AK Grandpa Loc: Anchorage, AK

If I put my 1.4 tele-extender on my Nikon DX 40 mm / 2.8 micro (macro), does that then make it a now a 56 mm macro (effectively 79mm) ?

I understand that I'll loose an f-stop . . .

Are there any advantages to doing this?

robertjerl Loc: Corona, California

First, check to see that it will fit without any damage (ie: do any elements protrude enough to touch and do damage?)

I use a Kenko Pro 300 on a Tamron 180 macro often, then when put on my 7DII that gives me 403 mm angle of view, I use it for birds and bugs. The image quality is still very good.

Yes you lose an f stop, it will still be and f/4, not bad.

More reach, stay further from subject, useful if an insect or something that could scratch the lenses, you are not putting the lens right up to it.

Nikonian72 Loc: Chico CA

I invite you to drop by the UHH section entitled True Macro-Photography Forum at http://www.uglyhedgehog.com/s-102-1.html
We have several expert MPs who can discuss the pros & cons of TCs with macro lenses.
I also suggest that you read: FAQ: Extension Tubes vs Bellows vs Tele-Extenders vs Add-on "Close-Up" Diopter Lenses at http://www.uglyhedgehog.com/t-26496-1.html

rwilson1942 Loc: Houston, TX

I regularly shoot macro with a Sigma 1.4X TC on my 180mm Sigma macro lens.
Gets me ~1.5:1 at minimum focus distance.
As I understand it not all TCs are compatible with all lenses so be sure to check for that.

blackest Loc: Ireland

My Tamron sp90 is 2:1 on its own but there is a 2x teleconverter or an extension tube to bring it to 1:1

I have a 1.5 teleconverter and that is quite useful for photographing 35mm negatives on a crop sensor camera with the sp90 as it scales the negative image to just fit on the crop sensor.

Nikonian72 Loc: Chico CA

This statement makes no sense. The Tamron SP 90MM F/2.8 Di VC USD achieves 1:1 magnification at Minimum Focusing Distance. View Tamron's lens description here:
http://www.tamron-usa.com/lenses/prod/90_vc_f004.php#ad-image-0
Adding a TC or extension tubes would increase magnification beyond 1:1.

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

No.

blackest Loc: Ireland

wrong sp90

http://www.pentaxforums.com/userreviews/tamron-adaptall-2-sp-90mm-f-2-5-52b.html

The version you are referring to is a f2.8 the one I am referring to is a f2.5

Specifications: 52B; 52BB
Focal Length (mm) 90
Aperture: f2.5 - f22
Field of view: 23deg horizontal full frame; 14.9deg APSC sensor.
Optical construction (elements / groups): 8/6
Coatings BBAR Multi layer
Minimum focus distance (from film/sensor plane) 39cm
Focus throw: ~360deg; ~330deg
magnification ratio 1:2
filter diameter: 49mm; 55mm
"length ( at infinity): 66mm; 74mm
maximum diameter: 64.5mm
"weight" 440g; 410g


There are a couple of variations with 49mm and 55mm filter rings sorry for the confusion.

Kmgw9v Loc: Miami, Florida

The lense is not compatible with the TC .

martinfisherphoto Loc: Lake Placid Florida

In your first reply, You stated your camera started at 2:1 and went to 1:1, while in fact your lens starts at 1:2 and goes to 1:1 with extender, big difference in the macro world. Simply mis type error....

blackest Loc: Ireland

Ok so left is object size and right the image size

i'm still not 100% on how this ratio works to be fair

is 1:2 eg 5mm object 10mm on sensor or 2.5mm?

or is the latter 1:0.5 ?

martinfisherphoto Loc: Lake Placid Florida

1:1 equals life size 2:1 equals two times life size 1:2 equals half life size

blackest Loc: Ireland

So look at them like fractions

e.g 1/1 2/1 1/2 (life size)

Thank you you taught me something.

ballsafire Loc: Lafayette, Louisiana

Let's see: Using the proper words ---
Tele-extender or Tele-converter (T.C.) = is a lens on front of a "regular" lens, ex. 1.5, 2x. etc.
Extension tube = a hollow tube between camera and lens - ex. 12, 20, and 36mm tubes with electrical or non-electrical connections.
Diopter = is like holding a magnifing glass in front of your lens.

I know this is a simple explanation but easy to sort out. Also: 1:1=life size; 2:1=twice life size; and 1:2=half life size.

amfoto1 Loc: San Jose, Calif. USA

It actually does make sense (except, yes, it's 1:2, not 2:1).

Tamron has been making SP 90mm macro lenses for more than 30 years and there have been a number of different version... several manual focus and several autofocus. The Tamron SP 90mm is a "cult classic" macro lens.

Several versions of earlier, manual focus Tamron 90mm SP macro Adaptall lenses were 1:2 on their own and came with a matched 1:1 adapter/teleconverter that looks like a standard teleconverter, but actually isn't. The 1:1 adapter fits between the interchangeable Adaptall mount and the lens body, so is only usable with this or other Adaptall-series lenses. In case you are unaware, Tamron's Adaptall system allows easy swap of the bayonet mount on lenses (all manual focus and mechanical aperture control), so that they can be used on a very wide variety of different manufacturers' cameras.

I have one of these lenses, along with Adaptall mounts to be able to use it on Canon EOS/EF, Canon FD, Nikon F, Konica K/AR, Pentax P/K and Olympus OM cameras. I also have the matching 1:1 adapter, but never use it. Instead I use standard macro extension tubes to increase the magnification of the lens, since those tubes are usable with all my other lenses in that mount, too.

Here's my Tamron SP 90mm with an EOS Adaptall mount installed and a Nikon Adaptall alongside (left) and the lens mounted on one of my Canon DSLRs (right)...


Here's a shot taken with that lens (with 20mm extension tube, if memory serves)...


The Tamron SP 90mm Macro manual focus/Adaptall came in a couple f2.5 versions initially, then in one or two f2.8 versions.

Current and recent autofocus Tamron SP 90mm have all been capable of 1:1 without any adapter. AFAIK, all the autofocus versions have been f2.8 lenses.

The latest and greatest of the modern autofocus versions is the Tamron SP 90mm "VC" and "USD"... stabilized and faster/quieter ultrasonic focus drive... it's also now an "IF" or "internal focusing" lens.

They still offer the SP 90mm non-VC, non-USD, non-IF version as a lower cost alternative.


None of this addresses the OP's questions about using a 1.4X on that 40mm Nikkor.

Don't have that lens, so I don't really know. Nikkor teleconverters.... probably not. (I know Nikon has a teleconverter compatibility list online, which you can check.)

Third party TCs... maybe. I'd look at the Kenko, in particular. They have two or three series, at different price points: "Pro 300" are their higher quality, "MC-4" are lower cost... and I think a new "HD", don't know how those compare.

However I would recommend trying a 2X, instead of 1.4X. Combined with a 2X you'll have a more useful effective 80mm f5.6.... Personally I don't think 1.4X to make a 56mm f4 is worth the trouble, not enough "longer" than the 40mm itself.