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03-02-2024, 12:37 AM - 1 Like   #1
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my quest for better focusing.

I am a budding nature - birds and animals mainly birds at present - and macro - mainly insects and equivalent creepies at present - photographer. In both cases focus and depth of field are very important. At the same time my eyes have never been excellent - my optometrist recently commented that he had moved my eyesight into the legal to drive range.

I have tried several approaches to improve focus and thought it would be useful to document them since while there is lots of information up here, it is scattered. If you want to know, my signature correctly lists all my lenses and camera body.


Autofocus lenses and body based focus technology.

This, while generally fairly good, will sometimes let you down. The big issues are:

1) it requires both light and contrast to autofocus and it can be known to hunt from close to far without finding the perfect focus.
2) speed of focus, noise and accuracy vary between lens and body.
3) getting the camera to agree with you as to the subject to focus on. The number of times it focuses on the leaf in front of the bird...

Having said all that, I have taken some superb shots with my two auto focus lenses.

Body based focus technology with a manual lens

Autofocus lenses tend to come at a premium. For the same cost you tend to get better manual or auto aperture (P/KA) lenses. With most manual lenses you can still use the autofocus system to aid focusing. The big difference between P/KA and full manual lenses is that you have slightly more work. In worst case you need to use the green button to get the camera to check light level through the lens. Personally I only use autofocus or P/KA lenses. My subjects have a habit of flying away if I take too long to take the photo.

Half pressing the shutter button while focusing will result in the display of a lighted hexagon through the viewfinder and a beep when you are in focus. I find, even so, there is a bit of twisting the focus ring back and forth or the more advanced technique of getting it close then rocking to get and keep the subject in focus.

Most Pentax bodies have a feature called Capture in Focus (CIF). This only allows the shutter to fire when the subject is in focus. The idea being that you press the shutter button while focusing and it will fire when in focus. I do find, though, that it is entirely possible to turn the focus past the point before the shutter fires. I have been using this feature for several months and am now considering turning it off.

Viewfinder Focusing Screen

Some Pentax bodies allow the replacement of the focusing screen for the view finder - my K5 for example. Pentax make a variety of screens, however, apart from different line patterns drawn on it, they are the same screen. 5-10 years ago you could purchase third party screens for your camera. Most companies doing this are now gone. FocusingScreen.com is still in place however they only seem to be selling the version based on the Canon S screen. This is a very good screen but is designed for fast lenses and tops out F2.8. Beyond that aperture Canon themselves say it doesn't add anything. There are also lots of Chinese screens that may or may not be useful.

Screens tend to be created for full frame cameras. So the alternative is to buy a full sized screen and cut it down to fit an APS/C . camera. There are YouTube tutorials on how to do this and FocusingScreen.com is a good source for which Canon and Nikon screens to consider. I decided making my own was a step too far.

Viewfinder Magnifier.

Many Pentax bodies allow you to replace the viewfinder eyepiece with a magnifying one. Pentax make their own - the O-ME53 and they also have a right angle eyepiece called the refconvertor A. The latter sometimes includes a 2x magnification depending on model.

Aftermarket versions have come and gone. You can easily get a Chinese one that may or may not be good. About the only highly recommended aftermarket one still available is the Tenpa Goldeneye. It comes in two versions: 1.22x and 1.35x. I bought the latter and it immediately improved my photography.

Apart from checking it will fit, and the required quality, the other key consideration is the magnification. The discussion I read suggested that anything above about 1.22 was counter productive. The issue being that you get steadily more vignetting through the viewfinder and so see less of what the camera is seeing. In addition you can lose sight of all the information that Pentax puts around the viewfinder screen. Using the 1.35x I tend not to see this information.

Still, I recommend the Tenpa as a very good option.

LiveView

One of the reasons that focusing screens have largely disappeared is that in ideal conditions, a feature called LiveView is better. LiveView shows what the camera sees on the LCD screen on the back of the camera. Many Pentax bodies include this feature. In addition, you can zoom in on your subject and even change the point of focus using the arrows on the camera.

There are problems though:

1) Because LiveView uses the LCD you almost have to use a tripod ie something else to carry and set up slowing the process of taking photos.
2) I found with my 400mm prime that using the focusing ring tended to move the camera so that it was no longer pointed where I wanted it.
3) The LCD - like all such displays - doesn't like bright light. Outside, where I take pictures, it was difficult to see the picture on the screen well enough to get good focus. You can get hoods for the LCD screen that may solve this problem.
4) On the K5, at least, using LiveView disables the auto focus mechanism so it is one or the other.
5) There was a medium amount of wind when I tried. This caused more shake on the tripod that I am aware of when holding the camera.

Overall I think for my nature photography and probably for the macro, this option is going to be too fussy.

