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Old Jul 24, 2007, 6:33 PM   #1
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Today I received a Kiron 105mm 2.8 lens and am raring to try it out(well I have played a little:-)).I think (?) I figured out how to get exposure..option in Custom for Aperture permiited..use it in Manual mode..use AEL button to get proper metering from the camera. My question is from what I read a true macro lens will give you a flat image across the screen when doing close-ups..is this true? I cannot get this and am wondering why? Also for 1:1 I almost have to get on top of the subject..is this the norm?Sorry for so many questions but I have not had much experience using a manual lens on this camera yet and after admiring the wonderful macros on this forum I know there are quite a few experts out here.Thanks so much in advance!
lisa
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Old Jul 24, 2007, 7:41 PM   #2
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Hi Kashka,
I also have this wonderful lens under the Lester A Dine name. I will take a stab at answering your questions in no particular order. :-) First of all, yes, to get 1:1 macro you will be very close to your subject, a few inches between subject and the front of the lens. Your lens should be marked with 1:1, 1:2, 1:4 settings, as you move smaller you will gain more focusing distance between yourself and the subject.

My Kiron does give a pretty flat focusing field, remember that it will be very thin at wide apertures. For most macro shots I am stopped down to f8 or smaller to get enough DOF.

Finally, does your lens not have the electric contacts (KA mount)? Mine does, so it can be used in Av mode with no need to use the AE Lock button. I thought I read that all of the Kiron 105mm macros were KA mount, but I could be wrong.

I hope something in there helps, looking forward to seeing your macros.

Tim
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Old Jul 24, 2007, 7:42 PM   #3
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Hi Lisa,

First of all, congrats on the Kiron 105 -- I don't have one, but it's a very nice lens.

All dedicated macros will give you a pretty flat field of focus across the image, but the depth of field will be very thin, so your field of view must be pretty exactly parallel to the sensor plane for everything to be in perfect focus. One thing that most macro shooters do is try to maximize the DOF by using very small apertures -- like f16 and smaller, though you need to realize that past f22, you'll probably see a decrease in sharpness due to diffraction. Because of this, diffused flash can be your friend, especially if you can use it off-camera. Another flash alternative is ring flash that surrounds the opening of the lens.

The working distance is going to be pretty short at 1:1, but that's the nature of the beast and most alternatives for shooting macros (like achromatic closeup lenses and macro converters) will probably require that you are even closer. Be consoled by the fact that shorter macros, like the 50mms require that you shoot at about half the distance as the 100mms, and longer ones, like the Pentax A* or FA*200 f4 macros are relatively huge, and would cost you @ $2000 -- that is, if you could find one.

Good luck with the macros -- it'll take some work, but hopefully it will be worth it.

BTW, I'm no macro expert, still working at getting reasonably competent at this. . . but I hope this gives you at least a start.

Scott
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Old Jul 24, 2007, 7:45 PM   #4
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sounds like you've got a good start.

not sure what you mean by "flat image". if your subject is flat (such as a document or picture) a true macro lens should give a "flat" image, ie one without distortions at the edges etc. but close up anything with anythickness at all requires a very small aperture just to get a tiny depth of field. sometimes you have to play with the dof to find what's important to be sharp as a lot of the picture (and maybe some of the subject) will be blurred. it helps also to line up the camera with the plane of the subject (if possible).

yeah at 1:1 i'd guess you'd be pretty close to the subject. this summer i've been using an M 135mm with extension tubes and with all my tubes i'm at very nearly 1:1 at about 14.5 inches. i rarely use all the tubes at once so i'm usually a little further away. your lens should be a little closer than mine at 1:1 because of it's shorter focal length.

have fun with your new lens!

all the best, eric


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Old Jul 24, 2007, 7:58 PM   #5
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Thank you so much for the very helpful advice! I guess sneaking up on the bees is going to be challenge...:-)..Along with Eric's reply I see now that I misunderstood the term of flat image across the field. I thought it meant everything would be in perfect focus but I see now I have to try to line up with the plane of the subject. And practice ..practice..practice! It just kind of threw me off when it didn't meter or show an aperture so I guess when you set the ring to the aperture you want.. it meters the shutter speed needed, after pressing the AEL button.There are no electrical contacts so I guess I will really buckle down and learn manual better...lol.I really love macro...and learning so this will be fun i think..and perhaps a little frustrating but one can't have everything easy,eh.Again thankyou for the replies and advice .It's so nice to have such a wonderful forum with such a great bunch of helpful people.
lisa
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