Venus cloud discontinuity and UV (20/04/23)

[Kon]

I managed a rushed session before clouds and rain came over. Despite this, the captures were pretty good despite the high winds. I capture them during daylight and when Venus was high up. My IR is showing some really nice features compared to yesterday, and looking online I may have capture the discontinuity cloud events (only visible in IR); I have contacted Paul Abel at BAA to confirm. These were visible before I even stretched the image in registax. The UV is also showing different features from yesterday as well. I also made a false colour. Your thoughts? 8" Dob, manual, asi462mm, 2.5x TV powermate, IR pass and UV filters. Image order, IR, UV and false colour.

 

 

Edited April 20, 2023 by Kon

[neil phillips]

Good catch between the clouds coming. I cant answer the IR question, as i haven't been following what is being picked up. Out of interest what wavelength are you capturing with IR ?

[Space Cowboy]

Nice captures again Kostas! I was amazed the cloud held off for another go last night but wind and seeing were not good.

[Kon]

2 hours ago, neil phillips said:

Good catch between the clouds coming. I cant answer the IR question, as i haven't been following what is being picked up. Out of interest what wavelength are you capturing with IR ?

Thanks Neil. I have the Svbony at 685nm. I also have the Astromania at 650nm. I feel the Svbony is performing better but I have not done a real side-by-side comparison.

[Kon]

1 hour ago, Space Cowboy said:

Nice captures again Kostas! I was amazed the cloud held off for another go last night but wind and seeing were not good.

Thanks. Yes wind was awful here too. I am looking forward to seeing what you managed.

[MarkRadice]

Looks really interesting, well done. 

[neil phillips]

2 hours ago, Kon said:

Thanks Neil. I have the Svbony at 685nm. I also have the Astromania at 650nm. I feel the Svbony is performing better but I have not done a real side-by-side comparison.

Yes longer wavelengths tend to do better on Venus. The best i had ever seen was taken with large optics at 1000nm impossible for a 8" scope. I am unsure how deep you can go with 8 " optics. but 742 might be worth trying. 

I should try 850 nm with the 12" if i get the chance. I am surprised your picking anything up, at those wavelengths. But you say its visible before stretching. It certainly looks to me like you are. What's likely helping is your consistently good focus

I dont have a single IR at 742. but here was a combined 742 and UV from 2012 Orion. 

Edited April 21, 2023 by neil phillips

[Kon]

5 hours ago, neil phillips said:

Yes longer wavelengths tend to do better on Venus. The best i had ever seen was taken with large optics at 1000nm impossible for a 8" scope. I am unsure how deep you can go with 8 " optics. but 742 might be worth trying. 

I should try 850 nm with the 12" if i get the chance. I am surprised your picking anything up, at those wavelengths. But you say its visible before stretching. It certainly looks to me like you are. What's likely helping is your consistently good focus

I dont have a single IR at 742. but here was a combined 742 and UV from 2012 Orion. 

Great image.

To be honest I am pushing it's limits at the moment but well surprised that both UV and IR are working well. I wonder if it's also down to modern cameras. But this season I have seen several good images in both true colour or IR with details.

I have seen some fantastic images at 1000nm from large scopes. I don't plan on getting more IR filters as yet unless something comes second hand.

I think you should get the 12" out, although you have explained the issues with cooling etc.

[neil phillips]

15 minutes ago, Kon said:

Great image.

To be honest I am pushing it's limits at the moment but well surprised that both UV and IR are working well. I wonder if it's also down to modern cameras. But this season I have seen several good images in both true colour or IR with details.

I have seen some fantastic images at 1000nm from large scopes. I don't plan on getting more IR filters as yet unless something comes second hand.

I think you should get the 12" out, although you have explained the issues with cooling etc.

Ive seen the Astronik 742.  £44 new so secondhand wouldn't be too bad. Wouldn't mind one myself actually. The gap between 685 and 850 nm. 

Yes i am sure your right newer cameras are helping. A good question for you Kon. what do you think of a shootout between IR 850 with a colour 462c or mono 178. I am thinking the colour will do better because. at 850 it essentially becomes monochromatic.  Its more sensitive in IR what's your thoughts ?

IR does better with larger optics and thermal issues. So yes your right i should probably try at 850 nm. weathers gone all silly again.

Edited April 21, 2023 by neil phillips

[Kon]

23 hours ago, neil phillips said:

Ive seen the Astronik 742.  £44 new so secondhand wouldn't be too bad. Wouldn't mind one myself actually. The gap between 685 and 850 nm. 

Yes i am sure your right newer cameras are helping. A good question for you Kon. what do you think of a shootout between IR 850 with a colour 462c or mono 178. I am thinking the colour will do better because. at 850 it essentially becomes monochromatic.  Its more sensitive in IR what's your thoughts ?

IR does better with larger optics and thermal issues. So yes your right i should probably try at 850 nm. weathers gone all silly again.

Looking at the QE responses the 462 MC is the better of the three, 90% and mm 80% than the 178mono, 50%.

Do you fancy testing the 850 with my 462mc? I am not currently using it much until the planets are higher up. I can post it over.

[neil phillips]

20 minutes ago, Kon said:

Looking at the QE responses the 462 MC is the better of the three, 90% and mm 80% than the 178mono, 50%.

Do you fancy testing the 850 with my 462mc? I am not currently using it much until the planets are higher up. I can post it over.

Yes i suspected as much. haven't looked into it. but damn the 178, is pretty low down isnt it. its awkward, because mono will do better in UV. But the the 462c better in IR. using a filter wheel i don't fancy changing cameras to do any combination. so stuck with the 178 for any false color. That's a very kind offer Kon. But i have a 462c here. Your a gentleman. much appreciate the generosity.

