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02-21-2016, 08:56 PM   #16
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I own the F 100 Macro which does not use or need a hood and the D FA 100 Macro WR. The D FA solution is elegant and I think you are missing the point. The hood doesn't move in and out because if it did it would get in the way as you reach the high magnification ratios at close focus distances. The F 100 did not have a hood but had a deeply set front element when focused far away. Chances are you are not going to need the hood as much as you get into high magnification situations anyway. You can always shade the lens from farther out using your hand or a magazine or a leaf etc.

02-21-2016, 10:09 PM   #17
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QuoteOriginally posted by UncleVanya Quote
I own the F 100 Macro which does not use or need a hood and the D FA 100 Macro WR. The D FA solution is elegant and I think you are missing the point. The hood doesn't move in and out because if it did it would get in the way as you reach the high magnification ratios at close focus distances. The F 100 did not have a hood but had a deeply set front element when focused far away. Chances are you are not going to need the hood as much as you get into high magnification situations anyway. You can always shade the lens from farther out using your hand or a magazine or a leaf etc.
Interesting point. Sounds like an interesting test would be a set of quick tests with my copy stand, light stand, protractor, rulers and lens hoods. I have 49mm diameter lens hoods from 25-80mm deep. I'll have time in a couple of weeks. A nice extra test.

However, my past and most recent experience indicates that a lens hood does not get in the way.

The Takumar 100mm macro has a 20mm recessed front element, similar to that of the F 100mm macro. The Tak also has the dedicated 49mm deep lens hood labeled "TAKUMAR 100mm F4". Using the Cosina dedicated 1:1 supplemental lens the exact same closest focus distance as the DFA macro lens. Using the Tak with the supplemental lens and the hood, I have not had any easily overcome lighting issues at closest focus distance.

Fifty millimeter macro lenses have given me fits with self caused shadows at close focusing distances. I strive, like almost everyone to keep any non-image reflected light from the lens front element to reduce veiling flare.

Last edited by lmd91343; 02-21-2016 at 10:11 PM. Reason: Eliminated redundant phrase
02-22-2016, 04:33 PM   #18
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QuoteOriginally posted by lmd91343 Quote
Interesting point. Sounds like an interesting test would be a set of quick tests with my copy stand, light stand, protractor, rulers and lens hoods. I have 49mm diameter lens hoods from 25-80mm deep. I'll have time in a couple of weeks. A nice extra test.

However, my past and most recent experience indicates that a lens hood does not get in the way.

The Takumar 100mm macro has a 20mm recessed front element, similar to that of the F 100mm macro. The Tak also has the dedicated 49mm deep lens hood labeled "TAKUMAR 100mm F4". Using the Cosina dedicated 1:1 supplemental lens the exact same closest focus distance as the DFA macro lens. Using the Tak with the supplemental lens and the hood, I have not had any easily overcome lighting issues at closest focus distance.

Fifty millimeter macro lenses have given me fits with self caused shadows at close focusing distances. I strive, like almost everyone to keep any non-image reflected light from the lens front element to reduce veiling flare.
In my experience (which is not on a copy stand) my lens gets really close to leaves and branches and things that would be in the way with a longer hood. But I'll have to grab the WR and take it for a spin to see how much I think it is really helping. I have never used a Macro lens with a hood - not ever. So I may be biased.
02-22-2016, 05:51 PM   #19
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QuoteOriginally posted by UncleVanya Quote
In my experience (which is not on a copy stand) my lens gets really close to leaves and branches and things that would be in the way with a longer hood. But I'll have to grab the WR and take it for a spin to see how much I think it is really helping. I have never used a Macro lens with a hood - not ever. So I may be biased.
I don't take photos where I am likely to get twigs and leaves entangled in a lens hood. My photos with a macro lens are much more controlled than that. I am paranoid about hurting my lenses. I almost always keep a good UV filter on my lens and a lens shade. The only time I don't is when I use macro lenses. I almost always use the hood. I figure the hood and the deeply recessed front element that allows me to drop the filter. That is why I am a bit upset with the new Pentax macro having only an inch of protection from the edge of the hood to the front element. I stick that macro lens right up to flowers and rocks. I am used to my Takumar which has 49mm of hood depth an 20mm of space in front of the front element totaling 69mm of protection.

