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April 2nd, 2009, 03:32 PM | #1 |
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EX Macro, Closeup, Achromatics, Zoom, Apertures...
I've been doing more macro photography of insects (rare and endangered butterflies, to be exact) as well as plants with my EX1.
I had been using some inexpensive Hoya single lens diopter filters, the kind you screw on the front, and I'd found the resulting images were well... bad. By bad I mean really bad CA around the edges, overall very soft, things looking blown out when they shouldn't have been, too short DOF not what I've come to expect from the EX1. I had previously done some close-up videography using a Sony V1U, which is a 1/4" sensor cmos and with the same setup these would come out, well... great. I read up on 'filter' type single lens diopters and read they were well... crappy, and that I should consider a achromatic diopter type lens, which are pricey but more immune to the problems that single lens diopters cause, so I just purchased one. Haven't really tested it out yet much but it seems a lot higher quality just at first glance. FYI, achromatic diopters use more expensive multi-element lenses that correct for chromatic aberration and other bad stuff. Before I get too much further though, I have a few questions for those that have experience in this: Zooming: For what I'm doing, I need to get as close as I can. That means zooming to 99 if possible. What I know is that zooming the the extremes with the EX1 lens can produce less than optimal images. I've noticed this myself when just zooming without a diopter on the front. There is a some CA and distortion at the edges, quite bad stuff. My question is here: What's the safe range but still getting the most zoom possible? Aperture: As you know, these diopters really reduce the depth of field. While this can be a good artistic 'filmic' effect, right now I would like to at least get my subjects in focus that may have depth of 1/2". That means smaller apertures. However, I also know that the EX, because of the sensor size and physics, doesn't like smaller apertures, like above f6.7 it starts getting soft. However, will adding the diopter change the 'physics' of all this and allow me to get sharp images even when beyond f6.7? Exposure: I know that getting up to 100 IRE (or 107 if I'm going to color correct in post), but not beyond, will give me less noise and more to work with. Are there any gotchas in still doing this with these diopters? Thanks in advance for any advice. |
April 2nd, 2009, 06:04 PM | #2 |
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For a few years I was using a PD150 (1/3’’) for close-ups of flowers and insects. I got reasonable results with a single element +2 diopter lens. For more extreme close-ups I attached a 150 mm focal length lens (i.e. ~ +6.7 d). The lens came from a 2 ¼” square Rollei projector and was mounted in reverse as recommended. I was pleased with the results even though my zoom range was limited, it was still useful. As expected depth of field was shallow. It is said that stopping down to below an aperture size of 5mm causes loss of image quality through diffraction as well as requiring light levels that may upset your subjects. With the PD150 my most pleasing results were obtaining under dull natural light. I now have an EX3 and a Nikon adapter with IRIS control. I also have a Canon 500D (+2D) achromatic close-up lens. I have tried fitting the Rollei lens to the supplied Fujinon, as expected vignetting is more of a problem than with the PD 150 and I am limited to a range of ~ 80 - 99. Working distance is around 100 mm. and width covered is around 17 mm. The image looks worth promising.
There is some interesting reading on macro techniques and principles in L.A. Mannheim’s book “The Rolleiflex SL66 and SLX Way” |
April 2nd, 2009, 10:31 PM | #3 |
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There is no getting away from physics. Large magnification means very small DOF. Diffraction is related to the diameter of the aperture, the smaller it is the greater the diffraction softening of the image. In basic terms using a diopter on the lens enables the image to be focussed on a close-up object with the lens set to infinity; obviously adjusting the lens affects the actual distance between subject and lens and hence magnification.
Are you using macro focussing on the EX1? If so there are a couple of things to remember. 1) doesn't work at focal lengths greater than about 25mm; 2) must not use full manual focus. 3) don't use it with diopter attachments. At 25mm focal length the camera will focus very close to the front element, giving a field width of about 50mm. I don't have 77 mm diopters so can't do a comparative test for you. In general Diopters work best at around their focal length (with the primary lens set near infinity). I expect you already appreciate that you need to move the camera to follow focus and not focus using the ring. Or you can move the subject. EDIT: "Highest screen quality results with lower power diopters. It is better to use a longer focal length prime lens and a less powerful diopter than the other way around. It is not necessary to increase exposure when photographing in this manner. When two diopters are used together, that of the highest power should be closest to the lens." Stuff I've shot of insects etc as been on 16mm using a 50mm lens with extension tubes (to give me enough room to get light in there), and there I was working in a studio with controlled lighting. This involved tracking to follow action. I had to use lights on a dimmer so I could bring them up before starting the shot, and take them down again before cooking the insect. Doing the same thing in the open could be very frustrating and I would expect difficulty. If you had an EX3 you could use the Frazier lens http://www.panavision.com/product_de...49,c50,c87,c90 Last edited by Serena Steuart; April 3rd, 2009 at 12:40 AM. Reason: edit to add quote from ACM |
April 3rd, 2009, 12:42 AM | #4 |
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Keith.
Do you have any sort of groundglass adaptor in your kit (Letus, Brevis, SGPro etc..) The purposed achromatic dioptres used in these specifically for the EX1 should make for good close-up lenses in the region of between about 150mm to 200mm approx distance of subjkect from camera. Last edited by Bob Hart; April 3rd, 2009 at 12:46 AM. Reason: not on top of the writing game today |
April 3rd, 2009, 12:46 AM | #5 | |
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In the open it can be frustrating, you have to know when the critters are going to stay in one place for you, that's part of the fun though. |
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April 3rd, 2009, 12:51 AM | #7 | |
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April 3rd, 2009, 12:57 AM | #8 |
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Well I did fish it out and it does look like a nice diopter, but, adapting it for practical use is too much effort at this time, threads, mounting and such. The 77mm Canon 500D I have is a bit easier at this time but thanks for the suggestion, I may at some point try it.
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April 3rd, 2009, 05:38 AM | #9 |
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There is the Nikon lens mount adapter you could use with Nikon macro lenses
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April 3rd, 2009, 01:03 PM | #10 |
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April 3rd, 2009, 02:25 PM | #11 | |
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I have just put some footage up on the Adaptimax site from one of our customers, who used a Nikon 105mm Macro lens on the Adaptimax. As you can see from the results, you get edge to edge sharpness and stunning macro. The customer works with insects in a biology lab in Hong Kong and has reported he is over the moon with the results the Adatimax gives for macro work. The footage can be found here. Its the second clip uploaded to Vimeo. As you can see in his tests, the closeup of the watch is quite remarkable. Sony PMW EX3 Nikon Adaptor. |
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April 3rd, 2009, 02:42 PM | #12 | |
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April 3rd, 2009, 04:33 PM | #13 | |
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I thought the EX1 was great. but the EX3 is a whole new beast. Stick a Nikon 300mm F4 on it via an Adaptimax, or 105mm 2.8 macro, and open up a whole new area of film making. |
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