Conclusion

So the two things I have found that help with focusing in my two genres are a viewfinder magnifier and the autofocus mechanism in the Pentax body with or without Capture in Focus.


Last edited by betchern0t; 03-02-2024 at 12:47 AM. Reason: corrections
03-02-2024, 01:10 AM   #2
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On the K5 you have a special mode where the camera will focus with mirror and go back to live view immediately after having focused the lens. Otherwise you can use a hoodloupe on live-view display of your K5. Generally, mirrorless cameras have solved that problem, as you can zoom and have focus peaking while looking into the electronic viewfinder.
03-02-2024, 02:55 AM   #3
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Thanks for taking the time to write this it's an important discussion.
Good AF is rather camera model dependent, and many lenses need to be checked for front or back focus as per this article:

Fixing Front and Back Focus - Introduction - In-Depth Articles

Good MF focus through an OVF begins with accurate diopter adjustment. Any softness in the viewfinder due to eyes or misadjustment will immediately handicap your ability to zero in on critical focus. The lines etc on the viewfinder screen must be sharply defined. I have to use an eyepiece magnifier as that can extend the range of adjustment (or not take my specs off).

I use LV a lot, both as the means of focus, and as a quick verification of my focusing by eye. There is a process of familiarisation with an MF lens so that you can learn what works best: focusing in or out, tending to err to one side of the appearance of the hexagon etc.
I have a decent lcd loupe to fit on the camera and I should use it more, it's a very good and accurate way to focus an MF long lens, but because it takes time to set up and use I tend not to bother. Also an important caveat for eg bird photography is the inherent slight but significant shutter delay in this mode. And you drain your battery quick. One other reason I don't use the loupe so often is my KS2 has a multiposition lcd that can be tilted easily to avoid light reflecting off it (and which faciltates use of eg a bean bag on a rock..)
One other small point re viewfinder magnifiers is that they darken the view, specifically noticeable with the 2x ones. I haven't found the 2x ones useful for general photography, due to the restricted view/vignetting, IMO they're mainly for eg macro. IMO the view is ok with 1.35x, you can see what you need to see with slight movements of your eye position.
Before LV became really good, swapping the focus screen was indeed a thing. I did that with my old K-r, and there were times when the split prism was indeed quite beneficial but overall the benefit was variable - little difference a lot of the time. Pick up a junk old pentax film camera from a garage sale then it can be an interesting option to try and see if a classic split prism/microprism helps with your lenses. As you say there's info out there on cutting the screen down, fitting and shimming etc. There is this big thread on the canon EES screen. All of this has indeed been, not negated, but alleviated by the advent of very good live view.
There's no doubt that mirrorless offers a certain advantage with in-the-evf magnification for manual focus.

Last edited by marcusBMG; 03-02-2024 at 03:02 AM.
03-02-2024, 08:48 AM   #4
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I don't have a K-5, I used to have a K-50 which was similar in focusing, I now use a KP and K-3iii which are both improved in the focus area. I do use live view a lot, but only on a tripod, and the KP and K-3iii have magnification and focus peaking, which is fantastic for manual focusing. A good sturdy tripod is indispensable. I shoot a lot at the beach which can be very windy as it was yesterday morning, the wind being no problem, sometimes wet sand can be a problem as the tripod leg can sink a bit.

The diopter being accurate is very important. You mentioned that the camera focuses on the leaf instead of the bird, are you using the single point for autofocusing? It really helps for critical focusing like a bird in a tree, I use the center point and re-compose, which I'm guessing you may also, but I still miss some too, but less on the bodies with more autofocus points.

I have never liked catch in focus, like you said, you can turn past it as it is sometimes slow, at least it was, I've not tried it on my current bodies. I have a had time holding the camera still while moving the focus ring with the support hand, that's just me.

Unfortunately only your doctor can help with the vision. I'm fortunate as I was corrected pretty well with contact lenses, and a year ago I had cataract surgery and now have excellent vision without correction (except for up real close), and that helps with photography.

03-02-2024, 08:58 AM   #5
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Thank you for a nice summary of your experiences. I've recently posted a thread about my difficulties in getting sharp wildlife photos using a K20D with a Pentax 300mm/f4 in conjunction with a 1.4x TC (giving me the equivalent of a 420mm/f5.6, more or less) and have found basically the same thing. My particular issue is size of the depth of field...with the K20D's limit of ISO 3200 it gives a practical limit to avoid noise of ISO 800...which in turn makes me either open up the aperture (reducing DoF), slow down the shutter speed (increasing shake effects), or both.

