Hi Derek

Just so everyone can see, I've taken a shot tonight at F16, 200 ISO with a softbox attached to my manual flashgun. The lens is a Pentax 100WR Macro on the end of a full set of extension tubes with aperture contacts. The shot is just my Marshall Guitar Amp knobs, not very exciting, but I can tell you that each knob is 2.5cms (1 inch) apart. So you can see what depth of field F16 gets you on the end of full tubes.




This is far more usable for general macro work than F2.8!

Hope this helps.

Hello and welcome from me too.


Regards
David

I agree to a point, but at F16 it would be nowhere near as extreme as Derek's images in this post are, not as extreme as the one I've uploaded to the post.

I've done a lot of work on this type of photography, F16 produces a usable DOF, even with tubes attached.

Regards
David

Nicely shot, very sharp and great colours.

Regards
David

I think John has hit the nail on the head here regarding price rises. Aren't Canon, Nikon, Olympus and Fuji products manufactured overseas? The Sterling depreciation will hit all equally so relative value should remain the same when comparing Brands. That makes it simpler for us! All we need to worry about is whether we want Pentax in preference to other Brands, whether we need / want to upgrade and whether or not we can afford it!

Regards
David

No problem Derek, glad I could be of assistance. However, once you've sorted out this issue I suspect your next problem will be that the flash isn't bright enough. It took me a long time to get a workable solution for apertures of F16 or thereabouts, you really need a lot of diffused light to make this work acceptably. Macro has to be the hardest of photography disciplines to get right.

Cheers
David

Thanks Derek, I have spent a lot of time practising macro in our back garden, with all manner of different equipment combinations. I did once have a Sigma 105 DG EX macro lens on the end of a full set of tubes and found out that it was always operating at F2.8, regardless of the aperture set on the lens. I now have a set of tubes with full contacts, so don't have an issue, but your images look a bit like some of mine at F2.8. Actually, using F2.8 on a full set of tubes is an interesting experience and can result in some pretty dramatic looking images, so much so that I started to use it intentionally sometimes. I've posted this image before so you might have seen it, this is an example of F2.8 on a 105mm macro lens, with a full set of extension tubes:




Cheers, David

Hi Derek

Are you sure the aperture was F32? Are your tubes the kind with aperture contacts? Even with full tubes I am surprised how thin the DOF is and I wonder if it's possible the tubes affected the ability to set the desired aperture and whether the camera was actually shooting at max aperture?

I might be completely wrong here, but these shots don't look as though F32 was used.

Regards
David

The lighting on these is nice and I would be interested to know what aperture was used as the DOF is wafer-thin. Not sure if the flash is up to shooting at smaller apertures to gain depth of field?

I find when shooting macro that the light source is the most important factor, i.e. it must be diffused and it must be powerful enough to shoot at apertures of F11 - F16, to get at least a bit of DOF. The best compromise I've found to date is a home-made softbox attached to a powerful manual flashgun.

Regards
David

It's all subjective and I actually don't think Chris Nicholls gives a poor review of the KP. I think he hits on some specific areas where he feels it doesn't justify the cost, especially when comparing to the K70, which I can't disagree with. BTW, I have no hands on experience with either the KP or the K70, so my opinion is based purely on what I see on the web and what people say on sites like this one.

FWIW, I still get the performance I need from my K-5iis and my K-3 mk1, I don't feel any need to upgrade at present. A quantum leap in AF performance would tempt me, as would high ISO performance as good as a K-1.

Regards
David