[UncleVanya]

It only bothers me when people espouse their preferences based on misinformation.

I haven't seen a lot of misinformation in the thread it in people's expressed preferences. What I have seen is a bunch of people that have very different priorities in photography communicating these values sometimes well and sometimes poorly.

[reh321]

It only bothers me when people espouse their preferences based on misinformation.

In my case, I did shoot most of a wedding {our daughter was getting married} shortly after getting my KP. I shot the entire event with the f/3.5-5.6 18-135mm that is usually on the camera, and my KP never failed to focus quickly and surely. If I had shot the wedding with a f/1.4 DFA 70-200 mounted on a K-1, my camera could not have focused better - but I would have had problems similar to those faced by the “pro” our daughter hired (*), who had to “zoom with her feet” so far back at times that she was practically out of the room for photos of large groups of the wedding party. I know from personal experience that a ‘fast’ but ‘longer’ lens mounted on a “FF” camera is not a better choice for a wedding - it is sometimes too long and a ‘slower’ lens can have focus at a wedding when mounted on a modern Pentax camera.

(*) she shot the entire wedding with an 85mm Nikon lens mounted on some Nikon body.

[UncleVanya]

In my case, I did shoot most of a wedding {our daughter was getting married} shortly after getting my KP. I shot the entire event with the f/3.5-5.6 18-135mm that is usually on the camera, and my KP never failed to focus quickly and surely. If I had shot the wedding with a f/1.4 DFA 70-200 mounted on a K-1, my camera could not have focused better - but I would have had problems similar to those faced by the “pro” our daughter hired (*), who had to “zoom with her feet” so far back at times that she was practically out of the room for photos of large groups of the wedding party. I know from personal experience that a ‘fast’ but ‘longer’ lens mounted on a “FF” camera is not a better choice for a wedding - it is sometimes too long and a ‘slower’ lens can have focus at a wedding when mounted on a modern Pentax camera.

(*) she shot the entire wedding with an 85mm Nikon lens mounted on some Nikon body.

To be fair, most PROs would have two bodies, one with 70-200 and the other with 24-70.

[reh321]

To be fair, most PROs would have two bodies, one with 70-200 and the other with 24-70.

My major point was that a ‘slower’ lens did focus on a modern Pentax body at a wedding, so I’m sure that a DFA 70-200mm f/4 would have focused also.

[Erictator]

My major point was that a ‘slower’ lens did focus on a modern Pentax body at a wedding, so I’m sure that a DFA 70-200mm f/4 would have focused also.

In all fairness and due respect, your F3.5 lens was faster at the wide end than a constant F4. Comparing across 2 different brand bodies with different capabilities, and at different focal lengths isn't exactly what I'd call a lab test either.
Eric

[Erictator]

I haven't seen a lot of misinformation in the thread it in people's expressed preferences. What I have seen is a bunch of people that have very different priorities in photography communicating these values sometimes well and sometimes poorly.

The misinformation is exactly as I stated it in my previous post. Several posters said they would never use that Fstop or so they didn't perceive any other advantage from it, so they preferred the lighter F4 alternative. My point was this:

F2.8 isn't just there for shooting with at that set Fstop, it is also the brightness you see in your viewfinder before you trip the shutter, because the lens only stops down to what you set it to when you take the photo... it is also what the F2.8 cross type AF points see, so you get faster AF, more accurate AF, and better low light AF, . So to say you will never use it is totally wrong, because you are actually using the F2.8 advantage ALL THE TIME.

I just wanted them to have a better understanding before they made a very important purchase choice. Not to mention that manufacturers tend to put their best build quality and effort into their more expensive F2.8 zooms... but that wasn't the main thrust of my point, just the part as I stated and re-quoted above.

Eric

[reh321]

In all fairness and due respect, your F3.5 lens was faster at the wide end than a constant F4. Comparing across 2 different brand bodies with different capabilities, and at different focal lengths isn't exactly what I'd call a lab test either.
Eric

and stating that a f/2.8 lens is better than an f/4 lens purely based on theory or past experience is not exactly a lab test either.

At least mine was based on recent real-life experience at a real-life wedding with a real-life Pentax camera.

[monochrome]

^^ Same can be said of an f/1.4 50 or f/2 35 that you rarely shoot below f/5.6.

[reh321]

^^ Same can be said of an f/1.4 50 or f/2 35 that you rarely shoot below f/5.6.

