Just out of curiosity, are you shooting with Pentax? In one of your posts you where referring shooting with a 50-135mm lens if I remember correctly..
If so – why did you choose Pentax?
There are numerous reasons I went down the Pentax route (after having a Canon 40D + 50D and initially starting out with Sony). So I'll list them in no particular order. Keep in mind this is what applies to me, and that all camera systems have their advantages and draw backs.
The short version: Pentax has lenses that I like and need, and I like Pentax's focus on their products
At some point, I decided that I didn't really need more than APS-C. Equipment afficionados will wax lyrical about the benefits of full frame cameras, but for my needs which is weddings and portraits FF adds no visible benefit. I'm sure you could pixel peep and find some minute difference in quality, but if you use a decent RAW converter like DXO for large prints the point is practically moot. For weddings, I rarely go larger than 8x10" and for portraits I've never gone larger than 20x30". I'm sure you can point to numerous wedding photogs who use full frame and medium format bodies. My response to this is two fold: They charge more than I do
and my work will improve more if I improve my technique rather than improve my gear (which is pretty high end to begin with).
With that out of the way, what benefits do APS-C bring to the table? The things that matter to me are size, weight and price. The 50-135mm lens is half the weight and half the price of the equivalent 70-200mm f/2.8. The weight aspect is significant because I'm running about with the camera for hours. The price aspect is significant initially, but you should pay off the price of your equipment over time if you're taking on paid assignments.
So why Pentax as opposed to other manufacturers with cropped sensors? Olympus with their 4/3rds sensor means that I'm going to have to sell a lot of 8x10" prints or I'll have to constantly crop to a 3:2 aspect ratio
. Ideally, I'd like the equivalent
of a 24-70mm + 70-200mm lens for APS-C as this is a useful range for the stuff I do. Sony do not have any lens then matches this criteria, unless you go full frame. Canon and Nikon have the 17-55mm, but no 50-135+mm. I had a 70-200mm lens on my 50D for a while and I found that range to be a little too long on APS-C. On full frame, it'll be ideal as you can get zoom out to get full length portraits and then immediately zoom in to get close ups.
Then you have Pentax. Given that they have repeatedly stated that they have no full frame ambitions, their lens line up has been tailored to suit the APS-C shooter. The 16-50mm + 50-135mm is a very very
. Compared to the Nikon/Canon equivalents, the DA* 16-50mm is weather sealed, holds up optically, and has IS (Nikon has none). The DA* 50-135mm has no equivalent in the Canikony camp, and you're either forced to buy the 70-200mm f/2.8 which is twice as heavy and twice as expensive, or you have to get the Sigma 50-150mm HSM.
Then there is other miscelleneous stuff. Pentax supports DNG natively, saving me the step of converting them during import. The rarity of Pentax is also particularly nice when covering weddings where half the guests have DSLRs and seem to love checking out the photographer to see how their gear stacks up. Most just see Pentax and have no idea what to make of it
. The Pentax K-7 is also a very nice camera.
The things that annoy me about Pentax as a system: 1) Maximum flash sync speed of 1/180. Seriously, get with the program and give us 1/250! 2) Give us a more capable wireless flash system built-in to the cameras. Nikon have CLS, Canon have whatever their system is called, both are capable of triggering multiple channels and thus specifying ratios. Pentax have 1 channel, meaning you have to set the ratios on each flash individually.
Common whines on forums that have little to no impact on actual photography:
1) Pentax has poor high ISO performance. Irrelevant as this only applies to JPEG. Shoot RAW, use a decent RAW converter and the point is moot.
2) Pentax AF is not fast enough. It's fast enough for my uses and the majority of photographers. 51 AF points with continuous 3D tracking is nice to have, but we've been taking photos for over 100 years without autofocus. I think we can cope
3) Pentax K-7 has poor dynamic range. This is again a JPEG problem. If you're bothered about this, you're probably shooting RAW... so what's the problem?
Anyway, that's enough of a rant from me.