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Orio
Joined: 24 Feb 2007 Posts: 29545 Location: West Emilia
Expire: 2012-12-04
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Posted: Fri Nov 02, 2012 1:37 am Post subject: f/22 |
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Orio wrote:
Two quick notes:
- it seems to me that photographers today give attention and consideration only to one end of the aperture spectrum: the wide end.
Nobody, instead, seems to be interested in the other end anymore, the full stopped down end. And this in spite of many's claimed admiration for Ansel Adams,
who was somebody who instead often explored the full stopped down avenue;
- I really hate it when I read this type of advice to newbies: "never shoot more stopped down than f/8 (or f/11), because after that limit, diffraction will ruin your pictures".
Often said by people who frequently use wide open aperture, but never notice/complain about the problems of residual aberrations of various kind, which really can -and do-
"ruin" their pictures just like diffraction, if not even more!
The reality is, that not to use the extreme apertures of a lens, is like having a piano and not using the two extreme octaves.
Sure, you can play beautiful music without them, but it's a limitation of your expression. The extreme octaves don't get used often, but when they do,
they provide specific effects that are unique. The same is with photography: you don't use often wide open (at least, you shouldn't), and you don't use often full stopped down,
but when you do use them, in an appropriate way, they expand your expressions vocabulary.
Here's a picture I took when testing Gelios-103 53mm f/1.8 lens on my M9. This picture is taken with the lens fully stopped down to f/22. The focus is on the foreground plant:
I think that the result is quite convincing, and is something that is different from what you commonly see around in web albums.
It is a creative possibility that many people never explore because they believe that shooting f/22 will ruin their pictures.
Well, here's a 100% crop from this picture, that shows that in spite of diffraction, there is still plenty of detail in the photograph,
surely more than enough to obtain a good quality print:
So, don't be afraid, and don't let commonplaces scare you away from the other end of your lens' aperture. Explore it without fretting! _________________ Orio, Administrator
T*
NE CEDE MALIS AUDENTIOR ITO
Ferrania film is reborn! http://www.filmferrania.it/
Support the Ornano film chemicals company and help them survive!
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Attila
Joined: 24 Feb 2007 Posts: 57865 Location: Hungary
Expire: 2025-11-18
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Posted: Fri Nov 02, 2012 2:09 am Post subject: |
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Attila wrote:
Thank you for sharing it! I use F16 for product shoots and happy with that _________________ -------------------------------
Items on sale on Ebay
Sony NEX-7 Carl Zeiss Planar 85mm f1.4, Minolta MD 35mm f1.8, Konica 135mm f2.5, Minolta MD 50mm f1.2, Minolta MD 250mm f5.6, Carl Zeiss Sonnar 180mm f2.8
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skida
Joined: 02 Mar 2012 Posts: 1826 Location: North East England
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Posted: Fri Nov 02, 2012 2:11 am Post subject: |
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skida wrote:
A very good point, Orio. I couldn't help noticing in that magazine zoom test, posted in the lens forum, that all the lenses were resolving best at f8 to f16.
Great photo to illustrate your point too. |
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visualopsins
Joined: 05 Mar 2009 Posts: 11059 Location: California
Expire: 2025-04-11
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Posted: Fri Nov 02, 2012 4:03 am Post subject: |
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visualopsins wrote:
Recently I began exploring narrow apertures using macro lenses I'd previous only stopped to f/8 to get maximum resolution; f/16-f/22. I am liking the results -- I can't see any diffraction effects; the extra dof seems to make for me more keepers. With landscapes I cannot discern any difference between f/8 & f/16; I continue to use f/8.
