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Valued Member
United States
67 Posts |
Looking nice! Definitely better with the lights this time.
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Pillar of the Community
 2087 Posts |
Had another play this afternoon. Its a real novelty getting decent resolution shots using very low magnification. I had previously assumed that high(er) res needed close to life sized magnification or more. First shot is reduced substantively to post, but that is the only editing.Second shot is a 100% crop from the full sized image. Ruler is in cm with mm graduations. Unless I have done my maths very poorly magnification is 0.17333 which is in the optimal magnification range of this lens. The working distance is very usable at this level....problem is not many coins are large enough for this magnification level.   Edited by austrokiwi
03/28/2016 2:52 pm
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Pillar of the Community
 United States
4038 Posts |
I just do a relative calculation. I know the DLA for my T2i, which has 4.3um pixels, is f6.8. So the DLA for your camera with 3.75um pixels would be 3.75/4.3 * 6.8 = f5.93.
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Pillar of the Community
2087 Posts |
Quote:
So the DLA for your camera with 3.75um pixels would be 3.75/4.3 * 6.8 = f5.93. OK works for me. Cambridge colour calculator( there is more than one) came out at 6.9 Quote:
The more-squarish MFT sensor (about 4:3) should be better suited to whole-coin photos than the 3:2 (6000x4000 pixels) found in the newer Canon APS-C DSLRs That was my initial thoughts Edited by austrokiwi
03/28/2016 4:30 pm
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Pillar of the Community
United States
4038 Posts |
Agree, I'd prefer a 4:3 aspect ratio for coins.
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Pillar of the Community
2087 Posts |
I went back and gave the oly 135mm F4.5 a go again...with the lights high @5.6 and around half sized magnification:  |
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Pillar of the Community
2087 Posts |
The last couple of evenings I have been trying out the oly 60mm F2.8 macro and the oly ED 50mm F2 macro. The 60mm is native to the camera.. and its cute(I never thought I would ever say that about a lens). When its on the camera the camera and lens feel like a toy. The performance is good(but not great). I tried focus stacking and immediately saw a problem. The focus bracketing works in silent shutter mode its very fast and silent but as each shot is effectively a video scan, you can get banding( bands of light and dark) with artificial lighting. I got it on every try. I only set the bracketing to five shots and I wasn't overly impressed with the result although the banding didn't seem to effect the final picture( reduced substantively for posting).  The 60mm has to be stopped down as it isn't sharp edge to edge. But its the only game in town if the requirement is a native lens that makes use of Olympus' focus bracketing. I quickly found out that the ED 50mm F2 isn't compatible with the in camera stacking. But it is a razor sharp lens from F2. On the OMD-Em10II its huge...you mount the camera on the lens(not the other way round) via an adapter. The camera and lens together weigh over 800 grams....the camera on its own is only just over 300 grams. I can not imagine many people walking around with the 50mm on an OMD or Pen camera. I certainly won't be. Its not that the combination is too heavy just that it is too heavy for the size of the camera..it is uncomfortably unbalanced and the camera is not big enough for two hands. From what I have seen so far the 50mm will get a lot of use with coins.(100%crop of the florin taken with the 50mm)  This is a set of crops(center and corners) of a picture of our DVD rack. Taken at F2 The result is heaps better than the 60mm at F2.8 the 60mm only started to come close at a round F4  The next set of pictures give you and idea of size in this shot is the SK 45mm, the oly 60 and 50 mm and the Sony 90mm( which doesn't go on the oly)  Here is the 50mm on the oly:  Hopefully this shot gives a good idea of the difference in sensor ( and Camera size) Sony's sensor is 3.8 times bigger than the Oly's  I should add that I didn't buy either lens new. The 50mm has been out for a good many years the 4/3 DSLR system is going the way of film cameras. You can buy the lens new and some retailers are giving huge discounts just to get their last examples off the shelves. Mine is second hand from a German shop...I could have got it cheaper on ebay but the shop has given me a 12 month warranty . The 60mm was also second hand. Edited by austrokiwi
03/31/2016 2:33 pm
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Pillar of the Community
