[noelpolar]

One thing that confuses me with TCs is...... when we add a 1.4tc to ... say a lens at f 5.6.... we often think in terms of aperture being 1.4 stops on from 5.6... but isn't the apperture still 5.6.... but camera sensor only sees f9 worth of light....... ie the t stop went up.... so the lens probally isn't at it's best to f8 plus 1.4tc.... ie f12ish?....

FWIW.... I didn't fall in love with the 150-450 on my K3 at the time... I noticed the lens ate more light then the 300 I was using.... even at 300.... it was like it was a "t" stop or more slower for the same aperture. The low light performance of the K1 made up for that... I think.

From a justification perspective.... I only have the 150-450 because it covers well over half of what I like to do photographicaly..... ie I dont have any normal zoom lens even.

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Last edited by noelpolar; 06-21-2020 at 05:36 AM.

[bobmaxja]

Interesting that thread and I decide to try my Tamron2x Pz-AF BBAR MC7 teleconverter with my DA55-300 PLM and it's does not work, but work with my Sigma 105 2.8 DG macro

[acoufap]

I guess that would be expected. I wondered if anyone has done a couple of simple tripod tests to compare. For anyone owning a DFA 150-450 it might be confronting result

Tripod up, KP+DFA set to 420mm and f9 vs 55-300PLM+1.4TC set to 300mm (420mm) and f9 also. Just take images of some still life stuff, flowers etc, and compare IQ. I would LOVE to see that. I've no doubt the DFA would win but does it destroy and annihilate or does the combo actually do pretty well!

The thing is it's very hard to judge lens performances from different users and shooting conditions, a single user with this equipment done with a tripod and stationary subject I think would really be useful.

If weight doesn‘t matter you simply take the DFA150-450 - faster and better IQ. If you need / want to go lightweight take the lightweight combo. If you want best reach and weight doesn‘t matter take the KP, DA TC1.4x and DFA150-450 - you get real optical 630mm and open aperture f/8. It‘s that simple. A restricted comparison test as you described takes time and doesn‘t show much value IMO. ;-)

[SSGGeezer]

Interesting that thread and I decide to try my Tamron2x Pz-AF BBAR MC7 teleconverter with my DA55-300 PLM and it's does not work, but work with my Sigma 105 2.8 DG macro

Focus issues? Or doe the Tamron x2 not have the electrical contacts to power the PLM system? Too dark is the issue I suspect.

[bobmaxja]

Focus issues? Or doe the Tamron x2 not have the electrical contacts to power the PLM system? Too dark is the issue I suspect.

Unable to keep focus, back and forth from focus to out of focus continually.
The F# is the one of the PLM on the screen of the KP

[swanlefitte]

One thing that confuses me with TCs is...... when we add a 1.4tc to ... say a lens at f 5.6.... we often think in terms of aperture being 1.4 stops on from 5.6...

Aperture is the size of the entrance pupil in relation to the length of the lens. Say a 100mm f/4 has an entrance pupil of 25mm (100/25=4)
But you extend the theoretical length of the lens 1.4x to 140mm. The entrance pupil is still 25mm. 140/25=5.6. The f# stated f5.6 is not correct. F/5.6 is because f=140/5.6 which = 25.

Note we now use telephoto to mean a lens longer than a normal lens. A telephoto lens is actually a lens with a telephoto element that puts the theoretical center of the lens groups in front of the physical length of the lens. 1 200mm lens that is 200mm is a long lens not a telephoto. A 200mm lens that is 80mm long is a telephoto. A wide angle lens can actually be a telephoto except with a 45mm registration distance the lens would be inside the mount.

[BruceBanner]

If weight doesn‘t matter you simply take the DFA150-450 - faster and better IQ. If you need / want to go lightweight take the lightweight combo. If you want best reach and weight doesn‘t matter take the KP, DA TC1.4x and DFA150-450 - you get real optical 630mm and open aperture f/8. It‘s that simple. A restricted comparison test as you described takes time and doesn‘t show much value IMO. ;-)

I think you missed some vital points.

DFA 150-450 = $3459AUD
55-300PLM = $609AUD (got mine for $500AUD)
1.4TC = $659AUD

The DFA 150-450 is 3x the price of the PLM+TC combo! It's a serious piece of kit, so I am not surprised it will be better. The question is how much better? Do I think I can make up for any loss of IQ through decent PP skills and knowhow? Is it good enough for a print x size etc.

