catch in focus is such a wonderful thing

knaff · 02-16-2011, 02:44 AM

Just had a go with my IR remote....it worked a treat - great for self portraits !!

**crewl1** · 02-16-2011, 10:14 AM

@boriscleto

Thanks will have to rig something up like that.

@knaff - The IR works but you have to use it every time to reset after a picture is taken.

By using something that holds the shutter down and setting the drive mode to continuous you can leave the area and the camera will take pictures whenever an object comes in focus.

Ubuntu_user · 02-16-2011, 05:15 PM

Originally posted by crewl1

@knaff - The IR works but you have to use it every time to reset after a picture is taken.

By using something that holds the shutter down and setting the drive mode to continuous you can leave the area and the camera will take pictures whenever an object comes in focus.

How many photos do you want though?

**crewl1** · 02-16-2011, 05:37 PM

The way I've used it on the k10d for hummingbirds is to leave it up for a period of time, no preset number of shots.

Lloydy · 02-17-2011, 04:42 PM

I like catch in focus, I have aluminium tape on the back of a few lenses like my Helios and it works perfectly.

However, my Takumar 135mm is a slim lens that doesn't cover the camera contacts

On the base of the lens there is a recess, arrowed 'A' - the face arrowed 'B' is where the adaptor fits.
This recess is on a non rotating part of the lens.

So I made an aluminium disc 1.2mm thick, 52mm inside dia' and 67mm outside dia'. I didn't make the disc to tight tolerances, it was a compass and file job, and I smoothed it off with wet and dry.

The ring fits the recess, and when on the camera shorts out, and protects to a degree, the contacts.
It's not so tight that it fouls anything, doesn't make the mount tight or alter infinity focus because the lens still mounts on the proper face.

If you want catch in focus on a lens that is slim then look to see if there's a recess, or if you want to do close work where infinity focus isn't going to be used you could make a ring to trap under the adaptor, for that you could use something very thin like a drink can which can be cut with scissors.

techmulla · 03-02-2011, 03:31 PM

I am going to try that the next time i shoot manual

fiveseven · 03-02-2011, 04:25 PM

The problem with catch in focus and manual lenses is that, when you try to focus with your lens the camera takes a shot while the lens is still rotating (focusing) and you get a blurry shot.

Even if your very careful you can still easily over focus the lens by a little bit.

RioRico · 03-02-2011, 04:51 PM - **1 Like**

Originally posted by fiveseven

The problem with catch in focus and manual lenses is that, when you try to focus with your lens the camera takes a shot while the lens is still rotating (focusing) and you get a blurry shot.

Even if your very careful you can still easily over focus the lens by a little bit.

Some tricks there are to:

1) Focus s-l-o-w-l-y. This works better with long-throw than short-throw lenses.

2) Half-press the shutter and wait for the focus-lock signal to flicker, then press the shutter and s-l-o-w-l-y move back and forth till CIF fires. This works better at fairly close distances.

3) Set the drive mode to CONTINUOUS and hold the shutter down. CIF will fire whenever it sees a focus-lock, so you're more likely to get a shot that's actually sharp.

4) Prefocus on a spot where you expect a moving subject to appear, and hold the shutter down. Maybe be in CONTINUOUS mode. Whenever something comes into focus, CIF fires.

There are probably other CIF tricks I haven't thought of yet.

"There's more than one way to skin a cat,", she mused,
as she pinned its little feet to the dissection board.

fiveseven · 03-02-2011, 06:41 PM

Quote:

1) Focus s-l-o-w-l-y. This works better with long-throw than short-throw lenses.

If you focus to slowly it actually defeats the benefit of this feature as it takes up more time and even then might as well press the shutter yourself right then and there if you see the viewfinder being sharp.

Quote:

2) Half-press the shutter and wait for the focus-lock signal to flicker, then press the shutter and s-l-o-w-l-y move back and forth till CIF fires. This works better at fairly close distances.

The problem is when shutter fires you usually still in the process of rotating focus ring (lag between the brain and the shutter) even if you are slow it can still miss the shot of being optimal sharp.

