Help please with choice of macro lens

[Mike Buckley]

Thanks for the idea about the Tokina lens, John. I eliminated it at least temporarily because I had planned to rent some lenses from Lens Rentals (though I'm now rethinking that) and they don't rent that lens. Also, I hope to be able to ultimately purchase a used lens from one of the reputable businesses I've done business with in the past and none of those three companies currently has a used Tokina in stock.

[Mike Buckley]

Does adding an extension tube increase the minimum focusing distance (focusing plane to subject) at least as much as the thickness of the tube?

Ahhhhhhhh. Now that I understand why an extension tube works the way it does, I see that it actually reduces the minimum focusing distance.

[george013]

Does adding an extension tube increase the minimum focusing distance (focusing plane to subject) at least as much as the thickness of the tube? I assume yes, but I would like to know with absolute certainty.

It reduces the working distance for sure. Probably you mean that.
http://www.the-digital-picture.com/P...-distance.aspx

In general you can use the lens formula. 1/focal length=1/object distance+1/image distance.
Enlarging the image distance by adding extension tubes and the same focal length will make the object distance shorter. And the working distance.

Be careful with especially the cheaper extension tubes. I tried once on my lens and couldn't get it off anymore. It was blocked and had to saw it from the lens.

If you want to play with macro first, you can try a reverse ring and a cheap 50mm lens. Gives good results and you've to do everything manual. Forces you to be aware of what you do.

And of course the Raynox.
http://raynox.co.jp/english/digital/d_slr/index.html

George

[Shadowman]

Ahhhhhhhh. You just now indirectly reminded me that focusing distance is the distance between the plane of focus and the subject, not the front lens element and the subject. That would seem to eliminate my consideration of a 40mm macro lens for reasons having to do with lighting flexibility mentioned by Allan and other issues.

The R1C1 wireless close-up system helps with lighting flexibility, only downsides can only be used manually focused as it could damage the auto focus system and it doesn't take rechargeable batteries. The system comes with two SB-R200 flash heads but more can be purchased separately.

http://www.nikonusa.com/en/Nikon-Pro...ht-System.html

[DanK]

Mike,

Your note prompted me to look to see how much variation there is in MWD across lenses of a given focal length. Much to my surprise, there is quite a bit. For example, check this review, which shows that the MWD of the Tamron 90mm is very small compared to the 100mm Canons. All of my experience has been with Canon lenses, so that is what I had in mind when I referred to the MWDs I have experienced. Unfortunately, the review doesn't have any Nikors. However, it's enough to show that it would be worth your time to get the MWD for any lenses you are considering.

Re the dessicated flowers and leaves: thanks, very kind of you. I had a very busy fall and didn't do much photography, but winter is here and I have a bit more time, so I may get back to those.

Dan

[Mike Buckley]

Thank you everyone for your help in getting my thinking accurate and effectively organized. Very helpful!

I eliminated the lens that has the 2:1 magnification without renting it partly because the one negative reputation among reviews is that the throw of the focusing ring is too small, especially when working at the larger magnifications. I know the top-drawer quality of photos by one of the reviewers very well and he made it a deal breaker for him. That on its own probably wouldn't be a concern for me but I also have to take into account that I am a total klutz with absolutely no coordination. As I get older, I assume my capabilities are only going to get worse, not better. That and an overly short throw is not a good combination. Add to that that the lens has no automatic aperture, that it must focus manually even when not using it as a macro lens, and that it's not possible for the camera to "read" information about the lens and embed it in the EXIF data, and I finally came around to giving up on the possibility of the lens being a good long-term fit for me.

I ordered a used copy from KEH of the Tamron 90mm lens that has no vibration control for only $300. KEH has a reputation for rating its used equipment accurately if not conservatively and this one is rated "Like New Minus," which means that it is at 97% to 99% of the original condition, that the glass is perfect and that only the closest inspections will reveal slight wear. This particular copy comes with a case, caps and hood. KEH has a no-questions-asked, 14-day return policy and provides a six-month warranty on the lens. I also like Tamron's 3-day repair policy. This lens will probably never be in my camera bag because it will instead always stay in my makeshift studio, as that is the only kind of use I intend for it.

