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 Replies: 19 / Views: 8,247 |
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Pillar of the Community
2087 Posts |
Over the last few months I have been trying out different manual focus macro lenses trying to sort out which ones best suit my purpose. So far the minolta MD 50mm has been outstanding. That 50mm is its cheap, has virtually no distortion and, with the 1-1 extension tube that comes with it, handles small coins through to large dollars. Late last year I heard about a rare lens and it was recommended to me. I managed to find one at a cheap price(GBP 211). That amount may not seem cheap but when other examples sell for €500-700 what I paid was reasonable. My plan was to try it out and if not happy sell it. After one single trial though I think its going to be a keeper. Its a long lens and should come with a clamp that enables you to attach the lens to a tripod. Mounting this lens to a camera and then mounting the camera to a copy-stand or Tripod is going to see camera mount damage. If you ever think of buying one don't go near an example that doesn't have the clamp! So here is the fist photo. Lens to subject distance = 59mm( slightly under 2 feet). For my copy stand that's brilliant I can get heaps of lighting adjust the composition with out the lens getting in the way. You can see with this shot I went a little crazy and even turned on a daylight CFL ( hence the gold highlights). Shot at F 11 using a standard test subject ( New Zealand 3d) I am impressed. Off the copy stand however this lens is demanding. with out Image stabilization High ISO and fast shutter speeds are going to be a must or alternatively It will have to be on a tripod every time you take a shot  I was using this lens on a FF mirror-less camera....and I suspect this is where this lens excels. IMHO it would be useless on a DSLR and Overkill on a APSC or four thirds system Its effective focal length will be just too long on A standard APSC camera. I am sure that more full frame mirror-less cameras will be coming to the market so this lens needs to filed away in memory. Later to day I will post a photo of this monster and the A7r mounted on the copy stand so You can get idea of size and usability. I will be experimenting with this lens a little longer...and then will have to decide which lens is going on eBay( unless I find some major problems its not going to be this 200mm! |
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Pillar of the Community
 2087 Posts |
On the copy stand:  on the camera  |
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Moderator
 United States
23522 Posts |
I *love* that last image - new tech camera mounting old tech lens and bringing home the bacon.  How's it look at 100% crop? |
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Pillar of the Community
2087 Posts |
Good question: As its a test photo And I didn't wear my reading glasses any softness might possibly be operator error. Tomorrow I will put more effort in and give this lens a good chance to show what its made of. For now: 100 % center crop  To really test the lens 200% edge crop. Spot the CA( purple fringing)  |
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Pillar of the Community
2087 Posts |
opp mistake. Focal distance is 590 mm not 59mm
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Pillar of the Community
2087 Posts |
An update:I know that a few people who use micro four-thirds, or Sony NEX/E-mount systems are interested in this lens. I've used it in the field and it performs well as an outdoor macro. The Half metre minimum focusing distance allows you to photograph insects a little( I mean a little!) easier. To do full one to one shots in the field my couple of times outdoors reinforced the need for a solid tripod, and a focusing rail. Indoors its a brilliant lens with coins that are the size of a quarter or less. With such coins the minimum focusing distance is actually really good. I can get all the lighting set up with plenty of room. Yesturday for the thread on Axial Lighting I photographed a Venetian ducat with a modern SIGMA EX 105mm Macro Lens. To be honest I didn't like the result. So this evening I blew the cob webs of the canon and this is the result. I am much happier with the photo( Taken using axial lighting) however I did notice something I hadn't picked up earlier: quite strong Vignetting. So instead of doing the usual circular crop I am posting the photo unedited. Look at the corners of the photo you will see considerable light fall off(that's the Vignetting) For coins of course its not a problem. However if any one wanted to use the lens outside it may be an issue they would want to be be aware of. Here is the picture:  Edited by austrokiwi
03/29/2014 2:32 pm
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Pillar of the Community
United States
4038 Posts |
The darkening at the corners is "falloff" and can be corrected in photoshop or other programs. The information is there, it's just that there is less light hitting the sensor as you move away from the center. True "vignetting" is unrecoverable, as there is no information present.
