Moon, without disturbing flickering of the air

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I wanted to take an astronomical image. The night was clear with very few atmospheric disturbances. Focusing (Live View) was a challenge as the tripod still resonates after adjusting the focus ring. I used an old Linhoff studio tripod, which is built like a tank. Nevertheless, it takes 10 seconds for all the vibrations to settle. In the end, it took 15 attempts to get the photo in this state. In post-processing, I manipulated the contrast and toned down the light yellow tone of the moon.

A6400, MC Rubinar 5.6/500 macro mirror telephoto lens
Exposure time 1/250s - ISO 100 - 50% crop
Processed with PL7

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Quick question - how did you test for the resonation in the tripod, to know when it was safe to capture an image?

500mm lens, f/5.6, ISO 100, 1/250th ?

I would have guessed that an old Linhoff studio tripod wouldn’t have had those vibration issues - would adding more weight on top of the tripod have helped?

I’d like to try this again. I hadn’t even considered tripod vibrations last time I did this. Fascinating!

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The earth rotates quite quickly, which means that stars and planets move faster in the lens than expected. Astronomers have been working on this for some time and FrĂ©dĂ©ric Michaud has developed two formulas (NPF) which determine the minimum exposure time necessary to avoid distorting stars into stripes - unless this is intentional. (La RĂšgle NPF – SociĂ©tĂ© Astronomique du Havre) The website and calculator are in French, but you are sure to find a calculator for many languages. In practice, this means increasing the ISO value until the exposure time is significantly less than the limit time determined according to the NPF. According to the NPF formula, the longer the focal length, the shorter the exposure time must be for the same ISO - which is logical.

On the day the photo was taken, the moon was close to the earth, i.e. bright enough to photograph at ISO100. The exposure time in this case was indeed 1/250s. We have PL for denoising higher ISO values :-). The swinging of the tripod can be recognized with practice via the Liveview. Add a little waiting time and it’s fine. It is also important to deactivate all image stabilizers and work in manual mode.

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Hi @gserim

Just to let you know how I photographed the moon


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Nikon D810 with AF VR Zoom-Nikkor 80-400mm @ 400mm, f/11, 1/250sec, ISO 200.

Handheld thanks to the VR.

You must never forget, to photograph the moon, the exposure need only be the same as the Sunny 16 rule for shooting in full daylight, minus one stop. (100 ISO, 1/100 sec @ f/11)

But, since we are using DxO’s excellent noise reduction, were I to take it again, I would crank up the ISO to give me a much faster shutter speed.

You could easily manage 1/5000sec @ f/10, ISO 4000 for the same exposure.

I would ask why you were adjusting the focus whilst shooting? Once you have manually set the focus on the edge of the moon, you should never need to touch it again.

Oh, and the maximum time before the movement of the moon becomes evident is around 6 secs.

Thanks for that link. There is actually an English version of the calculator under the French one.

I have always used the 500 rule for star photography (slowest shutter speed should be faster than 500 / focal length. But that does give very short trails and I look forward to trying this calculator, since I see it takes into account pixel size.

I look forwards to trying the “full NPF” exposure at higher ISO and seeing if DeepPRIME XD2s can remove the noise without losing too many stars.

But, as always, in anticipation of night sky photography, The skies over the north west of Bretagne are covered in cloud for the next week or so :crazy_face:

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Using my DSLR I currently have a limit of 300mm, my longest lens. That means a lot of cropping. As Joanna noted, hand-held seemed adequate, with a high shutter speed just to be safe.

This is the best I’ve been able to do, but I wanted something “extra”. It’s real, not fake:

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When/if I get a longer lens, I want to try again for the moon, on an especially clear day, when there is a full moon.

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Mike. Send me the original and I will put it through Topaz Photo AI to enlarge and sharpen it.

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I don’t see the moon. I see a plane :wink:.

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Sure, will do. The ‘raw’ file from my camera. I’ll also send you my photo of an A380, but the profile was far too large to fit within the moon. Thank You!!!

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Wow, I’ll look for a test drive opportunity.

I’ve already used it to stack individual frames of a video with a variable focus. Is pointless with a moon view :slight_smile:

The times are usually significantly higher than those calculated using the NPF rule.

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And this is the best I could do


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 which really isn’t that much better at all, if not slightly worse. The biggest problem was a simple lack of pixels.

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Thanks for trying. I can live with this. :slight_smile:
Very happy to do so.
Your image seems “smoother”, if that is an appropriate word?