Understanding Soft Focus and Sharp fall-off

[ewood]

I just purchased a Calumet 8x10 camera and now I need to buy a lens. I'm new to film and new to large format so I'm reading as much as I can and filling in the gaps with posts to this forum.

I would like to do close up portraits (waist level and up) and I want a very sharp focus with very short depth of field and a sharp fall-off. Now, by this I mean that I would like to compose and setup a shot (indoors...in my home since I'm a hobbyist still) where I can have the subjects eyes in very sharp focus and have the hair, ears, neckline, etc quite noticeably out of focus.

I'm trying to select the right lens for this application (tight spaces, portrait lens, wide aperature on an 8x10). And obviously I would need a lens board so if I find a Copal #3 lens that suits my needs and budget then can I just buy any Copal #3 lens board and it will work with my camera? I'm still trying to navigate all of this. I'm doing more reading tonight. :)

Thanks in advance for anyone willling to help.
Cheers,
Eric

[eddie]

most very short DOF lenses (f3) will not fit on the 6x6 lens board AND cover 8x10. do you have a reducing back to 5x7? if so you can easily get what you want.

if not keep an eye out for the many f4.5 lenses that will cover 8x10. they include heliar. a 360 would be perfect. there are others too. the various tessar lenses will work as well. many are f4.5

none of the above are "soft focus" but they will give you sharp centers with excellent fall off.

eddie

[Jon Shiu]

You have to buy a lens board that fits your specific model of camera. For example Calumet 8x10 can mean a C-1, or it can mean a Calumet Cambo type, which takes a different type of lens board.

Assuming you have a Cambo type, you would want either a Calumet (or Cambo) 8x10, board with two notches at the top.

Jon

[Gem Singer]

Check out KEH (www.keh.com) for a large selection of previously owned lenses and lens boards.

Look for a lens with a focal length of 300-360mm. Any lens of that focal length, from one of the "big four" lens manufacturers, will do what you describe for portraiture.

Just be sure that you match up the proper lens board for your particular camera.

Lens boards that are milled for Copal 3 shutters are listed on the KEH website as having 65mm openings.

[Jay DeFehr]

Eric,

I don't think you want a SF lens. To get very shallow dof you'd have to use a wide aperture, and then you can forget about anything being in "very sharp focus" with a SF lens. I'd heed the excellent advice given by all above.

[ewood]

Thanks for all the feedback, it has definitely helped me to understand more about what I need. I will look for a 300 - 360mm lens f/4.5 which is paired with a cambo lens board. If it's not paired then I need to by a cambo lens board with the same Copal value as the lense? And KEH, B&H are good sites to start my search?

[ewood]

Ok, so I've found the following lens (couldn't find one on KEH or B&H with a f/4.5). However, I can't tell what lens board to buy because the lens information doesn't list the Copal value. Is there another way to figure this out? I appreciate you teaching a man to fish. :)

http://www.ebay.com/itm/VINTAGE-GERMAN-CARL-ZEISS-TESSAR-4-5-300mm-GLOBICA-FILM-LARGE-FORMAT-CAMERA-LENS-/170763374098?_trksid=p4340.m185&_trkparms=algo%3DSIC.NPJS%26its%3DI%252BC%26itu%3DUA%26otn%3D5%26pmod%3D370554516175%26ps%3D63%26clkid%3D5616388771155056368

Cheers, Eric

[Kimberly Anderson]

Canham 8x10 w/5x7 reducing back. Schneider G-claron 355, wide-open (f/9). About 10 feet away.

http://tawayama.com/5x7/slade_larryslade75th.jpg

The DOF is literally only the bridge of his glasses.

[Jon Shiu]

Ok, so I've found the following lens (couldn't find one on KEH or B&H with a f/4.5). However, I can't tell what lens board to buy because the lens information doesn't list the Copal value. Is there another way to figure this out? I appreciate you teaching a man to fish. :)

http://www.ebay.com/itm/VINTAGE-GERMAN-CARL-ZEISS-TESSAR-4-5-300mm-GLOBICA-FILM-LARGE-FORMAT-CAMERA-LENS-/170763374098?_trksid=p4340.m185&_trkparms=algo%3DSIC.NPJS%26its%3DI%252BC%26itu%3DUA%26otn%3D5%26pmod%3D370554516175%26ps%3D63%26clkid%3D5616388771155056368

Cheers, Eric

That's a lens in barrel, ie doesn't have a shutter. You need to buy a lens in shutter. A 300mm f5.6 lens also has shallow focus wide open.

