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rbrigham
11-17-2013, 05:37 AM
hi

can anybody advise me on high f stop
lenses
think f64 and above
I would like to fit one onto a 35mm movie camera
I will be shooting macro so an adaptor will not be too hard to make for pretty much any lens
I know that there are process lenses such as apo ronar with high stops
but I believe that the large intended format and long focal length
will not resolve well on the small 35mm film
are there any smaller format lenses designed to optimally shoot at really high stops

thanks

robin

AgX
11-17-2013, 05:51 AM
I don't understand why one could not use long focal lengths in 35mm cinematograpgy. Or do you refer to the fact that lenses designed for large formats yield lesser resolution than lenses designed for small fotmats?

The minimum absolute size of a standard aperture is technically given. That is the reason that you won't find smaller apertures than you got at those shorter focal lenght lenses.
An alternative approach to looking for lenses with extreme small apertures is mounting a additional small aperture just in front of the front lens.

The most sound approach though is to mount a smaller (drilled) aperture inside the lens at the original aperture location. With some lenses that location is easy to access. You just have to find an appropriate way to fix that accessory aperture at that location.

Dan Fromm
11-17-2013, 09:16 AM
Robin, what are you trying to accomplish? In particular, what magnification do you want to work at?

Has anyone explained diffraction to you? At f/64 diffraction limits the best resolution possible in the center of the field to approximately 23 lp/mm. The best resolution possible off-axis is lower. At 1:1 and f/64 set, the effective aperture will be f/128 and the best resolution possible in the center of the field will be 12 lp/mm.

Why do you want to shoot at a tiny aperture? What problem do you think that will solve for you?

How are you going to light your subject? Electronic flash is possible if you're shooting single frame (animation). Otherwise you're stuck with continuous sources. I'm not familiar with the latest most best, so can't say anything.

Mustafa Umut Sarac
11-17-2013, 11:50 AM
I think he mimics Weston did with vegetables. Weston used high stop and hours of exposure and he did with homemade apertures. I havent seen any high f 35mm lens. May be f:22 with some lenses. May be you can use an many square pinhole filter in front of aperture - you have to insert it-, final will blurred but you can correct the image at computer with some computer power and same pattern ,reverse code , control the dof at computer. Single image is easy but too many images , I dont think computer can handle.

Cinematography forum is better place to ask but if you will use an digital camera , homemade aperture is the best way.

ic-racer
11-17-2013, 01:50 PM
In addition to what Dan pointed out above, when doing close-up photography, the diffraction is worse than expected from the indicated aperture on the lens per the relationship below.
EFFECTIVE APERTURE = MARKED APERTURE * (MAGNIFICATION + 1)

Dr Croubie
11-17-2013, 03:36 PM
I always try and keep aperture as open as possible, and rarely go narrower than 5.6-8 on crop digital, 8-11 on 135, 11-16 on 120, and 22 on 4x5, for the diffraction problems. But if you're shooting movies, res is lower so maybe you can get away with it for higher DOF.

But as IC said, effective aperture gets narrower with magnification anyway. The only way to get decent DOF with macro is to a) stack digitally, b) tilt/swing, or c) get shorter focal length lenses. Regular retrofocus SLR wide-angles won't work with macro, that why there exist dedicated macro lenses like Canon's MP-E 65 for 1-5x mag, and the Olympus OM 38mm and 20mm lenses. They won't focus to infinity, but they'll get you up to 12x mag, there's a reason they'll still set you back $500+...

Dan Fromm
11-17-2013, 05:57 PM
Regular retrofocus SLR wide-angles won't work with macro

Of course they do. Some can be used on short extension tubes or on bellows facing normally or reversed. Others, e.g., the 24/2.8 Nikkor, can be used only reversed. For more details, see Nikon's instruction manual for the PB-4 bellows.

Because they're retrofocus the working distance (lens-to-subject) can never be less than their native mount's register. The downside to using them is that because their pupillary magnification is far from unity the relationship between aperture set and effective aperture depends on the lens' orientation (facing normally, reversed) and isn't as is implicit in my post #3 in this thread and as stated explicitly by ic-racer above. For further discussion, see Lester Lefkowitz' book The Manual of Closeup Photography. For examples, see the PB-4 instruction manual.

