big d Loc: Rossendale Lancashire

Hi looking for a 1.4 sigma convertor to pair up with my 120-300 sigma f2.8 lens. I have been offered an Ex 1.4 APO . Most of the convertors I have seen for sale or 1.4 ex APO DG ! I wonder would the 1.4 convertor without the DG coating be designed for film lenses? And would it have any detrimental effect(s) being used on digital cameras? Thanks in advance for your answers.

RWR Loc: La Mesa, CA

Either one is fine for digital, the DG denotes Sigma's new lens coating. See:

http://www.bhphotovideo.com/c/product/390165-USA/Sigma_824306_1_4x_DG_EX_APO.html

amehta Loc: Boston

For lenses, "DG" means "(digital) full frame", while "DC" means "APS-C". I doubt this is a "new" lens coating. :-)

joer Loc: Colorado/Illinois

Play it safe and get the 1.4X Teleconverter EX APO DG.

oldtool2 Loc: South Jersey

I use the Sigma 1.4X EX DG TC with my Sigma 120-300mm f2.8 lens. In fact it is mounted to that lens 75% of the time. It maintains AF and works very well with that lens, giving you a 168-420mm f4 lens.

http://www.adorama.com/SG14XEOS.html

If you find that one a little expensive look at this TC made by Tamron. It also works well.

http://www.adorama.com/SG14XEOS.html

For the $25.00 difference I would stay with the Sigma though. Whenever possible you are better off staying with the lens manufactures TC. If I can't then I usually go the Tamron. I have yet to find a lens it doesn't work with.

Jim D

imagemeister Loc: mid east Florida

Most, (not absolutely sure about Sigma) camera manufacturers TC's are optimised for PRIME lenses 300mm and longer - which is why a Tamron SP 1.4X may be just as good or better on that lens. I use the Tamron with my Sigma 100-300 f4 with superb results - it NEVER comes off- unless I absolutely need the f4 aperture !

RWR Loc: La Mesa, CA

The Sigma 1.4x DG EX APO Tele Converter (also known as a tele-extender) will multiply the focal length of your existing Nikon lens by 1.4x, and will cut back the amount of light by one f/stop. For example, using a 1.4x teleconverter with a 300mm lens will effectively increase the focal length to 420mm. A lens set to f/2.8 will now be f/4.

Note: Sigma APO Tele Converter 1.4x and 2x are dedicated teleconverter lenses. Due to the high optical quality of this teleconverter, this item will only fit and work with a select list of Nikon lenses. Please click here for a compatibility chart of all compatible lenses.

The DG denotes added coating that achieves the best color balance while cutting down on ghosting caused by reflections from the digital image sensor

Edit: This from the overview on B&H website.

jpsassy1965 Loc: Sahuarita, AZ

DG stand for Sigma line for full frame lenses and DC stands for Sigma APS-C line of lenses. Has nothing to do with lens coating. Go to the Sigma website and look it up.

joer Loc: Colorado/Illinois

It is a direct copy from the Sigma website.

RWR Loc: La Mesa, CA

Exactly. Clearly says that "DG" refers to the lens coating. In one review of the Sigma 70~300, the DG version was said to have better IQ than the D version, due to this coating.

GTinSoCal Loc: Palmdale, CA

Something from Sigma

Some Sigma lenses are designated "DG". What does this mean?
The DG designation applied to most newer Sigma lenses indicates that the lens is especially suited for use with digital SLR cameras. The DG lenses feature improved (more even) light distribution from image center to edge, and incorporate the latest multi-layer lens coatings to avoid reflections of the sensors of digital cameras. This is important in digital photography, but is also useful in 35mm photography, especially when slide film is used. Lenses designated as DC are designed exclusively for use with digital cameras having APS-C size image sensors. They feature smaller image circles and often feature shorter focal lengths (e.g. 10-20mm DC, 17-70mm DC, 18-50mm DC, 18-200mm DC, etc.). The shorter focal lengths are desirable, because most digital SLR cameras have image sensors whose dimensions are considerably smaller than a 35mm negative (usually by a factor of 1.3X to 2.0X), making the lens’ angle of view equivalent to that of a longer lens on a 35mm cameras.

GT