Finding infinity on Rokinon 12mm 2.0F

[WhistlerNorth]

Thanks for everyone's advice earlier as my Rokinon lens arrived today. I took it for a saunter in the neighbourhood and was trying to figure out infinity on the dial. Think Newbie Phewbie suggested somewhere to take a street name sign from a distance and see which one is clearest. Tried this and maybe I was too far away as all 3 on zooming were not that clear. Stop sign and street sign top right of hill. All hand held.




Closer range








Trying to find infinity

 

[Newbie Phewbie]

Your second attempt at finding infinity seems quite close to me.

A tripod may let you get closer. I can't tell what the temps were there, but don't try this when the blacktop is hot - the heat waves will cause distortion.

 

[WhistlerNorth]

There was no heat to speak of — probably about 15 Celsius or 62 Fahrenheit , probably less.. believe that spot was the left end of the white line. Should I be looking at zooming the license plate of the closer car or is that too close a distance for an infinity setting?

this is on a Sony a6500– when I put on flexible spot I could not get the focus magnifier to work so gather works with only larger focus area like centre. So much to remember. Using all the settings in manual is all new to me—- think shutter selection may be the hardest so far. I have left ISO on auto.

 

[Bender79ita]

Set the mode to Aperture for now. It works. Manual also works normally, just the aperture is on the lens instead of the camera. Don't panic.

Find something very far off in the distance (like a building 10 miles away) for infinity or for anything else you want to focus on.

Setup the camera so that a button is zooming in. Disable focus peaking, it's confusing on wide angles.

Zoom in as much as you can then focus. In a few days you'll do it without even thinking.

 

[Heritage Cameras]

Find something very far off in the distance (like a building 10 miles away) for infinity or for anything else you want to focus on.

While it's probably overkill for a 12mm lens, I find the moon handy for this as it's bright and high contrast. It's not really at infinity, but I think a quarter of a million miles is close enough... ;-)

 

[Bender79ita]

Find something very far off in the distance (like a building 10 miles away) for infinity or for anything else you want to focus on.

While it's probably overkill for a 12mm lens, I find the moon handy for this as it's bright and high contrast. It's not really at infinity, but I think a quarter of a million miles is close enough... ;-)

That's a good point, although it isn't always there. Actually, it's never there when I'm shooting astro... or I wouldn't be there myself

In daytime any distant hill will do (the moon too of course). The important thing is to develop the "muscle memory" to zoom in and focus, because you won't always be focusing on infinity specially if light is lacking and you're shooting larger then f4 (imagine inside woodlands or interior architecture handheld).

 

[Heritage Cameras]

Find something very far off in the distance (like a building 10 miles away) for infinity or for anything else you want to focus on.

While it's probably overkill for a 12mm lens, I find the moon handy for this as it's bright and high contrast. It's not really at infinity, but I think a quarter of a million miles is close enough... ;-)

That's a good point, although it isn't always there. Actually, it's never there when I'm shooting astro... or I wouldn't be there myself

Indeed! The OP wanted to calibrate the lens's focusing scale, though, so unless they are in a polar region with six-month seasons it will probably appear sometime soon... :-D

 

[WhistlerNorth]

I totally misunderstood as thought this lens needed to be used completely on manual.
I wanted this lens to use for night skies but also for landscape. Night skies will not be possible for awhile as under no travel order even from our own community at the moment due to Covid third wave. I am use to using aperture and shutter setting for specific situations so that will feel more comfortable now . Will play with finding that infinity spot as will need for those eventual night skies.

 

[Newbie Phewbie]

If you use Aperture priority, you need to match your lens aperture setting to the camera setting. If you can remember to do this, this method lets the camera control shutter speed and ISO (if you have auto ISO set). A very flexible method.

I find it easier to use it on Shutter Priority (S). That way, I don't have to match the camera aperture setting to that of the lens. In this mode, you have to use Auto ISO or the camera will have no way to automatically adjust exposure.

Good luck.

 

[WhistlerNorth]

Just back from playing a bit. As I can never see aperture setting other than what I set on lens( I cannot see a F value in viewfinder-)-- do I need to set aperture on camera before I change the lens which would be PIA?

In the brief manual that came with lens it says-- "If in A mode you can set the brightness by turning the aperture adjustment ring on the lens. the camera automatically changes the shutter speed, so you do not have to adjust the shutter speed as well, which is required in M mode" Sounds like I am ok in A mode.

 

[Newbie Phewbie]

No - you don't have to set aperture in your camera - just on the lens. The camera has no idea what aperture you are using on this lens, so it adjusts shutter speed (if not in shutter priority) and/or iso (if auto iso is enabled) to get the right exposure.

 

[WhistlerNorth]

If you use Aperture priority, you need to match your lens aperture setting to the camera setting. If you can remember to do this, this method lets the camera control shutter speed and ISO (if you have auto ISO set). A very flexible method

Good luck.

Sorry I misunderstood matching lens aperture setting to camera setting . I went out and shot some pictures playing with Aperture and focus range from close to infinity. Think I picked the spot for infinity as tried zooming photo image after to see which setting was clearest throughout so hope I have figured it out. Gather this is most important for night photos as well as better landscape shots.

 

[Bender79ita]

You seem to start getting the hang of focusing, the blacks on the pictures look very dark though. Is it some kind of in-camera preset?

I find it's a focal length that's very difficult to frame with, but very satisfactory.

Sometimes white balance can be challenging, as the scene often will include different kinds of light in the frame.

Don't be afraid to experiment and have fun with it.

 

[WhistlerNorth]

Maybe the darkness is coming from exposure compensation set to. —1/3. Read somewhere that someone bumped it up to +1/3 because they felt this lens underexposed. I had D-R off. WB AND ISO all on auto. I have generally in bright light set exposure compensation to —1/3 as have found it easier to adjust if needed in post Was suggested years ago at course I took. cannot think of anything else I have set. Will try without exposure comp., try bracketing.

 

[PhotoFactor]

If you use Aperture priority, you need to match your lens aperture setting to the camera setting. If you can remember to do this, this method lets the camera control shutter speed and ISO (if you have auto ISO set). A very flexible method.

I find it easier to use it on Shutter Priority (S). That way, I don't have to match the camera aperture setting to that of the lens. In this mode, you have to use Auto ISO or the camera will have no way to automatically adjust exposure.

Good luck.

I have no idea what this means. You don't have to "match" any aperture to anything.

If you set ISO (or use Auto ISO), and use aperture priority, the camera "sees" how much light is coming through the lens regardless of the aperture setting. It then sets the shutter speed automatically. Or you can use Manual as you would normally.

Note that when you focus you should be aperture wide open, as this is where your DOF is most narrow and gives you more focusing precision.

The steps I use are:

1. Set Aperture priority (if you want automatic exposure)

2. Set f2.0

3. Zoom in to focus using peaking and/or magnification; focus the lens

4. Stop the lens down to whatever you want.

5. Take the picture.

For astrophotography, focus on a distant object ideally during the day, or at night something like a light on a pole at least say 25 meters away. Wide open. Note where the focus scale is set. On mine, it's about one dot from the infinity mark, toward closer focus than infinity.

Note that in good light, you can set hyperfocal distance and pretty much never have to focus at all since the lens is so wide. Look up hyperfocal distance tables to learn the correct settings.

 

[WhistlerNorth]

I am thinking my spot is here

Hi Photofactor, I was probably trying to evaluate a sign/ lamplight further away than 25 meters. Is your marker slightly left of mine or closer to the right end of the white line towards the actual infinity symbol.

As to Newbie Phewbie we determined he actually meant the same as you described. I am using the Aperture program at the moment letting the camera determine Shutter , WB and ISO

 

[PhotoFactor]

I am thinking my spot is here

Hi Photofactor, I was probably trying to evaluate a sign/ lamplight further away than 25 meters. Is your marker slightly left of mine or closer to the right end of the white line towards the actual infinity symbol.
As to Newbie Phewbie we determined he actually meant the same as you described. I am using the Aperture program at the moment letting the camera determine Shutter , WB and ISO

My mark is on the other side of the "L" shaped mark. The white circle is about .75 circle width to the LEFT of the "L" vertical line. It's pretty much the same on both my A6000 and A6400, so seems to be a characteristic of my particular lens rather than camera variation.

My lens is quite sharp. The only thing I notice in sunlight is moderate chromatic aberration when the lens is near wide open. I just did some Milky Way shots on the last new moon and will post the best one shortly.

 

[PhotoFactor]

...and here is a picture of where my lens hits infinity, and also a milky way shot from an A6400 and the new moon earlier this week, near Joshua Tree National Park.

 

[Newbie Phewbie]

You're right! Thank you for pointing it out.

I have no idea what I was thinking of when I wrote about matching the camera aperture setting to the lens aperture.

 

[WhistlerNorth]

Nice to see—- what time in the night did you end up shooting at? Distant lights from Palm Springs desert area or ?