edit:
I should say the camera sensor (FF, 5D) diffraction limit is f/8 -- why I didn't go smaller -- only f/5.6 for crop. This is not a 'problem' with film! (Anybody know the diffraction limit for film?) _________________ ☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮ like attracts like! ☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮
Cameras: Sony ILCE-7RM2, Spotmatics II, F, and ESII, Nikon P4
Lenses:
M42 Asahi Optical Co., Takumar 1:4 f=35mm, 1:2 f=58mm (Sonnar), 1:2.4 f=58mm (Heliar), 1:2.2 f=55mm (Gaussian), 1:2.8 f=105mm (Model I), 1:2.8/105 (Model II), 1:5.6/200, Tele-Takumar 1:5.6/200, 1:6.3/300, Macro-Takumar 1:4/50, Auto-Takumar 1:2.3 f=35, 1:1.8 f=55mm, 1:2.2 f=55mm, Super-TAKUMAR 1:3.5/28 (fat), 1:2/35 (Fat), 1:1.4/50 (8-element), Super-Multi-Coated Fisheye-TAKUMAR 1:4/17, Super-Multi-Coated TAKUMAR 1:4.5/20, 1:3.5/24, 1:3.5/28, 1:2/35, 1:3.5/35, 1:1.8/85, 1:1.9/85 1:2.8/105, 1:3.5/135, 1:2.5/135 (II), 1:4/150, 1:4/200, 1:4/300, 1:4.5/500, Super-Multi-Coated Macro-TAKUMAR 1:4/50, 1:4/100, Super-Multi-Coated Bellows-TAKUMAR 1:4/100, SMC TAKUMAR 1:1.4/50, 1:1.8/55
M42 Carl Zeiss Jena Flektogon 2.4/35
Contax Carl Zeiss Vario-Sonnar T* 28-70mm F3.5-4.5
Pentax K-mount SMC PENTAX-A ZOOM 1:3.5 35~105mm, SMC PENTAX ZOOM 1:4 45~125mm
Nikon Micro-NIKKOR-P-C Auto 1:3.5 f=55mm, NIKKOR-P Auto 105mm f/2.5 Pre-AI (Sonnar), Micro-NIKKOR 105mm 1:4 AI, NIKKOR AI-S 35-135mm f/3,5-4,5
Tamron SP 17mm f/3.5 (51B), Tamron SP 17mm f/3.5 (151B), SP 500mm f/8 (55BB), SP 70-210mm f/3.5 (19AH)
Vivitar 100mm 1:2.8 MC 1:1 Macro Telephoto (Kiron)
Last edited by visualopsins on Fri Nov 02, 2012 5:49 am; edited 1 time in total |
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mo
Joined: 27 Aug 2009 Posts: 8979 Location: Australia
Expire: 2016-07-30
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Posted: Fri Nov 02, 2012 5:18 am Post subject: |
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mo wrote:
Thank you for the lesson on f22,I appreciate your thoughts and experience. _________________ Moira, Moderator
Fuji XE-1,Pentax K-01,Panasonic G1,Panasonic G5,Pentax MX
Ricoh Singlex TLS,KR-5,KR-5Super,XR-10
Lenses
Auto Rikenon's 55/1.4, 1.8, 2.8... 50/1.7 Takumar 2/58 Preset Takumar 2.8/105 Auto Takumar 2.2/55, 3.5/35 Super Takumar 1.8/55...Macro Takumar F4/50... CZJ Biotar ALU M42 2/58 CZJ Tessar ALU M42 2.8/50
CZJ DDR Flektogon Zebra M42 2.8/35 CZJ Pancolar M42 2/50 CZJ Pancolar Exakta 2/50
Auto Mamiya/Sekor 1.8/55 ...Auto Mamiya/Sekor 2/50 Auto Mamiya/Sekor 2.8/50 Auto Mamiya/Sekor 200/3.5 Tamron SP500/8 Tamron SP350/5.6 Tamron SP90/2.5
Primoplan 1.9/58 Primagon 4.5/35 Telemegor 5.5/150 Angenieux 3.5/28 Angenieux 3,5/135 Y 2
Canon FL 58/1.2,Canon FL85/1.8,Canon FL 100/3.5,Canon SSC 2.8/100 ,Konica AR 100/2.8, Nikkor P 105/2.5
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kds315*
Joined: 12 Mar 2008 Posts: 16664 Location: Weinheim, Germany
Expire: 2021-03-09
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Posted: Fri Nov 02, 2012 7:40 am Post subject: |
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kds315* wrote:
Cannot agree more! Well done Orio! _________________ Klaus - Admin
"S'il vient a point, me souviendra" [Thomas Bohier (1460-1523)]
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/uv_photos for UV Images and lens/filter info
https://www.flickr.com/photos/kds315/albums my albums using various lenses
http://photographyoftheinvisibleworld.blogspot.com/ my UV BLOG
http://www.travelmeetsfood.com/blog Food + Travel BLOG