Quote:

3) Set the drive mode to CONTINUOUS and hold the shutter down. CIF will fire whenever it sees a focus-lock, so you're more likely to get a shot that's actually sharp.

Wasting time in my opinion and you will still very likely to experience nearly all of your shots being out of focus unless your shutter speed is 1000 or more.

Quote:

4) Prefocus on a spot where you expect a moving subject to appear, and hold the shutter down. Maybe be in CONTINUOUS mode. Whenever something comes into focus, CIF fires.

Have not tried this and I assume it also requires very fast shutter speed. I would like to think this is probably the best use for this feature.

JeffJS · 03-02-2011, 07:39 PM

Originally posted by fiveseven

If you focus to slowly it actually defeats the benefit of this feature as it takes up more time and even then might as well press the shutter yourself right then and there if you see the viewfinder being sharp.

The problem is when shutter fires you usually still in the process of rotating focus ring (lag between the brain and the shutter) even if you are slow it can still miss the shot of being optimal sharp.

Wasting time in my opinion and you will still very likely to experience nearly all of your shots being out of focus unless your shutter speed is 1000 or more.

Have not tried this and I assume it also requires very fast shutter speed. I would like to think this is probably the best use for this feature.

Then don't use it. Simple.

tdannar · 03-03-2011, 11:30 AM

I misunderstood and thought that you could set it and walk away....

While searching, I found something that describes using the wireless remote and CIF. The post said that it would not work with a manual lens, but I was using a manual Pentax M 50mm lens and it seems to work fine. At least you don't have to hold down the shutter release.....I did not test to see how long one could wait, but it seemed to work with some quick tests, walking into the focus area, the camera would fire unattended. You could then press and release the remote to set it up for the next shot. This is kind of what I was looking for.......

Catch-in focus using Remote Control F.: Pentax SLR Talk Forum: Digital Photography Review

mjkwee · 03-07-2011, 10:56 PM

I use "Catch in Focus" or "Trap Focus" most of the time because I am disabled and have only use of one good hand - left hand. I smile at the comments made here where all one see is the negative aspect of this feature and how it can never result in good clear shots. I can vouch for this feature working all the time for me.

Without CIF, I would not be able to enjoy wildlife photography and not be able to use affordable manual Focus lenses that fits my budget. I have a Sigma 70-300mm APO lens too. I was frustrated with the AF locking on the bushes close by and not on the birds. I would eventually switch to MF to get a good shot. Especially the longer focal length lenses like the 300mm or 400mm Telephoto lenses. Longer focal length lenses, 500mm and up are difficult for me to handle with one hand because they are too heavy for me to juggle the lens, camera and the monopod all at once. With a decent Tele-Converter, I can get a decent effective Focal length in excess of 600mm effective Focal Length shots.

The focus rings on these long focal length lenses are quite a distant away from the shutter release to adjust focus and trigger at the same time with one hand. In so doing it most often creates blurry shots, even with SR enabled. Or by the time I focus then trigger the shutter, the subject is no longer in focus. In this case with Telephoto lenses, I use a remote cable shutter release that has a shutter lock. I lock the shutter on the cable release then I adjust the focus ring to trigger or stop triggering the shutter by de-focusing. I also use the burst mode settings so that it will trigger 2-3 shots per burst. Most of these 2-3 shots are in focus. In the beginning, I was too anxious and I try to hurry my focusing. That did not give me better results. But when you focus slowly and deliberately, you will get the feel and get the hang of it. The net result for me, is that I get to enjoy being out in the open taking wild life photographs including birds in flight using CIF.

Here are some sample result using a Pentax SMC 400mm/F5.6 Tele I recently acquired.

hcc · 03-07-2011, 11:37 PM

mjkwee,
Nice shots. I really like them as I love the coastlines.

I also fully agree with your views. Let us focus on the positives....

mjkwee · 03-08-2011, 03:50 AM

Originally posted by hcc

mjkwee,
Nice shots. I really like them as I love the coastlines.

I also fully agree with your views. Let us focus on the positives....

