macro lens - digital SLR
Discussion
Posted this across on general gassing - Doh, didn't know this forum existed.
OK needa macro lens for a digital SLR which I'll use to take pics of samples I'm testing at work. I cut the samples out of a larger block and I need to document the location and orientation of each sample. Ideally I want to have images of samples a few milimetres in length in some detail. So a working distance of 15 mm or so.
I have a microscope with a CCD camera attachd which I can use to take higher magnfifcation pics but I need somethng with slightly less magnification initialy.
So any advice / comments on which digital SLR (Cannon 300d ?) and which macro lens
Cheers !
OK needa macro lens for a digital SLR which I'll use to take pics of samples I'm testing at work. I cut the samples out of a larger block and I need to document the location and orientation of each sample. Ideally I want to have images of samples a few milimetres in length in some detail. So a working distance of 15 mm or so.
I have a microscope with a CCD camera attachd which I can use to take higher magnfifcation pics but I need somethng with slightly less magnification initialy.
So any advice / comments on which digital SLR (Cannon 300d ?) and which macro lens
Cheers !
I've got a Sigma 105mm Macro which is very good. It does 1:1, meaning the image on a 300D's sensor would be life size (22mmx15mm). On top of this, you could add extension tubes to further reduce the minimum focusing distance, and increase magnification.
To see some shots with this lens, check out www.pbase.com/srider/macro
I'm not allowed to post them here because of wimps who are afraid of teeny spiders
For higher magnifications, it starts to get pricey. Your options are a 180mm macro, or Canon do a dedicated macro lens (MP-E 65mm f/2.8 1-5x Macro) which goes upto 1:5 magnification, but is £715.
>> Edited by srider on Tuesday 3rd February 16:59
To see some shots with this lens, check out www.pbase.com/srider/macro
I'm not allowed to post them here because of wimps who are afraid of teeny spiders
For higher magnifications, it starts to get pricey. Your options are a 180mm macro, or Canon do a dedicated macro lens (MP-E 65mm f/2.8 1-5x Macro) which goes upto 1:5 magnification, but is £715.
>> Edited by srider on Tuesday 3rd February 16:59
911newbie said:
OK needa macro lens for a digital SLR which I'll use to take pics of samples I'm testing at work. I cut the samples out of a larger block and I need to document the location and orientation of each sample. Ideally I want to have images of samples a few milimetres in length in some detail. So a working distance of 15 mm or so.
srider has the answers, but I'd just like to add that 'macro' is not simply connected to distance from the subject. Equally important is focal length - which is why the 105mm lens mentioned above will get you 1:1 magnification without squashing the subject flat and obliterating all light! True macro is a wonderful thing - it suddenly doubles the number of possibilities.
I use a standard 50mm lens and a set of Kenko extension tubes on my EOS. Great results as there's no glass to distort things and a cheap investment as I already had the 50mm anyway.
You can also use the extension tubes on any lens in order to improve the close focussing ability. E.g. if you're photgraphing something that will fly away if you get too close.
You can also use the extension tubes on any lens in order to improve the close focussing ability. E.g. if you're photgraphing something that will fly away if you get too close.
te51cle said:
I use a standard 50mm lens and a set of Kenko extension tubes on my EOS. Great results as there's no glass to distort things and a cheap investment as I already had the 50mm anyway.
Good point. Another way is to mount your std 50mm lens onto the camera backwards (using a reversing ring) - may sound daft but it's a known technique and works very well. If you don't believe me, hold the lens backwards against the camera body (carefully) and see what you get!
You can't do the old fashioned reversing ring technique on EOS cameras without buying an expensive convertor. As all the connections to the lens are electronic there's no way to manually stop down the lens to take the picture. When I was first thinking about macro I borrowed an old lens off my dad's Zenith. I was able to make it work on my EOS with the aid of a T2 adaptor and reversing ring. This Frankenstein's monster of a combination gave good images but was clumsy and slow to use.
The extension tubes are much more flexible giving a range of different magnifications and are much easier to use !
The extension tubes are much more flexible giving a range of different magnifications and are much easier to use !
Guys - did anyone mention the DSLR magnification factor?
Bear in mind that most (except.. errr.. a Canon D1?) will apply 1.6x magnification to any standard lens fitted. So a 28-80mm becomes 45-128, rather unhelpfully.
What does this do for macro focusing? Can we focus to the same distance, further or less? Macro doesn't seem great on my 10D with 75-300 or 17-35.
later
Rusty
Bear in mind that most (except.. errr.. a Canon D1?) will apply 1.6x magnification to any standard lens fitted. So a 28-80mm becomes 45-128, rather unhelpfully.
What does this do for macro focusing? Can we focus to the same distance, further or less? Macro doesn't seem great on my 10D with 75-300 or 17-35.
later
Rusty
pentoman said:
Bear in mind that most (except.. errr.. a Canon D1?) will apply 1.6x magnification to any standard lens fitted. So a 28-80mm becomes 45-128, rather unhelpfully.
What does this do for macro focusing? Can we focus to the same distance, further or less? Macro doesn't seem great on my 10D with 75-300 or 17-35.
Macro is about magnification, which is a combination of focal length and image distance. True macro is at least 1:1 magnification, which is a technical way of saying that an object, say a postage stamp, is the same size on the negative (or chip) as it is in real life.
Most digital SLRs have a chip that's smaller than 35mm film, which is why you get the 1.x multiplication factor becasue the image 'spills off' the edge of the chip - you just get the central part. As long as the focal length is the same, and if the distance from lens to film/chip plane is the same, then that magnification should help you get better macro results - ie a bigger image.
I think!
pentoman said:
Guys - did anyone mention the DSLR magnification factor?
Bear in mind that most (except.. errr.. a Canon D1?) will apply 1.6x magnification to any standard lens fitted. So a 28-80mm becomes 45-128, rather unhelpfully.
What does this do for macro focusing? Can we focus to the same distance, further or less? Macro doesn't seem great on my 10D with 75-300 or 17-35.
later
Rusty
This gets quite complicated. The smaller sensor of most dSLRs doesn't magnify, it actually crops edges off the image you'd get if it was full frame. The 1.6x figure tells you what lens would give you the same field of view on a 35mm camera. I.e., the view through a 100mm lens on a 300D would cover the same area as a 160mm lens on a film SLR, just as it would if you cropped a 35mm picture by the equivilent amount. However, the depth of field, magnification and focus characteristics remain the same in both cases.
In practise, a 100mm macro on a 300D will give a similar view as a 160mm macro, but with it's usual minimum focus distance and depth of field.
Hope that clears it up, but probably not!
Oh, and the 1D has a 1.3 crop.
>> Edited by srider on Friday 13th February 12:45
srider said:
This gets quite complicated. The smaller sensor of most dSLRs doesn't magnify, it actually crops edges off the image you'd get if it was full frame.
Yep, so it's not really magnification, but if you make equivalent size prints from both 35mm and most digital images, the digital one will be slightly 'zoomed in'. Hence the 1.6 etc. Heck, suck it and see!
Chim girl, whatever happened to your O-level/GCSE physics notes?!!
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