Should I buy samyang 14mm if I already have 17-40L?

Hello
Ive been wondering if should I get the samyang 14mm f/2.8 for astronomy photography.
I already have the canon 17-40L and its kinda soft at f/4 at the left corner, and it doesnt have wide aperture.

Should I get the samyang 14mm? Will it be sharper at the corners than the 17-40 at 17mm at f/4?
There have been few times that the 17-40 wasnt wide enough for me, maybe I should try the sigma 15mm f/2.8 fisheye? Is it sharp wide open?
I already had a samyang 8mm, really liked it and sold it due to upgrading to 5DC.

The Samyang 14 is extremely sharp! Even in the corners. It is one of the sharpest lenses on the market. I think it is a really nice lens for astro photography.

I am thinking about buying the Samyang 14mm, but not quite sure if the lens does have the Full Time Manual Focus? How do I know the subject that I am about to frame is in focus? Sorry for such question because never owned a manual focus lens before.

I have both and the Samyang is incedible. While shooting I always don't have a good feeling when shooting with the Samyang because it has no AF confirm but when i look at the pictures on the computer - they are so SHARP!!! Compared to the 17-40 it is great.

Myduc1098 wrote in post #15894106
I am thinking about buying the Samyang 14mm, but not quite sure if the lens does have the Full Time Manual Focus? How do I know the subject that I am about to frame is in focus? Sorry for such question because never owned a manual focus lens before.

"Full Time Manual" is the word that you use to say that you have a autofocus lens where you can twist the focus ring although the switch is switched to AF.
The Samyang has just manual focus and it has no AF confirmation (this is the "beep" when something is in focus), but you can use Live View with the 5x or 10x magnifier or buy an AF confirmation chip.

lennartsw wrote in post #15894112
I have both and the Samyang is incedible. While shooting I always don't have a good feeling when shooting with the Samyang because it has no AF confirm but when i look at the pictures on the computer - they are so SHARP!!! Compared to the 17-40 it is great.

"Full Time Manual" is the word that you use to say that you have a autofocus lens where you can twist the focus ring although the switch is switched to AF.
The Samyang has just manual focus and it has no AF confirmation (this is the "beep" when something is in focus), but you can use Live View with the 5x or 10x magnifier or buy an AF confirmation chip.

This is GREAT information there Lennartsw. Thank you.
I've been lusting over 14mm 2.8L II for a long time, but find it too much money for just what it is (landscape), Samyang 14mm with AF confirmation chip is the way to go.

Bonbridge wrote in post #15893971
The Samyang 14 is extremely sharp! Even in the corners. It is one of the sharpest lenses on the market. I think it is a really nice lens for astro photography.

Its very good to know thanks

Myduc1098 wrote in post #15894106
I am thinking about buying the Samyang 14mm, but not quite sure if the lens does have the Full Time Manual Focus? How do I know the subject that I am about to frame is in focus? Sorry for such question because never owned a manual focus lens before.

For me its not a downside at all, I had the samyang 8mm and it was very easy to get image in focus, im sure Ill deal with the 14mm in the same way.
When Ill use it for astrophotography and then I just focus to infinity (or maybe HFD)
When Ill use it not for astrophotography (and filters dont needed) Ill stop it down to f/8 and focus to infinity or near it so everything will be in focus..

lennartsw wrote in post #15894112
I have both and the Samyang is incedible. While shooting I always don't have a good feeling when shooting with the Samyang because it has no AF confirm but when i look at the pictures on the computer - they are so SHARP!!! Compared to the 17-40 it is great.

"Full Time Manual" is the word that you use to say that you have a autofocus lens where you can twist the focus ring although the switch is switched to AF.
The Samyang has just manual focus and it has no AF confirmation (this is the "beep" when something is in focus), but you can use Live View with the 5x or 10x magnifier or buy an AF confirmation chip.

I see..
If ill buy the AF confirmation chip will it transfer EXIF data to the camera?
And if you shoot at f/2.8 and you focus to infinity, is it out of focus at 2meter away? Because I think Ill have to use HFD at f/2.8

TheNewLegend wrote in post #15893897
Hello
Ive been wondering if should I get the samyang 14mm f/2.8 for astronomy photography.
I already have the canon 17-40L and its kinda soft at f/4 at the left corner, and it doesnt have wide aperture.