I'll be experimenting with higher ISO this spring to see what works better, but in the meantime I'm just going to try a few other things including shooting TAv and letting the camera pick the ISO for a given shot...and then playing with both aperture and shutter speed to see how high/low I can go and still get a sharp picture with the deepest DoF.
03-02-2024, 02:15 PM   #6
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Original Poster
QuoteOriginally posted by biz-engineer Quote
On the K5 you have a special mode where the camera will focus with mirror and go back to live view immediately after having focused the lens. Otherwise you can use a hoodloupe on live-view display of your K5. Generally, mirrorless cameras have solved that problem, as you can zoom and have focus peaking while looking into the electronic viewfinder.
Hi Biz, when I said hood I meant to include the loupes. These are manual lenses - P/KA. thanks....

---------- Post added 03-03-24 at 05:34 AM ----------

QuoteOriginally posted by marcusBMG Quote
Thanks for taking the time to write this it's an important discussion.
Good AF is rather camera model dependent, and many lenses need to be checked for front or back focus as per this article:

Fixing Front and Back Focus - Introduction - In-Depth Articles
Hi Marcus, the AF fine adjustment on the K5, at least, indexes settings based on the lens id. Manual and KA lenses return a generic id and so AF can't be used - would love to since I have been told in the past that one of my lenses is tending to front focus


QuoteOriginally posted by marcusBMG Quote
Good MF focus through an OVF begins with accurate diopter adjustment. Any softness in the viewfinder due to eyes or misadjustment will immediately handicap your ability to zero in on critical focus. The lines etc on the viewfinder screen must be sharply defined. I have to use an eyepiece magnifier as that can extend the range of adjustment (or not take my specs off).

I am currently in the process of changing my contact lenses. Three trips to the optometrist so far. I plan to adjust up the dioptera again once a good pair have settled. It probably won't be worth it until then. Very good point though.

QuoteOriginally posted by marcusBMG Quote
I use LV a lot, both as the means of focus, and as a quick verification of my focusing by eye. There is a process of familiarisation with an MF lens so that you can learn what works best: focusing in or out, tending to err to one side of the appearance of the hexagon etc.
I have a decent lcd loupe to fit on the camera and I should use it more, it's a very good and accurate way to focus an MF long lens, but because it takes time to set up and use I tend not to bother. Also an important caveat for eg bird photography is the inherent slight but significant shutter delay in this mode. And you drain your battery quick. One other reason I don't use the loupe so often is my KS2 has a multiposition lcd that can be tilted easily to avoid light reflecting off it (and which faciltates use of eg a bean bag on a rock..)
I will have to look into familiarisation. I feel that liveview will probably prove to be too cumbersome except in static contexts.

QuoteOriginally posted by marcusBMG Quote
One other small point re viewfinder magnifiers is that they darken the view, specifically noticeable with the 2x ones. I haven't found the 2x ones useful for general photography, due to the restricted view/vignetting, IMO they're mainly for eg macro. IMO the view is ok with 1.35x, you can see what you need to see with slight movements of your eye position.
A key reason I went with the 1.35x was a bit of extra magnification due to my eyes while avoiding the issues of higher power. I avoided the O-ME53 because in my reading it wasn't clear what magnification it actually delivered - 1.18x or 1.03x. I think there is some disinformation out there. Also 1.18x is below what I wanted. I can see the vignetting on the 1.35x and it doesn't bother me. I tend not to watch those metrics. I have not noticed loss of light so something to be aware of for higher magnifications.

QuoteOriginally posted by marcusBMG Quote
Before LV became really good, swapping the focus screen was indeed a thing. I did that with my old K-r, and there were times when the split prism was indeed quite beneficial but overall the benefit was variable - little difference a lot of the time. Pick up a junk old pentax film camera from a garage sale then it can be an interesting option to try and see if a classic split prism/microprism helps with your lenses. As you say there's info out there on cutting the screen down, fitting and shimming etc. There is this big thread on the canon EES screen. All of this has indeed been, not negated, but alleviated by the advent of very good live view.
There's no doubt that mirrorless offers a certain advantage with in-the-evf magnification for manual focus.
03-02-2024, 02:37 PM   #7
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I do use the LCD in LV with focus peeking for handheld macro and for mirror lenses (500mm...900mm) with a loupe or lcd viewer like this MEIKE MK-VF2 LCD viewfinder reviews - Pentax Camera Accessory Review Database . Several options on-line, select one for your screen size 3 or 3.2 inch and 4:3 aspect ratio typically.
It is bit bulky but your camera becomes like EVF , no problem with sunlight because hood shields, etc...
On my camera LV doesn’t turn off AF but uses different focus system and with focus peaking ”On” you can see on lcd what part of image is in focus. Some camera allow also ’zooming in’ the lcd view for even more magnification.

With heavy and long lenses, as it adds 6cm behind camera, the lens weight shifts forward and feels heavier, so monopod or similar might be needed.