[Mike Buckley]

Dan,

I noticed the variation in MWD you mentioned when I manually calculated it for each lens when mounted on my Nikon body using information provided at this website. If I remember correctly, the distance of the Nikon 105mm lens is surprisingly at least to me almost twice as much as the Tamron 90mm lens. Even so, the distance of the Tamron 90mm lens is almost exactly the same as my Nikon 35mm lens that I have been using almost all of the time in my makeshift studio and often at the closest focusing distance. So, I'm reasonably comfortable that the Tamron lens will work fine for me in that regard.

Considering the price and quality of the Tamron lens that I purchased (described in my previous post), I really feel there is very little chance that the decision will prove to be a bad one. Even so, I can always return it within 14 days or I can sell it later for little or no loss of money.

[Mike Buckley]

I have now ordered the Kenko extension tubes (new) for $100. I have no idea how much I'll use them or when I'll use them the first time but I do know that when when that time comes I'll want them immediately available rather than having to order them.

[Dave Humphries]

I have now ordered the Kenko extension tubes (new) for $100. I have no idea how much I'll use them or when I'll use them the first time but I do know that when when that time comes I'll want them immediately available rather than having to order them.

I was going to suggest just getting tubes for now - and using them on your 35mm, then adding a lens later, but you ordered the Tamron first

[Mike Buckley]

I considered doing that, Dave, but I didn't want to pass up the seemingly excellent opportunity to order the used Tammy.

[loosecanon]

Note Mikes decision, but would like to add info for others to consider.

Firstly for macro up to life size Most Macro lenses willbe ok, however it is easier to work with one with internal focusing otherwise one has to keep adjusting focus and distance from subject.

As one increases magnification final focus is obtained by the camera to subject distance - so a focus rail is very helpful.

As magnification increases so the extension required increases - so you will not get 2x life size with the Kenco tube set with a 90mm lens, just look at images of Canon's super macro for 5X life size, which is in effect a 60mm lens with a built in tube set.

The problem is lighting the subject, where the front element diameter is the problem. Canon used to sell a 20mm (for 3 to 10 X life size) and 35mm (for 1 to 3 X life size) bellows lenses to go on a bellows. These are tapered at the front to give a minimum area to enable lighting. So just using a wide angle lens to give greater magnification does not help. One option with readily available adaptors is to use an enlarger lens, some of which are quite small, and can be used reversed, and are designed to give a flat field. An enlarger lens on a bellows gives a very powerful macro set up.

For those who wish to experiment you can pick up a bellows on a focus rail quite cheaply. Adapt the bellows by fixing a quality filter to seal the bellows from the camera ( they can pump dust like nothing else into a camera body). I put my filter on the FD to EOS adaptor.

[James G]

Adapt the bellows by fixing a quality filter to seal the bellows from the camera ( they can pump dust like nothing else into a camera body). I put my filter on the FD to EOS adaptor.

Now that is a REALY useful tip, I would never have thought of.
I'm just now considering a bellows rail for a project I've had in mind for a year or so....

[Mike Buckley]

Firstly for macro up to life size Most Macro lenses willbe ok, however it is easier to work with one with internal focusing otherwise one has to keep adjusting focus and distance from subject.

I wish the lens I purchased has internal focusing. Unfortunately, that capability is only on the the more expensive lens that also has VC, which I won't need because I'll always be using a tripod. On the other hand, I assume internal focusing isn't quite as important when using a tripod as when shooting handheld; when using a tripod, everything slows down, so it seems it would be less of a problem to have to also slow down to deal with the lack of internal focusing.

Yet as I evaluate the lens, if I ultimately decide not to keep it one reason could certainly be the lack of internal focusing.

[Stagecoach]

As magnification increases so the extension required increases - so you will not get 2x life size with the Kenco tube set with a 90mm lens, just look at images of Canon's super macro for 5X life size, which is in effect a 60mm lens with a built in tube set.

Not sure why this would be different on the Tamron to the Nikon non internal focusing lenses?

So I just did a check with my old Nikon 105D 1:1 macro which has the extending front element and confirmed that it will achieve 2:1 with 68mm of Kenko tubes.

[DanK]

As magnification increases so the extension required increases - so you will not get 2x life size with the Kenco tube set with a 90mm lens,

Mike should come very close to 2:1, although the precise number will depend on the lens design. All other things being equal, longer focal lengths will produce less magnification with a given extension. While Grahame got 2.1 x with his Nikor 105 and 68mm of extension, I just tried my Canon 100mm and got about 1.9 x. A 90mm should give a tad higher magnification.

