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Author Topic: Macro Lens  (Read 7850 times)

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Offline PtolemAE

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Macro Lens
« on: January 04, 2018, 11:49:27 pm »
In the thread on Sony A6000 camera, Doug Smith made a very helpful post with photo showing a long focal length macro lens (Canon, 100mm) and suggested the longer focal length might work better than the 30mm focal length macro I had at the time.  The point, well taken, is that the longer focal length allows more 'stand-off' room between the coin and the front of the lens - room to set up and adjust lights.  Happy to report that has turned out to be a great recommendation.  Turns out it's fairly easy to adapt older SLR film-camera lenses to the A6000 and those lenses can often be purchased very economically.  Just did first tests with a Canon FD 100mm focal-length macro lens connected to the A6000 with an adapter.  A Sony 90mm macro costs about $1000 and the Canon 'manual only' (which is dandy for copy-stand work) 100mm macro in excellent condition was only about $100.  And indeed the new (actually pretty old) lens allows 'standing off' from the coin by about 10" instead of the 3" range required by the 30mm Sony macro I was using.   That 10" or so is plenty of room for better lighting and the first result is show here.  It's an 11.5mm coin and the photo is about 1500 x 1500 pixels, or about 130 pixels per millimeter (!) and the result with improved lighting is better than similar photos with the 30mm macro that couldn't be lit as well due to being so much closer to the coin.  The resolution now is better than 10 microns per pixel with a good sharpness and it's much easier to use with the big 10" stand-off (and it still fits fine on the copy stand).  It was possible to 'fill the frame' with a U.S. cent (19mm) and get about 4000 pixels spanning its diameter (over 200 pixels per millimeter, about 5 microns resolution).   The 30mm macro by Sony, designed for this camera, still has its uses but the 100mm 'adapted' Canon lens is going to be the 'go-to' lens for taking pictures of coins.  Point of reference - the 100mm Canon lens allows setting of F value from 4 up to 22.  Seems F8 works well to get enough depth of field to make the coin look sharp throughout its thickness.

Started this as a new thread because the Sony A6000 thread was so long ago.

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Offline maridvnvm

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Re: Macro Lens
« Reply #1 on: January 05, 2018, 09:02:58 am »
I use a fairly antequated setup, which seems to work for me.

I have a Canon 400D, which was marketed as the Digital Rebel XTi in North America and dates back to 2006. It's only a 10.2 megapixel resolution but I combine if with a Canon 60mm Macro lens. It took me some time with this setup to get to a stage where I was taking images that I was happy with.

I find that it's as much about the stability and the lighting as it it to do with the camera, Having the best optics that you can is a must.

Here are two recent images that I am relatively happy with. I use F8 which was the best compromise after much experimentation.

Regards,
Martin




Offline PtolemAE

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Re: Macro Lens
« Reply #2 on: January 05, 2018, 11:59:21 am »
I use a fairly antequated setup, which seems to work for me.

I have a Canon 400D, which was marketed as the Digital Rebel XTi in North America and dates back to 2006. It's only a 10.2 megapixel resolution but I combine if with a Canon 60mm Macro lens. It took me some time with this setup to get to a stage where I was taking images that I was happy with.

I find that it's as much about the stability and the lighting as it it to do with the camera, Having the best optics that you can is a must.

Here are two recent images that I am relatively happy with. I use F8 which was the best compromise after much experimentation.

Regards,
Martin

Thanks for this info.  What's the distance from the front of your camera lens to the coin?  What's the size of the coin?

For stability it's best to let the computer control the camera by USB so it can snap the photo without anyone touching the camera itself.  That allows setting shutter down to as slow as 1/20 second to accomodate the F8 and some reasonable ISO to keep noise down.  Pretty sure that Canon's EOS software will work with your camera.

Your pics look excellent.  If you can get a 4000-pixel-wide sensor to span a coin it's going to work out just fine.  The higher resolution of the a6000 (24 megapixel) allows for cropping on coins that are too small even to fill the sensor field with a macro lens.

Seems the macro lens is a big help, regardless.

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Offline Akropolis

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Re: Macro Lens
« Reply #3 on: January 05, 2018, 12:38:34 pm »
Seems a bit dark....to me. Perhaps it is my monitor settings.
PeteB

Offline peterpil19

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Re: Macro Lens
« Reply #4 on: January 05, 2018, 10:52:27 pm »
I use a Canon EF 100mm f.2.8 L Macro IS USM. These lens cost me more than my (almost) base model dSLR on advice from many that the lens are more important.

I take photos from higher up for depth of field reasons. If I take the photo too close to the coin the outer parts become too blurry and I have to use a higher f-stop number which comes at the cost of diffraction, which Doug refers to in another thread.

