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Hi everyone!
My mind's stuck on this beautiful and well-known photograph by M. Quinn Jacobson:
Attachment 175361
Can someone explain me how to achieve such a short dof?
I saw a few videos where this plate is hanging on the wall. It doesn't seem to be a huge monster plate...
Is it the lens opening/distance factor only or is there any kind of tilt movement? Something like tilted down plus on one side? What's the lens used on this serie?
Thank you very much for your help!
I dunno anything about the guy. But note how much blacker the deeper tones are around the relatively in-focus face versus the torso etc, which makes me think something greasy was smeared on the neg or contact glass.
Looks as if it may be a longer than normal lens, straight shot, wide aperture for the shallow depth of field.
Don't think Quinn uses much movement for straight portraits.
The neck is stretched forward, placing the face on a different focal plane.
It's also done on wet plate collodion which means an unusually fast (for LF) lens was likely used. f/3.6-ish is probably the slowest that's likely to be.
Short DOF can come from a long lens, a wide aperture and a close subject, in that shot there are some 30mm DOF, here you can find combinations: http://www.dofmaster.com/dofjs.htmlQuote:
Originally Posted by john_vandale_
That particular DOF look it's easy to obtain with very big plates or negatives. If you shot 16x20" plates (like Quinn) narrow DOF in portraits isn't difficult, what would be dificult it's the counter :)
You can use old brass monster petzals (and other). Here Kurt Moser shows the entire process in a TV show (min 1:30):
https://www.youtube.com/watch?v=7Cbg58F98Uw
https://www.youtube.com/watch?v=HmBkXmWgScg
Long process lenses can also be used http://www.galerie-photo.com/apo-pro...ikkors-en.html
Cameras can be really big, you may want a truck to make one for an APO NIkkor 1780mm; https://www.lightcatcher.it/#Ural
You can also take an SLR or DSLR with a nikon or canon 50mm f/1.2, (or even 1.0 for canon) and make a digital negative/positive for alternative process printing, look won't be excatly the same but if the thing ends in a tintype then many people may see the same, anyway something shot with ULF format really big plate is very special, if one has the criterion to feel it.
PD: It looks that there is no tilt or swing movement, because the plane of focus looks well perpendicular to the front axis. Both eyes are in focus and at the same distance, so no swing, also focus in the lips and in tthe the forehead also looks at the same distance, so no tilt. When tilt/swing used then the plane of focus is not perpendicular to the view direction, with movements you can swing and tilt the plane of focus as you want.
Here you can see a shot with tilt : https://www.flickr.com/photos/colton...125592977@N05/
You see the head is in focus, behind subject the floor is out of focus, but the wall in the back is again in focus (the up side), this is because the plane of focus it has been inclinated with a tilt.
Thx everyone!
Are you sure a long lens is part of the solution? I'm a bit sceptical about it... I was thinking dof only depends on two factors, lens aperture and growth factor. This last point depends on focal length relatively to focussing distance, and of course, film size... In other words: I was thinking you obtain the exact same dof with a shorter lens and a shorter distance. Only perspective problems may occur... but with the same head a shoulder shot, only the aperture and plate size may give a difference on dof.
And I saw this plate on youtube videos, it's not a huge mammoth plate... seems to be around 18x24...
It maybe this size of plate with a very fast lens...
There is the same effect on this plate:
Attachment 175364
I hope my future 2.8/150mm will allow me to approch this kind of images on 4x5 plates!
Theorically (DOF Master), my 4.5/210mm @1.5 meter would give me 40mmDOF on my 4x5 plates. But the results are much more commons! :(Quote:
Originally Posted by Pere Casals
Attachment 175365
Is wet-plate orthochromatic ? In other words, comparatively insensitive to red ? In that case, skin pigment is rendered rather dark and blue eyes are rendered light.
Yap! But my trouble is mainly on DOF questions!