Except that I would hate to lug around the most recent "perfect" Pentax DFA* 50mm f/1.4!!!

[Erictator]

and stating that a f/2.8 lens is better than an f/4 lens purely based on theory or past experience is not exactly a lab test either.

At least mine was based on recent real-life experience at a real-life wedding with a real-life Pentax camera.

Wow... Mea Culpa! I didn't mean to get into a urinating contest over this. Oh well. Enjoy your lens, I'm sure it is great, and that those F2.8 rated cross type sensors don't really need to be activated to achieve good results as long as you are having fun. Keep on keepin on!
Eric

PS: I can see with my own eyes very real difference in my viewfinder with F2.8 lens vs/ F4 brightness when using these. It has made the difference between being able to even FIND the subject to shoot or not. The F4 lens is darker to look through, especially in dusk or low light.

This is an extreme crop, exposure lifted considerably, and was hard to even see the subject with the naked eye, but the K-1 with an F2.8 lens nailed it every time that night. You will note I wasn't shooting any where near F2.8, but the advantage of being able to see through the lens and have the AF work in low light was there. My other lens (the old F series, cult classic f4-5.6 35-105) just wracked back and forth and I couldn't hardly see through it at the 105 end that night.


Pentax K-1 Tamron SP AF 70-200mm F2.8 Di LD [IF] Macro ƒ/6.7 200.0 mm 1/180 iso1600

[monochrome]

Except that I would hate to lug around the most recent "perfect" Pentax DFA* 50mm f/1.4!!!

FA43/1.9 then and deal.

[reh321]

FA43/1.9 then and deal.

You may use a prime lens if you desire. I am more happy with more flexible 18-135mm f/3.5-5.6 lens.

[Serkevan]

Wow... Mea Culpa! I didn't mean to get into a urinating contest over this. Oh well. Enjoy your lens, I'm sure it is great, and that those F2.8 rated cross type sensors don't really need to be activated to achieve good results as long as you are having fun. Keep on keepin on!
Eric

To be fair, if you shoot at f/4, DOF is deep enough to get the subject nicely "there" without the AF struggling a lot. Also, lots of birders get perfectly sharp images with glass that is close to the limit of the AF sensor.

EDIT: just saw the addition (great picture! Was it a medieval reenactment?). I think we were talking about decent light settings here: I and some others have been expressed desire for the 70-200/4 precisely for outdoors photography, where weight is very much important and you have more than enough light for the viewfinder.

[BarryE]

Funny isn't it how we can spend so much time bouncing around a subject. Clearly a fast lens has more available light to focus but is larger and heavier and maybe necessary to catch tricky focusing conditions. Indoors, outdoors, hiking, wedding, slow and considered, tripod or not, etc etc., are examples of usage parameters which we consider when buying. And then our requirements/subjects change and we realise we 'need' something different. Or do we? By not having the temptation of a FF 70-200 f4 variant available I re-discovered the DA* 50-135 f2.8 on a K3. I've now decided to keep my FF gear for paid work only, which has allowed me to use my old, previously unused, cropped lenses for personal. I now remember how much good glass we have available to us already on cropped and FF. It gives me a good feeling to be able to use old gear, but not as good a feeling as I get ignoring Dismal Black Friday ;-)

[Hattifnatt]

It pains me to admit, but it drives me a little crazy when people say they will never use the F2.8...F2.8 isn't just there for shooting with at that set Fstop, it is also the brightness you see in your viewfinder before you trip the shutter, because the lens only stops down to what you set it to when you take the photo... it is also what the F2.8 cross type AF points see, so you get faster AF, more accurate AF, and better low light AF, . So to say you will never use it is a totally wrong, because you are actually using the F2.8 advantage ALL THE TIME.

I get your point but I'm not exactly sure about this. For instance, initially I wanted the 70-200 f4 for hiking trips. Since lately I do a lot of low light photography, I ended up buying the DFA 70-200 f/2.8 since I thought that for now it will do both. When I'm using this lens for landscapes, almost always I use it on a tripod, composition and focus done in live view. Then it's contrast AF as opposed to phase AF, so I am not using any of the f/2.8 stuff, right? Point is, if no f4 lens was planned and I would do landscapes only, I would never (or very rarely) actually make use of f/2.8... unless I'm missing something.