Dr Croubie
11-17-2013, 07:54 PM
Clarification: Can't work easily with macro, which I should have written. And by that I mainly meant with extension tubes. Turning from infinity to MFD on most of my widest lenses only moves the elements by 1-2mm away from the film plane at most. With my thinnest extension tube being something like 10mm thick or so, I've never been able to focus on anything with lenses wider than 28mm. (I've got my RokiBowYang 35/1.4 just working with 10mm tubes, and my Super Ozeck II Macro 28/2.8 works ok, but not the Mir 20/2.5 or Tokina 17/3.5, and I've just realised I don't have a 24mm prime. I'd best rectify that with GAS).
Not as nice as with the OM 20mm macro, which you can rack out to 12x and the working-distance doesn't change much with focussing, stays fairly constant at "bugger-all mm". Still I want one, for when I need to take photos of match-heads and all.

But yeah, I wasn't thinking about reversed, which I've also done a bit of (manual-lenses only, there are ways to use EF but it gets complicated). And with the whole thing of pupil factors and effective apertures and all that, I'm too lazy to work it all out so I don't even bother attempting macro without accurate TTL metering, and only use flash when I can chimp on the digital...

Anyway, the OP hasn't clarified exactly how close 'macro' will be, we're all presuming that the smaller aperture is to get bigger DOF, but there could be other reasons like to purposefully introduce diffraction (in which case, may I suggest a pinhole?)

RalphLambrecht
11-17-2013, 08:05 PM
hi

can anybody advise me on high f stop
lenses
think f64 and above
I would like to fit one onto a 35mm movie camera
I will be shooting macro so an adaptor will not be too hard to make for pretty much any lens
I know that there are process lenses such as apo ronar with high stops
but I believe that the large intended format and long focal length
will not resolve well on the small 35mm film
are there any smaller format lenses designed to optimally shoot at really high stops

thanks

robin
wow; pinhole filming ;sounds interesting

John Koehrer
11-17-2013, 08:09 PM
I think he mimics Weston did with vegetables. Weston used high stop and hours of exposure and he did with homemade apertures.

I've never seen a reference to E. Weston making his own apertures. Anything in his biographies/daybooks refer to commercial products.

The small stop and long exposures were results of the films available at the time.

Dan Fromm
11-17-2013, 08:30 PM
Clarification: Can't work easily with macro, which I should have written. And by that I mainly meant with extension tubes.

Many are the ways.


Not as nice as with the OM 20mm macro, which you can rack out to 12x and the working-distance doesn't change much with focussing, stays fairly constant at "bugger-all mm". Still I want one, for when I need to take photos of match-heads and all.

Really? As I pointed out, a reversed retrofocus lens has working distance much greater than its focal length.


But yeah, I wasn't thinking about reversed, which I've also done a bit of (manual-lenses only, there are ways to use EF but it gets complicated). And with the whole thing of pupil factors and effective apertures and all that, I'm too lazy to work it all out so I don't even bother attempting macro without accurate TTL metering, and only use flash when I can chimp on the digital...

Intellectually lazy, too. The key trick to using manual flash close up is to settle on a flash rig -- always the same camera-flash-subject geometry, including distances -- and shoot a series of calibration shots. Many are the ways. Calculate only to see roughly what's possible, then test.


Anyway, the OP hasn't clarified exactly how close 'macro' will be, we're all presuming that the smaller aperture is to get bigger DOF, but there could be other reasons like to purposefully introduce diffraction (in which case, may I suggest a pinhole?)

The OP posted and ran. I don't know whether it was a troll, too ignorant to understand the responses so far, or timid. Until proven otherwise -- I hope it will happen soon -- the OP is in the ignorant fantasist bucket. Anyone who can afford to run a 35 mm cine camera can afford a good education in basic photography and then a good education in cinematography. In the real world (H*O*L*L*Y*W*O*O*D) no one gets near a 35 mm camera without a good education.

rbrigham
11-18-2013, 11:34 AM
Hi All

thanks for the replays
Sorry its been over a day since I posted !

I'm trying to shoot really deep focus
something like this

http://vimeo.com/15533975

the real footage is sharper than what is on vimeo
but that lens is not available to me

I have got it in my head that there are lenses that are optimised to shoot at tiny apertures

Ralph you have a PM

robin

E. von Hoegh
11-18-2013, 12:18 PM
Hi All

thanks for the replays
Sorry its been over a day since I posted !