Jon

[tgtaylor]

Ok, so I've found the following lens (couldn't find one on KEH or B&H with a f/4.5). However, I can't tell what lens board to buy because the lens information doesn't list the Copal value. Is there another way to figure this out? I appreciate you teaching a man to fish. :)

http://www.ebay.com/itm/VINTAGE-GERMAN-CARL-ZEISS-TESSAR-4-5-300mm-GLOBICA-FILM-LARGE-FORMAT-CAMERA-LENS-/170763374098?_trksid=p4340.m185&_trkparms=algo%3DSIC.NPJS%26its%3DI%252BC%26itu%3DUA%26otn%3D5%26pmod%3D370554516175%26ps%3D63%26clkid%3D5616388771155056368

Cheers, Eric

Ewood,

That lens doesn't have a shutter. To use it as it is, you will have to stop the exposure with the cap or a hat. Otherwise you will have to buy a shutter to mount it in.

Thomas

[ic-racer]

The difference in DOF between that lens wide open (f4.5) and the typical 300mm f5.6 plasmat is very small (less than the difference between a f1.4 and f1.8 lens on a 35mm camera). For that price you could have had a nice 300mm f5.6 lens in a Copal 3 shutter. http://www.largeformatphotography.info/forum/showthread.php?t=85400

[ewood]

Ok, thanks. I really need to learn how to notice these things.

Michael Slade, that shot is beautiful. That's exactly what I'm aiming for. I know it's quite the journey for me to be able to accomplish a shot like that but I want to get the gear that's going to be capable of it and then I want to focus on my own capabilities. I will keep looking for a lense that will work. Mostly searching ebay because all I found from 300mm and up said they were Macro lenses. Most of what I found on KEH were wide angle or f/5.6 or f/8.0. Now, it seems those may be okay.

[ewood]

So is it a barrel lens if I only see a single lever on the lense in the pictures shown AND all they indicate is Bulb? ic-racer, does that lens have a shutter included? I'm confused as how I'm supposed to tell. I would think price would be a key indicator...I'm seeing several at between $350 and $450 and then they seem to jump up to $900 and beyond.

[ewood]

Ok, sorry for all the posts but I appreciate your patience and advice everyone.

So this would be a good lens? Any ideas of what a fair price would be?
http://www.ebay.com/itm/Schneider-355mm-G-Claron-lens-Copal-3-shutter-/280804590073?pt=Film_Cameras&hash=item41614201f9

[Brian Ellis]

So is it a barrel lens if I only see a single lever on the lense in the pictures shown AND all they indicate is Bulb? ic-racer, does that lens have a shutter included? I'm confused as how I'm supposed to tell. I would think price would be a key indicator...I'm seeing several at between $350 and $450 and then they seem to jump up to $900 and beyond.

It's a barrel lens if the lens isn't mounted in a shutter. You tell that by looking at the lens. If you just look at a few lenses that have a shutter - most LF lenses listed on ebay do - I think you'll be able to easily see what a shutter looks like and it will quickly become obvious when a lens doesn't have one.

Bulb is a setting on a shutter. When there's no shutter there's no Bulb setting.

[bobpin]

I use a 270mm Petzval lens with Sinar shutter to do close up portrait:
http://www.flickr.com/photos/58933716@N00/2563879988/in/photostream

Most of my works here were taken by this lens:
http://www.flickr.com/photos/58933716@N00/page8/

http://www.flickr.com/photos/58933716@N00/2816894260/in/photostream/

I think u don't need a long focal length lens (300mm or longer) to do close up works, it requires very long bellow and the sharp fall-off effect is less noticeable than the short focal length portrait lens.

The short focal length (240~270mm) portrait lens can't cover 8x10 when focus to infinity but I don't think this is what u concern, right? :)

[polyglot]

Copal is one brand of shutter; the common sizes are 0, 1 and 3. Do a google image search for "Copal 3" and you will see what the shutter looks like. While barrel lenses are "a thing" in certain circles, they are not a good place to begin. Definitely get a lens with a working shutter that includes flash sync.

Don't forget that there is a lot more to this website than the forum; there is a huge amount of valuable introductory reading (http://www.largeformatphotography.info) too.

For even shallower DOF in a portrait, you can use a little back-tilt which will cause the plane of focus to come out of the subjects eyes and travel back down their jaw. Net effect is nothing but eyes are even remotely sharp. Tilt and swing will also reduce DOF outright in addition to changing the plane of focus.