2087 Posts |
I think this is my final posting, on this camera for a while...as fun as playing with a new camera is I really want to get back to a real camera ( my Sony A7rii) For what use it may be, my observations: I think the OMD-EM10II. is a great second camera. Every time I found my self getting annoyed with it I realized I was trying to get it to do what my main camera does. It might be a great buy for someone who is buying their first new camera and wants to also take photos of coins. For ordinary photography its a nice portable camera. I suggested to a friend of mine his wife might like one as it is handbag sized( my wife really likes it for that reason). His wife has a canon that is dying and she only ever used the canon like a point and shoot. My old Mate came back and said( as is typical of our conversations) "but you don't have a handbag". Hes right I have lived in Europe now for 15 years... and I still won't buy a mans handbag. Ignoring the joke that discussion bears consideration, meaning: Its too big for my jacket pocket and it is almost two small to handle easily. For that reason I have a Swiss Arca standard L plate in the mail. The L plate extends the grip slightly so hopefully will make the camera easier for me. That grip will also allow me to mount the camera more swiftly to my macro rig. I really like the IQ of the photos, and with the small sensor there is a huge advantage with the DOF. The camera does produce, through focus bracketing, pictures for stacking, but I have hours a head of me working out what each stacking differential( from1-10 in the camera) means in focus shift at each F stop and magnification. Olympus refuse to release that info labelled it commercially sensitive(that's the story they told me and I wasn't impressed). For now it looks like setting 1 shifts the focus .75 - 1 X the depth of field, as calculated by contrast detection in the camera ( I used a calibration slide mounted at 45 Degrees to see the movement). If that is correct then setting 2-10 will never be used for coins. If you have an Oly MFT camera and want a good macro lens and don't need the stacking feature.... go for the ED 50mm F2, its only 1:2 magnification but on a MFT sensor you don't really have a need for 1-1. If you are looking at focus stacking on a budget then you will have to go for the native 60mm. If you want the tethering and are looking at MFT then skip this camera as it doesn't tether. You would need to spend nearly US$400 more for the OMD-EM5II. It has the same sensor can be tethered and will, for coins produce photos that compete with those produced by the SonyA7rII with a lot less effort. That would mean spending around US$1600.00 Camera plus 60mm macro. That may seem a lot but compare it with the cost of the same ability using the Sony A7rii Camera plus native macro lens plus stack shot system and the soft ware for tethering there is very little change left out of US$5000.00, and for coins I think the smaller MFT sensor gives you a huge advantage over the FF sensor. Final shot for a while( in this thread) Proof ASE shot at F 2.8, using the ED 50mm F 2. I left the coin in the sealed capsule so you can see some artifacts from the capsule in the photo. Lighting was my home made lens mounted LED panel. For all the faults of the photo remember this was at F2.8 where there is all the DOF that is needed.  Edited by austrokiwi
04/02/2016 03:30 am
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Pillar of the Community
Canada
2784 Posts |
austrokiwi you have done a wonderful job representing. this camera. you are right about the depth of field. simply incredible. I have purchased a couple of macro lens. I may have to take a closer look at this camera. first I will try to get them to work on the Sony A7R mark II. if not then I may look at buying this unit. I have one other way that. I may be able to make these lens work. it will mean I will have to destroy a camera. I would have build a pipe camera. that would be the only way. I can mount the sensor chip. to work with these lens. I am hoping they work with the Sony. have a great one. this is and outstanding camera. wonderful images.
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Pillar of the Community
2087 Posts |
I do have to add there is one very annoying feature that so far I have found no way to change( so I think it can't be changed). With my Sony A7rII the picture seen in the camera's rear screen is the picture that I will get. With the OMD-EM10II The rear screen and EVF Substantively brighten the image. I get caught out reasonably often, so I have to continually remind myself to check the exposure level indicator before operating the shutter. So far I have learned with this camera I have to underexpose.
