Venus May29th UV/OSC 1st light QHY5-iii-462 mono

[Space Cowboy]

Quick false colour process from last night combining my new QHY462mono & colour QHY585 :

The live view of the 462 looked like a stacked version of the old QHY5L-ii.  Seeing was once again very stable.  The 462 uv image used here was oversampled probably f20. Need to get the f ratio right.

 

 

 

Edited May 30, 2023 by Space Cowboy

[neil phillips]

looking tasty. Some wispy fine detail on show. 

[Kon]

46 minutes ago, Space Cowboy said:

Quick false colour process from last night combining my new QHY462mono & colour QHY585 :

The live view of the 462 looked like a stacked version of the old QHY5L-ii.  Seeing was once again very stable.  The 462 uv image used here was oversampled probably f20. Need to get the f ratio right.

 

 

 

Looks great and nice fine details. What sort of fps are you managing with the new camera? At daylight I manage 300 at 640x480 (~3.2ms exposures) for a histogram of 70-90%.

[Space Cowboy]

2 hours ago, Space Cowboy said:

Quick false colour process from last night combining my new QHY462mono & colour QHY585 :

The live view of the 462 looked like a stacked version of the old QHY5L-ii.  Seeing was once again very stable.  The 462 uv image used here was oversampled probably f20. Need to get the f ratio right.

 

 

 

Thanks Neil. The UV was using Gaussian wavelets.  I reckon the 462 is about 5x more sensitive than the old qhy5ll.

 

[Space Cowboy]

1 hour ago, Kon said:

Looks great and nice fine details. What sort of fps are you managing with the new camera? At daylight I manage 300 at 640x480 (~3.2ms exposures) for a histogram of 70-90%.

Cheers Kostas! I didn't go mad with FPS. Had gain just below 50% so FPS was about 80-90 at 60% histo. I'll post up the capture details later. Sky was a bit hazy 

[neil phillips]

My 178 is on  30 to 60 FPS 90 to 100% gain.  

[Space Cowboy]

27 minutes ago, neil phillips said:

My 178 is on  30 to 60 FPS 90 to 100% gain.  

Interesting to compare. The fps was actually 65fps for the over sampled run and 81 for the smaller undersampled captures I took. Looks like the goldielocks zone is in the middle. The nose piece I screwed on so i could remove the cover glass and attached the UV filter threw off my fl from the 585c.

These are the 2 sizes straight out of registax and their capture details. The f ratio quoted by FC is not correct.

 

2023-05-29-1946_3-SJG-L-Ven.txt 2023-05-29-2001_2-SJG-L-Ven.txt

Edited May 30, 2023 by Space Cowboy

[neil phillips]

Just now, Space Cowboy said:

Interesting to compare. The fps was actually 65fps for the over sampled run and 81 for the smaller undersampled captures I took. Looks like the goldielocks zone is in the middle. The nose piece I screwed on so i could remove the cover glass and attached the UV filter threw off my fl from the 585c.

These are the 2 sizes straight out of registax and their capture details :

 

2023-05-29-1946_3-SJG-L-Ven.txt 359.66 kB · 0 downloads 2023-05-29-2001_2-SJG-L-Ven.txt 449.03 kB · 0 downloads

That camera chip although smaller. leaves my 178 in the dust judging by what you guys are finding

[Kon]

I have personally found that during daylight captures I can go down to 3ms with a gain of ~400 (ASI capture), probably 80%, but as it is getting darker (maybe correlated to poor seeing/transparency) I have to up my exposures to 8-12ms to get my histogram 70-90%, not bad but fps drops quite a bit. At daylight, I tried to lower my gain by increasing the exposure but I found the images noisier. I do not image at dusk/night anymore.

(my images are at f15)

I suppose the three of us are using different filters wit different transmission that will affect the exposures.

[Space Cowboy]

5 hours ago, neil phillips said:

That camera chip although smaller. leaves my 178 in the dust judging by what you guys are finding

From what Christophe pellier has been saying it has no rivals in the UV stakes.

[Space Cowboy]

5 hours ago, Kon said:

I have personally found that during daylight captures I can go down to 3ms with a gain of ~400 (ASI capture), probably 80%, but as it is getting darker (maybe correlated to poor seeing/transparency) I have to up my exposures to 8-12ms to get my histogram 70-90%, not bad but fps drops quite a bit. At daylight, I tried to lower my gain by increasing the exposure but I found the images noisier. I do not image at dusk/night anymore.

(my images are at f15)

I suppose the three of us are using different filters wit different transmission that will affect the exposures.

I imagine fast frame rates are your main priority considering you don't have tracking Kostas. Its easy to forget that when seeing the quality of your images.  I'm not keen on daylight as my shroud is only a camping mat so the strut ends are still open to the daylight.

