[jva59]

I've been 'birding' more than ever before. My longest lens, which I love, is my F* 300 4.5. Unsurprisingly I sometimes find myself wanting a bit more reach. I've been looking with interest at the new 150 - 450. It is, however, both expensive and heavy, so my thoughts have turned to teleconverters, which I don't understand very well. The description of the new one says it should be used with lenses faster than 4 (not mine), but seems to imply one could use it with other lenses, though at the cost of sacrificing something (functionality, image quality??). Are there older ones out there better suited to my F * 300?

I'd be grateful for any advice forum members can offer. Thanks & best JVA

[aslyfox]

I would recommend a review of this article to start with:

Pentax K-Mount Teleconverter Guide
Features and Lens Compatibility
By PF Staff in Articles and Tips on Apr 28, 2013

Read more at: Pentax K-Mount Teleconverter Guide - Articles and Tips | PentaxForums.com

as well as

https://www.pentaxforums.com/lensreviews/Pentax-K-Mount-Teleconverters-c50.html

https://www.pentaxforums.com/lensreviews/da-teleconverters-c70.html

https://www.pentaxforums.com/userreviews/pentax-off-brand-teleconverters-c90.html

[jva59]

I would recommend a review of this article to start with:




Read more at: Pentax K-Mount Teleconverter Guide - Articles and Tips | PentaxForums.com

as well as

Pentax K-mount Teleconverters and Adapters - Lens Reviews and Specifications - SLR and Interchangeable Lenses - Pentax Lens Reviews & Lens Database

Pentax DA Teleconverters - Lens Reviews and Specifications - SLR and Interchangeable Lenses - Pentax Lens Reviews & Lens Database

Miscellaneous Lenses for Pentax: Teleconverters (All Brands) - Pentax Lens Review Database

Many thanks, aslyfox! Just what I was looking for.

[BigMackCam]

Your profile shows the K-5IIs as your current camera. If you're still shooting this or another APS-C body, consider the HD DA 1.4x WR rear converter. I use it with my DA*60-250 and I've been 100% satisfied with it. Although you're supposed to use it with f/4 or faster lenses, f/4.5 is close enough and will be fine unless you're in low light situations.

Another option, perhaps thinking a little outside the box, would be to upgrade to a more recent, higher-resolution body such as the K-3, K-3II, or - better still, if it suits your needs in other areas - the KP. That in itself won't give you greater "reach", but it will allow you to crop further whilst retaining acceptable resolution. If you trade your K-5IIs or sell it privately, the difference in price of a good, used body won't be much different than an HD DA 1.4x WR...

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Last edited by BigMackCam; 01-16-2021 at 03:25 PM.

[ramseybuckeye]

I'll second what Mike says about the DA 1.4. I have a DA*300 and was thinking about the 150-450 or the teleconverter. I actually looked at some photos taken with the converter and 300 and was really impressed, so I finally broke down and bought it. Now I wonder why I waited so long. I no longer use the 300 without the converter. I can also use the converter on my DA55-300 PLM lens if the light is good, I used it today when I was walking more for exercise, but did not want to miss an opportunity. On the Ricoh Japan web site there is a compatibility chart, it does not list you lens, but also does not say it is incompatible. Hopefully, someone will chime in that has it.

[aslyfox]

Many thanks, aslyfox! Just what I was looking for.

Glad I could help you out

[UncleVanya]

I have the f4.5 FA* 300 and the HD DA 1.4x and it works wonderfully with it.

[DWS1]

i agree with others here. The Pentax HD 1.4x teleconverter works extremely well with the 300mm. I normally shoot with this lens at an aperture of f5.6-f11 anyway, so the loss of one stop of light doesn't really bother me much. Also, the DOF is not as large as one might think it would be at those apertures because of the 420mm focal length.

[pacerr]

A few years ago I had the HD Pentax DA 1.4x AW AF, two Tamron Pz AF 1.4X MC4's, and two Tamron Adaptall 01F TC's along with the Pentax DA* 300, Tamron 70-200 F2.8 Di LD and Adaptall SP 300 F2.8 (360) and SP 80-200 F2.8 LD.



In practical use in the field I could tell no difference in the product of any of the TC's. Shot-to-shot technique and environmental variables were by far the noticeable difference in all images.


I found no advantage to using the Pentax AF in the field with manual focus lenses as I was constantly manually verifying the focus solution.


The 'crop-ability' of high MP sensors has largely taken the place of TC's in my shooting except when using a TC to enhance minimum focus distance.


If a TC is used as a tool to solve a problem with no other option any perceived image quality difference becomes a moot point. I've found no apparent optical difference in MY four Tamron 1.4X TC's not attributable to the age of the older Adaptalls.

[Des]

Any 1.4x converter will reduce light by one stop, so the 300mm f4.5 effectively becomes 420mm f6.3. The manufacturer recommendation for using it only on a lens that is f4 or faster is because on many bodies autofocus performance falls away after f5.6. But don't be put off - many of us have used TCs on the F*/FA*300 f4.5 with good results, at least when the light is reasonable.

Are there older ones out there better suited to my F * 300?

