| Author |
 Replies: 16 / Views: 3,977 |
|
Pillar of the Community
 United States
4593 Posts |
(Also I'm not yet tethering, so there is PTB vibration) Here is the rig:  While there is a lot of (once upon a time expen$ive) stuff there, the only serious purchase was the DSLR (which I've been lusting after for a long time, thanks M&D for the birthday present!). The Fotodiox adapts a whole bunch of old film macro equipment I had (which can be bought cheap on ebay today - thanks Olympus for not providing an upgrade path from the OM mount) to the DSLR and cost $75. The Spirotone Macrotel sells for $15 on ebay. It's a 150mm so you can see the HUGE working distance... 14 inches! There's an auction today for the Auto Bellows including the box, it's at $40 bid (although there are $130 BIN listings too). Given the size of the T3i I was a little worried about clearances mounting the box, so I used the OM Auto Extension tube (25mm) - ebay $9 0 bids, or $20 BIN. The Testrite CS2 Copy Stand is also from my film macro days and is big and solid. But rmc and I have been talking about how to build a simple gusseted A-frame out of wood that would do exactly the same thing. Anyway... 1st light - this is a cropped to 800x600 and even then lower quality jpg compressed to meet the upload limits. Oh, and I haven't tethered to the computer yet, so I was manually focusing and pushing the button on the camera and I also obviously can't focus for beans. Again this is about the rig:  And here is a 640x480 CROP (i.e. 100% size) of the palm tree...  The luxuries... The Artograph is recommended elsewhere for non-flat objects such as rings since it gives a seamless non-shadow background. The Panatone HueyPro color calibrator is something I also had from past projects - it adjusts the laptop panel so that the presentation is true-color. Does NOTHING for the image capture, that type of tuning will have to be in Paint.Net or it's relatives. -----Burton -----Burton 50+ year / Life / Emeritus ANA member (joined 12/1/1973) Life member: Numismatics International, CONECA Member: TNA, FtWCC, NETCC, EveryCountry (online) coin club Owned by three cats and a wife of 40+ years (joined 1983) Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/ |
|
|
|
Pillar of the Community
United States
8517 Posts |
Isn't the LightPad causing the pic to washout ?
Oregon coin geek.....*** GO BEAVS ! ! ! ***
|
|
Pillar of the Community
 United States
4593 Posts |
It shouldn't but I have a fair bit of experimentation to do. It's meant for tracing, so it's not that strong a light. This has a little better focus:  I figure this is 1:1.6 -----Burton 50+ year / Life / Emeritus ANA member (joined 12/1/1973) Life member: Numismatics International, CONECA Member: TNA, FtWCC, NETCC, EveryCountry (online) coin club Owned by three cats and a wife of 40+ years (joined 1983) Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/ |
|
Moderator
 United States
23522 Posts |
Quote:
Isn't the LightPad causing the pic to washout ?
Beyond any doubt. Burton, you're an inspiration to anyone who's considering the path you've taken, and the service you're doing to the community by so freely sharing the steps in the process. I'm going to be bookmarking your threads for future reference as links for those wanting to do this as well. And wait until you can focus your image on the computer's monitor instead of a silly 3" LCD....it's another world. But please, please please don't shine light directly into a lens.  |
|
Pillar of the Community
United States
4038 Posts |
If you are going to do the backlighting thing, I recommend you block off any light coming from the light box outside the field of view. Just put cardboard or some other way to block the excess light. The concern is that the excess light will hit the sensor and reduce your contrast. Light coming from the field is what you are trying for (if I understand your setup correctly) but light from outside can still make it to the sensor. I'd also recommend putting additional diffusion to reduce the intensity of the light. You can judge yourself how well it works by the pics you take. If the light is pegging the sensor (255,255,255) then it is too bright.
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
|
Pillar of the Community
United States
4593 Posts |
There is definitely room to play - that original image is close to pegged. However, I cut up a milk jug as a diffuser (shooting down through the cut off top and with a cut off bottom resting on the lightpad and that one has a lot of room to adjust:  Unfortunately I won't be able to play anymore until next weekend... had to put away my toys to get to bed for the flight tomorrow am. As for SsuperDdave's comment, Quote:
Beyond any doubt. Burton, you're an inspiration to anyone who's considering the path you've taken, and the service you're doing to the community by so freely sharing the steps in the process. Pshaw I'm very new at this - gave up on macro years & years ago because film was so frustrating - you would spend an hour on setup, half an hour on tear down and then wouldn't see the results until a week later when the film came back, lather rinse and repeat. Everything *I* know is from reading Ray's posts and the back&forth with rmc last week. Quote:
Dicebat Bernardus Carnotensis nos esse quasi nanos, gigantium humeris insidentes, ut possimus plura eis et remotiora videre, non utique proprii visus acumine, aut eminentia corporis, sed quia in altum subvenimur et extollimur magnitudine gigantea. Bernard of Chartres from John of Salisbury's Metalogicon: "we are like dwarfs on the shoulders of giants, so that we can see more than they, and things at a greater distance, not by virtue of any sharpness of sight on our part, or any physical distinction, but because we are carried high and raised up by their giant size." -----Burton -----Burton 50+ year / Life / Emeritus ANA member (joined 12/1/1973) Life member: Numismatics International, CONECA Member: TNA, FtWCC, NETCC, EveryCountry (online) coin club Owned by three cats and a wife of 40+ years (joined 1983) Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/ |
|
Moderator
United States
23522 Posts |
Quote:
Everything *I* know is from reading Ray's posts and the back&forth with rmc last week.
