Kenko DGX 2x Teleplus Pro 300 with 60D

Started Jan 27, 2013 | Discussions
SmallTownUSA
Forum MemberPosts: 52
Like?
Kenko DGX 2x Teleplus Pro 300 with 60D
Jan 27, 2013

Hi Guys: I always get good advice from this forum, so here is another request. I have a Caon 60D and would like to get an extender. I realize there will be some issues associated with an extender, but would still like to extend the range on my 100-400L USM lens. The reviews I have read basically suggest I stay away from Canon. There appears to be some good words for Kenko DGX. I would consider either the 1.4x or the 2.0x.

Any advice/suggestions would be greatly appreciated.

Thanks,

Harold

Canon EOS 60D
If you believe there are incorrect tags, please send us this post using our feedback form.
tonyjr
Veteran MemberPosts: 5,156Gear list
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to SmallTownUSA, Jan 27, 2013

I like my canon 2 X III , but it will not fit on most of my lenses . It does a better job on my 70-200 than others .

If you can , try out in a camera store - I use the wall where film is displayed .

Otherwise , order from 2 or 3 companies that have good return and send back what you don't like .

I pay a little more , but can try out in a camera store and I do pay more just because I like to test and don't think it is really that much more when you figure in my time and gas to post office .

 tonyjr's gear list:tonyjr's gear list
Canon EOS 400D Canon EOS 7D Canon EF 35mm f/2.0 Canon EF-S 10-22mm f/3.5-4.5 USM Canon EF-S 17-55mm f/2.8 IS USM +14 more
Reply   Reply with quote   Complain
OhioBob
Regular MemberPosts: 303Gear list
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to tonyjr, Jan 27, 2013

With any 2X teleconverter you will lose auto focus on a 100-400. Some have reported using the DGX 1.4 and still auto focusing in good light. My 7D with canon 1.4 and 100-400 hunts badly unless very good light and high contrast subject.

 OhioBob's gear list:OhioBob's gear list
Canon EOS 7D Canon EF 50mm f/1.8 II Canon EF 85mm f/1.8 USM Canon EF-S 17-55mm f/2.8 IS USM Canon EF 100-400mm f/4.5-5.6L IS USM +6 more
Reply   Reply with quote   Complain
Jim A
Regular MemberPosts: 237Gear list
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to OhioBob, Jan 28, 2013

I use the canon 1.4x II. You can tape the pins or use live view.

-- hide signature --

Jim :^)

 Jim A's gear list:Jim A's gear list
Canon PowerShot SD990 IS Olympus C-5050 Zoom Olympus C-8080 Wide Zoom Olympus E-20 Canon PowerShot G12 +20 more
Reply   Reply with quote   Complain
KentG
Veteran MemberPosts: 3,693
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to SmallTownUSA, Jan 28, 2013

Well the Canon TC will give you better optical performance but in many cases will not allow you to do AF, which admittedly will be very marginal anyway (that is where taping the contacts can make it AF). Even with a 3rd party TC the 60D will not AF reliably even with a 1.4x TC because the effective f-ratio will be F8 and the 60D unlike some of the pro bodies does not have AF sensors capable of AF at F8. It is limited to F5.6 (although F6.3 will work).

Personally the 100-400 is not great at 400mm(it is good however) and adding a TC will make it worse in all cases, with a 2x being the worst of all. Remember TC s are designed to be used on either F2.8 lenses (1.4x and 2.0X) or F4 lenses (1.4x only). That is so the effective maximum aperture is no worse than F5.6 which is well within the camera's abilities.

In my film days I carried both 1.4x and 2x TCs with me in my bag but over decades I could count the number of times I was willing to put up with the reduced IQ of the 2x on the fingers of one hand, even when using a 300/2.8. I found the 1.4x was useful many times but not always.

Kent Gittings

Reply   Reply with quote   Complain
Steve Balcombe
Forum ProPosts: 10,780
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to SmallTownUSA, Jan 28, 2013

SmallTownUSA wrote:

Hi Guys: I always get good advice from this forum, so here is another request. I have a Caon 60D and would like to get an extender. I realize there will be some issues associated with an extender, but would still like to extend the range on my 100-400L USM lens. The reviews I have read basically suggest I stay away from Canon. There appears to be some good words for Kenko DGX. I would consider either the 1.4x or the 2.0x.

