I was thinking about this while I was out and about today... I attached my contact-less Tamron 2x TC to my Tamron 70-300 lens, and set the aperture to f/22. Sure enough, the VF was dim, but not so dim as to prevent me from focusing properly.
Most lenses made within the last 30-40 years (even manual focus ones) maintain automatic aperture, meaning that the aperture stays at f/2 (or whatever the max aperture is) until a moment before the shutter opens. Then the aperture lever stops down the aperture for proper exposure. This is sometimes true even when using old lenses on modern DSLRs...for example, the Nikon D300 can offer auto-aperture in A and M modes with most older Nikkor manual focus lenses.
If you lose all contact with the lens (whether it be mechanical or electronic), the lens will not stop down by itself before the exposure and you must stop it down to meter.
Try this on your DSLR: set a lens to f/22 and press the DoF preview button. That's how dark the viewfinder looks at f/22. It's even a bit darker for macro b/c of the close subject distance reducing the effective aperture of the lens.
Being an old junkie from the film single l reflex days, I sure remember how that step lens down stuff was done.
And while you could view the brighter non stepped down image until the moment of exposure, once you pressed the shutter, this little dohickus engaged, pressed a pin on the lens itself, and steeped down the lens to whatever aperture you had preselected. And once actual exposure had been accomplished, the dohickus retracted and once again the view was at wide open lens aperture.
Sadly, as everything has gone electronic in digital SLR days, I very much wonder if that dohickus function would have been better be retained. It was simple, effective, and cheap. Why did we lose such a marvelous mechanism?
interesting mod!!! Would I still need to mod the lens for my Cannon Rebel XS DSLR?
Being an old junkie from the film single l reflex days, I sure remember how that step lens down stuff was done.
And while you could view the brighter non stepped down image until the moment of exposure, once you pressed the shutter, this little dohickus engaged, pressed a pin on the lens itself, and steeped down the lens to whatever aperture you had preselected. And once actual exposure had been accomplished, the dohickus retracted and once again the view was at wide open lens aperture.
Sadly, as everything has gone electronic in digital SLR days, I very much wonder if that dohickus function would have been better be retained. It was simple, effective, and cheap. Why did we lose such a marvelous mechanism?
Buy a cheap older Nikon manual focus prime lens (50mm, 35mm, 28mm) and a reversing ring. Hacking yourself a cheap 1:1 macro setup isn't hard for any brand of camera. Just beware of the usual limitations: manual focus (typically by moving the camera back/forth), very short working distance, you need to stop down the lens quite a bit to get decent depth-of-field, and the whole process almost necessitates a tripod or set of macro-focusing rails.
If you want a point-and-click macro setup, you're still better off with a macro lens.
Most dedicated macro lenses will not reach 1.71x unless several extension tubes are stacked behind them, which makes this feat even more impressive on a $40 modded zoom lens.
I thought most dedicated macro lenses do at least 1:1, with extension tubes going beyond 1:1.
I thought most dedicated macro lenses do at least 1:1, with extension tubes going beyond 1:1.
Just got it in the mail a few minutes ago. I have a shaky tripod, my wife was walking around, and poor lighting. I'll try to do better later. Anyway, can you guess what this is?
I just want to add that if you do decide to go this route, get the manual focus 55mm Micro-Nikkor f/3.5. It's a real macro lens (1:2) that will mount on any Nikon DSLRs (AI version) without need for any reversing rings. Everything jpeyton said above is true about its limitations, but it's one of the sharpest lens I own.
Bread?
It's the top of a salt shaker. You can see the metal, holes, some salt, and some corrosion. This lens is pretty slick!
Is that a salt shaker you currently use? lol
To 996GT2,
You are somewhat my hero as you have motivated me to get such a lens. And since your original post on 2/17/2010, you have probably otherwise inflated the ebay market because everyone and their brother in law now wants one.
I have somewhat held my peace until today, when I oh happy day, I got one of those EF 35-80 mm lens that fully works for $30.00 shipped. Not here yet, but within a week.
Now my dilemma starts.
(1) Like most people, I have a canon digital camera with the kit 18-55 mm kits lens. And for my type needs, the 35-80mm lens sounds like a better walk around lens for my needs. And like many others that like wildlife photos, I also have a 70-300 mm EF lens to reach out at distance. Would be nice to have L quality lens, but like many others, there are champagne tastes and beer pocketbooks.
(2) In Indiana, its many months before insect season will start. And therefore as a patient man, my next project is to knock down another such 35-80mm lens cheap, and then take the lens that does the worst job at automatic focusing and do the mod you are talking about.
(3) And now we are talking about the newbie factor as I am totally baffled at your set of instructions. As you, mumble something about removing the front lens decal, what lens decal?, then removing some screws, what screws?, and then removing one, two, or three front lens elements how?. And are these modifications reversible? In short, if I screw up, I only waste my money.
Therefore, can you please please post some step by agonizing step photo's
--------------------------------------------------------------------------------------------------I'll be searching CL and Ebay for these now I guess. Darnit, more money to spend on something I didn't need 'till I found out it existed