A-Mount Teleconverters Guide

by ECCL

Introduction

Most A-Mount users will be looking at a teleconverter to extend the reach of their lenses. Since there are quite a few teleconverters in the market and not many user are aware of the compatibility issue between the teleconverter and their lens, the following is an attempt to use as a quick reference guide until Dyxum website is updated with lens and teleconverter cross reference functionality.

Note: Since this is my first attempt in writing something like this, please let me know if you have any question or found error in the guide and I'll continue to update it with latest information.

Common Information

When adding a teleconverter to your lens, the effective aperture will be reduced by 1, 1.5, 2 or 3 stops and the resulting focal length will be muliplted by the factor of the teleconverter. The following list the factor, F stop loss and the resulting focal length using a 100/2 lens.

1.4X     1 stop     140/2.8

1.5X     1 stop      150/2.8

1.7X     1.5 stop   170/3.5

2X       2 stops     200/4

3X       3 stops     300/5.6

Minolta AF system requires a minimum aperture of F6.3 (except 500/8 AF) to function. If you have a lens with variable aperture such as F3.5-4.5, F4-5.6, if the smallest F stop is not faster than the minimum required aperture, AF will not function. You can always use manual focus if AF does not work. The following chart lists the aperture you should have on your original lens to get AF working in the resulting combination:

F4.5     1.4X or 1.5X TC

F4.5     1.7X TC

F4        2X TC

F2.8     3X TC

Examples:

1.4X teleconverter + 24-105/3.5-4.5: AF works because minimum aperture F4.5

1.4X teleconverter + 75-300/4.5-5.6: AF does not work because minimum aperture F5.6 is smaller than F4.5

Most 1.4X, 1.5X or 1.7X teleconverter has only 4 elements or 5 elements. While some 2X teleconverter has either 4 or 7 elements. 7 elements model is supposed to have better image quality than the 4 or 5 elements version.

Most A-Mount Teleconverters will either have 5 pins or 8 pins. Both 5 pins or 8 pins teleconverter will work with all Minolta AF lenses. However if you have a xi or D lens, or a SSM lens you should get a teleconverter with 8 pins to maintain xi or D functionality and to provide power for the SSM. Based on my observation, the number of pin does not affect AF operation including AS/SSS (Antishake). ADI flash function may be affected only if you need to use flash with your lens with a teleconverter.

5 Pin vs 8 Pin Comparison

Types of Teleconverters

There are 2 types of AF Teleconverters.

• Generic
• Matched (dedicated)

Generic teleconverters are compatible with all lenses. Matched teleconverters might be limited to a group of lenses, please read on.

Generic Teleconverters

Generic teleconverter can be used with any lenses (from fisheye 16/2.8 to 600/4 and include any lens in between). Usually a generic teleconverter has the first element flushed to lens assembly and has about 8-9mm of clearance (from the glass to the lens mount). This is good enough to physically mated with any lens.

Generic TC brands: Bower, CPC, Kalimar, Kenko, Phoneix, Promaster, Quantary, Magnicon, Rokunar, Sakar, Tamron, Tokina, Vivitar etc.

Common focal length multipliers: 1.4X, 1.5X, 1.7X, 2X

Vivitar 1.4X AF TC

Sakar 1.7X AF TC

Vivitar 2X AF TC

Dedicated or Matched Teleconverters

Dedicated or matched teleconverters are specially design for certain lenses to achieve optimum performance. There are only 3 dedicated/matched teleconverters for Minolta AF

• Minolta APO / Sony APO
• Kenko Pro 300 (Pro 300 DG) / Tamron SP
• Sigma EX / EX DG

Dedicated/Matched teleconverters are only for specific lens because the distance between the first element and the mount is much shorter than 8-9mm therefore it will not physically fit with all lenses

Minolta APO Teleconverter (1.4X or 2X)

There are 3 versions APO, APO-II and APO (D), there are lots of information regarding the Minolta APO TC on Dyxum and Minolta own website.

1. Minolta APO Original -- has 5 contact pin (for non-HS APO lenses)
2. Minolta APO II -- has 5 contact pin (for HS APO lenses)
3. Minolta APO (D) -- has 8 contact pin, will AF with SSM lenses and (D) lenses compatible.

Minolta APO teleconverters are designed specifically for certain Minolta lenses only, all of the Minolta AF Telephoto G lenses such as 135/2.8 STF, 200/2.8, 300/2.8, 300/2.8 SSM, 300/4, 400/4.5, 600/4, 200/4, 70-200/2.8 SSM etc.

Minolta APO Teleconverter has the first element almost flushed to the lens mount, the clearance is only 1mm therefore it is not possible to use Minolta APO teleconverter with other lenses.