[johnielvis]

hey dude---you're just starting out--if you shoot just about ANY lens wide open on 8x10 up close, you'll get shallow depth of field....you don't need a f4.5 lens to get that--a longer lens at f11 can give more blur than a shorter lens at f4---this is because the focal length acts to magnify things--the longer the focal length the bigger the magnifications in the image---and magnification means it magnifies EVERYTHING---so it magnifies BLUR too---so a longer lens can give just as much blur as a faster shorter lens--because the shorter lens magnifies the blur less....(blur of 2 magnified times 1 equals a blur of 1 magnified times 2)----and there's the tilt tricks too---anyways--just get the longest lens that you can use with your camera is what I'd do....

calumet/cambos are like 30" monorail--figure 8x10's you can get 30" with most cameras at the max extension--you want head and shoulders, that's like a magnification of 1:2 (M=0.5).....so the max focal length you can use with a 30" extension is about

(1+M)f=x (x = eXtension of bellows) so plug in the numbers and get

(1+.5)f=30" or f=20" or about 500mm

at 1:2 magnificaion, you'll get your blur with 20" lens--just find one in that area that's got the biggest aperture---probably the best is gonna be a process lens--the f9 variety of 480mm or so lenses...they come up for sale a lot..they are for sale at keh...these are the app ronars and artars.

and they are nice super sharp lenses for regular applications too.....anyways...that's my suggestion---this may be the only lens you ever need....

[johnielvis]

blasted thing won't let me change app ronar to apo ronar....friends computer....anyways that APO RONAR

[johnielvis]

OH...if you want SHARP with blur falloff do NOT get a "portrait" soft focus lens---this will eliminate all of those f4.5 "portrait" varieties...those are SOFT lenses...there is a difference between SOFT and depth of field falloff---you want SHARP with falloff....so you're not gonna see that anywhere except with them $$$$ petzval type or triplets....huge, heavy, expensive, and relatively short focal lengths....you do better with a process lens---longest one you can fit.

[ewood]

This is a wealth of information. I'm definitely going to check out the "valuable introductory reading" that polyglot recommended and I like the idea about using back-tilt for additional reduction of DoF and to focus it on the eyes (chin would be soft, eyes crisp).

Johnielvis, your calculations totally threw me. I need to do some reading so that I can better understand the formulas and process you describe. I'll search for lenses with flash synch and the longest I can get that has at least a 10" circle. You mention 20" but I'm not sure you mean it can product a 20" image circle on the ground plate? Seems I would be buying something far beyond what my camera can accomodate. Unless I'm misunderstanding.

Here is the camera I purchased (without the lens).
http://www.facebook.com/#!/photo.php?fbid=264172846979234&set=a.264172830312569.63275.191031970959989&type=1&theater

[Mark Barendt]

I'd suggest contacting Jim Galli directly. http://www.largeformatphotography.info/forum/member.php?u=1545

He may have something to fit your needs and he is very sharp on the specifics of the lenses he has.

[johnielvis]

sorry dude---20" is the MAXIMUM focal length you should be using if you got that much extension on the camera--the formula is there so you can measure your camera and figure out what the maximum focal length you can use would be...if you have 30" and you want to shoot no smaller than an 16x20 field, then the 20" focal length lens (about 500mm) is for you....so I suggest the process lenses as they are sharp up close (which is what you want) and are the max length possible with your camera to give the biggest blur magnification. They are also sharp wide open--and the larger ones are relatively fast, considering the focal length--f9 is nothing to sneeze at.

anyways...blur is a function of both focal length AND f/number--the longer the lens the more the blur---like a 300mm f4 lens will be the same blur as a 600 f8 lens due to the blur magnification of 600mm vs the 300mm...the 600 magnifies the blur twice as much.

note that a 300 f4 lens will have the same entrance diameter (glass diameter) as a 600 f8 lens---so the bigger the front glass--no matter WHAT the f number is, will give you the same blur.

your camera looks like a cambo monorail--them are 30"length right? mine is like that long--you rail is measured so just read off the length on that--that will give you the longest bellows extension possible with your setup.

[ewood]

The monorail is marked in centimeters up to 32 in both directions (starting a 0 in the center). When I measure it with a yard stick, I can comfortably accomodate 25" total.

I already have a high bid on a lens I found on ebay that was recommended in this thread so I've got to wait and see if I win that. If not, I will reach out to Jim Galli as suggested.

[Dan Dozer]

Hi Eric,

Portrait lenses for 8 x 10 are definitely going to be a learning experience for you as you have already found out. Almost of all of my work is portrait type of images and most of what I use is around 360mm. The 355mm G-Claron is an excellent portrait lens for sharp focus work and I use mine all the time. However, the price as it is now on your link won't stay at that price. It is a pretty popular lens and it might get up over $800 by the time the sale is over. As others have said, for starting out, stay away from the soft focus lenses until you learn more about the process and gear. The most important thing for you right now in considering lenses is what is your total bellows extension length. If you use a 14" lens for the work you are talking about, you're going to need probably more like 18" - 20" of bellows length. The focal length of the lens is the approximate length of the bellows if you are focusing at infinity, and as you focus closer, the bellows length has to get longer.

One thing you are going to have to consider is whether or not you want/need a shutter on your lens. If you are coming up from smaller format, you might think a shutter is an absolute necessity. However, it really isn't and most of my portrait type of lenses don't have shutters. I normally just use the lens cap for exposures around 1/4 sec. and for those around 1/25 sec. I use either a packard shutter or the Jim Galli shutter method. Do a little searching for his posts and you will find out what the Galli shutter is (doesn't cost a dime either).

