Problem when shooting high-res moonshots ... help appreciated ...

[f6cvalkyrie]

Last night I experimented with the high-resolution mode of my Oly E-M1X and lens Panaleica 100-400/4-6.3 ... for moonshots ... the sky was cristal clear and the temperature was -19°C ...

I've already used it without problems for daily shots, but "moon shots" remained a problem for the time being ... sometimes blurry images and sometimes an error message after the capture ... so doom and gloom ...

Yesterday I mounted the camera on a (not particularly sturdy) tripod, set the high resolution to 'tripod', and dialled in an 8 second delay between pressing the shutter button and the actual shot, to avoid any juddering... so I should get good pictures with a resolution of 80 Mp.
In the RAW processing program CaptureOne v22 I was able to edit the images without any problem. But, the sharpness still leaves something to be desired, in my opinion ... it doesn't look bad, but it's not razor sharp ...

Apart from a better tripod and longer delay, what else could I do better ???

Here's the best view from the session...

 

[AlanS]

What is the shutter speed?

 

[MGrayson]

Some back of the envelope: The moon is 1/2 degree wide. It moves basically 360 degrees/day (I'm ignoring the moon's actual motion, as it is 360 degrees/28 days), so that's about 1/100 moon diameter every second (720/(24*3600) = .008333...). So even at 1000 pixels across, that's 10 pixels/second, which is a lot for a supersampling algorithm. I think you'd need a motorized mount.

 

[AlanS]

That's where I was going with my question Matt.

 

[Shashin]

Crystal clear nights are also the nights with the most atmospheric turbulence. The atmosphere can be a major issue. Planetary and lunar astrophotographers tend to take multiple images so they can choose the best/sharpest frames to stack. Fortunately, the moon is bright and so exposure times can be short, which helps, but does not eliminate the effects of the atmosphere.

Also, 400mm is not very long. This is an image taken with an Olympus E-P1 on a tracking mount and a 1,250mm telescope on a slightly hazy night and not cropped:

 

[MGrayson]

Funny (and true) story. I was at my father-in-law's 90th birthday party. Sitting at my table was someone who worked on the Event Horizon Telescope project. I pointed out that the angular resolution of that array was so good that this would be the image of Neil Armstrong's famous footprint as seen from Earth. (Blur filter set to correct radius...)



Now the EHT doesn't work at short enough wavelengths to actually take that picture, but it was much more visceral than 0.000..001 arc-seconds. I got an enthusiastic "Can we use this?". Fine with me, but I've never seen it used since.

 

[Shashin]

Well, NASA has a better picture of that...

Arc-seconds is such an intuitive unit, especially to a larger number of decimal places.

 

[f6cvalkyrie]

hi, thanks for your inputs ...
Shutterspeed was 1/800 sec ... shouldn't that be short enough to eliminate the need for a tracking mount ?
I do get sharp moon pictures when I do not use the high-res mode of my E-M1X

CU,
Rafael

 

[MGrayson]

hi, thanks for your inputs ...
Shutterspeed was 1/800 sec ... shouldn't that be short enough to eliminate the need for a tracking mount ?
I do get sharp moon pictures when I do not use the high-res mode of my E-M1X

CU,
Rafael

It’s not the shutter speed. It’s the frame rate. For a single shot, the shutter speed counts. For a multi shot, they all need to be VERY close in time.

 

[f6cvalkyrie]

I have been exercising with these High-Res moonshots every night with clear skies (not very often here in wintery Russia) and have found that handholding with a short shutter delay gives the better results ... this is from yesterday evening ...

Stay safe while you're having fun,
Rafael