If you've already researched this and you know that there will be issues but still want to go ahead, then the Kenko DGX is a good choice. "Stay away from the Canon" seems pretty strong given that they are optically excellent and better built than the Kenko, but the Kenko does have some practical advantages - no need to tape pins and it fits any EF lens - and of course it costs much less.

I definitely would not get the 2x. Apart from IQ issues, you will struggle with focusing. The Kenko bypasses the camera's ability to disable AF above f/5.6 but it can't make the AF sensor work any better than it was designed to. You might get away with the 1.4x (f/8) but the 2x gives you an f/11 lens. AF simply won't function, and manual focus through an f/11 lens (especially with a crop camera viewfinder) is pretty difficult.

Another point to bear in mind is that being limited to f/11 will mean using a slower shutter speed and /or a higher ISO speed to compensate, either of which can affect image quality. And camera shake is twice as bad with a 2x TC. So while test chart shots in ideal conditions will show a definite benefit from using the TC, in the real world the practical difficulties tend to negate this.

Reply   Reply with quote   Complain
bluestreakrem
Regular MemberPosts: 144
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to Steve Balcombe, Jan 28, 2013

Steve Balcombe wrote:

I definitely would not get the 2x. Apart from IQ issues, you will struggle with focusing. The Kenko bypasses the camera's ability to disable AF above f/5.6 but it can't make the AF sensor work any better than it was designed to.

What is the problem with AF above f5.6?

You might get away with the 1.4x (f/8) but the 2x gives you an f/11 lens............ AF simply won't function,.................. and manual focus through an f/11 lens (especially with a crop camera viewfinder) is pretty difficult.

Why won't the AF function at f11?

Sorry if my questions are beginner in nature.  I'm still trying to understand this stuff.

Thanks in advance to those that educate me.

Reply   Reply with quote   Complain
Flying Fish
Veteran MemberPosts: 3,997
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to bluestreakrem, Jan 28, 2013

We probably should talk about "below f/5.6," because we're talking about a smaller aperture than f/5.6.  Anyway, although I don't understand the technicality of this, the practicality is that the AF on a crop-sensor Canon camera works poorly if at all at smaller maximum lens apertures than f/5.6.  I think it has to do with the geometry of the light circle and the sensor.  Canon lenses report their maximum aperture to the camera and if it's smaller than f/5.6--which is what would happen if you put an extender on the 100-400 mm Canon lens--the AF is disabled.

For manual focus, you need light.  The less light you have, the harder it is to see if the image in the viewfinder is sharp or not, which is how you have to manually focus.  If you put a 2X extender on a Canon 100-400 f/4.5-5.6L lens, you get an 800 mm f/9-11 lens.  f/11 is pretty dark, so pretty hard to manually focus.

In addition, as other posters have pointed out, the Canon 100-400 f/4.5-5.6L lens doesn't really perform well with extenders.

FF

Reply   Reply with quote   Complain
Steve Balcombe
Forum ProPosts: 10,780
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to bluestreakrem, Jan 28, 2013

bluestreakrem wrote:

Steve Balcombe wrote:

I definitely would not get the 2x. Apart from IQ issues, you will struggle with focusing. The Kenko bypasses the camera's ability to disable AF above f/5.6 but it can't make the AF sensor work any better than it was designed to.

What is the problem with AF above f5.6?

You might get away with the 1.4x (f/8) but the 2x gives you an f/11 lens............ AF simply won't function,.................. and manual focus through an f/11 lens (especially with a crop camera viewfinder) is pretty difficult.

Why won't the AF function at f11?

Imagine yourself as a tiny creature sitting in the middle of your sensor, looking forwards through the lens. The f-number tells you how big the aperture (or more strictly the "exit pupil") will appear to be, as seen from that position. F/5.6 always looks a certain size, f/4 is bigger and f/8 is smaller.

The AF sensor looks through the lens in a similar way (although via a mirror) and it works by looking at a beam of light from the left hand edge of the aperture and another beam from the right hand edge. By combining these it can work out the focusing distance - using clever science that I can't begin to explain. The important thing to know is that it relies on the angle between these beams, and the angle can be bigger if the apparent aperture is bigger.

