Berndt
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Post by Berndt on Dec 21, 2011 6:04:18 GMT -5
Did my first experiment today ... but it has been a total failure ... hahaha ...
Photopaper seems to be much more light sensitive than I expected.
I exposed 4 sheets using the method, Dave suggested:
Sheet 1: F 5.6 at 1,2,3,4,5 sec Sheet 2: F 5.6 at 5,10,15,20,25 sec Sheet 3: F 8 at 5,10,15,20,25 sec Sheet 4: F 16 at 5,10,15,20,25 sec
They all turned out just black, means totally overexposed. Conditions: Daylight, ISO 100, F:8, 1/120 sec from the lightmeter.
But ... if the light sensitivity of photopaper is about 10 ASA, as Mickey assumed, the result is not that surprising. Then, I should have stopped the lens already down to 32 or 45 for exposing just 1 sec.
Will need to do another test tomorrow, but if that is true, I might definitely need an ND filter for avoiding to use a decent shutter on that camera.
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mickeyobe
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Post by mickeyobe on Dec 21, 2011 6:43:46 GMT -5
berndt,
I did not assume 10 ASA. Ilford gave me that information for Multigrade. Have you checked with the manufacturer of your paper?
Assuming it is 10ASA/ISO, a daylight exposure would be approximately 1/10 second at f16. The lens I used was an APO - Nikkor 480mm f9 process lens that stopped down to f128.
The make or focal length is immaterial. The ability to greatly reduce the aperture is a big help in getting long exposures to minimize almost certain errors in manually counting down the time.
Assuming your paper is ASA 100, if you had exposed at 1/100 second at f16 you should have been close to the correct exposure.
It looks like you completely ignored the readings your lightmeter gave you which should have been f8 at q/120 second or f16 at 1/60 second.
The closest you came to correct exposure f16 at 5 seconds is many, many times over exposure.
Rachel's excellent suggestion of making test strips using the dark slide would save you a lot of paper, chemicals and darkroom time.
Keep at it. I am sure you will get what you want.
Mickey
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Berndt
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Post by Berndt on Dec 21, 2011 9:10:17 GMT -5
Thanks Mickey. Any input is much appreciated. Couldn't find much in internet Just, what is written on the package: ISO speed P500 ISO range R110 ... but no idea, what that means. I think, it's hard to say anyway, because the light sensitivity also depends much on the temperature of the light. I just tried an indoor shot ( it's night in Japan now ) and had to exposure 20 sec at a full open lens to get something ... but that might me completely different at daylight. Indoor light is more reddish and photopaper is not sensitive for that. However, another interesting experiment. Tomorrow, I will try a new series of outdoor shots. Yes but ... the main reason for me to use large format at all is the incredible shallow DOF. I mainly want to use the lens wide open. That's the real benefit of large format ... except you want to enlarge a landscape picture up to a wallpaper.
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mickeyobe
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Post by mickeyobe on Dec 21, 2011 9:31:22 GMT -5
berndt,
Once you have control over your exposure and any other variables such as colour temperature of the lighting then you can comfortably experiment with DOF.
I do not know how or if the size of the camera will make a difference to DOF. I do know that with my 35mm cameras I can, through choice of focal length and aperture and distance from the subject achieve everything from almost no DOF to very deep DOF.
Oh for PeterW's sage advice.
Mickey
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Post by nikonbob on Dec 21, 2011 12:31:08 GMT -5
berndt Just did a quick search for photo paper iso and found this www.apug.org/forums/forum48/8456-photo-paper-iso.html and there is more info on the APUG site. Assuming iso 6 is correct then the correct approximate exposure for your meter reading of f8 and 1/120 @ iso 100 would be either f8 and 1/8 sec or f22 and 1 sec. For DOF you have to consider that you have a great deal less DOF for any given f stop at any given distance with large format vs 35mm. Don't be too worried about stopping down too much. You can always use a DOF table such as www.fineart-photography.com/dof_plus.html to compare the two formats. I don't know if you are taking a meter reading by incident or reflected method. I would try to use reflected if possible.
