Starscape question R6 mki

I've noticed that the only way I can capture stars without streaking is shooting an exposure of 2.5 seconds or less. If I use a longer exposure nothing in the sky is sharp. I first noticed on an RF 35 1.8 and the other night on an EF 100-400L f4.5 approximately 100mm focal length) mechanical shutter. Is there a trick or something I'm missing on long exposures?

Without knowing the elevation and direction you are aiming your camera a 4 second exposure would be the best you can hope for. Shooting at 100mm you will get streaking at about 2 seconds.

I have a 24mm f/1.8 and a 15-35mm f/2.8. If you used those lenses you could shoot 6.5 seconds with the 24mm and 12 seconds with the 15mm.

The take away from this is the widest aperture combined with the wider angle allows for longer shutter speeds without star blur. If I used my 100-500mm at 500mm and the widest aperture of f/7.1 my shutter speed would need to be less than 1/2 of a second.

Check out Shutter Time Calculator on The Lonely Speck website. Personally I use the Photopills app because I have my phone with me.

Thank you that's what I was guessing

To get sharp and bright stars the only real option is to get a star tracker to mount the camera on to follow them across the sky.

Deepgreen said:

To get sharp and bright stars the only real option is to get a star tracker to mount the camera on to follow them across the sky.

Click to expand...

...and if you can't afford a star tracker, then stacking using software is a great option. Of course this involves also taking flat frames, dark frames and bias frames. But that's probably more than you are interested in at this point.

I would love to have a tracker myself.

The 'Star Adventurer' series is not too expensive - mine was about £300 a few years back - if you can afford a good-ish camera, it's not too much on top of that. It gives quite nice results: