DA 18-135 infinity focus at night?

hmirchev · 06-28-2016, 12:30 PM

Hey guys, so I was at Red Rock Canyon last night, trying to do some night shooting, long exposures, and I had the DA 18-135 WR lens on my K3. I couldn't figure out a way to focus it, since it was pretty much pitch-black, and the focus kept hunting back and forth, never stopping. Then, I turned it onto MF and tried to focus it myself, but the focus ring kept turning and turning. Any advice on finding the infinity focus spot on this lens? I had to resort to using my Rokinon 8mm, which I could focus without a problem.

Also, when the camera was trying to focus in the dark, I couldn't press the shutter all the way, i.e it wouldn't take a photo.

I'm gonna try to go out there tonight again, and I might just use my Takumar 17mm f4 instead...

**jatrax** · 06-28-2016, 12:42 PM

Focus first, when there is enough light. Then put the camera in Manual focus and put a piece of tape across the focus ring so it does not move. I have a few all manual primes that I use for this and I have the focus ring taped where I want it so I don't have to mess with the focus on site.

Adam · 06-28-2016, 01:06 PM

Originally posted by hmirchev

Hey guys, so I was at Red Rock Canyon last night, trying to do some night shooting, long exposures, and I had the DA 18-135 WR lens on my K3. I couldn't figure out a way to focus it, since it was pretty much pitch-black, and the focus kept hunting back and forth, never stopping. Then, I turned it onto MF and tried to focus it myself, but the focus ring kept turning and turning. Any advice on finding the infinity focus spot on this lens? I had to resort to using my Rokinon 8mm, which I could focus without a problem.

Also, when the camera was trying to focus in the dark, I couldn't press the shutter all the way, i.e it wouldn't take a photo.

I'm gonna try to go out there tonight again, and I might just use my Takumar 17mm f4 instead...

You will feel more resistance in the focus ring when the lens reaches infinity.

It can be touch to focus in near darkness, but if there's a moon out, you can use that to achieve infinity focus. Live view may help, too.

**ramseybuckeye** · 06-28-2016, 03:24 PM

Use manual focus, live view and focus peaking, fp really makes night shooting easier. but you have to have some light. Also your lens should not keep turning, thats a concern.

pakinjapan · 06-28-2016, 04:36 PM

I got the same problem with all of my modern primes. And I am using K5 which is not good at night at all. my workaround is to remember where is the real infinity point on each of my lenses and use manual focus when shoot at night. (most of my night photos are Sky, city and landscape.)
However from my experience, the infinity marks are trustworthy on Pre-Digital prime. I am not sure about zoom.

**southlander** · 06-28-2016, 05:49 PM

Autofocus won't cut it in really low light, so manual focus is required.

One technique I use is to find a distant bright point of light, then, using manual focus and liveview, go into the magnified view and move the focus point around until this bright light is visible. Carefully manually adjust the focus until the size of this light is minimised to as small a point source as you can make it. You will see it expand very quickly into a bokeh circle either side of correct focus. Then take care not to touch the focusing ring while taking your shots. This bright light doesn't need to be part of your intended composition - just find a bright point source light somewhere and use it to focus, then turn the camera back to your intended composition. Might be a bright star, distant street light. You could even get someone to walk a torch some distance away and use that.

If using a zoom lens and I decide to take further shots at a different focus length, I repeat the focus method described above at the new focal length. Often there is just a whisker of adjustment needed even for zooms that generally appear to be parfocal.

calsan · 06-28-2016, 06:31 PM

Like southlander says, use liveview on a bright star, like Sirius. (Acutally, the 55-300 will autofocus on Sirius if set at 300mm, but i haven't tried the 18-135)
My 'trick' is to then masking tape the focus ring in place.
Of my lenses, the 15 and 35 ltds and the FA50 produce the best tiny star points, the zooms are harder to work with. It's also good if you can let all your equipment cool down outside for a while before shooting so you don't get 'heat haze' effects inside the lens and camera.

As for shutter release, I would recommend using the remote control with 2 second delay and having the custom setting for "AF with remote control" set to off. That way, it will take a shot without trying to focus and you avoid mirror slap and shaking the camera.

DeadJohn · 06-28-2016, 09:42 PM

Manual focus on a star or another far away light.

hmirchev · 06-28-2016, 10:41 PM - **1 Like**

Thanks guys, I'll try it out again tonight, I'll use some tape to secure the focusing ring in place

**UncleVanya** · 06-29-2016, 06:38 PM

Originally posted by ramseybuckeye

Use manual focus, live view and focus peaking, fp really makes night shooting easier. but you have to have some light. Also your lens should not keep turning, thats a concern.

The DA 18-135 DC lens does not stop at infinity or MFD. It is like the DA* lenses in that respect not like M, A, or K lenses. The focus ring should give a little more resistance at either extreme end of the scale however it is subtle if you are not used to it.