If the aperture is less than f/5.6, the angle between the edges is too small for the AF system in most Canon cameras to work reliably, so Canon's engineers took the decision to disable AF in these circumstances. Better to draw a clear line, than to have complaints from photographers with f/8 lenses when their cameras wouldn't focus reliably.

Of course, we all want to squeeze a little bit more out of our gear and we all want to get something for nothing. It didn't take long for people to work out that if you disable the communication between a lens and a TC by taping over a certain three pins, an f/5.6 lens with a 1.4x TC (which is physically an f/8 combination) can be made to appear as if it was the bare f/5.6 lens. So the camera is tricked into trying to AF through an f/8 combo - i.e. through an aperture which is too narrow. It can work, if the conditions are ideal, but the AF sensor is at and probably beyond its design limits and it lets you know by failing to focus some of the time.

If you take this one stage further by using a 2x TC, you now have a very narrow f/11 aperture and the chances of success become basically nil.

If you'd like to read a more technical explanation with diagrams, this one is pretty good:

http://dougkerr.net/pumpkin/articles/Split_Prism.pdf - starting at the bottom of page 12.

Reply   Reply with quote   Complain
Flying Fish
Veteran MemberPosts: 3,997
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to Steve Balcombe, Jan 29, 2013

Steve:  Your explanation makes perfect sense, but my Canon 450D (XSi) could autofocus quite fast on Venus with my 55-250 f/4-5.6 IS kit lens.  Even at 250 mm, the disc of Venus was tiny in the frame.  How--if at all--does that fit into the explanation?

FF

Reply   Reply with quote   Complain
tonyjr
Veteran MemberPosts: 5,156Gear list
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to Flying Fish, Jan 29, 2013

Not really . The Camera focuses at the largest opening and then shifts to your setting .

It has to do with a lot of things - To put it kind of simple , the sensor is like a solar cell . It take a minium amount of light to work - produce electricity - AF needs that and rather than pixelate the shot , Canon sensors just won't turn on the AF till that voltage / setting is meat .

This is where the pin taping comes in . If enough light - might work , but most of time lenses will just hunt .

Looking to be corrected - soon

 tonyjr's gear list:tonyjr's gear list
Canon EOS 400D Canon EOS 7D Canon EF 35mm f/2.0 Canon EF-S 10-22mm f/3.5-4.5 USM Canon EF-S 17-55mm f/2.8 IS USM +14 more
Reply   Reply with quote   Complain
Steve Balcombe
Forum ProPosts: 10,780
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to Flying Fish, Jan 29, 2013

Flying Fish wrote:

Steve: Your explanation makes perfect sense, but my Canon 450D (XSi) could autofocus quite fast on Venus with my 55-250 f/4-5.6 IS kit lens. Even at 250 mm, the disc of Venus was tiny in the frame. How--if at all--does that fit into the explanation?

Hmmm sorry I don't understand the question. Yours is an f/5.6 lens so the aperture is within the specification of the AF system.

Reply   Reply with quote   Complain
Flying Fish
Veteran MemberPosts: 3,997
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to Steve Balcombe, Jan 29, 2013

You're assuming too much understanding on my part.    My question is if Venus is so tiny, how does it make a difference if the maximum aperture is f/5.6 or f/11 for such a tiny object?  I'm having trouble visualizing the geometry your explanation implied.  And from there, if you can focus on tiny Venus, then why not on an elephant?

FF

Reply   Reply with quote   Complain
tonyjr
Veteran MemberPosts: 5,156Gear list
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to Flying Fish, Jan 29, 2013

Venus is one the wrong side of the lens .

 tonyjr's gear list:tonyjr's gear list
Canon EOS 400D Canon EOS 7D Canon EF 35mm f/2.0 Canon EF-S 10-22mm f/3.5-4.5 USM Canon EF-S 17-55mm f/2.8 IS USM +14 more
Reply   Reply with quote   Complain
digit
Contributing MemberPosts: 579
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to SmallTownUSA, Jan 29, 2013

I have the 1.4 and I used it a lot for birding on my 70 -300.  No, the AF will not work with it but I am an old schooler and manual focus is not problem.  Bumping up contast in LR and i'm good.  It will meter through and does reflect info in the EXIF.

