Canon 20-35mm f/ 3.5-4.5

hey guys..i have canon 20-35mm f/3.5-4.5 lens..And i have a problem with finding infinity focus..Does anybody have that lens and can help me?
Cause night shots are blurry,but i saw that other people with that lens have a great night shoots..
I have Canon eos 600D..(second lens 75-300 is usm)..
Thank you

How are you focusing now? If you're trying to use the distance scale on the lens, don't bother; they tend to be inaccurate on auto-focus lenses.
If the moon is out that's usually the easiest target. Go to Live View, aim at the moon, turn the focus ring until it's in focus.

tnx i'll try that too..And can u tell me wich lens is good for nice shots (but still not too expensive)..

For night shots you generally want something faster, which would take you to prime lenses.
With your mention of "infinity focus" and "night shots" I'm guessing you're either doing astro-photography or nighttime landscapes? If so, you'll want to use a tripod (if you're not already), and fast lenses.
Samyang makes some good inexpensive lenses that work well for astro (14mm f/2.8, 24mm f/1.4, 35mm f/1.4)

As said already, use Live View and focus on the moon, a planet, bright star, or even trees on the horizon if they're far enough away. I don't have that lens but infinity focus is usually just less than all the way to the long end of the focus ring. Figure out which way your lens focuses (if like every other Canon lens I've used you want to rotate it counter-clockwise to get towards infinity focus, and then just a bit back from the end).

If you're looking into another lens for this purpose, I would highly recommend the Tokina 11-16/2.8 as I've had a lot of success with it for celestial work. I've also heard great things about the Samyang/Rokinon 14/2.8.

Also as mentioned, ensure your tripod is sturdy enough for the shutter speed and focal length used.

Thank you guys..Yeah yellowt2 it is for astrophotography and night time landscapes..I have a tripod,and i will try one of those lenses..
jkdwings thank you
When i find something interesting i will post here for your opinion too..

What do you say about Canon EF 50mm f/1.8 STM for night shoots and astro?

The EF 50 f1.8 STM (and its predecessors) have issues with coma at the borders. Probably not the best candidate for astro.

jasamjunction wrote in post #17737449
What do you say about Canon EF 50mm f/1.8 STM for night shoots and astro?

take a look at what the 20-35 offers for field of view. My guess is that anything more than 35mm is going to be too long for your tastes … well, until you get up to the 200-400 range for detailed moon shots.

also, in live view, make sure to turn off AF first. there have been a number of times i manual focused and then when I went to press the shutter the camera auto focused to screw up my MF.

yellowt2 wrote in post #17733776
How are you focusing now? If you're trying to use the distance scale on the lens, don't bother; they tend to be inaccurate on auto-focus lenses.
If the moon is out that's usually the easiest target. Go to Live View, aim at the moon, turn the focus ring until it's in focus.

Agreed. Distance scales are certainly not accurate on most zoom lenses, however on some primes, especially the decent ones they can be quite accurate. Still for something as critical as this I would still manually focus in live view to be sure.

Anyway, to the OP, apart from the aperture, I'm not sure anyone said this was a bad lens for Astrophotography. OK, f3.5 isn't 'fast', but it's not that slow. Really 'fast' lenses like the 24/35 f1.4's and other 1.4 to 1.8 lenses tend to have bad coma and are thus not good for astro.

However (and I've never use this lens) the supposed king of inexpensive astrophotography lenses would be the Rokinon 14mm f2.8 from what I have been reading the last few years here. However, the Rokinon is mostly recommended to folks with 'Full Frame' cameras like the 6D etc.. It is also manual focus only - but you should probably be doing that for night photography (as mentioned with Live View) anyway.

The Tokina mentioned might be a better bet for you - AF and more versatility for when you might want to use it for something else.

thanks guys..

ejenner wrote in post #17738415
Agreed. Distance scales are certainly not accurate on most zoom lenses, however on some primes, especially the decent ones they can be quite accurate. Still for something as critical as this I would still manually focus in live view to be sure.

Anyway, to the OP, apart from the aperture, I'm not sure anyone said this was a bad lens for Astrophotography. OK, f3.5 isn't 'fast', but it's not that slow. Really 'fast' lenses like the 24/35 f1.4's and other 1.4 to 1.8 lenses tend to have bad coma and are thus not good for astro.

However (and I've never use this lens) the supposed king of inexpensive astrophotography lenses would be the Rokinon 14mm f2.8 from what I have been reading the last few years here. However, the Rokinon is mostly recommended to folks with 'Full Frame' cameras like the 6D etc.. It is also manual focus only - but you should probably be doing that for night photography (as mentioned with Live View) anyway.

The Tokina mentioned might be a better bet for you - AF and more versatility for when you might want to use it for something else.

I will look and take a view on Rokinon..Thank you for advice..I will search for it..

The Samyang/Rokinon 24/1.4 is also apparently very good for astro work - sharp and very little coma