I don't think i am going to do well. until Venus enters the morning, i am learning all the time. I have two choices. Two or three captures as it starts to get dark around 26 degrees and falling. 3 short captures in and it hits a roof lol. Or setup in the other location. I get longer But by the time it clears the tree, its dropping to 22 degrees and falling. Its a waste of time for real quality i cant work with that.

The one thing you need with venus is get on it early ( so its high )  and work at it for 20 mins or so. I am just snatching in one location. and its too low in the other. I may keep a eye on how its behaving under good seeing the low location is likely better at least i dont lose it quickly. But as spring progresses the tree will get broader. even more trouble so. Yeah i am not in the ball park i don't think at this location. But will watch watch you guys are doing. Everyone is doing great. 

[Kon]

19 minutes ago, neil phillips said:

Yes i suspected as much. haven't looked into it. but damn the 178, is pretty low down isnt it. its awkward, because mono will do better in UV. But the the 462c better in IR. using a filter wheel i don't fancy changing cameras to do any combination. so stuck with the 178 for any false color. That's a very kind offer Kon. But i have a 462c here. Your a gentleman. much appreciate the generosity.

I don't think i am going to do well. until Venus enters the morning, i am learning all the time. I have two choices. Two or three captures as it starts to get dark around 26 degrees and falling. 3 short captures in and it hits a roof lol. Or setup in the other location. I get longer But by the time it clears the tree, its dropping to 22 degrees and falling. Its a waste of time for real quality i cant work with that.

The one thing you need with venus is get on it early ( so its high )  and work at it for 20 mins or so. I am just snatching in one location. and its too low in the other. I may keep a eye on how its behaving under good seeing the low location is likely better at least i dont lose it quickly. But as spring progresses the tree will get broader. even more trouble so. Yeah i am not in the ball park i don't think at this location. But will watch watch you guys are doing. Everyone is doing great. 

No worries at all!

It sucks about the tree and i noticed that my captures at lower elevations are awful. My best captures this season are at broad daylight. A bit harder to find Venus but I roughly know where it is now. 

 

Going back to filters, the 850 might not be too bad for an 8" Dob. I am not sure if you have seen this post a few months ago? Or would your advise be to go for a 742? You know I value and listen to your advise and so far it has paid dividends, including getting a mono camera 😄.

https://stargazerslounge.com/topic/406904-venus-irguv-feb-14th/

 

[neil phillips]

21 minutes ago, Kon said:

No worries at all!

It sucks about the tree and i noticed that my captures at lower elevations are awful. My best captures this season are at broad daylight. A bit harder to find Venus but I roughly know where it is now. 

 

Going back to filters, the 850 might not be too bad for an 8" Dob. I am not sure if you have seen this post a few months ago? Or would your advise be to go for a 742? You know I value and listen to your advise and so far it has paid dividends, including getting a mono camera 😄.

https://stargazerslounge.com/topic/406904-venus-irguv-feb-14th/

 

Your doing exactly the right thing. getting on it as early as possible. Where seeing is likely going to be best. Even in my high location its getting dark before i can get on it. Let alone focus and everything else. thats whats good about the morning return. rising into better seeing until too faint. 

I cant be certain. i haven't tested these filters with a 8" Its been sometime since i had a 742. Do more research. CN or where ever. Personally i think you would get away with 850nm. But dont hold me too it.

If it helps here's what Anthony wesley says. Was just looking for opinions 

to get a sense of how much IR detail you can expect to see with a 1000nm filter. I've tried other filters as well, eg 850nm longpass and 750nm longpass, they certainly work but the contrast is lower.

 

 

[neil phillips]

Seems to suggest 850nm will have higher contrast no ? 

[Kon]

33 minutes ago, neil phillips said:

Seems to suggest 850nm will have higher contrast no ? 

I need to get my head around it as 850 or less has higher energy compared to longer wavelength, 1000nm. Therefore, the shorter wavelength should give us better signal to noise compared to  longer wavelengths .  But why the contrast is better is a bit unclear.

[neil phillips]

52 minutes ago, Kon said:

I need to get my head around it as 850 or less has higher energy compared to longer wavelength, 1000nm. Therefore, the shorter wavelength should give us better signal to noise compared to  longer wavelengths .  But why the contrast is better is a bit unclear.

Good question. But coming from Anthony Wesley. its likely correct. But of course one could ask how much did he try the other filters ? And of course better signal to noise. with the shorter than 1000nm. but is that less of a hindrance. Noise can be controlled with more frames

Edited April 22, 2023 by neil phillips

[Chrissyfbpe]

Well done Neil on getting 2nd in the terminator challenge and 3rd in the pick a planet 2022.  I can barely use a telescope, I wouldn't even know how to setup a camera on it to take photos 🤷‍♀️

[neil phillips]

7 minutes ago, Chrissyfbpe said:

Well done Neil on getting 2nd in the terminator challenge and 3rd in the pick a planet 2022.  I can barely use a telescope, I wouldn't even know how to setup a camera on it to take photos 🤷‍♀️

Hi Chrissy if you ever want to know something start a thread, or message. I am sure someone can help. Welcome to the forum.

[Pete Presland]

Nicely imaged, very interesting discussion about the different filter wavelengths. i have never manged any details with any filters other than the UV, that said i dont think i have been trying hard enough. I know there are plenty of I/R images showing cloud details online.

[Kon]

1 hour ago, Pete Presland said:

Nicely imaged, very interesting discussion about the different filter wavelengths. i have never manged any details with any filters other than the UV, that said i dont think i have been trying hard enough. I know there are plenty of I/R images showing cloud details online.

I feel if conditions are good IR can pull some nice details in the same way colour images do. But of course UV will have the best results.