https://galeriafotografia.com Architecture + Drone photography
Currently most FAV lens(es):
X80QF f3.2/80mm
Hypergon f11/26mm
ELCAN UV f5.6/52mm
Zeiss UV-Planar f4/60mm
Zeiss UV-Planar f2/62mm
Lomo Уфар-12 f2.5/41mm
Lomo Зуфар-2 f4.0/350mm
Lomo ZIKAR-1A f1.2/100mm
Nikon UV Nikkor f4.5/105mm
Zeiss UV-Sonnar f4.3/105mm
CERCO UV-VIS-NIR f1.8/45mm
CERCO UV-VIS-NIR f4.1/94mm
CERCO UV-VIS-NIR f2.8/100mm
Steinheil Quarzobjektiv f1.8/50mm
Pentax Quartz Takumar f3.5/85mm
Carl Zeiss Jena UV-Objektiv f4/60mm
NYE OPTICAL Lyman-Alpha II f1.1/90mm
NYE OPTICAL Lyman-Alpha I f2.8/200mm
COASTAL OPTICS f4/60mm UV-VIS-IR Apo
COASTAL OPTICS f4.5/105mm UV-Micro-Apo
Pentax Ultra-Achromatic Takumar f4.5/85mm
Pentax Ultra-Achromatic Takumar f5.6/300mm
Rodenstock UV-Rodagon f5.6/60mm + 105mm + 150mm
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Excalibur
Joined: 19 Jul 2009 Posts: 5017 Location: UK
Expire: 2014-04-21
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Posted: Fri Nov 02, 2012 8:18 am Post subject: |
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Excalibur wrote:
erm On a film camera you would have to carry a tripod around to use a tele lens @f16 or f22 to avoid camera shake In sunny Ibiza I was using a 135mm lens @ 1/250, f11 with 100asa film and the pictures came out sharp, but f16@ 1/125........................... _________________ Canon A1, AV1, T70 & T90, EOS 300 and EOS300v, Chinon CE and CP-7M. Contax 139, Fuji STX-2, Konica Autoreflex TC, FS-1, FT-1, Minolta X-700, X-300, XD-11, SRT101b, Nikon EM, FM, F4, F90X, Olympus OM2, Pentax S3, Spotmatic, Pentax ME super, Praktica TL 5B, & BC1, , Ricoh KR10super, Yashica T5D, Bronica Etrs, Mamiya RB67 pro AND drum roll:- a Sony Nex 3
.........past gear Tele Rolleiflex and Rollei SL66.
Many lenses from good to excellent.
Last edited by Excalibur on Fri Nov 02, 2012 8:36 am; edited 2 times in total |
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Pontus
Joined: 18 Dec 2011 Posts: 1471 Location: Jakobstad, Finland
Expire: 2016-08-25
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Posted: Fri Nov 02, 2012 8:21 am Post subject: |
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Pontus wrote:
I was having thoughts along the same line a while ago: http://forum.mflenses.com/diffraction-limited-aperture-in-real-life-t48718.html
Another aspect worth mentioning is that if you want star effects from lights or pronounced sun rays, you need a small aperture. _________________ Follow this link for my FOR SALE list (partially updated 19.11.2015) |
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poilu
Joined: 26 Aug 2007 Posts: 10472 Location: Greece
Expire: 2019-08-29
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Posted: Fri Nov 02, 2012 8:31 am Post subject: |
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poilu wrote:
Orio wrote: |
And this in spite of many's claimed admiration for Ansel Adams |
Ansel Adams used f64, f64 on the large format is f8 on 24x36 and f4 on m4:3
using f22 on 24x36 is like using f176 on large format
f22 can be useful for macro if focus stacking cannot be used
btw you can also use focus stacking for landscape
f22 of 24x36 is f4 on my phone, my phone is always at f2,8 who is f16 on 24x36
Orio wrote: |
I think that the result is quite convincing, and is something that is different from what you commonly see around in web albums.
It is a creative possibility that many people never explore because they believe that shooting f/22 will ruin their pictures.