I control the camera (including its settings) from my laptop to avoid touching the camera. No cord is necessary nowadays as most devices can connect wirelessly. This also allows me the opportunity to review each photo as it is taken and make adjustments.

This is a photo of an exceptionally small coin. Its maximum-diameter is 10mm. I think it came out reasonably well.
No post-processing has been applied and there is zero sharpening.
I do need to invest in a sturdier stand as the photos suffer from slight vibrations caused by the camera.

Peter



Offline Jay GT4

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Re: Macro Lens
« Reply #5 on: January 06, 2018, 12:24:53 am »
Peter that's very impressive.

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Re: Macro Lens
« Reply #6 on: January 06, 2018, 03:27:26 am »
Nice thread...  ;)+++

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Offline peterpil19

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Re: Macro Lens
« Reply #7 on: January 06, 2018, 03:34:24 am »

Offline PtolemAE

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Re: Macro Lens
« Reply #8 on: January 06, 2018, 08:28:34 pm »
I use a Canon EF 100mm f.2.8 L Macro IS USM. These lens cost me more than my (almost) base model dSLR on advice from many that the lens are more important.

I take photos from higher up for depth of field reasons. If I take the photo too close to the coin the outer parts become too blurry and I have to use a higher f-stop number which comes at the cost of diffraction, which Doug refers to in another thread.

I control the camera (including its settings) from my laptop to avoid touching the camera. No cord is necessary nowadays as most devices can connect wirelessly. This also allows me the opportunity to review each photo as it is taken and make adjustments.

This is a photo of an exceptionally small coin. Its maximum-diameter is 10mm. I think it came out reasonably well.
No post-processing has been applied and there is zero sharpening.
I do need to invest in a sturdier stand as the photos suffer from slight vibrations caused by the camera.

Peter

Nice - looks like about 1000 pixels for the 10mm coin, ~100 pixels per mm (~10 micron pixels).  Nice and crisp and the goal of hi-resolution pic of small coins is clearly achieved here.  Canon glass has a very good reputation and the FD older lens, only $100, probably is quite similar in quality but simply can't auto-focus of course when adapted to the Sony a6000 camera.  Not important for this application - but the affordability was.  The a6000 can transmit images over wi-fi but not sure if there's a wireless version of the camera control program for it.  USB is pretty easy.  Basic copy stands are not very expensive and very helpful for setting up.  There's some good coin photography happening out there... :)

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Offline Carausius

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Re: Macro Lens
« Reply #9 on: January 07, 2018, 12:20:36 am »
I use a Canon EF 100mm f.2.8 L Macro IS USM.

I've been considering purchasing this very lens for a couple years now.  Price has always scared me off it.  Canon makes the same lens without IS for much less money. Given that my primary reason for buying a macro lens is copy stand coin photography, I wonder if IS is needed at all.  I use a wired shutter control to snap the photos, making camera shake practically nonexistent.   I suppose nixing the IS would pretty much relegate the lens to coin work, and maybe that's penny wise and pound foolish.  I've been using a kit lens to date and the results haven't been too bad.  I think a macro lens would improve results.  

Offline peterpil19

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Re: Macro Lens
« Reply #10 on: January 07, 2018, 01:23:36 am »
I turn image stabilisation off when my camera is mounted to the copy stand. Not that I notice any difference with it on vs. off, but many advise to turn it off when the camera is fixed e.g. on a tripod or copy stand.

These macro lens also take exceptional portrait photos. Therefore IS comes in handy if you plan to use the lens for this purpose. I never expected that I would find myself taking portrait photos and enjoying it, but like all hobbies, one thing certainly leads to another...

Peter

Offline agord

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Re: Macro Lens
« Reply #11 on: March 19, 2018, 12:10:59 am »
Here is a 10 mm obol from Cyzicus taken with a Canon 100mm macro lens on a Canon 7D camera. 7 images of each side were focus stacked to get the depth of field. About 5" from front of lens to coin.

Offline dougsmit

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Re: Macro Lens
« Reply #12 on: March 22, 2018, 07:26:34 am »
Focus stacking is fun.  Macro lenses may be better in many ways (I have an old Canon non-IS 100mm) but I took just as good photos with my 70-200mm zoom before I bought the macro.  Macro lenses do better in the corners but round coins don't use that part of the image so much of the benefit is lost.  A solid stand is much more important.

I discover than I have lost the ability to make good coin photos by my definition.  Too many of my photos now look as ugly as the coins they represent.  I should be buying prettier coins. ;D


Focus stack 6 shots for each side of this Rhodes bronze.


Offline stevex6

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Re: Macro Lens
« Reply #13 on: March 22, 2018, 08:36:35 am »
Doug ... your new Rhodes coin looks sweet (nice photos)

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Offline wileyc

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Re: Macro Lens
« Reply #14 on: May 08, 2018, 11:48:53 pm »
Excellent picture Doug. +++

 

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