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daveh
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Post by daveh on Dec 21, 2011 22:32:43 GMT -5
berndt, sorry for having you overexpose things! I wasn't necessarily thinking of my quoted times as being anything other than just using the doubling up principle. There can be a big difference in light levels of course, and f-stops too (and colour temperature sensitivities as you have said). Certainly old 'film' was so slow and indoor lighting so poor that the only shutter needed was a lens cap and counting one-and-two-and-three-and.....No wonder that video had the subjects head held on a rest. I suspect that modern paper is probably faster than that I used to use years ago - but as I haven't used any for years I don't know if that is the case. Going back to the early 1970s, and the house I had then, there was a downstairs cloakroom. A hardboard window shutter with a thick curtain kept most of the light out from that side. A draft excluder on the floor and a blanket draped on the frame did likewise for the door. It was never quite pitch black, but was good enough. We have been here before, on this forum, about how much (or otherwise) we miss the old chemical techniques. I have something of an urge to try, but at present not a strong enough urge to actually do it. Hats off to you for so doing. Dave. p.s. if you have too small an aperture, and so too much depth of field, just move the background further away!
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Berndt
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Post by Berndt on Dec 21, 2011 23:10:13 GMT -5
In theory, Mickey Often missunderstood, the DOF is just depending on the focal length, the aperture and distance to the object, completely regardless the type or format of the camera, which will be used ... BUT ... and this is a big "BUT" ... depending on the film/sensor format, you will get different things in frame. For example, mounting a 210 mm lens on a large format camera, you will get a standard to wideangle frame, while it is a telephoto lens on your 35 mm camera. So theoretically, you can take any picture, you can take on a large format camera, on you 35 mm one as well ... but you need to step back a lot, which is mostly impossible in reality unless you take pictures just in a wide open desert Shooting at more narrow spaces ( for example indoors or just in a park or city like Tokyo ), you simply can't step back that much. Here is a good example picture, I quickly found at Flickr ( not taken by me though, but I hope, it's okay to post in here ). A full body shot in a room - not really a rare demand in photography. You would need to mount a wideangle lens on your 35 mm camera to take this picture and even keeping the lens full open, you could never ever reach such a DOF. flic.kr/p/aXiAmMThis autumn, I experimented a lot with taking autumn leaves sceneries ( the autumn colors are pretty amazing here in Japan, especially the famous red maple trees ). It's easy to get a shallow DOF on a single leaf or limb ... but on the whole tree or even forrest ? I used only medium format this year ... but it hasn't been enough and I couldn't get what I wanted I can't find it anymore, but I once saw a picture of a girl standing in a forrest. Just the girl has been in focus and the whole forrest slowly disappeared in the shallow DOF. What a fantastic magical picture. Or sometimes, you can see portraits, where just a few mm are in focus: flic.kr/p/aVp1JpUsing a 35 mm camera, you would just be able to capture a tiny part of this frame ( maybe just the finger ) ... or you might need to break the wall of the photo studio and step back for a few blocks
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daveh
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Post by daveh on Dec 22, 2011 0:29:00 GMT -5
The problem these days is working out if the effect is real or photoshopped. I presume it's real as it has been achieved by bringing the subject, Rosie, well in front of anything else that appears on the photo, other than the chair. It is something of an optical delusion as well as use of DOF. It may well be that the new type digital camera (somewhere else on this forum) will totally change our thinking with its ability to change focus post-production
The trouble is we talk in terms of focal lengths. Focal length only really means something if used in conjunction with film (or sensor) size. It would make much more sense if we used angle of view. That is really where a more transportable comparison between the formats lies.
In terms of actual focus, only the point focused on is truly in focus, everything else depends on the magnification. What appears to be in focus, often isn't when magnified. At low magnification it is a dot: magnified it becomes a circle of confusion.
