greasiness of dust and all that stuff .. anyway i will give it a try and see what it does ! Thanks Cuiv!

I see no problem reusing flats, the only time I take fresh ones is if I rotate the camera to frame a specific subject. As for vignetting, as far as I know, is pronounced vinyetting. 😁

@CuivTheLazyGeek

4 жыл бұрын

Thank you Brian! Vinyetting :D

Hello cuiv, may be you can help me here, i heard that dosen't realy matter to take flats if your are imaging with a DSLR camera how true is that?. Great channell you are greaaaaat👍

@CuivTheLazyGeek

4 жыл бұрын

Thanks for the feedback! Well, DSLRs are not magic and are therefore affected by optical issues, the same as other cameras. But any such issues will be much less visible on wife field, high signal to noise ratio Milky Way pictures for example! And then, vignetting for a given lens can be fixed by Lightroom's lens dictionary, and dust motes won't be very visible. Otherwise, DSLRs require flats, same as other cameras (afaik!)

Hi Cuiv. I have contacted you before and aplogolgies to you and everyone if I am posting incorrectly? I have seen videos, such as Peter Zelinka, which say you have to make sure the focus is the same as your light frames? This does not make sense to me as taking a picture with a "white cloth" over the lens will result in an out of focus "image" anyway? My question is, when taking "Flat Frames" , do they need to be the same temperature and duration as the light frames I have just taken at night? More specifficaly , if I am taking Subs, at different exposures ( L,R,G,B for example) and using the ZWO EAF to re-focus, each time I move to the different filter, I would have to tranlate this to the Flat frame exposures, a daunting thought? I look at your videos and Peter Zelinka, Astrobackyard and many other people. Thank you for your very understandable explanations. I am fairly new to Astro Imaging just retired from work - my kit is FLT91, EQ6 R PRO, ZWO 7 postition filter wheel, LRGB Filters, 12nm H, O, S filters, asi air Plus, and ASI EAF. Again - apologies to everyone if I am not supposed to ask so many questions like this on you tube? Regards Keith

Thanks Cuiv, another very useful video. Question for you, do you use a coma corrector on your tube? . My question is: With a coma corrector, is it best to put filters before or after it? camera/coma/filter/scope or camera/filter/coma/scope ??. Thanks. Dave

@CuivTheLazyGeek

4 жыл бұрын

I do have a coma corrector (which is actually within the focuser tube). Otherwise, in general you want your filters as close as possible to your camera sensor (to avoid vignetting!), so you'd want scope -> CC -> filter -> camera (e.g. filter right in front of camera). Thanks for the feedback and clear skies!

@FrootyRecords

4 жыл бұрын

r@@CuivTheLazyGeek Thanks Cuiv, I only ask because I recently bought a baader MkIII coma corrector for my newt, when I first tried it, the coma was much much worse! but then i realised the spacing was off (not 55mm) , so after I sorted that out the coma was very minimal and I was quite pleased with it, however I have a 1.25 inch ZWO duo band filter with ring adaptor screwed just in front of the asi1294mcpro window, or as close as I can get it (like it always has been) and now it appears I am getting pretty bad vignetting on mainly the middle to left side. Perhaps its something external but I never had it before the coma corrector was fitted. I had seen a few other guys and girls screw a 2 inch multi-band filter directly on the front of the coma corrector which is why I was asking about it. Thanks for any suggestions. Dave

I take flats every time, and for each filter seperate ... even with observatory-grade Equipment .... every little dust particle is my enemy :) .... and if there is one on a filter you do not correct it ;)

@CuivTheLazyGeek

4 жыл бұрын

Wow, now that is dedication! I'm too lazy for that!! Somehow, dust doesn't seem to move around much for my equipment... Flats can be so painful! Thanks for the feedback and clear skies :)

Reuse flats? You are gonna pay the troll tax for that. Those trollers also say longer is better for sub times. I say keep an open mind.

@CuivTheLazyGeek

4 жыл бұрын

Hahaha, troll tax! I'm fine with other opinions of course- I'll reuse my flats as long as it seems to work well, I'm too lazy to retake flats too often!