NikonGear'23
Gear Talk => Lens Talk => Topic started by: Bent Hjarbo on April 05, 2018, 20:48:23
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When I bought a Nikon PB-4 bellow I also got the 105mm f4 bellows lens.
When searching for information for this lens on Bjørns legasy site I found that it should be good together with the normal Micro-Nikor 105 f4.
I then got the Micro-Nikkor, used, in not to good condition, but looking Richard Haws site I managed to fix it.
Now I had to search for a K3 ring, got a nice set yesterday, and start playing.
I am new to macro, but have been inspired by Michaels Erlewines very nice work, I am not in that league and is not going to invest as much in it, but try to get the best out of the few items I have.
Now to a question about this setup:
It seem to have pronounced field curvature, or at leat my setup has.
I have attached images of my simple setup, done my best to have the ruler parallel to the sensor, as can be seen the sides are not sharp.
I have also attached some more practical images to show the resolution I have at moment.
All taken with mirror-up, and the flowers with a wired remote. (MC-36)
Anyone with experience with this set-up?
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There is some curvature, yes. For stacking purposes shouldn't be a major problem.
Have you tried adding more extension to the host lens?
Been a while since I experimented with this setup, and that occurred mainly back in the film days. I might retrieve these lens components and try once the spring arrives over here.
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There is some curvature, yes. For stacking purposes shouldn't be a major problem.
Have you tried adding more extension to the host lens?
Been a while since I experimented with this setup, and that occurred mainly back in the film days. I might retrieve these lens components and try once the spring arrives over here.
No I only used the build-in extension, from min to max.
Is the resolution in the pictures ok? Or at least what to expect.
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The images does look sharp ...
Remember only the first lens (ie., the Bellows-Nikkor) should be stopped down.
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Ok, I tried that as well, but the images shown are all taken with the aperture on the main lens in use.
Will try to see the difference.
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I actually made these two images @f8 the filename shows which lens was stopped down.
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I just tested quickly the similar set-up with my Df, but using the 105 AIS Micro-Nikkor instead of the early AI used previously. Not much difference whether front or rear lens was stopped down except when aperture went beyond f/8. Then using the host lens for stopping down clearly avoided most of the curvature issue. Images looked sharp across the entire frame.
As these tests were rather improvised and informal, I should repeat on a "real" subject later.
PS: Noted the Jansjö light (IKEA) -- seems this light fixture has become a golden standard for close-up work these days DS
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PS: Noted the Jansjö light (IKEA) -- seems this light fixture has become a golden standard for close-up work these days DS
Time to buy shares in Ikea? ;D ;D ;D
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It looks like you are getting better results by stopping down the Micro-Nikkor rather than the bellows lens.
To determine the shape of the field curvature, shoot a flat, highly detailed surface at 45° angle, you will clearly see which way the focus plane curves. If you know the field curvature you can use it to your advantage by matching it to your subject to get more in focus.
The flower pictures above certainly look sharp enough - good detail and contrast.
Apart from the very high magnification picture of the anthers, the other flower shots could probably have been shot with the 105/4 alone, or with the PN-11 (which gives 1:2 - 1:1 magnification plus a handy built-in tripod mount). This might give better results optically, and will give you more working distance, although the aperture is slower and viewfinder image will be darker.
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As the Jansjö is cheap, I don’t this that should be the reason for buying shares :D
It is very handy and the colour of the light seem ok, a bit warm.
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As the Jansjö is cheap, I don’t this that should be the reason for buying shares :D
It is very handy and the colour of the light seem ok, a bit warm.
Hi :)
I use Jansjös for my own studio macro work, but IMO you have the single light way too close (esp. w/o a diffuser).
Those whom I know who use a Jansjö that close use a Styrofoam cup as a diffuser (usu. for very high-mag macro work).
I personally don't go much beyond 3x to 5x magnification, so I pull my Jansjös (5 total, 2 on each side of the subject, 1 overhead) back at least 8-12" away from the subject (I also have a slight diffuser).
If you have the direct lights only, no diffuser, I would aim the Jansjös "up" a bit, to keep the harsh direct light off (and the attendant specular highlights to a minimum), while letting the slight "glow" illuminate the subject. (Generally, my SS is 1/10, my ISO ~320 to 460.)
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PS: That photo was taken last year.
I have the same configuration, but aim the lights "up" a bit ... with a custom diffuser over each one.
Below, is before I added a padded layer over the breadboard (https://www.thorlabs.com/thorproduct.cfm?partnumber=MB1824).
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BTW which leds you use with the Jansjö? Thank you!
On the Ikea site, you cannot replace the leds?!
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BTW which leds you use with the Jansjö? Thank you!
On the Ikea site, you cannot replace the leds?!
I use these (https://www.ikea.com/us/en/catalog/products/00385941) and these (https://www.ikea.com/us/en/catalog/products/70386305/#/80386319).
