Canon 17-40mm f4 for night photography

[Sylar]

Hi all
Well i made it to Antarctica and am posting this thread as i look out my window over newcomeb bay and think of the time that will come when the darkness will be upon us and the aurora will be in the sky and wonder will a Canon 17-40mm f4 be good enough for night photography? Is f4 ok for night photography or should i be looking at something in the f2.8 realm? the 16-35 looks like an awesome lens and am yet to read a bad review but $1700 for a lens i will not use that much seems a bit steep where as the 17-40 is almost $1000 cheaper, is 1.2 stops worth 1k more?
I already own the kit 24-105 f4 and a 8-15mm fish-eye at f4 and so far i love both lenses that said it is daylight 24hrs a day hear at the moment so its not like i can go outside and take a few star shots and decide if what i have is good enough.
what recommendations can be made in the way of a good wide lens for night shooting?

[fabian628]

The extra stop of light from the 16-35 can be the difference between 15second and 30 second exposure, and you can get star movement in a shot where you do not want any. I'll let people who have experience shooting aurora let you know about exposure times (maybe having super long exposures is not an issue), however for most star shooting applications the faster the better, many people shoot the night sky with the 24mm f/1.4 to get an extra 2 stops over the 2.8 lens, keeping the iso lower, and getting faster shutter speeds so you can freeze the star motion.
Have a look for the 16-35mm second hand, you can get them a lot cheaper.

[fess67]

Ummm - is there a camera shop close by? YOu state that you are already there so unless Australia Post is able to freight the new lens to you I guess you are stuck with what you have. As far as your question goes, fabian pretty much nailed it, the f2.8 will allow you to use a shorter exposure time or lower ISO.

[Dylan & Marianne]

Sylar - depends on the body you have too.
the F4 will be OK at 6400 for the same exposure time that F2.8 can get you at iso3200 , so if your camera produces results at that extra stop of iso difference, then it would be OK but honestly, 6400 vs 3200 on the 6D and 5dmk3 is still a noticeable difference.
Aurora speaking, it's not so much of an issue as the ambient light will reduce your requirement for long exposures (talking about visible aurora and not the faint stuff that you happen to capture on very high iso long exposures).

[Sylar]

Ummm - is there a camera shop close by? YOu state that you are already there so unless Australia Post is able to freight the new lens to you I guess you are stuck with what you have.

It might shock you to know that Australia runs a, air link from Casey station so mail comes about once a fortnight until the end of February so getting a new lens is a hard as shopping on ebay or any one of the hundreds of online stores.

[ameerat42]

Meanwhile, have you tried your f/4 lens here at night?
Am.

[Sylar]

Meanwhile, have you tried your f/4 lens here at night?
Am.

i would love to however i havent seen the stars in almost a month now, its daylight for 24hrs a day this time of the year! closest i get is when the sun touches the horizon about 10pm at night then its back up and bright all day. We wont get stars for some 3 months yet.

I did get a good deal on a 16-35mm f2.8 mk2 and BG-E11 from ebay and have it on its way with some luck i will have it come early January so i think i should be set!

[ameerat42]

...I did get a good deal on a 16-35mm f2.8 mk2 and BG-E11 from ebay and have it on its way with some luck i will have it come early January so i think i should be set!...

Well, the f/2.8 should help. That lets in twice the light intensity of an f/4 lens - all other things being equal. Hope it works out. Update the thread when you've got it.
Am.

[William W]

I understand that you have purchased the 16 to 35/2.8. I suggest that if you do not what star trails you use that lens at F/2.8. I also suggest that you use the lens without a filter on it to lessen the likelihood of Ghost Images.

I suggest that you research what is commonly referred to as "The Rule of 600 for Astrophotography" also research details of that rule pertaining to the LATITUDE at which your camera is situated when you make the shot.

*

For the archive of this thread

If one wants to make images of night skies without star trails then the EF 24 F/1.4 L MkII on a 135 Format Camera Body (aka 'Full Frame') is the best Canon Solution, next would be the original 24/1.4L lens and then the 28/1.8 lens is a good budget compromise.

As already allude to, for Night Skies without star trails the SHUTTER SPEED is critical (unless you have a special gyro-rig for your tripod). And the necessary SHUTTER SPEED is attained by using a very fast aperture lens. Also a very fast lens allows a lower ISO to be used (for any given shutter speed).

Shooting near the poles, these facts can be more important than shooting closer the equator.


WW

[ameerat42]

...If one wants to make images of night skies without star trails then the EF 24 F/1.4 L MkII on a 135 Format Camera Body (aka 'Full Frame') is the best Canon Solution, next would be the original 24/1.4L lens and then the 28/1.8 lens is a good budget compromise.
...
As already allude to, for Night Skies without star trails the SHUTTER SPEED is critical (unless you have a special gyro-rig for your tripod). And the necessary SHUTTER SPEED is attained by using a very fast aperture lens. Also a very fast lens allows a lower ISO to be used (for any given shutter speed).
...
Shooting near the poles, these facts can be more important than shooting closer the equator.