The DA 1.4x is the gold standard. It is the only one which transmits the adjusted focal length to the camera, so makes for a more accurate shake reduction setting and the recording of correct information in the EXIF. It is also the only one that is WR (not that that matters with the F*300, but it would if you use it with a WR lens). As has been said, it also works reliably with the DA 55-300 PLM - if the light is sufficient (300mm f6.3 becomes effectively 420mm f9).

The only downside of the DA 1.4x TC is the cost. For discussion of cheaper alternatives, see these threads (and those linked from there):
Teleconverter for FA* 300mm f4.5 ? - PentaxForums.com
Teleconverter challenge Sigma vs Kenko vs Tamron X1.4 - PentaxForums.com
The crazy world of modern teleconverters... - PentaxForums.com

I have the Kenko Pz-AF 1.5x Teleplus SHQ (despite the name the magnification is really 1.4x). It has worked fine for me with the FA*300mm f4.5 (I have only used it on APS-C bodies). It is one of the few (apart from the DA 1.4x) which has the electrical contacts to allow it to work effectively with the DA 55-300 PLM. I saw one of the Kenkos (same as mine) offered on Gumtree recently for $A150, which is about a quarter of the price of the DA 1.4x here.

[acoufap]

The only downside of the DA 1.4x TC is the cost.

... and if you plan to use it in addition with your K-1 in FF mode the image circle of the lens / tc combo in most cases may not be sufficient. By example that's the case with DFA150-450 in FF mode.

Concerning cost I'd say it's one of the rare cases where European prices seem to be a bit better than us prices - street price about 350,- €.

I'd subscribe what you write about APS-C usage concerning the DA TC1.4x but still wait for a FF variant of this tc to get this one too. ;-)

[Des]

I'd subscribe what you write about APS-C usage concerning the DA TC1.4x but still wait for a FF variant of this tc to get this one too. ;-)

AFAIK, Asahi Man's pronouncement in November 2018 that two FF TCs were "in late prototype condition" (FF TC - full frame teleconverter - Page 2 - PentaxForums.com) is the only meagre nourishment for those hopes.

[Lowell Goudge]

Birding is a “natural” extension of photography for many. After all, I am willing to bet some of every photographers first shots are ducks

But joking aside, so you can make a good decision.. Pentax AF works reliably with optics that have a combined / native aperture of F6.9 or less. A native aperture of F8 only works on the very best of days. This goes as far back as 1990 and the PZ1.

I base this on personal experience using F4.0 lenses like the K300/4 with the 1.7x AF converter. That works very well even in shaded conditions, and also stacking my sigma 1.4x behind the 2x on my 70-200/2.8. On a sunny day although it would hunt quite a bit it could achieve focus lock.

Therefore a 1.4x behind the 300/4.5 will work

As far as image quality, the issues with a TC are that they magnify everything, including all the faults of the prime lens. If you have lateral CA, a TC will give you more, but a good TC does not really degrade the image significantly, from that of the lens it is attached to.

As some have noted, one big advantage of a TC is it does not modify close focus, and your 300 with a TC might be better than some longer lenses if you are in close. What this means is don’t get rid of your 300 and TC if eventually get a longer lens. It still has some uses.

The other advantage is the TC on your 300/4.5 will be a lot lighter, and again even if you get something bigger and badder for your main birding activities, you might want a light option for travel. I would never (probably) take my DA560 on an overseas trip, but would take in its place my trusty old Sigma 70-200/2.7 and 2x TC. Lighter, smaller, and much more versatile overall, when considering true birding activities might only be 10% of my trips time.

Even when you get a TC, and don’t worry about any vignetting you may get even with the Pentax 1.4x which is only for crop sensors. If you are close enough to a bird to be using the full frame of a K1, you don’t need the TC any way. Most of the time you will still be cropping in. From a lot of experience I can tell you that it is very rare that with my K1 that I do not crop even with the DA560. The sad reality is that for birding, you NEVER have a long enough or FAST enough lens. You simply make due with what you have.

[jva59]

Many, many thanks for all the immensely valuable & illuminating advice!

---------- Post added 01-17-21 at 06:55 PM ----------

Your profile shows the K-5IIs as your current camera. If you're still shooting this or another APS-C body, consider the HD DA 1.4x WR rear converter. I use it with my DA*60-250 and I've been 100% satisfied with it. Although you're supposed to use it with f/4 or faster lenses, f/4.5 is close enough and will be fine unless you're in low light situations.

Another option, perhaps thinking a little outside the box, would be to upgrade to a more recent, higher-resolution body such as the K-3, K-3II, or - better still, if it suits your needs in other areas - the KP. That in itself won't give you greater "reach", but it will allow you to crop further whilst retaining acceptable resolution. If you trade your K-5IIs or sell it privately, the difference in price of a good, used body won't be much different than an HD DA 1.4x WR...

Thanks, should have updated. Am now shooting with the K-1.

[luftfluss]

Thanks, should have updated. Am now shooting with the K-1.

Keep in mind that the HD DA 1.4x TC is designed for APS-C, and thus will vignette on the K-1.