Well, here's a 100% crop from this picture, that shows that in spite of diffraction, there is still plenty of detail in the photograph,
surely more than enough to obtain a good quality print |
indeed f22 can be used differently that common web albums
even at wide open, pics can look very different depending where we put the focus point
experiment is always interesting and when I was testing the Samyang 14:2.8, I make each shot at every aperture available
I show wide open shots not because it is the way the lens should be used
but to show that the lens can be trusted at every aperture click here to see it
digital is 'free', don't care to take shots that will not be used _________________ T* |
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iangreenhalgh1
Joined: 18 Mar 2011 Posts: 15679
Expire: 2014-01-07
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Posted: Fri Nov 02, 2012 12:54 pm Post subject: |
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iangreenhalgh1 wrote:
I used to get people telling me I was stupid for using f22 to shoot my panoramic landscapes, that diffraction would make them soft.
Simply not true, not with my NEX-3 at least. Whatever diffraction there is is hardly visible, the images are still more than sharp enough, even if printed large (1.2m width).
This was f16 (min aperture of the lens) with a Konica Hexanon 3.5/28:
_________________ I don't care who designed it, who made it or what country it comes from - I just enjoy using it! |
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ForenSeil
Joined: 15 Apr 2011 Posts: 2726 Location: Kiel, Germany.
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Posted: Fri Nov 02, 2012 5:29 pm Post subject: |
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ForenSeil wrote:
Orio wrote: |
Two quick notes:
- it seems to me that photographers today give attention and consideration only to one end of the aperture spectrum: the wide end.
Nobody, instead, seems to be interested in the other end anymore, the full stopped down end. And this in spite of many's claimed admiration for Ansel Adams,
who was somebody who instead often explored the full stopped down avenue;
... |
Don't forget that Ansel Adams was using a pretty large format film which behaves very different than a crop sensor
But otherwise I also couldn't agree more. F16-F22 can be very useful, especially stacked for landscape etc. - there's a reson why except a very few all lenses have them. _________________ I'm not a collector, I'm a tester
My camera: Sony A7+Zeiss Sonnar 55/1.8
Current favourite lenses (I have many more):
A few macro-Tominons, Samyang 12/2.8, Noritsu 50.7/9.5, Rodagon 105/5.6 on bellows, Samyang 135/2, Nikon ED 180/2.8, Leitz Elmar-R 250/4, Celestron C8 2000mm F10
Most wanted: Samyang 24/1.4, Samyang 35/1.4, Nikon 200/2 ED
My Blog: http://picturechemistry.own-blog.com/
(German language) |
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Lloydy
Joined: 02 Sep 2009 Posts: 7796 Location: Ironbridge. UK.
Expire: 2022-01-01
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Posted: Fri Nov 02, 2012 6:01 pm Post subject: |
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Lloydy wrote:
I generally head for the closed end, and it's a rare occasion when I haven't got a tripod, or at least my beloved monopod, with me. If there's any distance in my picture, a landscape, I always close down.
Good point though Orio, we read these 'words of wisdom' about going wide and accept it as the best way. It isn't, it's just one way. _________________ LENSES & CAMERAS FOR SALE.....
I have loads of stuff that I have to get rid of, if you see me commenting about something I have got and you want one, ask me.
My Flickr https://www.flickr.com/photos/mudplugga/
My ipernity -
http://www.ipernity.com/home/294337 |
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LucisPictor
Joined: 26 Feb 2007 Posts: 17633 Location: Oberhessen, Germany / Maidstone ('95-'96)
Expire: 2013-12-03
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Posted: Fri Nov 02, 2012 6:59 pm Post subject: |
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LucisPictor wrote:
I have re-discovered an (almost) infinite DoF by using the Voigtländer Heliar 4.5/15 on my Leica M8 recently.
You're perfectly right, Orio. Not in every shot the DoF has to be narrow. _________________ Personal forum activity on pause every now and again (due to job obligations)!
Carsten, former Moderator
Things ON SALE
Carsten = "KAPCTEH" = "Karusutenu" | T-shirt?.........................My photos from Emilia: http://www.schouler.net/emilia/emilia2011.html
My gear: http://retrocameracs.wordpress.com/ausrustung/
Old list: http://forum.mflenses.com/viewtopic.php?t=65 (Not up-to-date, sorry!) | http://www.lucispictor.de | http://www.alensaweek.wordpress.com |
http://www.retrocamera.de |
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fermy
Joined: 17 Feb 2012 Posts: 1974
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Posted: Fri Nov 02, 2012 11:50 pm Post subject: |
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fermy wrote:
This is a very interesting discussion topic, kudos for coming up with it. I have to say that I have reservations regarding the original message. The diffraction effect is real, it's not a scary tale for people that don't know any better. There are two major reasons for using wide aperture: to thin the DOF and to improve exposure (get lower ISO or faster shutter). And yes, almost all lenses are better stopped down than wide open. So when going to the wider aperture, there is a clear tradeoff and it's up to photographer to decide on the best compromise.