06-28-2016, 12:30 PM	#1
hmirchev Veteran Member Join Date: Feb 2014 Posts: 332	DA 18-135 infinity focus at night? Hey guys, so I was at Red Rock Canyon last night, trying to do some night shooting, long exposures, and I had the DA 18-135 WR lens on my K3. I couldn't figure out a way to focus it, since it was pretty much pitch-black, and the focus kept hunting back and forth, never stopping. Then, I turned it onto MF and tried to focus it myself, but the focus ring kept turning and turning. Any advice on finding the infinity focus spot on this lens? I had to resort to using my Rokinon 8mm, which I could focus without a problem. Also, when the camera was trying to focus in the dark, I couldn't press the shutter all the way, i.e it wouldn't take a photo. I'm gonna try to go out there tonight again, and I might just use my Takumar 17mm f4 instead...

06-28-2016, 01:06 PM	#3
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Originally posted by hmirchev Hey guys, so I was at Red Rock Canyon last night, trying to do some night shooting, long exposures, and I had the DA 18-135 WR lens on my K3. I couldn't figure out a way to focus it, since it was pretty much pitch-black, and the focus kept hunting back and forth, never stopping. Then, I turned it onto MF and tried to focus it myself, but the focus ring kept turning and turning. Any advice on finding the infinity focus spot on this lens? I had to resort to using my Rokinon 8mm, which I could focus without a problem. Also, when the camera was trying to focus in the dark, I couldn't press the shutter all the way, i.e it wouldn't take a photo. I'm gonna try to go out there tonight again, and I might just use my Takumar 17mm f4 instead... You will feel more resistance in the focus ring when the lens reaches infinity. It can be touch to focus in near darkness, but if there's a moon out, you can use that to achieve infinity focus. Live view may help, too. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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06-28-2016, 12:42 PM	#2
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Focus first, when there is enough light. Then put the camera in Manual focus and put a piece of tape across the focus ring so it does not move. I have a few all manual primes that I use for this and I have the focus ring taped where I want it so I don't have to mess with the focus on site.

06-28-2016, 03:24 PM	#4
ramseybuckeye Site Supporter Join Date: Apr 2009 Location: Hampstead, NC Photos: Gallery Posts: 17,292	Use manual focus, live view and focus peaking, fp really makes night shooting easier. but you have to have some light. Also your lens should not keep turning, thats a concern.

06-28-2016, 04:36 PM	#5
pakinjapan Veteran Member Join Date: Jun 2012 Location: Tokyo Photos: Gallery Posts: 1,041	I got the same problem with all of my modern primes. And I am using K5 which is not good at night at all. my workaround is to remember where is the real infinity point on each of my lenses and use manual focus when shoot at night. (most of my night photos are Sky, city and landscape.) However from my experience, the infinity marks are trustworthy on Pre-Digital prime. I am not sure about zoom.

06-28-2016, 05:49 PM	#6
southlander Site Supporter Join Date: May 2012 Location: Adelaide Photos: Gallery \| Albums Posts: 1,364	Autofocus won't cut it in really low light, so manual focus is required. One technique I use is to find a distant bright point of light, then, using manual focus and liveview, go into the magnified view and move the focus point around until this bright light is visible. Carefully manually adjust the focus until the size of this light is minimised to as small a point source as you can make it. You will see it expand very quickly into a bokeh circle either side of correct focus. Then take care not to touch the focusing ring while taking your shots. This bright light doesn't need to be part of your intended composition - just find a bright point source light somewhere and use it to focus, then turn the camera back to your intended composition. Might be a bright star, distant street light. You could even get someone to walk a torch some distance away and use that. If using a zoom lens and I decide to take further shots at a different focus length, I repeat the focus method described above at the new focal length. Often there is just a whisker of adjustment needed even for zooms that generally appear to be parfocal.

06-28-2016, 06:31 PM	#7
calsan Pentaxian Join Date: Nov 2008 Location: Perth, Australia Photos: Gallery Posts: 1,548	Like southlander says, use liveview on a bright star, like Sirius. (Acutally, the 55-300 will autofocus on Sirius if set at 300mm, but i haven't tried the 18-135) My 'trick' is to then masking tape the focus ring in place. Of my lenses, the 15 and 35 ltds and the FA50 produce the best tiny star points, the zooms are harder to work with. It's also good if you can let all your equipment cool down outside for a while before shooting so you don't get 'heat haze' effects inside the lens and camera. As for shutter release, I would recommend using the remote control with 2 second delay and having the custom setting for "AF with remote control" set to off. That way, it will take a shot without trying to focus and you avoid mirror slap and shaking the camera.

06-28-2016, 09:42 PM	#8
DeadJohn Pentaxian Join Date: Jan 2011 Location: New York Posts: 4,834	Manual focus on a star or another far away light.

06-28-2016, 10:41 PM - 1 Like	#9
hmirchev Veteran Member Join Date: Feb 2014 Posts: 332 Original Poster	Thanks guys, I'll try it out again tonight, I'll use some tape to secure the focusing ring in place

06-29-2016, 06:38 PM	#10
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	Originally posted by ramseybuckeye Use manual focus, live view and focus peaking, fp really makes night shooting easier. but you have to have some light. Also your lens should not keep turning, thats a concern. The DA 18-135 DC lens does not stop at infinity or MFD. It is like the DA* lenses in that respect not like M, A, or K lenses. The focus ring should give a little more resistance at either extreme end of the scale however it is subtle if you are not used to it.