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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Pillar of the Community
2087 Posts |
Quote:
The darkening at the corners is "falloff" and can be corrected in photoshop or other programs. Huh? The other name for light fall off is Vignetting. At least that's what is in the photography books I have. In the photo I posted we can see Optical Vignetting caused by the lens its self. The photo was taken at F 11 So even though it seems mild, one could expect it to be much worse at larger apertures. Online you can find many references to it and this is a typical example: http://photographylife.com/what-is-vignettingEdited by austrokiwi
03/30/2014 05:26 am
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Moderator
United States
23522 Posts |
If it were optical vignetting the lens would do it regardless of what camera it was mounted on, as the lens itself is the cause. What you're looking at with the ducat is probably "natural" vignetting (natural illumination falloff), a physical manifestation described by the cosine fourth law of illumination falloff - correctable in post - or possibly pixel vignetting.
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Pillar of the Community
2087 Posts |
Its too dark to try outside ( for testing for vignetting). I am pretty sure its optical or, now coming in a close second) a mechanical function of the lens or the lens and the A7r's 35mm sensor. In the picture I posted you are looking at a coin that is 20mm in diametre. The photo was taken at a 1-1 ratio and this results in a lens, with adapter length, of 260mm long ( 1.5 inches shy of a foot). The picture dimensions are 7360 pixels by 4912 pixels. Its a huge picture covering a very small area. The lighting was very strong 60 LED lighting panel @ 5600 K. For the small area that was shot I don't think there is any likelihood of it being natural illumination fall off. I will try a white wall tomorrow and see what I get. I don't normally use the whole photo I usually crop out the background and replace it with a white field in Adobe elements. Useful discussion!
Edited by austrokiwi
03/30/2014 2:37 pm
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Pillar of the Community
United States
4038 Posts |
All I'm seeing is a little darkening in the corners. While this can indeed be called vignetting, that term is usually reserved for mechanical vignetting where the corners are black due to blockage of the light path, not slightly darkened due to normal optical properties of the lens.
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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Moderator
United States
23522 Posts |
What we call "optical vignetting" is also mechanical in nature, caused by lens elements further from the sensor physically shading elements closer to it.
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Pillar of the Community
2087 Posts |
Quote:
All I'm seeing is a little darkening in the corners. While this can indeed be called vignetting, that term is usually reserved for mechanical vignetting where the corners are black due to blockage of the light path, not slightly darkened due to normal optical properties of the lens. I am new to photography ( last 5 years) but I understand Vignetting is darkening in the corners: I am not sure you accessed the link I posted: here is the intro-text on that page: Quote:Vignetting, also known as "light fall-off" (sometimes spelled "light falloff") is common in optics and photography, which in simple terms means darkening of image corners when compared to the center. Vignetting is either caused by optics, or is purposefully added in post-processing in order to draw the viewer's eye away from the distractions in the corner, towards the center of the image. Depending on the type and cause of vignetting, it can be gradual or abrupt. There are a number of causes of optical vignetting â€" it can naturally occur in all lenses, or can be caused or increased/intensified due to use of external tools such as filters, filter holders and lens hoods. In this article, I will talk about each type of vignetting and also discuss ways to reduce or increase the amount of vignetting in photographs using post-processing software like Lightroom and Photoshop. Read more: http://photographylife.com/what-is-...xzz2xW349u5S I haven't had my second coffee yet but the sun was up and I photographed a white wall. As I said I hadn't had my second coffee so I didn't think adjust the exposure, or ISO from last night; when I had a quick try using room lights . The result of the failure to adjust last nights settings is that the photo is a little dark. In this test shot the lens set to 1-1 magnification and wide open(F4). The light falloff/Vignetting is readily noticeable {and it gives an antique look}. For coins its not a big deal and of course , as pointed out earlier, the effect can be edited out.  |
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Pillar of the Community
2087 Posts |
Well in real life who would even notice the light fall off: ( sorry its not a coin,looking at that spider through the focus magnification assist was creepy!)  So Edited by austrokiwi
03/31/2014 09:41 am
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Pillar of the Community
United States
4038 Posts |
I've never heard of minor natural fall-off referred to as vignetting, only intentional darkening created to give a particular "look" to the image, or mechanical reduction of field of view that gives the same effect. Lens reviewers call what you are showing "falloff", not "vignetting".
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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Pillar of the Community
2087 Posts |
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I've never heard of minor natural fall-off referred to as vignetting, Do an internet search nearly every result refers to lightfall off as being vignetting. |
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Replies: 19 / Views: 8,247 |
Posted 02/14/2014 09:32 am