Hubert, Thanks...Michael

reeftool · 03-08-2011, 09:21 AM

I haven't had much blur problems using trap focus. Once you have focus, you aren't moving the focus ring much or if at all. Like everything else in photography it takes practice. Rather then being self defeating, it allows me to take a lot of shots I wouldn't get without an AF lens.

02-17-2011, 04:42 PM	#20
Lloydy Veteran Member Join Date: Aug 2007 Location: Shropshire, UK Posts: 1,114	I like catch in focus, I have aluminium tape on the back of a few lenses like my Helios and it works perfectly. However, my Takumar 135mm is a slim lens that doesn't cover the camera contacts On the base of the lens there is a recess, arrowed 'A' - the face arrowed 'B' is where the adaptor fits. This recess is on a non rotating part of the lens. So I made an aluminium disc 1.2mm thick, 52mm inside dia' and 67mm outside dia'. I didn't make the disc to tight tolerances, it was a compass and file job, and I smoothed it off with wet and dry. The ring fits the recess, and when on the camera shorts out, and protects to a degree, the contacts. It's not so tight that it fouls anything, doesn't make the mount tight or alter infinity focus because the lens still mounts on the proper face. If you want catch in focus on a lens that is slim then look to see if there's a recess, or if you want to do close work where infinity focus isn't going to be used you could make a ring to trap under the adaptor, for that you could use something very thin like a drink can which can be cut with scissors. Last edited by Lloydy; 02-17-2011 at 05:03 PM. Reason: Crappy picture, taken with a C*** !*

03-02-2011, 04:51 PM - 1 Like	#23
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	Originally posted by fiveseven The problem with catch in focus and manual lenses is that, when you try to focus with your lens the camera takes a shot while the lens is still rotating (focusing) and you get a blurry shot. Even if your very careful you can still easily over focus the lens by a little bit. Some tricks there are to: 1) Focus s-l-o-w-l-y. This works better with long-throw than short-throw lenses. 2) Half-press the shutter and wait for the focus-lock signal to flicker, then press the shutter and s-l-o-w-l-y move back and forth till CIF fires. This works better at fairly close distances. 3) Set the drive mode to CONTINUOUS and hold the shutter down. CIF will fire whenever it sees a focus-lock, so you're more likely to get a shot that's actually sharp. 4) Prefocus on a spot where you expect a moving subject to appear, and hold the shutter down. Maybe be in CONTINUOUS mode. Whenever something comes into focus, CIF fires. There are probably other CIF tricks I haven't thought of yet. "There's more than one way to skin a cat,", she mused, as she pinned its little feet to the dissection board.

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02-16-2011, 02:44 AM	#16
knaff Inactive Account Join Date: Jun 2010 Location: Darwin, NT Posts: 18	Just had a go with my IR remote....it worked a treat - great for self portraits !!

02-16-2011, 10:14 AM	#17
crewl1 Site Supporter Join Date: Jul 2010 Location: Los Angeles, CA Photos: Gallery \| Albums Posts: 9,807	@boriscleto Thanks will have to rig something up like that. @knaff - The IR works but you have to use it every time to reset after a picture is taken. By using something that holds the shutter down and setting the drive mode to continuous you can leave the area and the camera will take pictures whenever an object comes in focus.

02-16-2011, 05:15 PM	#18
Ubuntu_user Veteran Member Join Date: Mar 2010 Photos: Gallery \| Albums Posts: 1,545	Originally posted by crewl1 @knaff - The IR works but you have to use it every time to reset after a picture is taken. By using something that holds the shutter down and setting the drive mode to continuous you can leave the area and the camera will take pictures whenever an object comes in focus. How many photos do you want though?

02-16-2011, 05:37 PM	#19
crewl1 Site Supporter Join Date: Jul 2010 Location: Los Angeles, CA Photos: Gallery \| Albums Posts: 9,807	The way I've used it on the k10d for hummingbirds is to leave it up for a period of time, no preset number of shots.