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Berndt
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Post by Berndt on Dec 22, 2011 2:03:29 GMT -5
Well said, Dave !! I just wanted to explain it in a more simple way. Real or photoshopped ... sometimes hard to see, sometimes easily, I think. Experienced people can see it in most cases though. It's about what you pointed out as CoC. I am not sure, if I can express it right in English, but I would say, that the DOF is mostly "fading" (?). It's not that something is sharp and completely blurr, there is a graduation between those. It's, what we feel as "bokeh" and it is much more important for movies than for stills sometimes ( if I want a moving object to pass the DOF ). For example, I once wanted to take a scene, where a bicycle is driving into the camera at high speed and I wanted to keep it in focus for a few seconds while objects in the front and back keep being blurr. I could have "pulled the focus", but I didn't want to. It worked, but I needed a super telephoto lens for that. Another situation is, if having a lot of details and/or objects in different distances to the camera ( not only one object and a background ). Photoshopping becomes quite difficult then. As for example a tree with leafs. How can you decide the DOF for every singe leaf ? That would be insane, wouldn't it ... or even for simple potraits. The hair can be a problem then. Same as those tilt/shift stuff. So easy to apply as a postproduction effect ... but often not standing a closer look at it. Another not mentioned benefit of a larger format is the effect of less distortion. The picture looks flatter in general, because of using a longer focal length. One thing, I really hate about those P&S cameras ... everything looks like reflected on a christmas bulb, especially faces and buildings. The new type of digital camera, you mentioned ... yeah, I read about that as well ( you can completely decide the focus after taking the picture ). We'll see, how practical it really is. Might be the future of photography ... who knows ? But ... it also scares me somehow ... hahaha ... I think, we are drifting more and more away from what photography really is ... or has been. In the end, we might not need to take a picture anymore at all ... just create one from an empty sheet of paper But I know ... the borderline is fuzzy and everybody needs to make his own choices. There are always different ways to achieve the same result. I am personally more a photographer than a Photoshop virtuoso and I like the craftmanship. There are incredible things, we can do with Photoshop meanwhile, but film also has something "surprising". Imperfectionism is hard to copy or to achieve in digital postproduction. There are simply to many factors, which would need to be controlled and corrected. It's a little bit like music. If you compare a real drummer with a digital drum machine ... even if you add some random fuzziness for getting closer to a human touch, you will always hear the difference ... or ... I would hear it.
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Post by nikonbob on Dec 22, 2011 7:09:25 GMT -5
Dave You make some good points about the difference between focal length and angle of view when comparing DOF between formats. I normally try to compare lenses with similar angles of view between different formats not similar focal lengths. A normal FL , 50mm, in 35mm format will have more apparent DOF than a large format lens of equivalent angle of view at the same f stop. There are so many variables to consider with DOF and different format sizes it is mind boggling. This link is interesting brucebarrett.com/large_format/DOF.html . If this site is correct, then with an 8x10 format you would need to use f32 to get the equivalent DOF to f 1.4 using 35mm. That is why I would not worry too much about stopping a large format down too much. Then there is how a lens will portray the transition from what is in focus to out of focus. I just love how the old Zeiss 50/1.5 Sonnar handles that. Bob
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Berndt
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Post by Berndt on Dec 22, 2011 7:58:20 GMT -5
Me too ... but I think, the whole thing about formats and DOF is much easier to understand ( and to imagine ) if trying to look at the focal length. At the same focal length and same aperture, the DOF is also the same at any camera and format ... it's just the distance, which needs to be different for getting the same angle of view. In reality, I would also just consider the angle of view. Taking a picture from the same distance and wanting the same angle of view, we need a smaller focal length, which leads to a larger DOF. In the end, it's more about experience and limits than about starting to calculate an exact DOF, I think. For example, if I want to take a half body shot with a blurr background, 35 mm starts reaching its limits ( at an acceptable distance ), for portraits and close ups, 35 mm or "Full Frame" is still fine. The next stage ( medium format ) is very suitable for half body to body shots, wanting a decent DOF. Considering, that not everybody has a high end medium format camera with exchangeable lenses, lets talk about a TLR wide open here. When it comes to full body shots and the person is not covering the whole frame, medium format starts to reach its limits and we need to enter the world of large format cameras. It also makes sense, just to consider the limits ( a full open lens ), because I can stop down any camera for getting a larger DOF ... of course by paying for that with longer exposure times at larger formats. In general, I would say ( just by personal experience ), that 35 mm offers the biggest flexibility considering all situations ... and it is not always about the DOF. Saying this, I actually already need to correct myself, because I like medium format most. Considering "normal situations of daily life", it provides the most creativity for me and I barely miss anything if walking around with my TLR, not even the zoom capabilities ... but that depends much on personal habbits and likings ... wouldn't say that in general. And large format ? Those bulky inconvenient monsters Well ... for special purposes and projects, I guess ... when we want things, we can't achieve on a smaller format.
