Cheers Steve, plenty of useful info there,
Thanks for clarifying the aperture control, it made no sense that it couldn't be controlled via camera. Now it does rule out the bellows but maybe not the tubes with contacts.
It's hard to see why it wouldn't work.
Looking forward to further updates.
Hope the missus is better soon.

Derek

Cracking shots, and blog, if subscribed.
Little bit confused as to what lens, was actually used, Flickr exif says pentax f 35-70mm lens, but focal length say 20mm, and you say irix 15mm.
Regardless, cracking shots both. 👏👏👏

I don't use a hood as I have my own built into my ring flash diffuser.
I'd like to see a sample shot with irix at min focus distance and with the 100mm at min focus distance. At any aperture. Of same subject.
I have never used the distance scale on any lens, so no loss or gain for me.
Still don't know how you change aperture

Nice post, (fantastic 2nd post) makes some interesting points.
I have long lusted over Mike's lovely 180mm macro, but the cost is rather prohibitive, (for me) .
When I saw the initial preview of the irix I thought, this might be worth going for.
But then the bombshell, for me anyway, there would be no aperture ring, strange decision to do that to a macro lens, I do most of my macro shooting with bellows , so I knew the bellows were out. But then I had a thought, ext tubes with contacts should work and still allow the changing of aperture via camera, game on again. Then I read a review on the US forum that said ext tubes won't work either.
Game called off again.
I did ask the question on the forum but to be honest I didn't really get the why they won't work.
So hopefully seeing as you have one you can help me out here.
If the aperture is not controlled via camera body. Nor via aperture ring, just how do you change the aperture ?
Have you tried the lens with ext tubes ?
I too use a sigma 105mm for my macro shooting at present, although there is a Lester dine 105mm on its way to me as I write.
I would love a longer fl, so am rather keen to hear your answer if you can help clarify things.

Cheers
Derek

Fantastic Bill.

Of course we'll mind you, someone has to

Doesn't look like moire to me, looks lens related ( I could easily be wrong though ), have you tried taking the lens off and shining a light through to see if it shows up anything ???

You wouldn't have to shoot using the rear screen / live view. It would only be for the purpose of fine tuning the af,
It would do 2 things for you.
1 give you an accurate target to compare your af against, so it can be fine tuned properly.
2 it will show up if the af cannot be fine tuned enough to correct for front or back focusing.
In which case you could try Jak' s suggestion.

You can use live view to check the accuracy of your af, and keep adjusting till both are the same.
Live view is not affected by front or back focus issues. Take a test shot using live view, this should be accurate. Now switch back to vf, and fine tune to match your test shot.

Not sure Haris if he's talking about the stuff floating in the pond or there seems to be a touch of flare maybe or something on the lens, roughly mid wing on both shots.
As Haris said, the green bits are of course perfectly natural.

Makes sense now David. Thanks for that.
Genuinely didn't know.