I believe you are the odd man out regarding the UV filters. I have the bessel U the same as Neil. Once again you are performing miracles with a bargain filter. 😉

Edited May 30, 2023 by Space Cowboy

[Kon]

1 hour ago, Space Cowboy said:

I imagine fast frame rates are your main priority considering you don't have tracking Kostas. Its easy to forget that when seeing the quality of your images.  I'm not keen on daylight as my shroud is only a camping mat so the strut ends are still open to the daylight.

I believe you are the odd man out regarding the UV filters. I have the bessel U the same as Neil. Once again you are performing miracles with a bargain filter. 😉

The fast frame rate is to combat bad seeing, I thought from discussions last year that faster is better. I think Neil did some side by side comparison . It may be the case for Jupiter but happy to be corrected for Venus if you believe that longer exposure is better. Even with my manual tracking I still get 7-10mins on Venus at 640x480. The cheap filter is doing quite well to my surprise. 

 

It all makes sense why you want to avoid daylight captures (☀️).

[Space Cowboy]

A couple more from the smaller sampled runs. Minimal processing, just a touch of contrast after registax.

I must give Bernard at Modern Astronomy a special thanks for the QHY462 mono.

 

Edited May 30, 2023 by Space Cowboy

[neil phillips]

50 minutes ago, Kon said:

The fast frame rate is to combat bad seeing, I thought from discussions last year that faster is better. I think Neil did some side by side comparison . It may be the case for Jupiter but happy to be corrected for Venus if you believe that longer exposure is better. Even with my manual tracking I still get 7-10mins on Venus at 640x480. The cheap filter is doing quite well to my surprise. 

 

It all makes sense why you want to avoid daylight captures (☀️).

Yes i think it was Mars. Your correct. Geoff was capturing at a slower rate with a C14 my 245mm seemed to cope better on the same night. And i seemed to remember telling you and Geoff the faster frame rate was doing better that night. And after seeing the images you both tended to agree and took note. Each planet is different of course. Mars is small and bright. There's a cutoff point of speeds benefits. And its just a case of finding that cutoff point on each planet.  

[neil phillips]

16 minutes ago, Space Cowboy said:

A couple more from the smaller sampled runs. Minimal processing, just a touch of contrast after registax.

I must give Bernard at Modern Astronomy a special thanks for the QHY462 mono.

 

Those are just lovely. Right up my street. Not overcooked, Natural subtle, but very fine wispy cloud. Hey wanna trade locations ill throw in a laser

LASER CANNON

[Kon]

25 minutes ago, neil phillips said:

There's a cutoff point of speeds benefits. And its just a case of finding that cutoff point on each planet.  

I think I get what you are saying. But could you elaborate more on the benefits of capturing at longer exposures please?

I should retry Venus at longer vs short under good seeing and compare.

[neil phillips]

1 hour ago, Kon said:

I think I get what you are saying. But could you elaborate more on the benefits of capturing at longer exposures please?

I should retry Venus at longer vs short under good seeing and compare.

Yes you should compare, And likely do it more than once. Some conditions favor certain settings more than others. Really good seeing can tolerate longer exposures better for example.

The opposite is true of average or poorer seeing.

I just think there's often a sweet spot to be found with certain equipment, with certain seeing conditions. It has to be found by your own hand, at your location. with your own equipment. 

We can in theory just max out gain and set exposure accordingly each and every time we image.  But that approach wouldn't take into account better seeing which enables slower exposures less noise less gain. less frames needed in a stack.

I nearly always adjust exposure and frame rates during a planet session. I experiment I don't like sticking to procedures like glue. I like finding the ones that are working best at any given time

Yes i will say most often the faster exposure, higher gain, higher frame count turns out to produce the most detail.  Otherwise i wouldn't do it.

But not always. Because of many variables. Its worth experimenting. Then you get to learn the effects of what your doing without relying on pre determined numbers, or others recommended settings. It will make you a better imager in the long run. Though in your case its a little different because you have no drive. Which should favor a higher frame count per se. Shouldn't it

I don't like maxing out gain full stop. But will if i have to. Those recent Venus, i did just that. The higher scale with Barlow was working better on the 7.3 CC. As i found out twice. But your camera is better than mine. Chris go says don't be afraid of gain (if i am remembering correctly ) But pulling back a little can have its own virtues and benefits.  As i said i think there's a cutoff point of diminishing returns. If that wasn't so, Think about it, we might as well just do 100% gain and set exposure accordingly. Every time we image. But that is limiting ourselves.  Also sometimes a reduction in gain. Doesn't always equate to a reduction in frame rate.  Or exposure. A case in point

Not sure if i am making sense ?  