If you have free time during the week and want to come up to Solana Beach, I would be happy to meet over lunch and talk "shop". I can show you some of my lenses and it might make your decisions easier. My office is there and I'm in the office a couple of days a week.

Hope this helps.

Dan

[Mark Sawyer]

Just get the fastest 12-14 inch lens you can find in a good shutter. There are lots of nice 12" f/4.5's out there.

[eddie]

Jim Galli shutter method. Do a little searching for his posts and you will find out what the Galli shutter is (doesn't cost a dime either).


Dan

check this video of the galli shutter.....i just redid it

http://www.youtube.com/watch?v=Baa8Bwnn9Sk

[ewood]

The Galli shutter method is interesting. I guess I'm curious as to why someone would use a lens without an integrated shutter for a short exposure time. Is the attraction and market of the barrel lens (no integrated shutter) for longer exposures or for those on a tight budget? I'm not on a tight budget and I expect that 95% of my exposures will be shorter than a second (to reduce the chance of movement).

I also imagine it's pointless to go through the exercise of getting a price meter reading if the shutter is going to have so much play involved. Perhaps I'm just to focused on the mechanics while I'm learning.

[eddie]

Large fast lenses are too big for many shutters.

Big shutters run SLOW....most only hit 1/20. I am talking about big fast lenses that your first inquired about.....f4.5 etc

IMO shutters with flash a sync are the only useful ones ( again, for fast lenses)

[Mark Barendt]

The Galli shutter method is interesting. I guess I'm curious as to why someone would use a lens without an integrated shutter for a short exposure time. Is the attraction and market of the barrel lens (no integrated shutter) for longer exposures or for those on a tight budget? I'm not on a tight budget and I expect that 95% of my exposures will be shorter than a second (to reduce the chance of movement).

I also imagine it's pointless to go through the exercise of getting a price meter reading if the shutter is going to have so much play involved. Perhaps I'm just to focused on the mechanics while I'm learning.

Actually a nice meter and practice are both important.

With regard to the lens, glass has personality. See the following PDF, lots of great info.

http://research-repository.st-andrews.ac.uk/bitstream/10023/505/6/W%20Russell%20Young%20PhD%20thesis.pdf

[Mark Barendt]

Here is a possibility with a shutter http://www.largeformatphotography.info/forum/showthread.php?t=85663

[rdenney]

It has been mentioned that the larger format provides less depth of field without using a super-fast lens. To back that up, I just did a quick comparison at DOFMaster. Using their standard of acceptability (which assumes both are printed to 8x10), a 360mm lens on 8x10 at f/6.8 will provide less depth of field (read: narrower focus and more blur) than a 55mm lens on 35mm format at f/1.0. 360mm is a little longer than normal on 8x10, just like 55mm is a little longer than normal on 35mm, so they will encompass the same subject from the same distance.

Remember that fitting 36" of the subject's body into 6" of film is a 1:6 magnification. Fitting 36" of subject into one inch of a 35mm frame is a 1:36 magnification. In both cases, the subject will be the same distance from the camera when using equivalent lenses. A 360mm lens on 8x10 focused to 8 feet or so is not that far from the macro range, and you know what kind of depth of field you get in the macro range.

Any 360mm f/5.6 plasmat will do what you seek, but so will any 14" tessar design, of which the favorite is probably the Kodak Commercial Ektar. For portraiture, I'd prefer the tessar design because of the vintage way it transitions from focused to unfocused, while still being pretty sharp in the middle. But people spend a lot of time as they mature in large format learning those subtleties. So, find a 14" Kodak Commercial Ektar, or a 360mm plasmat like a Schneider Symmar or Rodenstock Sironar, and get going. KEH.com has two 360mm f/6.8 Rodenstock Sironar-N's in stock right now for under $500, one labeled Caltar II-N but it's the same lens. Both are in Copal No. 3 shutters. (Don't get the lenses in the Sinar DB mount, though--they have a couple of those right now, too. These require a Sinar camera and Sinar shutter.)

Rick "noting that keeping you subject still to avoid changing focus will not be a minor challenge" Denney

[johnielvis]

yes,it HAS been mentioned.....

also....git de LONGA lins an U GIT DA DEPF o FIELDS u wants...CHEEP!

[johnielvis]

I thingk rdenny h*s me

[rdenney]

I thingk rdenny h*s me

Sometimes, coming at the same issue from two different angles helps the learning process.

In any case, it bore repeating. Using a plain-ole plasmat or tessar such as the two that are available right now from KEH, with a warranty and without playing ebay games, this fellow can get narrower selective focus than is even possible with just about any lens used as he describes in formats he might be used to.

Rick "some things are worth saying twice" Denney