ISS - first effort

[Tommohawk]

Thought this might be a bit of a challenge - and so it proved!

I hit on the idea of using my dual mount with the Quattro for imaging with my ASI290MM - no powermate to start with - and my EOS550D with the Sigma 17-50mm lens as the finder. To align the viewfinder with the scope image, I got Vega in the imaging window, and used the alignment box on the EOS liveview to set Vega in the middle of the camera liveview screen. The plan was that when imaging, I would get the ISS in the camera viewfinder, and then progressively use the 5x and 10x liveview enlargement to refine the centration.

Once I'd cracked the basic technique, I would add in he 5x powermate, and Robert would be my uncle.

Couple of snags. I didn't have the mount powered up, since I was only going to pan manually, but this made it difficult to do the basic focussing, because of the pesky Earth rotation issue. So next time I'll power the mount, and then just undo the clutches to pan.

Filters - no idea. Any offers please? I tried the L filter just to get the fastest exposure, although TBH the L filter on planets is pants. I thought I read somewhere that orange was the way to go?, but I don't have an orange filter - maybe red?

Exposure - no idea. Somehow 1 ms sounds about right, but 1/1000 sec sounds too slow. (Yes yes, I know its the same) In fact I had an earlier effort with 1 ms and it all burned to blazes.... so I settled on 0.1ms. I could have turned the gain down but I wanted the fastest exposure I could get.

In fact the technique works quite well - finding the ISS in the camera viewfinder, lens at 50mm and then, doing 5x and then 10x does work. Panning is a nightmare - I had a couple of dummy runs and found that fully extending the tripod helps, but I was still pretty much sat on my backside when the ISS was overhead.

So - the ISS flashed on and off the screen a few times, and I was all done. 

Outcome. Image not great, maybe exposure needs tweaking, maybe filter? My laptop gets the claimed maximum FPS with reduced ROI, say 381 fps at 640x480, but doens't get near the maximum claimed FPS of 170 with the full 1936 x 1036 size. Not sure why it gets claimed rates at the reduced ROIs but not at full size - any thoughts? (Firecapture USB3 10 bit, 80% USB traffic, RAM buffer enabled)

So instead of 170 fps I got 19fps !! What's that all about? I used PIP to break up the AVI into TIFFS, rejecting empty frames, and got 408 frames, so that's pretty good - best efforts below, not stacked or processed:

Comment or criticism very welcome, thanks for looking. Not sure I've got a steady enough hand for the x5 powermate - might be worth a go just for a laugh!

[Davey-T]

Good job Tom, I haven't tried it for a while, usually think of it as it sails overhead while I'm busy doing other stuff , I just use the DSLR and set it off on fast continuous as it flashes through the view, works about 50% of the time 

I have 2 mounts that can track the ISS but haven't got around to trying that either, must be tricky panning by hand.

Dave

[tooth_dr]

Gotta be happy with that! Well done. Superb result  

[Sunshine]

Ok that's cool as all hell! i have to try that, not sure where to start lol.

[TheMan]

very impressive

[cletrac1922]

One of my club members recently imaged ISS passing in front of the moon

Hit and miss affair

Focused on the moon, and took series of shots, and bob your uncle

Image this months edition of Event Horizon, club website

http://sas.org.au/

 

 

[Demonperformer]

That is very good.

I prefer the one on the right.

Could I suggest that maybe the exposure could do with being even shorter if you were to try again and that might bring out even more detail?

[Tommohawk]

21 hours ago, Davey-T said:

Good job Tom, I haven't tried it for a while, usually think of it as it sails overhead while I'm busy doing other stuff , I just use the DSLR and set it off on fast continuous as it flashes through the view, works about 50% of the time 

I have 2 mounts that can track the ISS but haven't got around to trying that either, must be tricky panning by hand.

Dave

Hi Dave - yes I saw your 10Micron in action - it looks well capable of tracking the ISS, Fancy a swap... with my EQ3?

Panning by hand is tricky - but doable with FL1000mm. I think adding in the 5x powermate would probably make it more of a challenge though! My DEC axis bearings need adjusting - the drive is smooth but movement with clutch released seems a bit jerky. Once I've fixed that I'll have a go with the powermate.

If I could get the frame rate up I could just try focusing on a target in the ISS path and let is pass through - but at 20 fps its a long shot.

15 hours ago, Demonperformer said:

That is very good.

I prefer the one on the right.

Could I suggest that maybe the exposure could do with being even shorter if you were to try again and that might bring out even more detail?

I agree it does still look overexposed - however on some of the earlier shots where the solar panels are showing better, they look underexposed. 

Also maybe I should try reducing the gain - the noise isn't usually a problem when I'm doing planetary work and stacking 10s of thousands of frames, but with single frames it really shows.

In one clip where the ISS whizzed through the frame I managed to get about 15 consecutive images - but stacking them didn't really improve the image. Again if could improve the frame rate I out to get up to 170 fps and in the same clip I'd have maybe 100 consecutive frames - so stacking might then improve the image.

If I do try with the powermate Ill have too keep the gain high coz I'll need to increase the exposure by a factor of 5 ish I guess.

I cant help wondering if a filter would help - any thoughts anyone?

Thanks for all the other comments and likes!

 

[RayD]

21 minutes ago, Tommohawk said:

Hi Dave - yes I saw your 10Micron in action

I haven't yet ?

Look forward to finally seeing it working next weekend, Dave 

Great shots, Tom, it's a tough target and I think you've pulled it off really well.

[Tommohawk]

9 minutes ago, RayD said:

I haven't yet ?