Now, when stopping the lens down to f22, I don't see what the trade-off is. The downside is that the picture is less sharp than at optimal aperture and you lose shutter speed as well, but what is the upside? The DOF does not necessarily increase, since the whole picture is more blurry, the only difference is that in focus part looks less sharp. This could be an advantage for portraits, but hardly in pictures where one would consider using F22.
So unless one does gain DOF by stopping down, I don't see a photographic benefit. Then there must be a critical aperture, closing past which is not advisable. This aperture is not necessarily at the diffraction limit though. For me the interesting questions is how to determine such aperture. _________________ Many lenses and some film bodies for sale here: http://forum.mflenses.com/canon-fd-minolta-md-c-mounts-m42-pentax-and-more-t50465.html
Flickr http://www.flickr.com/photos/96060788@N06/ |
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Lloydy
Joined: 02 Sep 2009 Posts: 7796 Location: Ironbridge. UK.
Expire: 2022-01-01
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Posted: Sat Nov 03, 2012 1:24 am Post subject: |
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Lloydy wrote:
fermy wrote: |
This is a very interesting discussion topic, kudos for coming up with it. I have to say that I have reservations regarding the original message. The diffraction effect is real, it's not a scary tale for people that don't know any better. There are two major reasons for using wide aperture: to thin the DOF and to improve exposure (get lower ISO or faster shutter). And yes, almost all lenses are better stopped down than wide open. So when going to the wider aperture, there is a clear tradeoff and it's up to photographer to decide on the best compromise.
Now, when stopping the lens down to f22, I don't see what the trade-off is. The downside is that the picture is less sharp than at optimal aperture and you lose shutter speed as well, but what is the upside? The DOF does not necessarily increase, since the whole picture is more blurry, the only difference is that in focus part looks less sharp. This could be an advantage for portraits, but hardly in pictures where one would consider using F22.
So unless one does gain DOF by stopping down, I don't see a photographic benefit. Then there must be a critical aperture, closing past which is not advisable. This aperture is not necessarily at the diffraction limit though. For me the interesting questions is how to determine such aperture. |
Interesting question, one I'd like to know the answer to as well. _________________ LENSES & CAMERAS FOR SALE.....
I have loads of stuff that I have to get rid of, if you see me commenting about something I have got and you want one, ask me.
My Flickr https://www.flickr.com/photos/mudplugga/
My ipernity -
http://www.ipernity.com/home/294337 |
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LucisPictor
Joined: 26 Feb 2007 Posts: 17633 Location: Oberhessen, Germany / Maidstone ('95-'96)
Expire: 2013-12-03
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Posted: Sat Nov 03, 2012 7:12 am Post subject: |
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LucisPictor wrote:
Lloydy wrote: |
fermy wrote: |
This is a very interesting discussion topic, kudos for coming up with it. I have to say that I have reservations regarding the original message. The diffraction effect is real, it's not a scary tale for people that don't know any better. There are two major reasons for using wide aperture: to thin the DOF and to improve exposure (get lower ISO or faster shutter). And yes, almost all lenses are better stopped down than wide open. So when going to the wider aperture, there is a clear tradeoff and it's up to photographer to decide on the best compromise.
Now, when stopping the lens down to f22, I don't see what the trade-off is. The downside is that the picture is less sharp than at optimal aperture and you lose shutter speed as well, but what is the upside? The DOF does not necessarily increase, since the whole picture is more blurry, the only difference is that in focus part looks less sharp. This could be an advantage for portraits, but hardly in pictures where one would consider using F22.
So unless one does gain DOF by stopping down, I don't see a photographic benefit. Then there must be a critical aperture, closing past which is not advisable. This aperture is not necessarily at the diffraction limit though. For me the interesting questions is how to determine such aperture. |
Interesting question, one I'd like to know the answer to as well. |
I don't think that you could find a precise DIY solution. Determining the diffraction limit needs a scientific apporach with lab-like surroundings.