Also I have never shot closer than 2:1 (.5X reprodution ratio) outdoors. that increases the closest focus distance by four inches!

I'll run a test this weekend with my camera lens and lens hood on the copy stand with cardboard 60* and 45* angles. I will check the angle that the light can be at without having the lens shade interfere at .5X and 1X reproduction ratio distances. Than I'll take a picture of that set up.


Last edited by lmd91343; 02-22-2016 at 05:59 PM.
02-22-2016, 05:58 PM   #20
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Similar hood solution on the DFA100mm non-WR, and I used the hood for a few years before giving it up. The front element is pretty deeply recessed, I didn't find the hood added much except extra bulk and it was more likely to interfere with my lighting. I don't think I ran into branches too often, but it sometimes interfered when the camera was right on the ground. As for protection, I'm a lens cap on at all times I'm not actively shooting kind of guy.

I haven't been able to detect any appreciable drop in contrast with the hood removed. The major flare I've had with the DFA100mm is veiling flare when, for example, the sun is hitting the front element directly. Rare is the position that the hood would help with this, especially at close focus distances, and when I run into this I go with a little black card to flag off the sun.
02-22-2016, 11:23 PM   #21
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Results: Vivitar 90-180 flat field zoom failure

This could be the worst or best zoom and/or macro ever made. But this test cannot judge that lens. I dropped the lens out of the testing for two reasons. The first is that the largest distance from the sensor/film plane of the camera to the copy stand baseboard can accommodate is 24.5 ". The shortest focal distance of the lens is 27.5". With two extra brackets and a QR plate I can extend the sensor to baseboard distance to 27.5". I could just barely bring the image into focus. I could not bring focus to slightly in front of the baseboard. To jeopardize the camera and lens for the test is not appropriate. So the Vivitar is out. I can describe its attributes and use.

The Vivitar is difficult to handle. It is large and heavy. The aperture ring is hard to find and read on a DSLR. The camera's flash bump is in the way. The tripod foot is small. The tripod ring lock screw is almost too small to use. The head is smaller than a dime. There are no click stops at 0* or 90* in the tripod ring for lens rotation. The aperture ring has positive feedback, clicking at every half stop. The zoom and focus rings have the right amount of resistance. The focus and and reproduction ratios are easy to read as they are exposed on the barrel when the focus ring is rotated, not in a small window. The lens comes with a matched factory hood. It is a joy to use where a front to back focus rail and moving the tripod would otherwise be required, just focus and zoom. This optic is great for flowers and the like outdoors.
02-23-2016, 03:08 PM   #22
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Results: Vignetting

Vignetting was checked by taking a picture of a uniformly painted and uniformly illuminated interior wall. The camera was placed on a tripod five feet from the wall and manually focused. Images were captured at all apertures on all lenses. Images were also captured with the original factory lens hood at the widest aperture only. As there is no factory hood for the Cosina/Phoenix, I used the 105mm Takumar lens hood, which is 38mm deep. For comparison, the original factory hoods for the Takumar and the D-FA SMC WR's are 49mm and 55mm deep.

I desaturated (removed the color) each image. Using the PS eye dropper (3X3) tool I measured the color value at the center of the image, half way to the corner, and in the corner of the left lower side, averaging several samples at each spot. The several samples at each spot were all within 2% of each other. The results were then calculated as a percentage of the center spot value.

The Cosina/Phoenix was as good as or better than any other lenses, to my eye, that I have used. Its overall exposures were slightly brighter than the Pentax made lenses. With and without the lens shade, at f3.5, the lens had slightly more than one quarter of one stop of darkening in the corners and an eighth of a stop half way to the corners. At f 4.0, the corner had lightened to less than a quarter of a stop. At f 5.6 and smaller, the corners and the area half way to the corners, lightened even more and were consistent. At f 4.0 and greater, I could measure that this lens, beyond the center, was just slightly darker than the Pentax made lenses, I could not see it with my naked eye. I might be able to use a deeper lens shade than the 39mm deep one I used, as

The Takumar was almost perfect. This lens has about one quarter of one stop darkening in the corners with the aperture wide open. By f 5.6 and smaller, the vignetting is reduced to four percent or less. I could not find any variation with or without the original hood.

