Valid point or not - lens sharpness

I've posted a couple of threads recently on here and other forums as I'm considering my lens options. I currently use the Sigma 17-70 most of the time and whilst pleased with it wonder if the move to Prime lenses would provide me with better IQ/sharpness, especially as I've now upgraded to the K20D which without doubt provides more image detail than my previous GX10

A comment posted on another forum was to the effect that if you shoot predominately around F8/F11 (which I do) then the difference between a Prime and a zoom is less significant.

Interested in other peoples thoughts on this?

thanks

Simon

Simon, judging by your pictures I have seen, I don't think you have anything to worry about. They are beautiful

I'd pretty much agree on that. However, there are other factors involved other than sharpness. For example:
* Bokeh
* Colour rendition
* Contrast
* Distortion

However, having looked at your gallery (briefly) I would say there's not much to worry about

If you need a little extra sharpness, then you may find that a slight adjustment in post production workflow will give that to you for nothing rather than investing in primes.... although primes are rather nice (Only primes I have now are the 50/1.4 and 100/2.8 macro since the modern Pentax zooms are so darn good!)
Matt

One of the nice things about a prime is that it offers just one focal length so in some ways there's less to think about and I find it makes me move about more to get the composition just so.

They are also much smaller and discrete in use.

Mike

what on earth is Bokeh?

Feeb, Goggle is your friend but in general it's a much used and abused term relating to the treatment of out of focus objects. Look for Lilly's recent thread on the 21 ltd where I think you'll get an example of what's thought of as good bokeh.

Mike

Everything you always wanted to know about Bokeh, but were afraid to ask.

Martin.

Thread diversion now that this tread lost its legs, advice required again from Matmatic if you would be so kind.

As lens prices are set to rise I have spotted a 100m macro for a good price and just wondered if you think it would be a good idea get it while prices are low.

I don’t go in for bugs but do a lot of plant and landscape pictures, I currently have 17-70, 55-300 & 50-1.4. I can fill the frame with most of my shots but I do have to get close would you expect that I would get a visible benefit from 100m macro?

It is just timing is not good as I have just started on a project on my other hobby i.e. a new engine build for my toy.

Thanks for your help

Jim

Jim,
Difficult to answer for you... but here are some thoughts. I have the SMC-F 100/2.8 macro. It's a lovely lens, and gets used very occasionally for true macro work (flowers mostly). However, its main use was for low light stuff. And I bought a DA*50-135 (before the price hike :shock and that is utterly sublime! So, the macro now gets used hardly at all
I'm split between selling it on to help fund an iMac, and keeping it - since when it does get used for macro (like on extension tubes) there's nothing else that can touch it for super macro and quality.

It's a heavy little lens and not one that gets carried around much. But it is very, very good (sharp, contrasty, flat field).

To get 1:1 macro you'll be around 31cm away. Check out Bojidar's site: http://kmp.bdimitrov.de/lenses/primes/short-tele/F100f2.8-Macro.html

HTH!
Matt

I have the 100mm FA, and it gets very little use. It's a superb lens, but most of the time I don't need to get to macro distances.

Is the macro more of a theoretical benefit than an actual one?

Can't bring myself to sell it though.

Thanks Mat / John

Stay with plan A then.

Jim