You achieve the same DOF with short and long lenses with the same reproduction ratio, but once you are outside that sharp zone long lenses blur off more quickly. So there is an illusion of less depth of field.Quote:
Originally Posted by john_vandale_
You'd have a different perspective even with a very fast 150, but it might work in a slightly different sense. Logistically, you might be uncomfortably close to the sitter.
John,Quote:
Originally Posted by john_vandale_
One important thing to add is OOF roll off nature !!!
To have the same framing than in 4x5/210mm if you shot with a 16x20" camera you would be using a 840mm lens.
You may set an aperture in the 840mm to have the same 40mm DOF you mention, in that range the image will be the same, considering format equivalent CoC (circle of confusion).
but the way the image gets more blurred as it goes beyond the dof range should be different.
Sometimes I used an smartphone app to learn how a lens/distance/aperture will roll off in the OOF, see here how it shows the CoC grows :
Attachment 175369
This is why you see a different OOF nature from what you see from a 4x5, if I'm not mistaken...
PD: as Totias also points...
Why not address the question to M. Quinn Jacobson???Quote:
Originally Posted by john_vandale_
To my knowledge he is still alive and functioning.
regards
Tony
What app is that?Quote:
Originally Posted by Pere Casals
https://play.google.com/store/apps/d...achs.dof&hl=esQuote:
Originally Posted by williaty
you can add new custom cameras of any format, etc
"A compatible version of DoF is also available for Windows computers at:" www.dl-c.com/DoF
Anyone know of a similar app for iOS or macOS?Quote:
Originally Posted by Pere Casals
The image you're inquiring about is a wet plate collodion photo, either made on glass or metal. Lenses made for the process (dating to the early 1850s, when Wet Plate Collodion was invented) had very specific traits, especially evident in the portrait length lenses, and it was typical that they had very shallow depth of field, as they were meant to be used wide open (they had no apertures, and not until later years did they have slots for waterhouse stops). The lens designs of the 1850s (and for a period afterwards) were of the Petzval design, which did not have a flat focal plane, but was in fact curved. This Petzval curve enhanced the illusion of very limited DOF, and the closer you were to the subject, the more pronounced the effect becomes. This is what you are seeing in Quinn's photo. Its typical of the effect seen when using many (most?) of those early portrait lens designs.Quote:
Originally Posted by john_vandale_
This is one of the mid-1850s Petzval design lenses: a 15" f5 Lerebours et Secretan:
Attachment 175374
I'm friends with Quinn, shot with him at the Paris Foto Fair, and moderate his website Collodion.com. Why don't you ask him? He's a nice guy, and has several web sites and training youtube vids. But basically a fast lens with wetplate and natural lighting. Using a flash you won't get the deep blacks around the sitter, usually.
Or go to the Collodion website, or one of the facebook sites (he has one there called Wetplate Photographers), and read up on it. Lots of people doing wetplate today, compared to 10 years ago when I began (when there were about 1 in every state, max). Or if someone is interested, I occasionally do wetplate workshops in Tucson.
2010 wetplate demo booth:
https://c2.staticflickr.com/2/1289/4...73280db2_z.jpg
Hi guys! So much good information here!
I have to consider focal plane bending on Petzval lens and sharpness drop off with larger formats...
At this moment I only have a 4x5 camera for my wet plates, though with a few lenses.
Which one do you think will do the better job from this point of view?
- Schneider 5.6/240mm
- Industar 4.5/300mm
- An old brass f8/210mm
- Schneider xenotar f2.8/150mm
(I guess the first 5.6/240mm is out of this game...)
Just try !! you'll see it in the GG, you just need the head of mannequin.Quote:
Originally Posted by john_vandale_
The industar may deliver a softer focus...
For mug shot style you may prefer (or not...) a long focal, having some 3m distance to the subject, as you go closer the nose becomes larger than the ears. We humans do remember other's face like it's seen from around 3m, so in general "pleasing" portraits are not taken at 1m from the subject.
The thing it's not what the lens does. Normally it's the lens that has a problem with the photographer :)
All lenses you have should be very capable, the brass one may the the one with worse optical performance, but you can take advabtage of its personality.