-- hide signature --

Focus - Click - Repeat,
http://jbtty.dyndns.org/photo
There is only you and your camera. The limitations in your photography are in yourself, for what we see is what we are. Ernst Haas

Reply   Reply with quote   Complain
SmallTownUSA
Forum MemberPosts: 52
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to digit, Jan 30, 2013

Hi All: Many thanks for the great info. You have convinced me to go with a 1.4x. So now the questions is whether to get the Canon or the Kenko. Any advise?

Harold

Reply   Reply with quote   Complain
Steve Balcombe
Forum ProPosts: 10,780
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to Flying Fish, Jan 30, 2013

Flying Fish wrote:

You're assuming too much understanding on my part. My question is if Venus is so tiny, how does it make a difference if the maximum aperture is f/5.6 or f/11 for such a tiny object? I'm having trouble visualizing the geometry your explanation implied.

I think I see where you're coming from now. It's because light from any particular point in the image passes through the whole lens. Imagine a 'cone' of light from the point in the subject, to the circle of the lens, then another one from the lens to the corresponding point in the (upside down) image. That's what is happening for every point in the image. As every photographer knows, if you make the lens smaller (stopping down), you don't lose any of the points in the image, they just all get darker. In fact it doesn't matter which part of the lens you block out, you never lose any part of the image, it just gets darker. You could block out everything except a little part of the left of the lens and you would still get an image.

What the AF sensor does in effect is to look at that little bit of light from the left, plus another from the right, and using these together it can measure how far out of focus the image is. To be honest it really isn't all that useful to understand how this works at a science level - but it's very useful to know that it does, because it explains why it's the size of the aperture which matters, not the amount of light coming through it.

Reply   Reply with quote   Complain
tonyjr
Veteran MemberPosts: 5,156Gear list
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to SmallTownUSA, Jan 30, 2013

Canon is better [ if you are a really great photographer and crop a bunch ] , cost more and only fits a few lenses .

I went with canon , I need all the help I can . I do crop a lot sometimes- like a group of 8 people , I might crop out one face .

Canon 7 D , Epson 837 printer and 100 pack of costco 8.5 X 11 photo paper . I shoot raw + jpg .

I have various 1.4 , 2 and 3 X ones , but they are all at least 6 years old . The canon 2 X III is the best one I own .

If you can afford it get the canon III version , if not the canon II .

 tonyjr's gear list:tonyjr's gear list
Canon EOS 400D Canon EOS 7D Canon EF 35mm f/2.0 Canon EF-S 10-22mm f/3.5-4.5 USM Canon EF-S 17-55mm f/2.8 IS USM +14 more
Reply   Reply with quote   Complain
MrScary
Veteran MemberPosts: 6,203Gear list
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to tonyjr, Jan 31, 2013

AF on the older 300 Pro DG would not work...But lots are saying that a f5.6 will work on the New Kenko 300 Pro DGX or DXG cant remember the letters, but it's the NEw 1.4x DGX I think..Forget the 2x it won't work.

-- hide signature --
 MrScary's gear list:MrScary's gear list
Canon EOS 7D Canon EOS 5D Mark III Canon EF 400mm f/5.6L USM Canon EF 70-200mm f/4.0L USM Epson Stylus Photo R3000
Reply   Reply with quote   Complain
SmallTownUSA
Forum MemberPosts: 52
Like?
Re: Kenko DGX 2x Teleplus Pro 300 with 60D
In reply to SmallTownUSA, Feb 8, 2013

UPDATE: I purchased a Kenko Pro DGX 1.4. The results with my camera/lens is quite satisfactory. Camera is a Canon 60D, lens are:

1. 10-22mm EF-S Canon

2. 50mm 1.4USM Canon

3. 18-200 mm EF-S Canon

4. 100-400 mm IS USM Canon

Preliminary tests indicate I will be very happy with the extender. It as I knew when I purchased it, it does not work with either EF-S lens (the mountings are not compatible.) However, both on the 50mm and the 100-400mm it works great. Quite sharp and the AF works also.

Thanks all for the help and advice you gave me.

Harold

Reply   Reply with quote   Complain
Keyboard shortcuts:
FForum MMy threads