Is there a method/trick when focusing at stars or distant objects?

[Red Squirrel]

I find when taking night sky pics it's hard to tell in the viewfinder if I'm properly focused or not, and sometimes I think I am but the pictures end up blurry. Ex: when taking closeup pics of the moon, or far pics of all the stars. Especially stars as I will barely be able to see them in the viewfinder let alone know if they're in focus.

Is there a method to getting this right? Autofocus does not really work all that well in such situations so I set to manual.

 

[CuriousMike]

I'll be curious to hear this as well.

I've heard "try focusing on a far away tree" ( at night with no moon-light, never going to happen ) to "set the focus on a far-away tree before it gets dark - i.e., note where your focus indicator is at and manually focus to that spot at night. "

 

[DrPizza]

Manual focus at infinity? If your lens doesn't have a mark for where infinity is, then focus on the moon when it's up during the day; play with the focus until it's as clear as you can get it with your lens. Then, you'll know.

Maybe try liveview and attempt to focus in on a really bright star manually - just focus until the bright blob is as small as possible? Or, maybe attempt to focus on a street light that's at least a couple hundred meters away?

I also presume you're using a tripod? How about using the timer - a second or two after you press the button to take the picture - to eliminate any vibration to the camera?

And thanks - reminded me to go out and attempt this myself. Going to try some time-lapse astrophotography over the lake this weekend; I should probably see if I run into the same problem you're running into. (Problem #1 that I ran into - holy cow does it take a long time to render a 720p video in lightroom 5, on my wife's laptop.)

 

[Red Squirrel]

I do use a tripod, but what appears clear on the LCD screen is sometimes blurry once you look at it fully. Ex:



Could have been focused a bit better than that but hard to tell when looking at it through the viewfinder or even on the LCD after taking a pic.

The camera also still shakes a bit from movement or wind, the tripod itself is solid, but it shakes at the connection given it's just a single screw. Not sure what is the best solution for that, maybe a secondary tripod that I connect at the camera too so it has two points of support.

 

[iGas]

As said set lens at infinity in manual mode. Use a good tripod and weight down with sandbag or bag full of equipment, and use mirror lock up with remote shutter release or timer. Close down aperture and shoot at f11 and ISO 50 or slower.

 

[DrPizza]

I think I read somewhere the idea of putting a small sandbag on top of the camera. Do you hang a weight from the bottom of the tripod? And, no moon yet out back; I should check out front. Not a great night here for stars; a bit of a haze blocks the light from many.

 

[Red Squirrel]

The movement is actually right at the connection of the tripod, basically the part that holds the lens is where the movement is. (these big lens have their own tripod mount, you don't mount the camera or it would be too top heavy) So a weight or sand bag would just move along with it. though I may have to try my idea of using two tripods, one at the lens and one at the tripod. Will be a bit harder to aim though, I can adjust the legs on one of the tripods to do that, I guess.

The more I look at it though I think it is infact the movement that is causing the blur. IT may look like it stopped shaking by the time I take the pic but there's probably still some movement. With a regular lens it's not as bad.

Also if I set to infinity it's totally blur, the sweet spot is somewhere in the middle, it's just hard to know if it's exact as I'm going by my eye in the dark. I guess it's a trial and error thing, can try a pic then zoom in on the LCD. I can also use a nearby cell tower as reference, it seems if I focus to the antenna then the moon and sky is not too bad. I would need to do this during the day perhaps then not touch the focus and wait for night.

Went out just now to mess around real quick.


Took this one at a faster shutter speed and just enhanced a bit.


This one is unmodified, but guess it's still fairly clear, maybe only slightly out of focus.

Can't set F stop on my tele lens unfortunately.

Here's a few I tried with a 35mm, they seem clearer, so maybe tripod shake is really my main issue and not my eye sight/ability to see if I'm well focused.

 

[iGas]

I think I read somewhere the idea of putting a small sandbag on top of the camera. Do you hang a weight from the bottom of the tripod? And, no moon yet out back; I should check out front. Not a great night here for stars; a bit of a haze blocks the light from many.

Taking pictures with long heavy lenses exacerbates vibration, and then earth rotation/blur as is another factor.

Sand bag on top of the camera works, but you can hang more weight at the bottom of the tripod to dampen the tripod motion. Other motions that you want to minize are lens focus/zoom creep, off center lens and body weight creep, mirror and shutter motion.

Use sturdy tripod & weight it down to dampen tripod.
Use good tripod head to lock down the lens/camera body.
Turn off IS/VR/OS.
Use elastic bands or insulation cup sleeve to stop lens creep.
Use mirror lockup and remote shutter release or timer to eliminate mirror movement.
Use bulb mode and black card to stop shutter movement (move the card off the front of the lens to expose, and use 4-30 second time to minimize timing expossure error & earth rotation blur).

 

[Gintaras]

No tripod, handheld:

 

[Gintaras]

google, practice..google...practice...etc...

When I first bought 70-300mm lense, it took about a 1/2 year to get sharper photos...
Photos above taken with Olympus E-520 with Sigma 50-500 lense - no tripod, handheld.

Cameras don't have "Perfect Moon Shot" button...so, if you want to get better shots - you have to learn...

It may take a months or years...

 

[bigi]

read me

I also have learned to do a bunch of test shots at highest ISO to see what's going on. Once all is working to my liking, dial down the ISO and you good to go.

 

[Smoove910]

for moon pics, use the manual setting, F11-F13 with shutter speed around 1/125th. Any slower, the moon will blur since you are sitting on an object that moves (Earth) trying to shoot another moving object (moon).