The D-FA SMC WR was almost perfect also. This lens has less one quarter of one stop darkening in the corners with the aperture wide open. By f 4.0 and smaller, the vignetting is reduced to three percent or less. I could not find any variation with or without the original hood.

I have not posted any pictures. Twenty pictures of a uniform, gray, featureless field would be boring to almost all and a waste of storage space. My variability in the repetition of the tests is about three percent of luminosity. That is well less than one eighth of a stop.

The Cosina/Phoenix is very good. The two Pentax made lenses are small step better at the widest apertures, half way to the corner and in the corner. At all but the widest apertures, the Pentax made lenses are about 4-5% brighter than the Cosina half way to the corners and 5-7% in the corner, about 1/16 of a stop. Other than when the lenses are wide open, all the images are indistinguishable to my naked eye. These are all full frame 100mm macro lenses used on an APSc sensor. What else could you expect? With respect to vignetting, I could use these interchangeably.
02-24-2016, 10:53 AM - 1 Like   #23
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Results: Purple fringing

Purple fringing was tested by acquiring the same image from each lens at every full stop. The subject matter was selected in order to provoke purple fringing. The images are of bare tree branches against a bright blue sky. The bark is very light in color, the shadow side dark. These branches are more than 100 feet and less than 200 feet away. The images were captured with a light breeze during the break of a wind storm. The images presented here are extremely magnified from the central 0.4%, by area, of the capture. It is highlighted in yellow in the center of the index image.

All three lenses presented a very small amount of purple fringing, one pixel wide, as shown on my monitor in PS6 from the raw images when enlarged to the point of pixelation on actual pixel size setting. The samples from all three lenses, along with an index image showing the area of enlargement, are shown below.

With respect to purple fringing all three lenses are near perfect.



02-24-2016, 10:35 PM - 3 Likes   #24
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Results: Distortion and Decentering

The tests were conducted using my K3 on a copy stand with a sheet of graph paper taped to the baseboard, illuminated by daylight bulbs. The graph paper had a grid of lines at a 1.08mm spacing. The photos were taken at .5X magnification. All focusing was done manually. All apertures on all lenses were used.

When displayed at several different magnifications on my 23" monitor, all the lines on the grid where perfectly straight and normal to each other. All the images from all the lenses had a slight contrast loss in the lower right corner, created perhaps by the manner in which the lamps were set. I cannot tell one image from another as they vary by both taking lens and aperture. They are all equally sharp and undistorted. These lenses produce images equally sharp across the image.

No decentering was found any any image. All lenses amongst each other and all apertures. All apertures appear to be the same. Each of the four corners were compared to the other three. Only the decentering test image is displayed from f 4.0.

I would not worry about distortion, field flatness or decentering with any of these lenses.











02-25-2016, 05:48 AM   #25
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Good job -- thanks.
02-25-2016, 03:56 PM - 1 Like   #26
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Lens hood addendum

We have had a discussion about the appropriateness of lens hoods for these 100mm macro lenses. I said that I would run a quick experiment to see if a more appropriate lens hood could be used for shade and protection.

I made the observation that the D-FA hood does not move with the inner lens barrel. This leaves only 5mm of lens hood to shape and protect the front element of the lens at closest focus. The front element of that lens is recessed only a paltry 15mm. This gives only 20mm of shade and protection to the lens. This compares poorly with its Takumar ancestor with a front element recess of 20mm and a factory lens hood of 49mm for a total of 69mm of shade and protection at any focus position.

Two sets of tests were made. The first a high light angle of 60*, with a 75mm hood and also a 49mm hood. The second set of tests is based on a moderate light angle of 45*.

The first image is that of the lens mounted on a K5 with the closest lens focus set and the camera placed at that distance. This was confirmed by a live view check. The red object placed centered beneath the lens is the same size as the camera's APS sensor.