Look forward to finally seeing it working next weekend, Dave 

Great shots, Tom, it's a tough target and I think you've pulled it off really well.

Thanks Ray!

BTW isn't astrocamp this weekend, 5-7th? Maybe you're thinking of a different event? Or I have the dates wrong? 

Unfortunately I cant make either one though.

[RayD]

34 minutes ago, Tommohawk said:

Thanks Ray!

BTW isn't astrocamp this weekend, 5-7th? Maybe you're thinking of a different event? Or I have the dates wrong? 

Unfortunately I cant make either one though.

Yes it is, Tom.  Unfortunately I can't make this weekend, but Dave is at Lucksall next weekend so I hope to see it working there.  It's a very fine piece of engineering.

[Demonperformer]

7 hours ago, Tommohawk said:

If I do try with the powermate Ill have too keep the gain high coz I'll need to increase the exposure by a factor of 5 ish I guess.

Doesn't exposure meed to go up by the square of the power, which would make an increase by a factor of about 25x?

[Stub Mandrel]

Better than my effort!

[johnfosteruk]

32 minutes ago, Stub Mandrel said:

Better than my effort!

And yours is better than mine!!!

[Stub Mandrel]

58 minutes ago, johnfosteruk said:

And yours is better than mine!!!

I'm not so sure of that...

[johnfosteruk]

3 minutes ago, Stub Mandrel said:

I'm not so sure of that...

It clearly is, on the basis that you managed to keep it all in one place on the image, so to speak. I clearly did not.

Tom's on the other hand are marvellous, good to know it can be done manually, I'll have another go soon.

[Stub Mandrel]

51 minutes ago, johnfosteruk said:

It clearly is, on the basis that you managed to keep it all in one place on the image, so to speak. I clearly did not.

Tom's on the other hand are marvellous, good to know it can be done manually, I'll have another go soon.

Mine's a stack.....

[Davey-T]

ISS is transiting the Sun local to me tomorrow afternoon, may have a go at capturing it if it's shining and I can figure out exactly where I need to be, at least all I'll have to do is track the Sun and wait for it 

Dave

[Tommohawk]

On ‎06‎/‎10‎/‎2018 at 04:46, Demonperformer said:

Doesn't exposure meed to go up by the square of the power, which would make an increase by a factor of about 25x?

Ahhh - well spotted! 

I think I agree with you, notwithstanding the F ratio myth! That being so, I would need about 20x longer exposure (because the powermate is closer to the sensor than it is with the DSLR it was designed for and so gives rather less than 5x) so if I'm approximately doubly exposed at the moment, I will need say 10x more so 1ms. Give or take.

But 1 ms at 4000mm FL hand held is asking for a whole heap of blur. 

I looked at a thread somewhere - here - which gave a solution for tracking the ISS (or other satellites) using ASCOM/EQMOD with Stellarium. Might be worth a go - but the chance of the mount intercepting the path exactly at this sort of FL (small FOV) seems remote.

If it were possible that would make for a great video with serious stacking potential. I've got a 4 element apo x3 barlow somewhere - maybe I should try that... but optically I always found the Powermate superior.

On ‎06‎/‎10‎/‎2018 at 23:51, Davey-T said:

ISS is transiting the Sun local to me tomorrow afternoon, may have a go at capturing it if it's shining and I can figure out exactly where I need to be, at least all I'll have to do is track the Sun and wait for it 

Dave

Any joy with that Dave?

[Davey-T]

29 minutes ago, Tommohawk said:

Ahhh - well spotted! 

I think I agree with you, notwithstanding the F ratio myth! That being so, I would need about 20x longer exposure (because the powermate is closer to the sensor than it is with the DSLR it was designed for and so gives rather less than 5x) so if I'm approximately doubly exposed at the moment, I will need say 10x more so 1ms. Give or take.

But 1 ms at 4000mm FL hand held is asking for a whole heap of blur. 

I looked at a thread somewhere - here - which gave a solution for tracking the ISS (or other satellites) using ASCOM/EQMOD with Stellarium. Might be worth a go - but the chance of the mount intercepting the path exactly at this sort of FL (small FOV) seems remote.

If it were possible that would make for a great video with serious stacking potential. I've got a 4 element apo x3 barlow somewhere - maybe I should try that... but optically I always found the Powermate superior.

Any joy with that Dave?

No mate too many clouds 

Dave

[Jonk]

Imaging the ISS is definitely on my hit list of things to try.

My method will be to use the 16" dob and track it by hand in the finder and just see what happens.

I'll try it on a few satellites first to get the hang of it.

[Tommohawk]

11 minutes ago, Jonk said:

Imaging the ISS is definitely on my hit list of things to try.

My method will be to use the 16" dob and track it by hand in the finder and just see what happens.

I'll try it on a few satellites first to get the hang of it.

If you're doing visual for practice with a 16" Dob you might need some Ray Bans!

I think one of the problems is that the finder needs low enough mag to locate it in the first place, but higher mag to refine the centration once in the viewfinder - hence the idea of using the variable viewfinder mag on the EOS. The other thing is that using a right angled finder might be tricky - I'm guessing yours has this? In any event any kind of viewfinder at the top end of the scope will mean a lot of movement whilst panning and maybe slightly precarious when overhead? It must be doable somehow!

Good luck - be sure to post and let us know how you got on.

[Jonk]

I should have said, I have a Telrad and TS RDA so no mag. In theory it should be easy to follow and keep it fairly central, but the main magnification of the scope / fov of course will be key.

I will do it though! One day.