Edited May 31, 2023 by neil phillips

[Space Cowboy]

10 hours ago, neil phillips said:

Those are just lovely. Right up my street. Not overcooked, Natural subtle, but very fine wispy cloud. Hey wanna trade locations ill throw in a laser

LASER CANNON

Thanks Neil. Basically I used the same wavelets as I would on Jupiter or Mars. Fine gaussian rather than the sledgehammer dyadic. 

I was having to use a Laser cannon on the noise with the old cam lol

[neil phillips]

13 minutes ago, Space Cowboy said:

Thanks Neil. Basically I used the same wavelets as I would on Jupiter or Mars. Fine gaussian rather than the sledgehammer dyadic. 

I was having to use a Laser cannon on the noise with the old cam lol

Yeah. and it shows. Every reason to go that route when the data is good. you do get a finer more precise process with far less detail bloat. Take note everyone this is how its done. Note to self before the big guys show. Not long now. 

(ok my first efforts will probably be dyadic. ) But you get the point. When data is good, it needs fine sharpening. And you sir just re proved it to me. Its been a while since i was re taught any old lesson. We go back. And have done that through the years. Good to feel that dynamic influence again Bud. Kon is the king of the undriven dob. You are the driven. 

[Kon]

6 hours ago, Space Cowboy said:

Thanks Neil. Basically I used the same wavelets as I would on Jupiter or Mars. Fine gaussian rather than the sledgehammer dyadic. 

I was having to use a Laser cannon on the noise with the old cam lol

 

6 hours ago, neil phillips said:

Yeah. and it shows. Every reason to go that route when the data is good. you do get a finer more precise process with far less detail bloat. Take note everyone this is how its done. Note to self before the big guys show. Not long now. 

(ok my first efforts will probably be dyadic. ) But you get the point. When data is good, it needs fine sharpening. And you sir just re proved it to me. Its been a while since i was re taught any old lesson. We go back. And have done that through the years. Good to feel that dynamic influence again Bud. Kon is the king of the undriven dob. You are the driven. 

You are both spot on about processing. I have been using dyadic mostly on steroids with UV 🤣; I am still learning as it is my first serious imaging of Venus. I will probably/ want to go back to some of my good seeing images and tune them down a bit. I love Stuart's colour balance.  I have my colour way which I like but Stuart's is just very subtle.

[Kon]

13 hours ago, neil phillips said:

Yes you should compare, And likely do it more than once. Some conditions favor certain settings more than others. Really good seeing can tolerate longer exposures better for example.

The opposite is true of average or poorer seeing.

I just think there's often a sweet spot to be found with certain equipment, with certain seeing conditions. It has to be found by your own hand, at your location. with your own equipment. 

We can in theory just max out gain and set exposure accordingly each and every time we image.  But that approach wouldn't take into account better seeing which enables slower exposures less noise less gain. less frames needed in a stack.

I nearly always adjust exposure and frame rates during a planet session. I experiment I don't like sticking to procedures like glue. I like finding the ones that are working best at any given time

Yes i will say most often the faster exposure, higher gain, higher frame count turns out to produce the most detail.  Otherwise i wouldn't do it.

But not always. Because of many variables. Its worth experimenting. Then you get to learn the effects of what your doing without relying on pre determined numbers, or others recommended settings. It will make you a better imager in the long run. Though in your case its a little different because you have no drive. Which should favor a higher frame count per se. Shouldn't it

I don't like maxing out gain full stop. But will if i have to. Those recent Venus, i did just that. The higher scale with Barlow was working better on the 7.3 CC. As i found out twice. But your camera is better than mine. Chris go says don't be afraid of gain (if i am remembering correctly ) But pulling back a little can have its own virtues and benefits.  As i said i think there's a cutoff point of diminishing returns. If that wasn't so, Think about it, we might as well just do 100% gain and set exposure accordingly. Every time we image. But that is limiting ourselves.  Also sometimes a reduction in gain. Doesn't always equate to a reduction in frame rate.  Or exposure. A case in point

Not sure if i am making sense ?  

Thanks Neil. I am getting what you are saying and it makes sense. I have not maxed out my gain yet and finding the balance is key. I may have been a bit less experimental with the mono captures as the high speed mid-gain is giving me good results but I could well get better with other settings. Weekend is looking promising for this, and I will try make a post if I do get a good comparison.

[NenoVento]

12 hours ago, neil phillips said:

(...) Kon is the king of the undriven dob. You are the driven. 

Agree!

[Pete Presland]

A great start with the new camera, terrific images from registax before processing as well.

[Space Cowboy]

Thanks Pete! It's nice to have such good conditions to try out a new camera.