Picture of Minolta APO 1.4X Teleconveter - II

Sony Teleconverter (1.4X and 2X)

Sony has two teleconverters, SAL-14TC and SAL-20

Both of them are similar to the Minolta APO (D) version.

Sony teleconverters also have 8 pins and are SSM and (D) compatible.

Sony webite has listed the following Sony lenses to be compatible with Sony 1.4X and 2X teleconverters:

• Sony 135mm F2.8
• Sony 70-200mm F2.8 Sony 300mm F2.8
• Sony 70-400mm F4-5.6

Sony teleconverters can also be used with with older Minolta lenses such as 135/2.8 STF, 200/2.8, 300/2.8, 300/2.8 SSM, 300/4, 400/4.5, 600/4, 200/4, 70-200/2.8 SSM

Kenko Pro 300 / Tamron SP (Same teleconverter, different name) or Kenko Pro 300 DG (Black color only)

Kenko Pro 300 teleconverter comes in 1.4X, 2X and 3X

http://www.thkphoto.com/products/kenko/slrc-01.html

Kenko Pro 300 DG teleconverters comes in 1.4X, 2X and 3X. Major difference is the DG version has digital coating applied and the teleconverter is now in black color. More information for Kenko Pro 300 DG

Tamron SP teleconverters comes in 1.4X and 2X only.

http://www.tamron.com/lenses/prod/teleconverters.asp



Kenko Pro 300/Pro 300 DG/Tamron SP are also designed for certain Minolta lenses as well as Tokina ATX and Tamron SP lenses. Again the front element of the Kenk Pro 300/Pro 300 DG/Tamron SP teleconverter sticks out about 2mm outside the lens tube therefore the total clearance from the element to the mount is only about 5mm.



Tamron SP 1.4X Teleconverter

According to Kenko website, the following lenses are officially supported:

Minolta AF lenses:

• AF85mm F1.4G
• AF100mm F2.8 Macro
• AF100mm F2.8 Softfocus
• STF135mm F2.8 [T4.5]
• AF 200mm F2.8G
• AF 300mm F2.8G
• AF 300mm F4G
• AF 400mm F4.5G
• AF 600mm F4G
• AF 200mm F4G Macro

Tokina AF lenses:

• AT-X M100 AF100mm F2.8 MACRO (IF)
• EMZ M100 AF100mm F3.5 MACRO
• AT-X300 AF PRO 300mm F2.8
• AT-X304 AF300mm F4
• EMZ 282 AF28-210mm F4.2-6.5
• AF 353 AF35-300mm F4.5-6.7
• AT-X828 AF PRO 80-200mm F2.8
• EMZ 130 AF II AF100-300mm F5.6-6.7
• AT-X340 AF II AF100-300mm F4(IF)
• AT-X242 AF AF24-200mm F3.5-5.6(IF)

I have tried the following lenses and they are compatible with Kenko Pro 300/Tamron SP Teleconverters:

• AF 50mm F2.8 Macro
• AF 100mm F2
• AF 135mm F2.8
• AF 28-70mm F2.8
• AF 35-70mm F3.5-4.5
• AF 35-105mm F3.5-4.5 restyled
• AF 35-70mm F4
• AF 70-210mm F4
• AF 75-300mm F4.5-5.6 (First model with limit switch)
• Tokina AF SD 400mm F5.6
• Tokina ATX 24-200mm F3.5-5.6
• Tokina AF SD 70-210mm F4-5.6
• Tamron SP 24-135mm F3.5-5.6
• Tamron SP 35-105mm F2.8
• Tamron XR 28-200mm F3.5-5.6
• Tamron XR 28-300mm F3.5-6.3
• Sigma 18-125mm F3.5-5.6 DC
• Sigma 24mm F2.8
• Sigma 180mm F3.5 Macro
• Sigma 300mm F4 APO TELE MACRO
• Sigma 400mm F5.6
• Sigma 400mm F5.6 APO
• Sigma 400mm F5.6 APO TELE MACRO

Note: There has been report of AF hunting issue when using Pro 300 1.4X and 2X TC with Minolta/Sony 70-200/2.8 SSM

When using the 70-200/2.8 SSM lenses and 1.4X, AF will hunt for a while and eventually lock focus. This is probably due to the fact that there is no ROM/Chip inside the 1.4X TC and the camera has difficulty determining the actually focusing point based on the focal length reported by the lens. For the 2X TC AF also hunts but it will not lock focus. MF (Manual focus) is probably a better option if your Pro 300 does not work properly.