I'm trying to shoot really deep focus
something like this

http://vimeo.com/15533975

the real footage is sharper than what is on vimeo
but that lens is not available to me

I have got it in my head that there are lenses that are optimised to shoot at tiny apertures

Ralph you have a PM

robin

That really isn't possible. The diffraction limit can be approximated by dividing the f number into 1500, there really is no getting around it.

btaylor
11-18-2013, 01:19 PM
Sorry I can't add any technical knowledge to this discussion, macro 35mm motion picture work is not something I've ever done. But this is a big field that has been dealt with for years, there have been many specialty macro lens assemblies made for this type of work. Have you tried the local rental houses? Also a forum like cinematography.net (CML) or cinematography.com will have discussions and members with exactly the kind of knowledge and expertise you may be looking for. Good luck!

Dan Fromm
11-18-2013, 02:30 PM
Robin, the moral of this story is that when you ask for advice on solving a problem you shouldn't present a solution, you should present the problem.

A variety of deep focus lenses, all for cinematography, have been patented. None uses a tiny aperture to get the effect. The link you posted shows near and distant subjects more-or-less equally illuminated. This isn't possible in general with artificial illumination as would be required with the usual frame rates, capture media, and a tiny aperture. That should have been a tipoff that a tiny aperture isn't the solution.

If you don't have much budget your choices come down to renting a proper deep focus lens or buying a split diopter. None of the effects in the video seem to have been achieved with a split diopter.

miha
11-18-2013, 02:46 PM
A GoPro with it's wide lens and tiny sensor draws sharp pretty much everything.

E. von Hoegh
11-18-2013, 02:51 PM
A GoPro with it's wide lens and tiny sensor draws sharp pretty much everything.

Due to the miniscule reproduction ratio, not a small f number.

miha
11-18-2013, 02:58 PM
Sure.

rbrigham
11-18-2013, 03:43 PM
Hi Dan

I think the moral of the story is not to ask questions that you might feel the need to answer
can you advise on any subject that would be suitable for me to ask about

I am well aware of lens systems such as the Frazier lens which can get an amazing result and I am well aware of the methods used to get there

I was looking for something different hoping that somebody would say a Zeiss this or a Leitz that or whatever has a very good performance when stopped right down
presumably a plastic holga lens will not perform as well as a Zeiss macro under these conditions
it therefore follows that somewhere there is the best design for high stop deep focus work be it a tessar, planar or whatever or maybe just maybe something I don't know about

I do not know what methods steve downer used to get the results in the video i posted I can guess but I don't know

the reason I posted the question in the apug macro section was so that somebody who knows more than me might be able to advise me on my actual question
not so that you can guess at my education

and as for "Troll"

maybe you should look up the definition and think about if it applies to you

robin

Dan Fromm
11-18-2013, 05:33 PM
Robin, I'm slightly acquainted with closeup photography and photomacrography. That's why I asked what magnifications you'd be working at.

I'm slightly acquainted with high performance macro lenses from microscope manufacturers and merchant lens makers' microscopy divisions. I even have a few and sometimes use them. The only way to get any DoF at all at high magnification is to use confocal techniques, also called focus stacking. The conditions needed for this to work are stringent; the approach seems poorly suited to cinematography.

I'm slightly acquainted with process lenses that stop down to tiny apertures, have some and use 'em, but never stopped 'way down. The loss of image quality isn't worth the gain.

Ain't no magic bullets. The closest one can come to what you want on a budget is a split diopter. For cinema applications these are a little limiting, won't permit the pans shown in the video.

Re loss of image quality on stopping down, here's an exercise for you: pick a magnification, calculate DoF for it given a circle of confusion that makes sense in your work and a range of effective apertures. Then calculate the diffraction limit given effective aperture. You'll find that there's a limiting aperture; stopping down beyond it will give a diffraction blur circle large than the circle of confusion. H. Lou Gibson published the calculations and pictures showing the effect in Kodak Publications N-12B Photomacrography and N-16 Close-up Photography and Photomacrography. They're scary books.

Practically no one outside of Hollywood can afford the gear the studios use and, usually, rental houses own. That includes most, if not all, of the posters on this forum.

Troll? Me? Nah, I don't post with the intention of getting strangers to fight. The word you want to use is curmudgeon.