Here is a little more about it:
http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm
http://www.luminous-landscape.com/tutorials/understanding-series/u-diffraction.shtml _________________ Personal forum activity on pause every now and again (due to job obligations)!
Carsten, former Moderator
Things ON SALE
Carsten = "KAPCTEH" = "Karusutenu" | T-shirt?.........................My photos from Emilia: http://www.schouler.net/emilia/emilia2011.html
My gear: http://retrocameracs.wordpress.com/ausrustung/
Old list: http://forum.mflenses.com/viewtopic.php?t=65 (Not up-to-date, sorry!) | http://www.lucispictor.de | http://www.alensaweek.wordpress.com |
http://www.retrocamera.de |
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fermy
Joined: 17 Feb 2012 Posts: 1974
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Posted: Sat Nov 03, 2012 8:10 am Post subject: |
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fermy wrote:
It's not that hard provided you are ready to make reasonable simplifications (e.g. doing calculations for green channel only, assuming no AA filter, etc). The first link that you've supplied has a calculator similar to DOF calculator. It's as simple as combing this one with DOF calculator. The answer will obviously depend on FL and subject distance, but still having ballpark figures would definitely be useful. _________________ Many lenses and some film bodies for sale here: http://forum.mflenses.com/canon-fd-minolta-md-c-mounts-m42-pentax-and-more-t50465.html
Flickr http://www.flickr.com/photos/96060788@N06/ |
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Orio
Joined: 24 Feb 2007 Posts: 29545 Location: West Emilia
Expire: 2012-12-04
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Posted: Sat Nov 03, 2012 8:21 am Post subject: |
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Orio wrote:
fermy wrote: |
This is a very interesting discussion topic, kudos for coming up with it. I have to say that I have reservations regarding the original message. The diffraction effect is real, it's not a scary tale for people that don't know any better. |
You are a master in twisting the meaning obviously.
I never said that it wasn't real and that it was a scary tale for ignorant people.
I said that the consequence of diffraction is:
- not worse than the consequences of shooting a lens wide open
- not enough to make the picture useless
any other conclusions that you allege are not present in my message and I have to say, that I find your attitude offensive towards me. _________________ Orio, Administrator
T*
NE CEDE MALIS AUDENTIOR ITO
Ferrania film is reborn! http://www.filmferrania.it/
Support the Ornano film chemicals company and help them survive!
http://forum.mflenses.com/ornano-chemical-products-t55525.html |
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Rolf
Joined: 02 May 2009 Posts: 4123 Location: NRW/Germany
Expire: 2015-12-26
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Posted: Sat Nov 03, 2012 8:56 am Post subject: |
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Rolf wrote:
May be it is a "problem" due to the prices for lenses. If you must pay a lot of money for lenses with good wide open performance you will use it. Like a fast car. You will drive faster then too. But I fully agreee. In some situations f/16 or f/22 will be the right choice.
And btw some negative effects of lenses you can read in photo magazines and the test there are only visible in the test lab with test charts.
_________________ Rolf |
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Orio
Joined: 24 Feb 2007 Posts: 29545 Location: West Emilia
Expire: 2012-12-04
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Posted: Sat Nov 03, 2012 9:11 am Post subject: |
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Orio wrote:
fermy wrote: |
The DOF does not necessarily increase, since the whole picture is more blurry |
This assumption you make is not correct, and the whole reasoning you started from it, is affected by this error.
1- DOF does not exist. At any aperture, there is only one focus point, everything else is out of focus;
2- It is correct instead to speak of perceived DOF, meaning the apparent focused area determined
by the inability of the human vision to resolve the circles of confusion (COC) that are smaller than a given size
compared to the ideal focus point. This "acceptable" size (known as "acceptable COC") obviously changes with
the enlargement (this is why small pictures, such as 800x600, may look focused even when they're out of focus)
and can also vary with the sight ability of the individuals, but there is a general limit that is considered standard
for human vision and which corresponds to 0.05 mm for a 35mm negative/sensor size;
3- The narrower the lens aperture, the deeper the preceived DOF. This is a progressive optical illusion and it is
wrong to think that there is a moment when the apparent DOF stops to increase. An f/22 picture has a deeper
perceived DOF than a f/16 picture, and a f/16 picture has a deeper perceived DOF than a f/11 picture, and so on;
4- One must not mistake the unsharpness with the blurryness. It is wrong to say that in a f/22 "the picture is more blurry".