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Berndt
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Post by Berndt on Dec 22, 2011 8:49:55 GMT -5
BTW ... forgot to mention, that sometimes even formats, smaller than 35 mm ( M4/3 for example ) can have benefits ... when we don't want to get too close. My favorite "Paparazzi portrait combination" is an 85 mm 1.8 on a GH1 for example. Brilliant for "candid headshots" on weddings. Hard to get the same fast "Full Frame equivalent", which would be 170 mm. So, for all telephoto situations, a smaller sensor ( or crop ) can be sweet because lenses with the double focal lenght ( and same brighness ) are often not available or much more expensive.
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daveh
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Post by daveh on Dec 22, 2011 14:55:25 GMT -5
The future, of course, is 3D (or should it be 4D) holograms. We should have to show anything on a screen, nor wear glasses to make it 3D (as with the latest TVs.)
The smaller digital chips are wonderful, as you say Berndt. It's possible to have a 24x optical zoom with internal focussing in a lens hardly any larger than a standard lens for a 35mm SLR, at a reasonable f-stop too.
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Berndt
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Post by Berndt on Dec 23, 2011 7:45:02 GMT -5
Dave ... than I'll wait for the 4th dimension, travel back in time and take every picture when I have been younger ... hahaha ... but okay, actually every picture we take is always showing us "when we have been younger" at the moment, we look at it But seriously, before we will become blessed with holograms, I would be just happy, if they would finally release consumer digital cameras with larger sensors. I mean, medium format has been a standard even before 35 mm in the world of film and available for more than 100 years and now, we call it progress, taking pictures on tiny sensors ? And ... the camera doesn't need to be really large because of that ... nor it would need a mirror anymore like on those bulky and expensive DSLRs. Christmas is close now ... and if Santa would ask me to design a digital camera and give it to me as a present, it would look like this: A medium format sensor and a 50 mm F:0.95 prime lens mounted. The camera wouldn't even need an optical zoom anymore, because the resolution would be that high, that it could simply crop it by using just a smaller part of the sensor ( a technique, similar to the one for HD movies on the Lumix GH2 - some kind of "lossless" digital zoom ). No mirror, of course, because EVFs and monitors are high resoluted enough meanwhile. THAT would be actually the perfect camera and wouldn't need to be larger than about 6x9 cm. What do you think ?
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daveh
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Post by daveh on Dec 23, 2011 15:54:37 GMT -5
There are, of course, a few medium format digital cameras such as the Pentax 645. From memory I think it is 45megapixels - the trouble is that is also about £9,000!
This leads me to think of another lens parameter: coverage. A lens of say 50mm for a 2/3 sensor is always a 50 mm lens, but will have 'cut-off corners' if used on a full-size 35mm sensor.
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