Should I get the samyang 14mm? Will it be sharper at the corners than the 17-40 at 17mm at f/4?
There have been few times that the 17-40 wasnt wide enough for me, maybe I should try the sigma 15mm f/2.8 fisheye? Is it sharp wide open?
I already had a samyang 8mm, really liked it and sold it due to upgrading to 5DC.

I did, no regrets. Tha Rokinon rocks.!!

TheNewLegend wrote in post #15894182
I see..
If ill buy the AF confirmation chip will it transfer EXIF data to the camera?
And if you shoot at f/2.8 and you focus to infinity, is it out of focus at 2meter away? Because I think Ill have to use HFD at f/2.8

I don't think so because they not constructed for one special lens but work with all. But the important thing is that it beeps when your subject is in focus. You still have all EXIF datas except focal length and aperture.
What belongs the other question: Google "hyperfocal distance". As far as I know, it depends on if you are shooting full frame or crop.
When you use full frame, you have to set the lens at 2.35 meters to get everything from 1.17 meters to infinity sharp. If you use crop, you have to set it at 3.8 meters to get everything from 1.9 meters to infinity in focus.
But note that always just one point is 100% focused and the other points are a bit out of focus but still sharp enough.
There are several hyperfocal distance calculators in the web.

lennartsw wrote in post #15894297
Google "hyperfocal distance".

Yes, that is.


Also, you can create a depth of field scale and glue it to the lens, so you can focus without looking at the subject, just estimating the distance.

I do have a FF camera.
I used thiscalculator and it says I need to focus to 2.32m and the dof will be from 1.16m to infinity.
Im worried that the stars will be less sharp because I dont really focus to infinity.

I am interested in 14mm lens as well but I have Canon 5Dc which doesn't have live view. Looking only through viewfinder I noticed pictures I took with Rokinon fisheye lens were often a bit out of focus, so beside using focus confirm chip have you guys used viewfinder magnifier? I see 2x viewfinder selling for under $20 on ebay but I wonder if that will help at all.

I had samyang 14mm with my 5Dc and it was one of the best lenses I've used with it. Very sharp and for astronomy it's almost a must to have! Loved it. Sold it only because I want to use filters with my uwa lens. It's really easy to focus with it, just set it to 1.3-1.6m and everything will be in focus With stars I set the focus to infinity just in case and results are incredible

IMAGE LINK: http://www.flickr.com …irorautiainen/6​569549747/

IMAGE LINK: http://www.flickr.com …irorautiainen/6​569554965/

Bonbridge wrote in post #15893971
The Samyang 14 is extremely sharp! Even in the corners. It is one of the sharpest lenses on the market. I think it is a really nice lens for astro photography.

What are you comparing the Samyang to? The Canon 14mm f/2.8L II is way sharper in the corners then the Samyang 14mm f/2.8. Any lens is sharper in the corners then the Samyang wide open. http://www.the-digital-picture.com …omp=0&FLIComp=0​&APIComp=0

Take Care,
Cheers, Patrick

Saint728 wrote in post #15895499
What are you comparing the Samyang to? The Canon 14mm f/2.8L II is way sharper in the corners then the Samyang 14mm f/2.8. Any lens is sharper in the corners then the Samyang wide open. http://www.the-digital-picture.com …omp=0&FLIComp=0​&APIComp=0

Take Care,
Cheers, Patrick

I've read there's considerable sample variability with the Samyang, with some reporting it basically as sharp as the Canon throughout the frame. Not an excuse, obviously, since having to gamble on getting a good copy is never a good thing.

Also, for shooting stars, the Samyang has significantly less coma than the 14/2.8L. I actually know a few night landscapers who chose the Samyang for that reason.

Yep, unfortunalety there seems to be some sample variation in the Samyang 14mm regarding sharpness, I used to have an extremely sharp copy (in corners as well), sadly I had to sell it for financial reasons. I'm pretty sure that I plan to reacquire it this summer though.

I'm pretty sure Digital Picture (website) has kinda soft copy beeing tested on that link. I wish they would repeat the test with an additional copy or two to see if they can find sample variation..

For OP:
Absolutely, get the Samyang, it's an excelent lens for astronomy photography!