03-02-2024, 02:41 PM - 1 Like   #8
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QuoteOriginally posted by ramseybuckeye Quote
I don't have a K-5, I used to have a K-50 which was similar in focusing, I now use a KP and K-3iii which are both improved in the focus area. I do use live view a lot, but only on a tripod, and the KP and K-3iii have magnification and focus peaking, which is fantastic for manual focusing. A good sturdy tripod is indispensable. I shoot a lot at the beach which can be very windy as it was yesterday morning, the wind being no problem, sometimes wet sand can be a problem as the tripod leg can sink a bit.

The diopter being accurate is very important. You mentioned that the camera focuses on the leaf instead of the bird, are you using the single point for autofocusing? It really helps for critical focusing like a bird in a tree, I use the center point and re-compose, which I'm guessing you may also, but I still miss some too, but less on the bodies with more autofocus points.
Tripods are always a tradeoff between weight, cost and sturdiness. I got a carbon fibre tripod rated at 16kg and the lens and camera is about 2kg. Adding a stabiliser weight may have helped. Also a better head may have helped. I tend to use single point for both metering and autofocus. I think that part of the problem is that my subjects are at the end of the useable range of the lens.

The focusing on the leaf thing is in the context of an autofocus lens. The classic case is trying to take pictures of animals at the zoo. The lens focuses on the mesh rather than the animal

QuoteOriginally posted by ramseybuckeye Quote
I have never liked catch in focus, like you said, you can turn past it as it is sometimes slow, at least it was, I've not tried it on my current bodies. I have a had time holding the camera still while moving the focus ring with the support hand, that's just me.

good to see I wasn't imagining it...

QuoteOriginally posted by ramseybuckeye Quote
Unfortunately only your doctor can help with the vision. I'm fortunate as I was corrected pretty well with contact lenses, and a year ago I had cataract surgery and now have excellent vision without correction (except for up real close), and that helps with photography.
I remain hopeful. Many thanks....

---------- Post added 03-03-24 at 05:48 AM ----------

QuoteOriginally posted by Blackwing1 Quote
Thank you for a nice summary of your experiences. I've recently posted a thread about my difficulties in getting sharp wildlife photos using a K20D with a Pentax 300mm/f4 in conjunction with a 1.4x TC (giving me the equivalent of a 420mm/f5.6, more or less) and have found basically the same thing. My particular issue is size of the depth of field...with the K20D's limit of ISO 3200 it gives a practical limit to avoid noise of ISO 800...which in turn makes me either open up the aperture (reducing DoF), slow down the shutter speed (increasing shake effects), or both.
I recently stopped down iso to 100 to 3200. I got a lot of good advice from others up here to use TAV. So by default on the 400mm prime I use 1/400s with an aperture of between about F8 and F13. I was finding that otherwise the iso could end up at ridiculous levels. in the last few months I realised I that I was using a too low fstop for my macros resulting in DoF issues. I am now starting to get some really good shots - still a way to go.


QuoteOriginally posted by Blackwing1 Quote
I'll be experimenting with higher ISO this spring to see what works better, but in the meantime I'm just going to try a few other things including shooting TAv and letting the camera pick the ISO for a given shot...and then playing with both aperture and shutter speed to see how high/low I can go and still get a sharp picture with the deepest DoF.
Always the learning curve and new mountains to conquer.... Thanks Blackwing.

---------- Post added 03-03-24 at 05:51 AM ----------

QuoteOriginally posted by mlag Quote
I do use the LCD in LV with focus peeking for handheld macro and for mirror lenses (500mm...900mm) with a loupe or lcd viewer like this MEIKE MK-VF2 LCD viewfinder reviews - Pentax Camera Accessory Review Database . Several options on-line, select one for your screen size 3 or 3.2 inch and 4:3 aspect ratio typically.
It is bit bulky but your camera becomes like EVF , no problem with sunlight because hood shields, etc...
On my camera LV doesn’t turn off AF but uses different focus system and with focus peaking ”On” you can see on lcd what part of image is in focus. Some camera allow also ’zooming in’ the lcd view for even more magnification.

With heavy and long lenses, as it adds 6cm behind camera, the lens weight shifts forward and feels heavier, so monopod or similar might be needed.
focus peaking is on my list to try. The big issue with all this is portability and ease of setup. I will have to consider trying again but will probably decide that for wildlife I am better off with handheld and the magnifier eye piece. Thanks Miag

Last edited by betchern0t; 03-02-2024 at 03:10 PM.
03-08-2024, 08:55 AM - 1 Like   #9
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Telephoto photography has a lot in common with marksmanship in that a steady and stable platform is necessary to properly aim and hit a small target.

If a tripod seems to cumbersome a good monopod will also provide stability and support.
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