03-02-2011, 03:31 PM	#21
techmulla Senior Member Join Date: Mar 2010 Posts: 107	I am going to try that the next time i shoot manual

03-02-2011, 04:25 PM	#22
fiveseven Veteran Member Join Date: Jul 2010 Location: NV/CA Posts: 370	The problem with catch in focus and manual lenses is that, when you try to focus with your lens the camera takes a shot while the lens is still rotating (focusing) and you get a blurry shot. Even if your very careful you can still easily over focus the lens by a little bit.

03-02-2011, 06:41 PM	#24
fiveseven Veteran Member Join Date: Jul 2010 Location: NV/CA Posts: 370	Quote: 1) Focus s-l-o-w-l-y. This works better with long-throw than short-throw lenses. If you focus to slowly it actually defeats the benefit of this feature as it takes up more time and even then might as well press the shutter yourself right then and there if you see the viewfinder being sharp. Quote: 2) Half-press the shutter and wait for the focus-lock signal to flicker, then press the shutter and s-l-o-w-l-y move back and forth till CIF fires. This works better at fairly close distances. The problem is when shutter fires you usually still in the process of rotating focus ring (lag between the brain and the shutter) even if you are slow it can still miss the shot of being optimal sharp. Quote: 3) Set the drive mode to CONTINUOUS and hold the shutter down. CIF will fire whenever it sees a focus-lock, so you're more likely to get a shot that's actually sharp. Wasting time in my opinion and you will still very likely to experience nearly all of your shots being out of focus unless your shutter speed is 1000 or more. Quote: 4) Prefocus on a spot where you expect a moving subject to appear, and hold the shutter down. Maybe be in CONTINUOUS mode. Whenever something comes into focus, CIF fires. Have not tried this and I assume it also requires very fast shutter speed. I would like to think this is probably the best use for this feature.

03-02-2011, 07:39 PM	#25
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Originally posted by fiveseven If you focus to slowly it actually defeats the benefit of this feature as it takes up more time and even then might as well press the shutter yourself right then and there if you see the viewfinder being sharp. The problem is when shutter fires you usually still in the process of rotating focus ring (lag between the brain and the shutter) even if you are slow it can still miss the shot of being optimal sharp. Wasting time in my opinion and you will still very likely to experience nearly all of your shots being out of focus unless your shutter speed is 1000 or more. Have not tried this and I assume it also requires very fast shutter speed. I would like to think this is probably the best use for this feature. Then don't use it. Simple.

03-03-2011, 11:30 AM	#26
tdannar New Member Join Date: Jul 2010 Location: Sand Springs Photos: Gallery Posts: 11	I misunderstood and thought that you could set it and walk away.... While searching, I found something that describes using the wireless remote and CIF. The post said that it would not work with a manual lens, but I was using a manual Pentax M 50mm lens and it seems to work fine. At least you don't have to hold down the shutter release.....I did not test to see how long one could wait, but it seemed to work with some quick tests, walking into the focus area, the camera would fire unattended. You could then press and release the remote to set it up for the next shot. This is kind of what I was looking for....... Catch-in focus using Remote Control F.: Pentax SLR Talk Forum: Digital Photography Review

03-07-2011, 11:37 PM	#28
hcc Pentaxian Join Date: Nov 2009 Location: Brisbane, Australia Photos: Gallery \| Albums Posts: 4,002	mjkwee, Nice shots. I really like them as I love the coastlines. I also fully agree with your views. Let us focus on the positives....

03-08-2011, 03:50 AM	#29
mjkwee Junior Member Join Date: Sep 2009 Location: Sunnyvale CA Photos: Gallery Posts: 41	Originally posted by hcc mjkwee, Nice shots. I really like them as I love the coastlines. I also fully agree with your views. Let us focus on the positives.... Hubert, Thanks...Michael

03-08-2011, 09:21 AM	#30
reeftool Pentaxian Join Date: Dec 2007 Location: Upstate New York Photos: Gallery \| Albums Posts: 9,554	I haven't had much blur problems using trap focus. Once you have focus, you aren't moving the focus ring much or if at all. Like everything else in photography it takes practice. Rather then being self defeating, it allows me to take a lot of shots I wouldn't get without an AF lens.