Where to Focus for Optimum Depth of Field
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- เผยแพร่เมื่อ 23 พ.ค. 2022
- We often need to optimize our depth of field and sharpness. Here's a little known trick that lets your lens decide where the best point of focus is within your chosen depth of field. Good for landscapes, macro, portraits, in fact any photographs where you want to control subject sharpness and depth of field.
Thanks for watching
John
www.pictorialplanet.com
![Depth of Field Explained: Ultimate Guide to Camera Focus [Shot List Ep. 4]](/img/n.gif)
I love when people teach me something about my camera I didn't know despite owning it for years. Thank you so much! This is so helpful!
Remember did this at the school decade ago. The DOF should be 1/3 foreground and 2/3 from the focusing point. It’s a valuable info when I was working on a 50mm lens.
John, you have a special way of taking concepts and making them so accessibly concrete - I feel like I get an education and an "Aha!" moment with each video. Thanks so much for making this!
Thanks, I appreciate your support!
Fantastic one this John. Makes me want to dig my Takumars out ;)
Ha! No, send them to me ;-)
Wonderful explanation!
Thank you, Dustin!
Simply excellent and thank you for sharing John.
Cheers Dave
Great video, John. Very informative. Thank you for posting.
Thanks Frank!
Thanks for another great video.
Cheers Gabriel! You're very kind!!
Excellent explanation!
Thank you Markus!
Thanks John
Yes, the hyperfocal scale.
One of the basics of picture making, I usually like everything in focus and use a wide angle lens to give me that little bit more "sharpness" in my pictures without causing to much diffraction.
I suppose that I still admire those of the F64 club.
Thank you for your great advice 👍
Thanks for you comment Peter. The f64 club, that was a blast from the past.
@@PictorialPlanet
Ha ha, some things never change, they have some great advise, as do you 🥂
one of those things that you know is there, but never seen it in practice. very useful, thanks.
Cheers, C!
Thank you very much for sharing this! I recently had a little trouble with landscape photography using a TLR, I'll keep this technique in mind for my next outing!
Thanks Christos! I used a TLR for some years and really enjoyed it. It was a Mamiya C330f. Lovely lenses. Anyway, glad you will try this technique.
Thank you John for this video. I do not shoot 35mm, but medium format. The way I "let the lens do the work" for focusing is with the depth of preview lever. I initially focus in the middle of the two points I want to be sharp, then adjust the aperture while looking through the depth of preview. Seems to work, but I will try your technique as well. I enjoy your videos and personality for instruction. Best to you.
Thanks for your comment CG. I like your depth of field preview technique. My problem is I find it hard to see what's in focus when I close the lens down and it gets dark. Also the optimum focus point, for a given depth of field, is just in front of the middle so I learned that, due to the Len's focus markings being non linear, this described system lets the Len's place the focus point at the right place. When I moved the focus dial exactly between the 5m and the 15m it's not on 10m it's more like 8-9m. I find that fascinating!
I think this is going to be really useful when I shoot with my dad’s analogic Reflex, since it has central focus when entirely operated in manual mode
I love all manual cameras.
@@PictorialPlanet I'm using my dad's Nikon F401x 🥰
Very nice camera and has some good lenses. The 50mm 1.8 is very sharp.
Thank you very much for such an informative video. Was that film (fp4?) developed in Barry Thornton's two bath developer?
It was FP4+ shot at EI80 and developed in 510-pyro for 7.5 mins using 30 seconds agitation and then two inversions every 30 seconds.
Hello John. Very informative video as usual. Is that a 'prime' lens on your camera? If it is, would the same theory/practice work with a zoom type lens?
Yes and yes. That is a 50mm 1.7 Pentax prime in the video but a zoom with similar focus markings would work equally well. If you look at a zoom focus scale then it too is non-linear supporting the hyper focal focussing I.e. half way between 5m and 15m is not 10m but slightly less.
Brilliant video John, certainly a tip I will use going forward! Thankyou
Thanks Geoff
Great John
So if I were to focus in the centre of the bridge and choose a smaller aperture would that not give me even more depth of field ?
Yes, you can make the depth of field as large or small as you like but do know it's not equal front and rear! Your method would have more depth behind the bridge than in front. This is because the angle of the light rays hitting the lens are more parallel the further away they originate. That's why when you focus on infinity there is no rear (you could call it "far") depth of field but you do have one in front of your infinity focus. This is true even when stopped right down. So, when I moved the len's to between 5m and 15m it wasn't focussed on 10m because the scale is not linear.
Also, remember that your sharpest apertures are not the smallest but a couple of stops down from wide open so closing down for big depth of field un-sharpens your shot - not good for fine art.
@@PictorialPlanet yes it's rare I go past f11 , my lenses start at f4 and 5.6
What would be your thoughts on the use of a laser measurement device? One could aim to the center focal point and dial the measurement on the lens.
Interesting idea but unfortunately wouldn't optimise the focus point. The lens, in my example, doesn't focus on the center. Because of the way the lens works the focus ring is not linear. Therefore the point of focus, when I set the lens to half way between 5 and 15 metres is not 10 metres (as you might imagine) but less than that. If you examine a lens scale you'll see what I mean. So, the optimum focus point, within any depth of field, Is closer than half way between the nearest dof point and the farthest dof point. By using the lens as shown you don't need to guess how much closer than half way, the lens does it for you 🤔
Thx for your example, never saw it in this way. But if, as you said, the depth of field is not linear, would it not be better to focus nearer to 5m as in the middle between 5m and 15m?
I'm glad this got you thinking, Michael. It sounds like you understand that when focussed on an object the depth of field is about 1/3 in front and 2/3 behind not equally in front and behind, it's uneven. So if I focused on me, if I stood in the middle of the bridge, I might not get the front if the bridge within that depth of field, and I'd get too much behind. By using the lenses non-linear focussing, and moving the lens half way between the two measured distance points on the barrel, I automatically compensate for this non-even depth of field. Basically, half way between the two marks on the lenses focus ring is _not_ halfway between the bridge measured points by in fact a little nearer than half way.
I must admit I have no idea what this is, I just use my viewfinder and focus, as for depth of field, I don't know but I think there's a button to preview it on film cameras. I'll have to come back to this video once I start taking pictures again with my film camera, this weekend, well, come back later and see if I understand better.
Glad you watched it. Thank you
👋👋👋👋😍
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John, does your focus fall off at a faster rate with wider apertures compared with smaller apertures once you’ve reached the end of your DOF? Thanks!
Yes, wider apertures causes focus to fall faster.
@@PictorialPlanet thank you, John! You truly are a blessing :-)
Ha Ha !! MY PENTAX MX cameras are both worn out with so much local Press work ! The flash contacts on one are even burnt OUT with so much flash work !
How long did you do local press work for Peter?
@@PictorialPlanet JOHN - I started part-time in about 1959 getting some work from the 'Stratford Express' then when i left UCL London as Scientific Photographer i set up full time a freelance in 1970 Never 'Made My Fortune' and now all local Freelancers GONE BROKE !
They should have made you BOSS! They'd have had even better photography and would still be GOING!!