As one increases magnification final focus is obtained by the camera to subject distance - so a focus rail is very helpful.

First, while the Canon MP-E 65 attains focus only by changing the camera-to-subject distance, that is not the case with many other macro lenses. I do usually attain focus by moving the camera when I am chasing bugs, but I never do in studio macro work. I use live view with at least 5x magnification and use the lens to achieve focus.

A rail is not necessary for studio work up to 2:1, although there is no reason not to use one if one prefers. I have taken countless studio macro shots and have never once used a rail to achieve focus. At higher magnifications than 2:1, it's a different matter, as if you are stacking, the increments in distance to focus between shots becomes extremely small, and for that purpose, a rail may be essential.

[Mike Buckley]

EDIT: The information in this post assumed that all lenses lacking internal focus rotate when they extend and contract. Not so. Indeed, the Tamrom 90mm macro lens that I bought lacks internal focus and does not rotate.

I always wondered how practical the dot is on a polarizer, as I have never had the need to use it despite that I almost always use a polarizer when shooting outdoors. Now that we're discussing the lack of an internal focus, I wonder if that dot could become very useful when changing the focus during the capture phase of focus stacking. Could I mark the lens with two tiny pieces of gaffer's tape to somehow note the change of focus, then use the polarizer's dot to change the polarizer the same amount in the opposite direction to ensure that the position of the polarizer is always maintained throughout the series of captures? Just wondering. Or maybe I'm better off simply adjusting the polarizer while viewing the effect during Live View each time I change the focus.

I rarely use a polarizer in my makeshift studio, which is where I'll always use the macro lens. That's partly because a polarizer won't have any effect on so many of the subjects I photograph unless I also take the time to polarize the light source, which I've never done. The other reason is that it's always possible to make a pleasing photo by controlling the light to eliminate glare. Even so, there are rare situations when using a polarizer to do that is quicker than controlling the light.

[DanK]

Mike,

I have never used a polarizer in studio macro work. I initially used the ridges on the rubber focusing ring to keep track of how much I changed focus, but at this point, it's largely habit.

Dan

[loosecanon]

re Grahame comment - of course a smaller sensor gives a greater manification - both with the lens and when extended.

[DanK]

of course a smaller sensor gives a greater manification

No, it doesn't. A 1:1 lens will provide 1:1 magnification regardless of the size of the sensor. A 1 cm square object will cast a 1 cm square image on the sensor, regardless of the sensor size. The size of the image is a function of the optics, not the surface the image is projected onto.

However, sensor size does affect framing. A 1 cm square object will occupy a larger share of the sensor if the sensor is small, but only because the frame is smaller.

Does this matter? Not necessarily, because you can crop the image from the larger sensor. What does matter is pixel density, and smaller sensors often have higher pixel density. When that is the case, cropping the image from a larger sensor to the dimensions of the smaller sensor will leave you with fewer pixels on the subject. This is not a function of sensor size itself; it is entirely a result of differences in pixel density that often accompany differences in sensor size.

It's for this reason that I do almost all of my bug macros with a crop sensor camera, even though my full frame camera is newer and in other respects superior to it. My crop-sensor camera, a 7D, has 18 MP. My full-frame camera has 22 MP. If you do the arithmetic, you will see that the full-frame image, if cropped to the 7D sensor dimensions, has only about 48% as many pixels on a subject of any given size.

[rpcrowe]

Just a thought... I "think" that there are occasionally some older, manual focus Nikon macro lenses available, used, on eBay at decent prices. I don't remember which Nikkor lenses fit which Nikon cameras, so I cannot give better advice than to peruse eBay for older Nikon lenses and see if there any at good prices that will fit your camera.

Here's one: http://www.ebay.com/itm/Nikon-Micro-...0AAOSwvzRXze-G

I most often use manual focus when shooting macro, so lack of AF would not be a deal breaker for me.

Note: If you desire to combine the 90mm Tamron Macro with a tele extender, you might need to add an extension tube. This is true with adding a Canon 1.4x TC to the 90mm Tamron on my Canon but, I don't know about a Nikon combination.

Piggy backing on the comment above. When shooting at a 1:1 ratio, the largest area that a crop Nikon format will cover is about: 23.6mm x 15.7mm. That certainly is not a large area...