Considering how impressed I have been with the pairing of a KP with the PLM, with the 1.4TC we can get it into 420mm territory with f9. Whichever way you look at it that is now within the DFA 150-450 focal length range, PLM has played 'catch up' albeit at a price.

Then factor in some other things aside wallet savings, such as the PLM is lighter to carry, the 1.4TC investment can be used on other lenses etc. So now the only question for me is really how abysmal or how surprising are the results of the PLM+TC on the KP/K-1? I don't think I would really be considering this combo if not for the fact that I shoot in Australia where typically I am privy to very bright days so the loss in light might not be as big an issue as it could be for some other members who experience duller days more often (Brits etc).

I just don't find these kind of comments particularly useful, it's like going car shopping and choosing between two reasonably priced cars and being undecided and then the sales men steps in and just says "why bother with these two options, just go for this Ferrari!"

By the way, what exactly takes so long to get a tripod out, sit a KP on it, get your DFA 150-450 out, set it to 420mm and f9, use a timer/remote focus on a bottle on a wall or something. Take a shot, remove the lens, put the PLM+TC on, set to 300mm (which is now 420mm also), ensure aperture is f9, take a shot again, Review the two images (or don't even, just dump the RAWs somewhere for the chap to look and inspect

I've done heaps of tests for members over the years, both here and FB land, sometimes it's lensbaby questions such as crop results vs ff etc, but I make the time and in reality its a whopping 15mins out of my day. Ouch. And I'm sure they are appreciative, its called being a good community member and I like helping people where I can. Technical knowledge I may lack, but if I can do something for someone I will.

One thing that confuses me with TCs is...... when we add a 1.4tc to ... say a lens at f 5.6.... we often think in terms of aperture being 1.4 stops on from 5.6... but isn't the apperture still 5.6.... but camera sensor only sees f9 worth of light....... ie the t stop went up.... so the lens probally isn't at it's best to f8 plus 1.4tc.... ie f12ish?....

FWIW.... I didn't fall in love with the 150-450 on my K3 at the time... I noticed the lens ate more light then the 300 I was using.... even at 300.... it was like it was a "t" stop or more slower for the same aperture. The low light performance of the K1 made up for that... I think.

From a justification perspective.... I only have the 150-450 because it covers well over half of what I like to do photographicaly..... ie I dont have any normal zoom lens even.

Yeah, and I think I would be the same, if I had that lens I'd definitely sell the PLM and anything else I'd have at longer than 150mm. You have the best. The only think that might be noteworthy where a PLM+TC is a good alternative to the DFA 150-450 is if the weight and size of the lens is really an issue and the price of having to lose some IQ for a lighter trip is actually super important (ie the trip may not have been undertaken at all etc.)

[noelpolar]

I think you missed some vital points.


Yeah, and I think I would be the same, if I had that lens I'd definitely sell the PLM and anything else I'd have at longer than 150mm. You have the best. The only think that might be noteworthy where a PLM+TC is a good alternative to the DFA 150-450 is if the weight and size of the lens is really an issue and the price of having to lose some IQ for a lighter trip is actually super important (ie the trip may not have been undertaken at all etc.)

FWIW.... a Pentax friend has a Sigma 150-500 and we regulary go away together shooting.... and there is a real difference between that lens and the DFA. I couldn't be happy with it.... I'd rather take my 300 and 70-210 with me.... however when last up the Flinders I used it a bit and got some nice shots with it.... and could post one that I could easily say was a great shot from a great lens... but overall it was only ok in general use.... (a well lit close up of a lizard... both looked good..... fine detail in a 300-450mm landscape shot.... night and day... not web size images off course).

I will say.... to this day.... I love my F*300/4.5.... and... in $Aus.... the DFA is a $2,200 lens.... our dolar etc sucks.... I paid around $2,700 way back.... and I struggled with that big time... at the time.... but I'm mostly cheap... even if I have the money.... anyway... for something to do.....I'm going to see how I go getting a Robin shot today with the F*300 on the KP.... if I get one then one doesn't need a DFA.... QED.

I never sold my F* after getting the DFA.... form factor is so different.... I'd keep the PLM probally as well (general travel etc.... it's why we all have 5 different camera bags.....the DFA is my quiet time reclusive lens.... it's a zen lens).

Off interest... this is a 5mp crop of a F*300 K1 shot... hand held quick shot.... would a PLM do as well?... (I really don't know...not trying to be smart).


and this is a 4mp crop (2x2) at 450mm from DFA



All I know for sure is..... this forum is a habbit trigger for the Diderot Effect.... ahh... famous words.... Poverty has its freedoms; opulence has its obstacles.