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Pillar of the Community
United States
4038 Posts |
Canon cameras also have modes where the Live View does not match the final image. You may find that some particular setting impacts this. On my Canons, the only mode that properly simulates exposure is Av. All other modes give me an incorrect simulation, so that the image does not match the Live View.
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Pillar of the Community
2087 Posts |
I have gone through the manual tried different settigns and still no joy. The LCD is back lit so that may be the issue. I did discover one interesting possibility with the adapted 4/3 lens the ED 50mm F2. Olympus apparently made many, if not all, of their 4/3 DSLR lenses tele-centric. I did a quick check with some coffee cups placed a different distances from the camera....both looked to be the same height in the view finder so it seems the ED50mm may well be one of those tele-centric lenses. Although its only 1:2 ( half sized magnification) its an extremely impressive optic. reading Wikipedia ( not always the most reliable sources) I find this: Quote:
An image-space (or image-side) telecentric lens produces images of the same size regardless of the distance between the lens and the film or image sensor. This allows the lens to be focused to different distances without changing the size of the image. Image-space telecentric lenses have an exit pupil infinitely far in front of the lens; that is, if one looks in the back of the lens, the image of the aperture is very far away. The quote goes on to say this is the type of telecentricity used by the 4/3 system. Am I correct in interpreting this as meaning that the lens is resistant to focus breathing? Or would resistance to focus breathing be due to other design factors Edit: I double checked with a series of photos I had taken using the stackshot. I had already noticed the stacked photo was qualitatively different to what I had normally produced( I had put it down to using a lower magnification). But checking 15 shots in one stack I could find no discernible change in image size. given this lenses type of telecentricity I gather the lack of change in size was due to a lack of focus breathing. The 60mm native macro stacked shots showed definite( but small) changes in size through the stack I am also guessing that this lens has an extremely flat field, due to the image telecentricity. I haven't measured it but it is sharp cnr to cnr wide open Edited by austrokiwi
04/09/2016 3:42 pm
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Pillar of the Community
2087 Posts |
I asked the same question on another forum and learned a lot. The lens is image space tele-centric which means that after passing though the lens the image light beam hits the sensor at almost 90 degrees( perpendicular)It does tend to make the lens resistant( but not immune) to focus breathing. Focus breathing is where the image size changes when the focus changes. It can be an issue when focus stacking.
The main purpose for this telecentricity is to prevent vignetting( light fall off) near the edge of the sensor, it was an issue with the 4/3 DSLRs, that went away when the Micro 43 system was developed.
The lens does have some focus breathing( but it seems to be small) that breathing might be due to another aspect of the design ( it has a degree of internal focusing (changing the position of some of the lens elements.
Edited by austrokiwi
04/11/2016 05:41 am
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Pillar of the Community
2087 Posts |
With a Bellows converted to MFT mount I finally got around to trying out the Printing Nikkor 105/2.8 with this camera( I didn't need the MFT mount I just had the bellows set up and decided to give it a go). This composite photo is made of two 10 shot stacks.( I am pretty sure that 10 shots was overkill  100 percent crop  Edited by austrokiwi
04/21/2016 11:46 pm
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Pillar of the Community
2087 Posts |
In the process of looking at how to test for lateral CA I tested both the Native lenses( one is only semi native) for CA and though the resistance to CA appeared good I noticed something else. On the FF sensor at 1-1 all the lenses I had were easily producing images that differentiated the 0.02mm graduations on the microscope calibration slide that I was using. Not so the 60mm lens MFT lens. My suspicion is the cameras noise reduction system is the real issue here, because both the lenses should be able to resolve at that level easily. I am now going to have to hunt through the cameras menu system to find how to change the settings to a level more appropriate to coin macro work.
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Replies: 27 / Views: 5,208 |
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Posted 03/28/2016 2:22 pm