Here's a shot from the recent supermoon... not the greatest, but gives you an idea. (Pentax K5, DA 55-300mm)

 

[Smoove910]

As for stars, having a large aperture is key. I thankfully have a manual focus Rokinon 14mm F2.4 which works well for my application (wide landscape shots). Set to infinity, 30 second exposure to gather all the light from the stars. Any longer than 30 second exposure will exhibit star trails, which I personally don't care for.

Here's an example of a 14mm, 30 second exposure at ISO 800.

 

[Red Squirrel]

Wow that's pretty awesome, I never get that much detail like nebulas and stuff, I'm guessing you need to be outside of town to do this? I probably get too much light pollution doing it just from the field in front of my house. Now that summer is mostly over it also will be getting darker at night, I'll have to go try again and maybe drive a few miles out of town and find a field for better results. The trick is still trying to actually focus but if I set it during the day on a really far object I might be ok. Just can't touch it after.

Also maybe I'm missing something but what exactly does it mean to set to infinity? I find the focus point where the moon and stars appears the most in focus is about half way on the focusing wheel, so it's not as simple as just cranking it to the end.

 

[Nohr]

I find a bright star or planet and manually focus with live view & 10x zoom. The extra magnification helps to make sure your focus is correct.

 

[zCypher]

damn, Gintaras, nice shots.

i use a combination of optical view finder and screen, there isn't really one sole way that works best for all circumstances. i look in the viewfinder and try to get the best focus there. i switch to the screen, zoom in on the screen as far as i can go, and adjust the focus accordingly for what i want as best as i can, then zoom back out and compose the shot.

that way, most of the time i'm able to get the right focus for what i'm trying to do. having no zoom and no focus to infinity, i haven't gotten any spectacular moon shots though. hopefully i will take a little trip out of town to try and capture some nice star skies this summer though.

 

[pontifex]

been trying to take photos of stars and get all blurry images. stars aren't bright enough to focus on through the viewfinder. sometimes i focus all the way out and it starts to get clearer but then i have no more room to focus.

try set to infinity but not always good.

using a heavy tripod, remote shutter release or timer. 20-30 sec exposure usually. tried using 200 ISO, 800, and 1600. Tried different lenses.

 

[Red Squirrel]

Yeah I still have not gotten it 100%, it seems even when it looks in focus on the LCD or view finder, it's still a bit slightly off. I usually just take a whole bunch while slightly adjusting and sometimes get a nice one. I need to get a secondary tripod though, if I can put a tripod on the lens and one on the camera it will be much more steady as there will be two points of contact then I can put some weight on both tripods. Will be a bit more work to align though. But if I can get a really steady shot to any area in space it can make for some pretty cool time lapse videos too.

Too bad winter is already around the corner though, I really did not play with my camera as much as I wanted to. Too cold in winter to be outside with it, hard to operate with gloves.

 

[Spoooon]

That's awesome Smoove. I've just not had the greatest luck with stars.

I focus to infinity and am familiar enough with my lenses to know the ones that actually focus past it or not.

f/3.5, 30 seconds

 

[Imp]

Didn't read thoroughly, but are you using a timer or remote for the shot? Either would minimize movement from hitting the button. I have terrible hand control and learned to use a 5 second timer to limit the vibration and use both hands to help stabilize the tripod.

 

[Red Squirrel]

Yep using remote. I usually look in the viewfinder without touching it and wait till the lens is done moving from the last time I touched it then take the pic. Though it could be taking the actual shot makes it move enough too. If I do my idea with the two tripods that may solve that issue.

Though even day shots where I can get away with a really fast shutter speed I find it's hard to tell if I'm 100% focused. It looks in focus on the LCD or view finder, but once I bring the pic on the computer I realize I was not quite in focus. Though once I make my setup more stable it will be easier to just take a bunch of shots with very slight focus adjustments as I'll be able to touch the lens without having to wait for it to stop shaking. So I'll have to experiment further.

 

[Throckmorton]

I'm surprised you guys can't focus on stars. With my Sony cameras, the translucent mirror only sends 30% of light to the phase detectors, yet it can focus on a bright star. Or maybe that was only with f1.8 lenses, not sure.

So try a prime lens.

 

[Red Squirrel]

I'm surprised you guys can't focus on stars. With my Sony cameras, the translucent mirror only sends 30% of light to the phase detectors, yet it can focus on a bright star. Or maybe that was only with f1.8 lenses, not sure.

So try a prime lens.

Oh my photo lens is like F16 when fully extended. No autofocus either so can't try that. Maybe that's another issue, I don't have the best lens either, it's a cheaper one I paid maybe 250 for so maybe I'm just expecting too much of it.

With regular lenses the focusing seems to be slightly easier, that or the fact that I'm not getting so close to objects so it's harder to see if it's blurry.

These ones turned out not too bad with 18-105 kit lens (can't recall what I had it set to but it was a rather long exposure)

 

[Throckmorton]

Don't you need obscenely long exposures for f16?

 

[Red Squirrel]

Don't you need obscenely long exposures for f16?

Straight at the moon I can get away with under 1second but stars I want a few seconds typically, so I do expect some star trailing due to that.

Stars are tricky just to even aim at let alone try to get it in focus but I did manage to get saturn, you can sorta see the rings.



If I manage to catch a clear sky day again before winter comes I'll have to take it out again. I need to find a field or something I can go in out of the city so there's less light pollution too.