Trying & Testing

I am trying to figure out which of my lens and camera combination might be the best when it comes to sharpness, when taking photos of the moon. Well, it is rather tricky to say the least.

In terms of 100% pixel resolution - they all suck quite a bit. And that is mainly because when the air is moving and "glimmering" - you never really get plain sharp images. Especially not when the moon is low above the horizon. It is like trying to take a moon image over a fire !!

Overall, the Russian 500/6.3 mirror lens is at 100% screen resolution the least sharp one. Albeit, when you use a little AI and stuff, as well look at the photo at 50% - then it looks nice. And in that state comparing it with other lenses, adapters and cameras... there is not much visual difference, really.

I also tried something new.

Normally i can't use the Sigma SPORT 60-600mm lens (originally with Canon EF mount) on a Olympus OM-1 camera. But forgot that i have a Viltrox EF M2 II 0.71x focal reducer. That way, I was able to use the Sigma lens with the Olympus OM-1 camera. And the results where very good compared to all other combinations.

In effect a 850 mm ƒ 4.8 lens

So, the 600mm ƒ6.3 gets reduced to a 426 mm lens - but because the Olympus OM-1 crop factor of 2x = you end up with an effective 850 mm ƒ 4.8 lens aka 1 stop brighter. Sharpness seem to be a notch better even (The focal reducer gives 1 stop brighter image, and is said also to reduce optical errors by a notch).

I am VERY pleased how well this worked between Sigma 60-600mm, Viltrox 0.71x reducer, and the Olympus OM-1 camera. I like this combination very much (albeit ONLY as a manual focus lens, unfortunately because AF sucks and goes wrong with the Viltrox adapter).

Overall, the results seem to be a notch better, than when Sigma SPORT 60-600mm (at 600mm) is mounted on the Canon EOS R6 fullframe camera. The latter however does focus very well. While with Olympus OM-1 + Viltrox 0.71x adapter it doesn't work well at all.

The only advantage with the Russian lens (being a 1000mm lens on Olympus OM-1), is its relative "compact size" and "relative low" weight around 1.5 kilo. But still... the Sigma outperforms the Russian lens - do doubt ! Since I can use the Sigma zoom with the Olympus... it does open interesting views in the future.

I mean 850mm isn't bad - especially when the optical quality is a lot higher compared to the Russian lens.

What about Olympus 300/4 IS PRO (600mm) ?

I have to make new images) of the moon, with tripod and the Olympus ED 300/4 IS PRO lens (in effect a 600mm ƒ4 lens), as well with the 1.4x converter turning it into an effective 850 mm ƒ 5.6 lens. After all, this lens is my best super-telephoto lens i have among lenses.

In this moment - clouds have emerged now, which means i have to wait until those are gone. Or doing tests in the future when the night sky is clear again (and the moon is above the horizon)

Russian 500mm f 6.3 lens with Olympus OM-1 = 1000mm. The moon was only 3 or 4° above horizon... air flimmer was extreme = unsharp photo

500mm f 6.3 lens + Olympus OM-1 = 1000mm • Moon higher, but air was still unstable = quite unsharp photo but i did use AI sharpening.

Sigma SPORT 60-600mm = 600mm on Canon EOS R6

Sigma SPORT 60-600mm + Viltrox 0.71x = 850 mm ƒ 4.8 on Olympus OM-1

Overall

ALL images regardless combination - where not critically sharp when zoomed in at 100% without any use of sharpening. By using some AI sharpening, and making the images 50% smaller - you could benefit from a visually much better image, as things looked suddenly, much sharper.

The best quality combo was however Sigma 60-600mm with Viltrox 0.71x reducer mounted on the Olympus OM-1 camera. Tightly followed by the Sigma 60-600 mm directly mounted on the Canon EOS R6.

Since both cameras have 20 MP, sensors - you get a larger moon image with the Olympus OM-1 due to its almost 4 times smaller sensor (2.0x crop factor, while the EOS R6 has a 1.0x crop factor aka is a fullframe sensor.

Unsettled air is the largest enemy.

The higher the moon, the better sharpness you get. Preferably when the air layers are more stable. I think today the air is unstable, due to a strong jet stream present (i would guess is what that causes stronger movement in various air layers across the atmosphere)