That is not only false, but, in terms of optical perception, the opposite is true: the whole picture appears less blurry at f/22,
because the perceived DOF is deeper. The consequence of diffraction is simply that the resolution of the image is reduced,
and thus the preceived sharpness affected. Note: the sharpness, not the focus. The opposite of sharp
is unsharp, the opposite of blurry is focused. The consequence of diffraction is that the image appears less sharp in the
focused point, but still perfectly focused and not more blurry;
To get back to your question: what is the up-side of stopping the lens fully down? That the apparent DOF is increased.
Combined with the different focal lenghts, this optical effect can be used creatively. With a super wide angle lens, the apparent
DOF of a lens at full stop down can be virtually infinite, this way approaching the result that one would obtain with a pin-hole camera.
With a 50mm lens, such as the one I used in this example, what you obtain is a more gradual transition from focused to
unfocused/blurry. Applied to a landscape that offers uninterrupted sight from foreground to infinity, such as the one I photographed,
this more gradual transition reinforces the sense of depth and of the natural aerial perspective (if present).
Instead of making the subject "pop", as with an abrupt transition, you make it appear more "immersed" in the landscape. The
result is an image that looks more "credible" (realistic) than a "pop" image.
Note that the reason why the effect changes with the focal lenght, is the same as already mentioned in point #2: the enlargement.
The perceived DOF is affected by the enlargement not only at print/screen level, but also at taking level: of course, longer focal
lenght lenses enlarge the scene more than shorter focal lenght lenses. _________________ Orio, Administrator
T*
NE CEDE MALIS AUDENTIOR ITO
Ferrania film is reborn! http://www.filmferrania.it/
Support the Ornano film chemicals company and help them survive!
http://forum.mflenses.com/ornano-chemical-products-t55525.html |
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twinquartz
Joined: 11 Jun 2012 Posts: 316 Location: Sweden
Expire: 2013-10-29
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Posted: Sat Nov 03, 2012 10:47 am Post subject: |
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twinquartz wrote:
Would this calculator be of use http://www.photozone.de/depth-of-field?
See how the near/far limits change when you alter the Circle-of-Confusion parameter. |
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fermy
Joined: 17 Feb 2012 Posts: 1974
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Posted: Sat Nov 03, 2012 4:48 pm Post subject: |
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fermy wrote:
Orio wrote: |
I said that the consequence of diffraction is:
- not worse than the consequences of shooting a lens wide open
- not enough to make the picture useless
any other conclusions that you allege are not present in my message and I have to say, that I find your attitude offensive towards me. |
Shrug. No offense was intended. I don't know why you interpret slight disagreement as offense. _________________ Many lenses and some film bodies for sale here: http://forum.mflenses.com/canon-fd-minolta-md-c-mounts-m42-pentax-and-more-t50465.html
Flickr http://www.flickr.com/photos/96060788@N06/ |
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fermy
Joined: 17 Feb 2012 Posts: 1974
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Posted: Sat Nov 03, 2012 5:13 pm Post subject: |
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fermy wrote:
Orio wrote: |
fermy wrote: |
The DOF does not necessarily increase, since the whole picture is more blurry |
This assumption you make is not correct, and the whole reasoning you started from it, is affected by this error.
1- DOF does not exist. At any aperture, there is only one focus point, everything else is out of focus;
2- It is correct instead to speak of perceived DOF, meaning the apparent focused area determined
by the inability of the human vision to resolve the circles of confusion (COC) that are smaller than a given size
compared to the ideal focus point. This "acceptable" size (known as "acceptable COC") obviously changes with
the enlargement (this is why small pictures, such as 800x600, may look focused even when they're out of focus)
and can also vary with the sight ability of the individuals, but there is a general limit that is considered standard
for human vision and which corresponds to 0.05 mm for a 35mm negative/sensor size;
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DOF is a widely accepted shortcut for what you expanded in 2, so in 1 (and 4 as well) you are arguing semantics.