....which is exactly what we're trying to do here. The fact that you're documenting the process is the key, because many to follow will be asking the same questions and you're providing a neat all-in-one answer to those questions. This is much appreciated. |
|
Pillar of the Community
United States
8517 Posts |
I would love to see that same exact photo/set up with the lightpad turned off, just the Jansjo's.
Oregon coin geek.....*** GO BEAVS ! ! ! ***
|
|
Pillar of the Community
United States
4593 Posts |
Quote:
I would love to see that same exact photo/set up with the lightpad turned off, just the Jansjo's. Care to guess? Basically everything is automatic except the additional backlight. Both shot at 1/60th, one ISO 250, the other ISO 400, both at f4.  PS: The originals are 14MB, that's a little extreme to post :-)... -----Burton 50+ year / Life / Emeritus ANA member (joined 12/1/1973) Life member: Numismatics International, CONECA Member: TNA, FtWCC, NETCC, EveryCountry (online) coin club Owned by three cats and a wife of 40+ years (joined 1983) Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/ |
|
Moderator
United States
23522 Posts |
Quote:
PS: The originals are 14MB, that's a little extreme to post :-)... Ya think?  I'm going to guess the richer hues of the right-hand shot are the one which wasn't backlit; I expect that to be what I envision as the "advantage" of not backlighting it. If I'm wrong, I'm going to have to rethink some stuff, which is always a healthy practice anyway. Just for the record, I also own a CS-2, but it has a "parallelogram" mounting mechanism quite different from yours. I don't use it because that mechanism isn't square to the post or base, even though it adjusts through its' range perfectly evenly. More's the pity. |
|
Pillar of the Community
United States
4593 Posts |
I also cranked the Olympus 80mm macro about as large as I could get and ended up about 1.5x - around 10mm of coin on a 14.9mm high sensor. I had to scale & crank the quality way down to fit in 100K:  -----Burton 50+ year / Life / Emeritus ANA member (joined 12/1/1973) Life member: Numismatics International, CONECA Member: TNA, FtWCC, NETCC, EveryCountry (online) coin club Owned by three cats and a wife of 40+ years (joined 1983) Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/ |
|
Moderator
United States
23522 Posts |
I'll be darned. It's not what I thought. Idle question: are you using Auto white balance? That might have a bearing.
|
|
Pillar of the Community
United States
4593 Posts |
Yes & Yes
yes you are wrong the more coppery one is backlit and yes it's auto white balance.
But I need to do a fair bit more experimentation on this to confirm things before I really call you wrong....
-----Burton 50+ year / Life / Emeritus ANA member (joined 12/1/1973) Life member: Numismatics International, CONECA Member: TNA, FtWCC, NETCC, EveryCountry (online) coin club Owned by three cats and a wife of 40+ years (joined 1983) Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/ |
|
Pillar of the Community
United States
8517 Posts |
What's the purpose of backlighting ? I would've thought the darker coin also but I do see that you laid some black fabric down. That had to help cut the glare.
Oregon coin geek.....*** GO BEAVS ! ! ! ***
|
|
Pillar of the Community
United States
4593 Posts |
I have no clue what the purpose is - I meant it to punch the coin out of the background so I could place it into a presentation. Some results are quite interesting. Lighting is two Jansjo at 10 and 2 O'clock. With either a black background, white background (unlit) or white background (lit). The photos below are 640x480 jpgs at a low enough level to fit in 100K. I cropped a 1280x960 section and then sized that down to 50% to make them 640x480. No level adjustment and Auto White Balance. Big difference between bright copper and clad! Backlit:  White Background:  Black Background:  Backlit:  White Background:  Black Background:  -----Burton -----Burton 50+ year / Life / Emeritus ANA member (joined 12/1/1973) Life member: Numismatics International, CONECA Member: TNA, FtWCC, NETCC, EveryCountry (online) coin club Owned by three cats and a wife of 40+ years (joined 1983) Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/ |
|
Pillar of the Community
United States
4038 Posts |
I think the difference is simply AWB vs MWB. Most of the light hitting the sensor from the coin is reflected from the Jansjos. This assumes you are not attempting to reflect any light from the light pad back to the coin from above. If this is the case, then I'd suggest setting your WB to Tungsten and then seeing what the differences are between the backgrounds. There may still be some variation but I think it will be much more consistent.
The classic Nikon Multiphot system, which came with the highly respected Nikon Macro-Nikkor lenses (not a typo...), used a substage lighting arrangement that reflected light back to the subject. A parabolic Lieberkuhn reflector screwed onto the filter threads of the lens. Light from the substage hit the reflector and was parabolically-focused at the plane of the specimen. The specimen (coin, bug, whatever) was placed on small black disk that blocked any light from the source from directly hitting the lens. The Lieberkuhn reflector was invented in the mid-1700s...Ray
|
| |
Replies: 16 / Views: 3,977 |
Posted 09/22/2013 5:45 pm