No 'light' replacements; whole unit replacements.
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A main feature of 'cheap' LED desk lamps is the fixed and for the most part irreplaceable lamp.
Some time ago I researched LED's for photography and found that few manufacturers publish the spectra of their LED lamps.
The only one I could find was a local supplier (CPC Farnell) who list Kosnik GU10 lamps and publish the spectrum data.
http://www.farnell.com/datasheets/1782807.pdf
(https://farm1.staticflickr.com/889/40556157084_d868807dc8_o.jpg)
The 4000K version seemed to have the best available output with the least gaps, so that's what I got and they seem to work pretty well but GU10 lamps would I think be too heavy for the Ikia stems, they need a much stronger support, which kind of negates their usefulness for this task.
If one could find an LED chip with a known good spectrum then I am sure it would be entirely possible to install it in one of these Ikea gooseneck lamps. I have myself constructed a UV LED lamp with a Nichia 365nm 3W LED so I am sure it's no big deal with other LED's.
The trouble with LED's is not only are they either too warm, or too cold, they have massive gaps in their spectrum. Not sure if Michael will read this but one concern I have is when photographing flowers, esp. delicate whites that a poor light source like these 'cheap' LED's with un-determined spectrum must influence the photographic results and distort the natural colours, as compared with direct vision in daylight, bearing in mind our eyes have 'intelligent' white balance built into our brains. The camera only 'sees' the white balance which is set on the dial, the LED emits a distorted spectrum, yet we trust our vision of the photograph.
Given the vast expense of the lenses used for this type of photography and the huge debates between this lens and that, for the subtle shades, coolness and warmth etc. no account seems to be made for the light source, which to me seem to trump all the expensive lenses and fancy sensors, because the light is what is being recorded by the lens and sensor. They can only record what they see. In my opinion they are being starved of a full spectrum of light by using these 'cheap' LED's to illuminate the subject.
The lighting is probably the most important ingredient, yet seems to get the least attention and it's probably the cheapest to deal with.
Sorry if this seems a bit of a rant...
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Seapy, I completely agree!
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Thank you Erik. :)
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Seapy, I completely agree!
+1
Would be interesting if someone could measure the spectrum of the IKEA lamp, some of IKEAs other LED lighting has good ra values, so maybe this cheap lamp could be ok.
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I'm sure someone like Klaus will hook it up and check just for fun, but be prepared to be disappointed ;)
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Did a Google search, but did not find anything, let us hope that Klaus can do it
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Thanks Bent, I have to go out now won't be back till later tomorrow.
One thought I have had is to buy a light splitting prism, they are on eBay cheap enough as educational items, to project the light from these and other lamps through the prism then photograph it close up and framed on just the projected light. The resulting histogram may tell a story?
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Deleted: my reply was totally out of point.
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Thanks Bent, I have to go out now won't be back till later tomorrow.
One thought I have had is to buy a light splitting prism, they are on eBay cheap enough as educational items, to project the light from these and other lamps through the prism then photograph it close up and framed on just the projected light. The resulting histogram may tell a story?
Might be a way, I photographed a piece of white paper illuminated by the Jansjö, can get a perfect white picture in LR using the auto functions, but I don’t think it is the right way
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this morning I have ordered a light splitting 60-60-60º by 100mm long prism which I should have by Wednesday, I will run some experiments with different light sources to see what happens.
I think I may have to make a box to exclude stray light to prevent it from confusing the issue.
I am hoping this will reveal any gaps in the spectrum, I am also wondering if some sort of holder to mount on the front of a lens might be useful to project the split light rays through the lens to focus on the D3 sensor, perhaps a lens isn't needed? That way the histogram or levels in photoshop may give a clear defined reading of the intensity of the various colours. Probably not scientific but a reasonable indication of the spectrum I hope.
Could use sunlight and a flash gun for reference.
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Interesting, looking forward to the result.
I have considered to get/loan a painters colour patches and photograph them in different lightning.
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I just loaned a painters color scheme from my neighbor.
I made a rough setup, indoor in a black box with the Jansjö lamp, outdoor in todays overcast weather.
The shiny coating on the parches makes them more bright in the indoor setup.
The idea is to se if the all the colors are recorded.
Pictures taken with my Df and a AFD 24mm f2.8 @f11
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And then the sun came :)
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Interesting, need to put the colours from each type of lighting next to each other for comparison, I am really keen to see the analysis of the light.
Running the two different approaches together seems to me to be a very good idea. It would be very good if somebody with technical understanding, like Klaus could do a proper analysis of these different light sources as well. That would clinch it.
Also maybe photographing a nice flower or flowers under different lighting too.
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Maybe we should start a thread about lightning quality?
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Yes, I'm sorry, have taken this thread way OT.
When I get the prism I will start a new thread.
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Very good :)