Quote: |
3- The narrower the lens aperture, the deeper the preceived DOF. This is a progressive optical illusion and it is
wrong to think that there is a moment when the apparent DOF stops to increase. An f/22 picture has a deeper
perceived DOF than a f/16 picture, and a f/16 picture has a deeper perceived DOF than a f/11 picture, and so on;
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Why would that be? The perceived DOF would increase only provided that COC shrink, which is precisely not the case at f22 due to diffraction effects.
Quote: |
To get back to your question: what is the up-side of stopping the lens fully down? That the apparent DOF is increased.
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Yes, provided this happens, I agree that there is a clear upside. The gist of my argument is that for any given photographic situation (e.g. FL, subject distance and acceptable COC) apparent DOF does not increase past certain aperture, because past that aperture the COC do not shrink with aperture decrease. _________________ Many lenses and some film bodies for sale here: http://forum.mflenses.com/canon-fd-minolta-md-c-mounts-m42-pentax-and-more-t50465.html
Flickr http://www.flickr.com/photos/96060788@N06/ |
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peterqd
Joined: 28 Feb 2007 Posts: 7448 Location: near High Wycombe, UK
Expire: 2014-01-04
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Posted: Sat Nov 03, 2012 6:02 pm Post subject: |
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peterqd wrote:
Oh dear, I hope this interesting topic isn't going to be ruined by a rather pointless disagreement.
I remember when one of my early cameras had only one speed of film, one shutter speed and a lever which altered the aperture for cloudy or sunny settings. Aperture control is for adjusting the light entering the camera, just like the iris in your eye, not for adjusting the DOF. This is only a relatively recent advance brought about by the development of high speed films and fast shutter speeds. _________________ Peter - Moderator |
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sichko
Joined: 20 Jun 2008 Posts: 2475 Location: South West UK
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Posted: Sat Nov 03, 2012 6:13 pm Post subject: |
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sichko wrote:
fermy wrote: |
Orio wrote: |
fermy wrote: |
The DOF does not necessarily increase, since the whole picture is more blurry |
This assumption you make is not correct, and the whole reasoning you started from it, is affected by this error.
1- DOF does not exist. At any aperture, there is only one focus point, everything else is out of focus;
2- It is correct instead to speak of perceived DOF, meaning the apparent focused area determined
by the inability of the human vision to resolve the circles of confusion (COC) that are smaller than a given size
compared to the ideal focus point. This "acceptable" size (known as "acceptable COC") obviously changes with
the enlargement (this is why small pictures, such as 800x600, may look focused even when they're out of focus)
and can also vary with the sight ability of the individuals, but there is a general limit that is considered standard
for human vision and which corresponds to 0.05 mm for a 35mm negative/sensor size;
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DOF is a widely accepted shortcut for what you expanded in 2, so in 1 (and 4 as well) you are arguing semantics.
Quote: |
3- The narrower the lens aperture, the deeper the preceived DOF. This is a progressive optical illusion and it is
wrong to think that there is a moment when the apparent DOF stops to increase. An f/22 picture has a deeper
perceived DOF than a f/16 picture, and a f/16 picture has a deeper perceived DOF than a f/11 picture, and so on;
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Why would that be? The perceived DOF would increase only provided that COC shrink, which is precisely not the case at f22 due to diffraction effects.
Quote: |
To get back to your question: what is the up-side of stopping the lens fully down? That the apparent DOF is increased.
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Yes, provided this happens, I agree that there is a clear upside. The gist of my argument is that for any given photographic situation (e.g. FL, subject distance and acceptable COC) apparent DOF does not increase past certain aperture, because past that aperture the COC do not shrink with aperture decrease. |
I agree on all points. To emphasise - the DOF model does not include diffraction effects. Focus blur decreases with increasing lens f-number. Diffraction blur increases with increasing f-number. At some point diffraction wins.
There may be a case for using a large f-number - to increase depth of field - since there are lots of of reports which indicate that diffraction blur is particularly susceptible to removal by sharpening methods which use deconvolution algorithms (try Google for "Richardson-Lucy"). But I'm no expert. Those with ACR (CSX, LRX) may know something about it. Also Raw-Therapee (free ?) is supoosed to use a good implementation.
Norman Koren gives a "rule of thumb" approach to obtaining the optimum aperture - best compromise between DOF and diffraction blur. _________________ John |
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