Photoclubalpha

Ive never thought I would have this problem although maybe a blessing? I got the 100mm 3 weeks ago. 2 weeks ago I got the 50mm for dirt cheap. Is it an overkill to have both? Do I need to sell it seeing that I am still a student in need of cash?

I have a 16-80 and a 70-210.

They do have different uses, especially when you are out of the macro range and using them for portrait or landscape work. Then the difference in focal length becomes much more obvious.

David

I remember researching these for myself and found the 100/2.8 to be the winner. It has the longest working distance of all the f/2.8 macro lenses (The Cosina 100/3.5 is longer) and has the most appealing aperture with nine circular aperture blades. Personally, I'd keep the 100/2.8, but then if the 50/2.8 didn't cost you much then it can't be costing anything just to hang onto it for a while. Use them both and find out which you prefer.

henniebez wrote:Ive never thought I would have this problem although maybe a blessing? I got the 100mm 3 weeks ago. 2 weeks ago I got the 50mm for dirt cheap. Is it an overkill to have both? Do I need to sell it seeing that I am still a student in need of cash?

I've had both, and decided to sell the 50/2.8 after I got the 100/2.8. The 50/2.8 is sharper at the center at just the right aperture, but the 100/2.8 is sharp corner to corner anywhere from f/2.8 to about f/11 or so.

From a practical viewpoint, the real difference is in working distance though. At 1:1, your working distance with the 50 is a couple of inches, but with the 100 it's around a foot. Especially for pictures of things like insects, that makes a huge difference.

Most people who own only one macro lens use a 90 mm, 100 mm, or 105 mm lens. Also the Sigma Macro 150 mm 1:2.8 EX DG is pretty popular. These focal lengths are the most versatile. In particular they are very good for outdoor shooting, be it plants, flowers, landscape detail at all scales, or critters. It also can be used for portraiture.

The 50 mm lens is more like a specialist's lens. It is most useful for all kinds of copy work, e. g. to shoot photographs, stamps, documents, and (surprisingly often) paintings and other artwork. These days, many artists need to get their work on the Internet, and you can't just slap an oil painting on the flatbed scanner! So to copy with a DSLR camera and a 50 mm macro lens is the natural thing to do. If you do any of these kinds of work, be it often or occasionally, then you'll love the Macro 50 mm. If not then you'll love the Macro 100 mm more.

Anyway, I second Kevin's advice: Don't be too quick at selling good lenses! Even when you find yourself using the 50 mm rarely---it didn't cost you much, it doesn't consume food, so keep it. Sooner or later you'll be happy to have it.

-- Olaf

Correct me if I'm wrong ... but both lenses are giving you 1:1 magnification ratio. yes the 100mm give you almost the double of distance from the subject to the front lens element (easier for insect and subject who don't like when you are to near from them), but the 50mm at equivalent ratio will give you more depth of field ... And in macro depth of field is the inverse of when you are doing portrait, there is never enough There is a little bit difference in view angle too ... depending of the effect you are searching for.

I'm supposed to received two copy of 50mm 2.8 Macro (the RS , and the older one) , I will do some test shot. In the past I had the 50mm 2.8 first and did a lot of macro with the Minolta 7D and A700 with impressive and very good result. But I decided to switch to the 100mm 2.8 and sold the 50mm. But, with the A900 now... I'm trying to experiment again with the 50mm to see the result.

regards,

Frank

InTheSky wrote:Correct me if I'm wrong ...

Yeah ...

InTheSky wrote:... but both lenses are giving you 1:1 magnification ratio. Yes the 100 mm give you almost the double of distance from the subject to the front lens element [...], but the 50 mm at equivalent ratio will give you more depth of field ...

No, it won't. At 1:1 and the same aperture, both lenses will yield the same depth-of-field.

-- Olaf

"Fortunately" I know very little about macro, but as of late I have been playing around with the 200 f/4 from Minolta and the Twin Flash. I think I like this lens over the 100 and 50. Seems to me the 200 has a much longer working distance and is every bit as sharp and bokeh is unique to older Minolta lens coatings.
AJ

01af wrote:[
No, it won't. At 1:1 and the same aperture, both lenses will yield the same depth-of-field.
-- Olaf

Well, unless the lens manufacturers have changed specs over the last few years....
Here's the DOF figures for the 50mm and 100mm Macro lenses from olden times...
THEY ARE NOT THE SAME

01af wrote: The 50 mm lens is more like a specialist's lens. It is most useful for all kinds of copy work, e. g. to shoot photographs, stamps, documents, and (surprisingly often) paintings and other artwork.

I'm wondering if (thin) extension tubes would make a 50mm f/1.7 more useful for copy work where you want to be a little closer than the minimum focus for that lens. I can't find my tubes at the moment to try.

Also, I came across this crazy DIY idea for extreme macro which was quite amusing.

Harvey

Cogito wrote:

01af wrote:At 1:1 and the same aperture, both lenses will yield the same depth-of-field.

Well, unless the lens manufacturers have changed specs over the last few years ...

You mean, they have changed the laws of physics?

Cogito wrote:THEY ARE NOT THE SAME

They are.

harvey wrote:

01af wrote:The 50 mm lens is more like a specialist's lens. It is most useful for [...] (surprisingly often) paintings and other artwork.

I'm wondering if (thin) extension tubes would make a 50 mm f/1.7 more useful for copy work where you want to be a little closer than the minimum focus for that lens. I can't find my tubes at the moment to try.

With an extension tube, you'd be able to get closer indeed but the image quality will suffer significantly---in particular for copy work where good corner sharpness and a flat field are important. Better use close-up lenses on a non-macro lens. With high-quality double-element achromatic close-up lenses on your 50/1.7 lens you'd get an image quality that's almost up to a real macro lens (however not the same maximum magnification).

harvey wrote:Also, I came across this crazy DIY idea for extreme macro which was quite amusing.

The, umm, design is crazy but the optical principle behind it is not. That exactly is the proper way to achieve very high (beyond 1:1) magnification. Just replace the piece of cloth with a reverse ring and the 'Pringles' tube with a bellows unit.

-- Olaf

Olaf I've been having a look at the Minolta specification sheet that came with my AF100mm f/2.8(D) Macro and in it it lists the DOF tables for both Macro lenses.

At minimum focus (1:1) of 0.352m/1ft 1.86in the 100 macro @ f8 has a DOF of 0.352m/1ft 1.86in for both near and far, (ie. less than 1mm), it doesn't get a DOF of 1mm until you stop down to f16.

At minimum focus (1:1) of 0.200m/7.87in the 50 macro @ f8 has a DOF of between 0.201m/7.91in and 0.200/7.87in (ie. approx 1mm), @ f16 it has a DOF of approx 2mm.

Those are the figures listed in the table, so I'm not following what you are saying that they both have the same DOF at 1:1...can you elaborate?
Greg

Greg Beetham wrote:I've been having a look at the Minolta specification sheet that came with my AF100mm f/2.8(D) Macro and in it it lists the DOF tables for both Macro lenses. [...]

Those are the figures listed in the table ...

And therein lies the problem. Those values are rounded figures, and depending on exactly how you're doing the calculations, your results will give or take a millimeter or two. So don't take those tables as gospel.

As a matter of fact, the AF Macro 100 mm has a pupil magnification which is significantly smaller than the AF Macro 50 mm's. So at 1:1, the depth-of-field actually is slightly wider (!) with the 100 mm lens than with the 50 mm. However the difference is just a few micrometers so that's purely academical. For practical intents and purposes, DOF at 1:1 is the same with both lenses (approx. 1.1 mm at f/8 on 35-mm format).

-- Olaf