[clackers]

The big thing is that autofocus is rated only to f5.6. The lens makers understand this, and that's as slow as they usually let their designs go. It will be hit and miss beyond that.

That's why for wildlife photographers, the primes are f2.8 and f4, to add teleconverters afterwards and still stay within the ratings.

There are some Canons that attempt to do f8, but only for the centre focus point, forget all the others, and I have no way of telling how reliable it is anyway.

[BruceBanner]

FWIW.... a Pentax friend has a Sigma 150-500 and we regulary go away together shooting.... and there is a real difference between that lens and the DFA. I couldn't be happy with it.... I'd rather take my 300 and 70-210 with me.... however when last up the Flinders I used it a bit and got some nice shots with it.... and could post one that I could easily say was a great shot from a great lens... but overall it was only ok in general use.... (a well lit close up of a lizard... both looked good..... fine detail in a 300-450mm landscape shot.... night and day... not web size images off course).

I will say.... to this day.... I love my F*300/4.5.... and... in $Aus.... the DFA is a $2,200 lens.... our dolar etc sucks.... I paid around $2,700 way back.... and I struggled with that big time... at the time.... but I'm mostly cheap... even if I have the money.... anyway... for something to do.....I'm going to see how I go getting a Robin shot today with the F*300 on the KP.... if I get one then one doesn't need a DFA.... QED.

I never sold my F* after getting the DFA.... form factor is so different.... I'd keep the PLM probally as well (general travel etc.... it's why we all have 5 different camera bags.....the DFA is my quiet time reclusive lens.... it's a zen lens).

Off interest... this is a 5mp crop of a F*300 K1 shot... hand held quick shot.... would a PLM do as well?... (I really don't know...not trying to be smart).


and this is a 4mp crop (2x2) at 450mm from DFA



All I know for sure is..... this forum is a habbit trigger for the Diderot Effect.... ahh... famous words.... Poverty has its freedoms; opulence has its obstacles.

Yeah, I'm enjoying this thread for various different reasons and contributions that I am finding helpful, so thank you for contributing.

Covid is really the reason I got the PLM, all my portrait events cancelled I started snapping 'other stuff'. I started off with a friends DA* 60-250, but tbh I wasn't blown away and am happy I returned it and spent half the amount of coin on the lighter and more compact PLM. Unfortunately money is a strong factor in my lens choices, I have to weigh up cost and IQ constantly. If I had the funds I would just own all the best stuff and never make a post here ever again ahaha

I never expect a cheaper lens to really outperform another more expensive lens, it's about cost vs IQ ratio, I do believe you can find that sweet spot whereby the additional cost is marginal and the cheaper option (although perhaps not the best IQ) is still definitely best value.

If lens A = $3k and is 9/10, but lens B = $1k and is 8.5/10 then I would choose lens B based on my income/saving restraints.

There's a bit more to it than this. Other factors that contribute to the success of the final image being;

1) User (competency in that specific genre)
2) Luck (favourable lighting conditions at the time of shoot/shot taken)
3) Rendering skills, post processing competency to really amplify (tastefully)

I know we don't often talk about items 1-3 here often, just the lens in terms of performance but to me the other factors are important to the overall image. Akin to the idea that I'd rather give a crap camera to a skilled tog than really ace equipment in the hands of an amateur. Also I know I can fail lens tests easily. I've played that game, and I'm sure many would struggle to pass tests like DA 70 vs FA 77 bla bla.

So there we have it, curious because how I see things is there's a nice $500 lens (PLM) and the next is a behemoth 'take no prisoners' affair coming in at $3.5k.

What has been interesting in this 'Covid PLM' practice times is the 'zoom' aspect for me, because up until now most of my paid work is done with primes. Weddings and events, usually its the FA77, FA43 making up the majority with the odd wide angle shots such as DA 12-24 or HD DA 20-40 filling in the gaps (and often with those lenses it will be a fixed FL set that works ok with FF Mode on the K-1 and kept at that marker throughout the gig).

People are generally slow, and I can use my legs quickly to compose better, buffer constraints have often meant I need to dual wield these events so I have a couple of focal lengths to play with as well to help with that. Wildlife however... quite a different story. Practising shooting birds recently is telling me that the ability to change the focal length is quite important, these aren't humans you can instruct where to stand or how to be, they are a master to themselves and so I have to shoot quite differently to how I am used to. This issue has already made me think about the idea of swapping the PLM 55-300 over to a DA* 300 or (prime) something. I have no doubt the IQ could be better on a prime, and perhaps front and focus back issues are not such an issue (I think perhaps my 55-300 needs different FA values depending on what zoom amount I am using, though not tested quite enough yet to say that is the case for sure), but the idea of being stuck at a certain focal length for wildlife is a little scary.