WW...

William, I wouldn't mind a bit more explanation on these points. In particular, the last one sounds counter to what I think, ie, that there'd be less trailling (though more curvature)
in the star images nearer the poles than the equator.

Ta, Am.

[William W]

AM - yes thanks,

Considering what I was writing about earlier, I made sloppy wording for this sentence and it is confusing: "Shooting near the poles, these facts can be more important than shooting closer the equator".

Yes - if the OP has an F/2.8 lens and is at the South Pole (of the earth) and points the camera upward at a reasonable incline he should be able to use F/2.8 at most of the very wide angles (16mm to 24mm) and he should get very good results of images of stars, without trails.

WW


Addendum - AM, is that the only bit that you wanted clarified?

[ameerat42]

For myself, yes thanks, William. The two points above the one on the poles I thought might be expanded for people new to astrophotography.
Am.

[William W]

OK.

In simple terms, the earth is spinning on its axis and the camera is sitting on a tripod on the earth, looking up at the sky.
We don't usually think about the earth spinning when we take photos, because the people or things that we take photos of, are usually also on the earth and are spinning at the same rate as the camera.

If one sits in a train carriage and take a photo of the person in the seat on the other side of the aisle for example using 1/60s as a shutter speed the photo of the person might not be not blurred if the Subject is still and the photographer has a steady hand. But the background outside the window might be blurred because of the movement of the train relative to that scene outside the window . . . but if we could use a fast enough shutter speed so we could take a photograph and the scene outside the train would not be burred.
If we knew the speed of the train and the distance from the camera to the outside scene if the train and the Focal Length of the Lens and the format of the camera, we could calculate what shutter speed was necessary so the blur of the scene was not really noticeable in the final image.


The same applies to photographing stars: and we do know all the factors necessary to calculate the required shutter speed so that the stars to appear "fixed" the scene. This was how the “Rule of 600” was born (some use the “Rule of 500”). This is a “Rule of Thumb” so it is a guide only, much like the “1/FL Rule” is a rule of thumb to determine the shutter speed for Hand Holding and like that rule, it is a quick calculation that is to be used for 135 Format Cameras (aka “full frame cameras”).


The “Rule of 600”, says that if we don’t want Star Trails then we divide 600 by the Focal Length of the Lens and that will give us the longest Shutter Speed that we can use such that we do NOT see any star trails when viewing a ‘standard image’ at a ‘standard viewing distance’. For example, if we have a 16 to 35 mm lens on a 5D and we use the 16mm end of the zoom lens we can use a shutter speed as slow as 37.5 seconds [600/16 ≈ 38], but if we use the 35 mm end of the zoom we must use 17 seconds or faster [600/35 ≈ 17] to ensure that we do not have any star trails.

When using a smaller sensor camera, then the FoV effect is taken into account, for example if we use the 16 to 35 lens on a 50D, then we would multiply the focal length used by 1.6. So for example using the 16mm end of the zoom lens, we would need 23 seconds to arrest the movement of the stars [600/16*1.6 ≈ 23].


The “Rule of 600” can be honed more tightly to best address the Latitude of the position of the camera on the surface of the earth and also the inclination of the camera, upward from the horizon and also many other factors, which I will not discuss here, but are readily researchable.

Some photographers use 500, or even 450 to replace the 600 in their “Rule” – obviously using any smaller number that 600 will result in a shorter shutter speed for any given circumstance.

So this is why a really fast lens (i.e. large maximum aperture lens) is usually sort after for this type of astrophotography; and this is why I mentioned the 24/1.4, because that lens can be used at F/1.4 to make a shutter speed of about 25 seconds or less and the Photographer can use the lowest ISO possible to achieve the shot.


Here is a comparison example.
Let’s assume that we needed an exposure of: F/2.8 @ 25 seconds @ ISO1600 for a particular nightscape scene –

> If we use the EF 17 to 40 F/4 lens on a 5D and we set the lens at 24mm, we would need to use the ISO 3200 (i.e. “H” on a 5D) to get the required 25 seconds exposure.

> But if we had the 24/1.4 lens we could use ISO 400 for the same shot.

WW

[Bax]

Good post William.

Any thoughts about chromatic aberration? I've read that mist lenses should be stopped down to avoid it. Sounds counter intuitive to me because I'd want as much light as possible. Especially with my terrible sensor.

[William W]

Any thoughts about chromatic aberration?

Photography is full of compromises. I have an EF 24/1.4L and if I want a night sky without star trails, CA would be the least of my concerns; I would want to use a low ISO and a short Tv (Shutter Speed).

Some Chromatic Aberrations can be removed or at greatly least reduced in Post Production and that is not a difficult task.

WW