The second photo shows the lens, red target object, 49mm lens hood and a 30-60-90 drafting triangle with a blue color on the hypotenuse side. That blue color represents the light ray closest to the edge of the hood. With the 49mm hood, that light ray falls across and beyond the target area as indicated by the blue line covering the entirety of where red object touches the white paper underneath. This shows that the 49mm hood is the right size or too short.

The third photo shows the lens, red target object, 75mm lens hood and a 30-60-90 drafting triangle with a blue color on the hypotenuse side. That blue color represents the light ray closest to the edge of the hood. With the 75mm hood, that light ray falls just short of illuminating the target area as indicated by a portion of the red object touching the white paper underneath, not hidden by the blue triangle edge. Notice that you can seen where 2-3mm of the bottom of the red object and white paper interface. About 17mm of that object/white paper interface is covered. This shows that the 75mm hood is just barely too long.

I have not posted the photos for the 45* moderate angle light ray. If the 60* light ray clears or barely misses clearing the shallower 45* ray will easily clear.

The 49mm hood is the factory dedicated one for the Takumar 100mm macro. The 75mm lens shade is the one dedicated to the Takumar 200mm f 5.6 lens.

These tests are for APSc only.






Last edited by lmd91343; 02-25-2016 at 06:30 PM.
02-25-2016, 06:27 PM - 2 Likes   #27
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Results: Resolution 1X Magnification

This resolution test was conducted using a dedicated negative scanner’s calibration slide. The slide, already encased in a special holder, was placed in the carrier and set upon the light table, which in turn was placed upon the copy stand baseboard.

The D-FA lens natively will enlarge images to 1X magnification, and the Takumar and Phoenix lenses only to .5X magnification. The Phoenix comes with a dedicated supplemental lens that aattaches to the filter threads on the front of the barrel. That supplemental lens was used for this test on both the Takumar and Phoenix.

The calibration slide contains no resolution measurement information. It was used to find any differences between the lenses. This calibration slide has very sharp, fine lines printed upon it. I used the black on white and black on gray sections for my observations.

When the images were enlarged in Photoshop to fit my 23”monitors, I could not see any difference between any of the three lenses. Surprisingly, when the smallest portion, close to 5% of the image was enlarge to actual pixel size pixilation, the Takumar, was the very slightly sharper than the Phoenix, which in turn was very slightly sharper than the D-FA. It took 20 minutes of very careful checking. I saw perhaps a one or two pixel more of fuzziness This finding might be the result of focusing inaccuracies on my part.

I would use any of these lenses for this kind of work.

Presented below is about 10% by area of the image taken from the lower right corner from every lens at every aperture.

]

---------- Post added 02-25-16 at 05:28 PM ----------

QuoteOriginally posted by fwcetus Quote
Good job -- thanks.
I appreciate the note.
02-25-2016, 07:36 PM   #28
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Great series of tests. I've got the SMC Macro Takumar 100mm so it's interesting to see how it stands up to newer glass. Thank you!
02-25-2016, 10:51 PM   #29
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I'll keep "liking" your posts. Thanks!
02-26-2016, 05:46 PM - 1 Like   #30
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Results: Resolution .5X Magnification

This resolution test was conducted using a dedicated negative scanner’s calibration slide. The slide, already encased in a special holder, was placed in the carrier and set upon the light table, which in turn was placed upon the copy stand baseboard.

The calibration slide contains no resolution measurement information. It was used to find any differences between the lenses. This calibration slide has very sharp, fine lines printed upon it. I used the black on white and black on gray sections for my observations.

I could find very little difference between the lenses. However as with the 1X reproduction ratio test, when enlarged to pixilation, I could possibly discern a very, very slight increased sharpness with the D-FA lens over the Phoenix and the Phoenix over the Takumar by counting fuzzy pixels around image elements. That is opposite of the 1X test! I attribute that to focusing error on my part. I had to count pixels on extremely large enlargements, beyond anything reasonable for a macro lens alone.

I would use any of these lenses to take these kind of images. Essentially, the lenses are equal.

The images presented below represent about 56% of the central portion of the image.



I forgot to put f stop notations on the composite. The first row is 2.8, the second 3.5, third 4.0, fourth 5.6, fifth 11, sixth 16. -Sorry
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