Sigma EX Teleconverter

Sigma EX teleconverter or EX DG is a dedicated teleconverter designed for Sigma EX series telephoto and telephoto lenses:

http://www.sigmaphoto.com/lenses/lenses_tele.asp#minolta

Like other dedicated/matched teleconverter, it's front element also stick out of the lens tube. I have received some pictures of the Sigma APO EX DG teleconverters and it appears that the lens element actually stick out between 2-3mm beyond the lens mount (Special thanks to Nikola for supplying the detail Sigma TC pictures) and therefore it will not fit all lenses.

Note: Sigma has now introduced HSM lenses for Sony but according to users report the current Sigma 1.4X or 2X EX DG teleconverters are not compatible with its HSM lenses. Sigma is planning to introduce new teleconverters that are compatible with HSM lenses but the exact release date is still TBD.

Correct F Stop and Focal Length Information With A Teleconverter

If a teleconverter has an IC chip (ROM) inside, it should display the correct F stop and focal length information to the camera body and EXIF data.

Example:

• 50mm F1.4 + 1.4X TC = 75mm F2
• 50mm F1.4 + 2X TC = 100mm F2.8
• 50mm F1.4 + 3X TC = 150mm F4

Based on my observation, most 2X teleconveters (except Sigma EX and EX DG) report the correct F stop and focal length information.

For 1.4X and 1.7X teleconverter, it depends on the particular make and model. Minolta APO 1.4X, Sony 1.4X and Vivitar 1.4X TC report the correct information while some other 1.4X TC does not. Apparently some manufacturer has decided to design their TC without any IC Chip. This has resulted in incorrect information being displayed in the viewfinder and EXIF data. Other than the incorrect information, there is no issue of using the teleconverter except AS/SSS may not be as effective.

The following 1.4X, 1.7X and 2X teleconverters (partial list) do not have chip inside therefore it will not report the correct F stop or focal length information to the camera.

• Kenko Pro 300 1.4X (dedicated)
• Kenko Pro 300 DG 1.4X (dedicated)
• Promaster Spectrum 7 1.7X (generic)
• Soligor 1.4X Pro (Probably a rebadged Kenko Pro 300)
• Soligor 1.7X C/D4 AF (generic)
• Sakar MC4 1.7X (generic)
• Tamron SP 1.4X (dedicated)
• Tamron MC4 1.4X (generic)
• Sigma APO EX 1.4X (dedicated)
• Sigma APO EX DG 1.4X (dedicated)
• Sigma APO EX 2X (dedicated)
• Sigma APO EX DG 2X (dedicated)

The camera just ignores the presence of the teleconverter although you still have correct exposure since exposure is based on actual amount of light passing through the lens. You'll also notice the viewfinder is dimmer and the focusing is slower because of the reduction of light to the camera.

One side benefit of using non-chip passthrough TC is the camera will attempt to AF with a slower lens previously not possible.

Example:

75-300mm or 100-300mm F4.5-5.6 with a 1.4X TC will normally not AF, but with a non-chip 1.4X or even 1.7X TC, it will try to AF but whether it can lock focus is another story :)

Q&A Section

Which teleconverter should I buy for my lens?

All generic 1.4X, 1.5X, 1.7X or 2X teleconverter will fit ANY lenses. Majority of teleconverter owner will use it with their telephoto or telephoto zoom lenses to extend the reach. It doesn't make sense to use a teleconverter with a wide angle lens.

If your lens has a dedicated/matched teleconverter, use it, it will give you the best image quality.

Example:

Minolta APO teleconverter for Minolta G telephoto lenses, (D) teleconveter for 70-200/2.8 SSM G D zoom and Sony TC for Sony 70-200/2.8 or 70-400 SSM lenses.

Kenko Pro 300/Tamron SP if you have one of the supported lenses listed above.

Sigma EX or EX DG teleconverter for your Sigma EX lenses.

How about teleconverter for Minolta AF 50/1.7, 50/1.4?

Only generic will fit.

How about teleconverter for Minolta 80-200/2.8 APO G?

Generic or Kenko Pro 300/Tamron SP will fit.

How about teleconverter for Minolta 70-210/4 or 75-300/4.5-5.6 (Original with limit switch)?

Generic or Kenko Pro 300/Tamron SP will fit.

1.4X, 1.7X or 2X will AF with 70-210/4 but 75-300/4.5-5.6 will not AF with either 1.4X or 2X teleconverter, manual focus only. 1.7X teleconverter will AF with 75-300/4.5-5.6 lens.

How about teleconverter for Minolta 70-210/3.5-4.5, 100-300/4.5-5.6 APO, 100-400/4.5-6.7 APO?

Only generic will fit.

1.4X AF will function with 70-210/3.5-4.5

2X is manual focus only.

100-300APO and 100-400APO will not AF with either 1.4X or 2X due to slower minimum aperture at 300mm/400mm.

100-300APO or 100-400APO will attempt to AF with a non-chip 1.4X or 1.7X TC but AF accuracy depends on lighting situation.