The big thing is that autofocus is rated only to f5.6. The lens makers understand this, and that's as slow as they usually let their designs go. It will be hit and miss beyond that.

That's why for wildlife photographers, the primes are f2.8 and f4, to add teleconverters afterwards and still stay within the ratings.

There are some Canons that attempt to do f8, but only for the centre focus point, forget all the others, and I have no way of telling how reliable it is anyway.

So this is the second time I have heard this, thanks for continuing to educate me. Can you expand on this at all? What does it really mean when we say 'autofocus is rated to f5.6'?

Here's my confusion, please help to clean up the mess in my mind;

1) Are we talking PDAF here or CDAF when it comes to this aperture AF limit?

2) I always understood in PDAF the centre spot and spot directly above and below were 'rated to f2.8', I just took this to meaning they are better more accurate AF points to use, and that to use Spot AF mode (not centre point SEL spot) would actually even increase AF accuracy a little more. I never really thought about the other AF points in terms of f number accuracy.

3) If 5.6 is the maximum aperture for autofocus, then what is Pentax doing with the PLM 55-300 which has f6.3 as its minimum on the long end? What does that mean? Do we take it that Pentax are not the same as the others and have AF points rated higher than 5.6?

4) What does this mean when we use say a FA77 at f8? It's less accurate than using f2.8? Are we getting that depth of field trade off where AF accuracy is less but because focus plane is deeper the AF inaccuracies are harder to detect?

It's been more of a gut feeling than anything else, but my experience with the PLM thus far feels like it is sharper at its wide open apertures, it feels like I get 'fuzzier' shots when stopping down (even when light is not a problem), which perplexes me a little and perhaps what's happening is that exact AF inaccuracy? Perhaps a good tactic is to find focus on the wildlife at wide open apertures first, then stop down and shoot vs finding focus at the stopped down aperture... But then again it might be that I am getting front back focus issues also.

Thanks again everyone!

[swanlefitte]

With newer lenses you are focusing with the lens wide open. The aperture only stops down when you press the shutter. And if you are like me with my takumars you focus wide open then stop down so you can see.

Would like more explaination of the other points myself.

[Papa_Joe]

First I have to apologize, for contributing so late.

I went through the thread and I am a bit worried, if I just didn't notice the point of a bright viewfinder or if it really wasn't mentioned yet.
I will not question, that am 55-300 PLM will work with a 1.4 TC or that it will deliver a sufficient image quality for the usage intended.

But I personally would not use such a combo as a permanent solution, as the viewfinder would be to dim for me. I find aperture 5.6 akzeptable to work with, aperture 8.0 for me is just workable, if used on a tripod. For that I would never ever spent the money on the 1.4 TC to work it with a slow lens. The solution I would go for, if I needed something longer, less expensive then the 150-450, would be a used 300 4.0 mm with the 1.4 TC. Am I the only person who likes a brighter viewfinder?

EDIT: A new 200/2.8 with an used 2x TC would be an option as well and usable for FF.

[noelpolar]

Like most things.... we are only talking hobby stuff..... and off course the $ and or value in this case is a big thing.... and very individualised. If we each provided a "detailed brief" on what success looked like regarding a lens, it's use and desired outcomes then maybe we'd have enough detail to understand each others opinions.

FWIW.... one would have to have a fair amount of disposable income (or windfall) or a really strong need to bother going from the PLM to the DFA.

A couple of shots from the F*300/4.5 on KP today.... I had this bird get closer... but had a card full error... haha dual slots needed for forgetful me!


This is a bit over a one mega pixel crop.... going back to do better tomorrow

[Rondec]

I think you probably have your answer Eddie. From what I've seen, image quality from the 55-300 PLM with the TC is OK, but not great and really falls apart in anything but the best light. The 150-450 will be better, albeit for a price.

For casual shooting the TC is probably adequate. If you are turning into a wildlife specialist maybe you should get a dedicated longer telephoto or even a 300 prime to pair with a TC.

[SSGGeezer]

Bruce,
Here is one I suspect you would not get with the TC as it is wide open at f/5.6 with a poorly contrasting background and a bird flying at 20 MPH+ to cross a river avoiding a fox. SOOC and cropped to less than 1800px on the long side.