MacroMania

Quote:

---

Originally Posted by jcuknz

The question of image quality ... I have not done any tests but simply assumed that it comes from the quality of the CU lens and personally I remain content with a 2 dioptre since greater powered lenses do seem to lack IQ, particularly around the edges. The lens needs to be more than single element and in this situation I have a LF camera lens giving me about 7 dioptre and with its multi element construction gives good IQ. So while the cheap amazon [et al] sets get one started I think you need to go to Raynox or other multi-element lenses if one intends to do a lot of this work, and Raynox costs not that much more, though from the one I saw it is rather small and wouldn't work on a large DSLR lens. If the CU lens is smaller than the camera lens one looses light transmission as if one had added another iris up front.

---

As you will have read above, I did just the one test on a single inexpensive add on +10 lens - the George III silver shilling - which produced a good deal of CA, so I doubt I'll be returning to it in the near future, while there are so many more experiments to be done with other avenues into the world of the very small.

I am - I hope - learning as I go along, so comments and suggestions are always very welcome, even though I may not always come to agree with them. :)

Well a further comment relates to what focal length you use and the effectiveness of each.
If we have a lens capable of focusing to two inches or 50mm we have effectively a 20 dioptre lens. If we now add a moderate CU lens of 2d that gives us a 20+2=22d lens capable of focusing to 45.45r. It is obviously gaining very little. even adding a 10d lens gives us 30d or 33.33r mm. In view of the small gain it seems obvious to me better to not possibly degrade the image with the CU lens but to crop in editing.

On the other hand if we have a lens like my 430mm mentioned earlier which can only focus to two metres [ 0.5 dioptre ] then the addition of the moderate 2d lens enables me to focus to between 20 inches and 13 inches with the cameras focusing range ....the narrow angle of view of the 430mm lens provides the tight framing. My calculator corrects me and tells me that 2.5 d gives me 15.748 inches which in practice I had not noticed :)

So also in practice I would never use a short focal length lens for close work when one considers how the subject will be lit with the lens almost touching it.... ok for back lit subjects [slides] but not for other things. Exception being when I reversed my 25mm [movie camera lens] on the end of my bellows and got x9 magnification on my 35mm camera ... 4mm of a ruler filling the 36mm across frame. If that is not x9 I apologize but it seems that to me :)

With due respect to an earlier contributor but ....that spider ... hardly a close-up... when I have shot my neighbors I am looking for a shot where the spider is at least a third of the frame width if not bigger. As a bridge camera user I see this as an essential difference with the DSLR user ... it is so much easier to get BCU shots [ NOT macros ] with them with just the addition of a CU lens to the bridge camera. An illustration I have used in the past that WS/MS/CU/BCU depends on subject size rather than distance and we take a close-up of a mountain from five miles and a CU of a watch from 5cm. True when I worked for TV the studio cameramen, which I wasn't, had a very definite image size for WS/MS/CU/BCU so that the director could call the sort of shot he wanted within the studio setting.... it mystified me from my 'outdoors' experience :)

Finally found the photo of my usual setup for macro work. Have the Nikon 45mm PC lens on in this shot, not the bellows and Olympus bellows mount macro lenses...


https://www.cambridgeincolour.com/fo...1&d=1345567546



I like using the lightbox because all my images are consistently lit, which really streamlines the process when I have a lot of photos to take.

I don't recall seeing a picture of a spider in the MacroMania thread, and guess you must be thinking of somewhere else.

I'm sure there are many better ways and much better equipment for macro studies, but I shan't be in a position to buy any new equipment for some time, and must muddle through with the bits and pieces that I already have, or what I can cadge off the other pensioners in the retirement complex. :)

Aha, John! The good old rocket blower, and is that a Benbo tripod?

It all looks very familiar, except on my desk there will always be a mug of tea, and often a bacon sandwich, or signs of one having been there not long before.

I've sent off for an inexpensive 52mm Nikon reversing ring, so I'll be able to compare the reversed Nikkor AI-S 50mm f/1.8 images with the pictures turned out by the same lens when using the bellows.

It's just struck me that a Tamron 500mm mirror lens I bought thirty years ago claims some macro credentials, so I'll see what sort of results I can get with it using a hefty tripod.

Well actually, Christopher, that is a Slik Pro 814 carbon fiber tripod with a Gitzo Bubble Ball head suitable for landscape work (it has 4 separate spirit levels).

That is a rocket blower, along with an Arctic Butterfly sensor brush and a Sensor Loupe (both from Visible Dust).

There is a little HP touch screen laptop that the Nikon D700 is tethered to using Nikon's Camera Control Pro 2; and a double gooseneck variable intensity LED light source sitting on top of the lightbox.

No tea, or coffee; and definitely no bacon sandwiches, as I am a vegetarian ;-)

It will be very interesting to see how you fare with the reversing ring. I have no idea what to expect with the 500mm mirror lens; that design is fairly generic, and I had one with an Olympus mount but I found the contrast to be amazingly soft. Never tried it for macro, though; although I did mount it on an Olympus E510 (four thirds sensor, 2X crop factor) with a 2x teleconverter, which gave me an image stabilized 2,000mm (two meter) lens equivalent :-)

That was interesting.

I have the next few days off from work so I will try to get something happening with constructing that lens shading device...

Yes Brocken it is on another thread :( Grandad got confussed :)

Quote:

---

Originally Posted by jcuknz

Yes Brocken it is on another thread :( Grandad got confussed :)

---

I really don't think that is an appropriate comment.

http://i46.tinypic.com/6pask1.jpg

Coin diameter is 21mm - almost exactly the height of the frame

Here is my first test with the reversal ring which arrived this morning.

Lens is reversed Nikkor AI-S 50mm f/1.8.

Nikon D7000
ISO 200 - f/5.6 - 1 second - daylight

I think it might benefit from a lot more light and a much shorter exposure to crisp it up a bit. .

http://i48.tinypic.com/xfrhqp.jpg

Lens: reversed Nikkor 50mm f/1.8

The feather has curvature in several planes, making sharp focus across the entire frame difficult.

ISO 400 - f 5.6 - 1 second - daylight boosted with microscope mirror

Wow, these are great images Christopher! I haven't managed to set time aside yet to construct my lens shading implement but I will get around to that presently and post the results when I can manage to set everything up and sit down to it!

http://i47.tinypic.com/21115ro.jpg

The fogged centre problem again, but this time with a completely different macro set up!

Here I have fitted a x4 microscope objective to the Nikon D7000. The snout-like adapter has an internal RMS microscope thread at the pointed end, and an M42 thread at the other. The M42 end is then coupled to the camera by an M42-to-Nikon F adapter.

Grrrrr!


http://i46.tinypic.com/6r4xoy.jpg

John - Your "tipped over champagne glass" looks like a bunny to me. And, since they're rampant in the areas where he hung out, I wouldn't be surprised if that's what it is.

IJS....

virginia

Quote:

---

Originally Posted by drjuice

John - Your "tipped over champagne glass" looks like a bunny to me. And, since they're rampant in the areas where he hung out, I wouldn't be surprised if that's what it is.

IJS....

virginia

---

Hello Virginia,

I've examined some other coins from the Napoleonic Kingdom of Italy which are in a better state of preservation than mine, and it seems possible that the emblem I've jokingly described as a champagne glass may be an emblem of The Hand of Justice with its two fingers extended - seen in a number of Napoleonic portraits - while the emblem to the left may be the imperial crown.

Christopher