How about teleconverter for Minolta 24-85/3.5-4.5, 24-105/3.5-4.5?

Only generic will fit.

How about teleconverter for Minolta 28-135mm F4-4.5?

Only generic will fit.

How about teleconverter for Minolta 500mm F8 reflex, mirror lens?

Only generic will fit.

Can I stack multiple teleconverter to increase the magnification?

Yes, generic and Kenko Pro 300/Tamron SP can be stacked together. Minolta APO cannot be stacked.

If you need to stack a 1.4X and a 2X it is better to get a 3X as it is lighter and yield better image quality.

Manual Focus Lens Section

Can I use manual focus lenses on my 5D/7D?

There are 2 official Minolta MD->AF adapter: 2X M/A teleconverter L and 2X M/A teleconverter S.

These adapter allows you to use a Minolta MC MD mount lens on a Minolta AF body.

2X M/A S is for lenses shorter than 300mm and 2X M/A L is for lenses longer than 300mm

Minolta 2X M/A Converter S and L Front

Minolta 2X M/A Converter S and L Back

Note that only stop down metering is possible and you must disable your camera lens lock.

There are also generic brand MD->AF adapter:

Generic brand MD/AF 9000 adapter

This has an optical element inside the adapter and allow the lens to focus to infinity. Magnification is around 1.2X so the total magnification factor will be around 1.2X + 1.5X = 1.8X so a 50mm lens become 135mm

It can be used with most Minolta manual focus lenses (as long as they can be fit together physically).

Note: There are now chipped MD-AF adapter that provide focus confirmation and also allow A200, A300, A350 and A900 to operate in A mode.

Ther are also 2 rare MD-AF adapters from Sigma that allows autofocus of MD lenses or Nikon F/AI lenses on certain Minolta AF body.

Sigma 1.6X MD/MAF adapter and Sigma 1.6X Nikon/MAF adapter. These adapter will only AF with lenses faster than F3.5

These 2 adapters achieve autofocusing by moving the lens element inside the adapter similar to the early Nikon AF TC-16A. It has 5 contact pins on the back and support full metering.

These 2 adapters were designed for the Maxxum 5000/7000/9000 camera and will not function on new AF body such as 5D/7D.

How about using other brand manual focus lens on Minolta AF body?

Generic brand adapter is available in the following mount:

• Canon FD
• Nikon F
• Olympus OM
• Pentax K
• Pentax M42 screw (Universal)
• Tamron adaptall
• T mount
• Hasselbad C F adapter
• Kiev/Pentacon adapte

Generic brand Canon, Nikon, Olympus, Pentax -> Minolta AF adapters

The Canon FD, Nikon F, Olympus OM, Pentax K adapters are similar to the Minolta MD-AF adapter, it has an optic in it to allow for infinity focusing.

The magnification factor is around 1.2X

Note that you must use a lens that has an aperture ring othewise you'll not be able to adjust the aperture. (Example Nikon F/AI not G)

Pentax M42 screw (Universal) adapter

This M42 adpater will allow any M42 screw mount lenses to be used on a Minolta AF body. Stop down metering and manual focus only.

Note there are different version of M42-AF adatper and there were some report of infinity focusing problem or physical compatiblity issue.

I am using a Made in Japan M42-MAF adapter on both 5D and 7D without any problem.

Pentax M42 screw chipped adapter

This adapter is the same as a regular M42-Minolta AF adapter but with the addition of a chip. This adapter will provide AF confirmation and also allow A200, A300, A350 and A900 to use M42 lenses in A mode.

(Chipless lenses can only be operate in M mode on A200, A300, A350 and A900).

There are 2 version of chipped adapter

1. Fixed focal length and aperture (example: 50mm F1.7)
2. Multiple focal length and aperture (Pre-programmed and user selectable, example: 28mm, 50mm, 135mm all in one chip)

More information on chipped adapter can be found in the M42 section of Dyxum.

Tamron adaptall to Minolta AF adapter:

This Tamron adpatall will allow all Tamron adaptall lenses to be used on Minolta AF body, there is no optic inside the adapter and it support stop down metering and manual focus only.

T mount adapter

This adapter allows you to use any T adapter lens on the Minolta AF body, there is no optic inside the adapter.

Stop down metering and manual focus only.

Hasselblad C F adapter

This adapter allows you to use any Hasselblad C or F medium format lens on the Minolta AF body, there is no optic inside the adapter.

Stop down metering and manual focus only.

Kiev/Pentacon adapter

This adapter allows Pentacon 6, Exakta 66, Kiev 60, Kiev 88CM medium format lenses to be used on a Minolta AF body.

There is no optic inside the adatper. Stop down metering and manaul focus only.