[Piotrek K]

I'm trying to explore which of my lenses are good enough for macro on Q (I don't want to buy 50 mm macro, because I don't have a plan to use it on a DSLR) I found that my Rikenon 50/2 on a small tube is really good as a macro lens substitute. But for greater magnifications M 40/2,8 seems to be also not that bad.

I have also DA 40XS that should be sharper then its M predecessor, but I use self made adapter without possibliity to control the aperture. So I'm thinking to get a new one from Fotodiox.

Am I right in thinking that I can use DA 40XS with a small extension tube (tube without A contacts) with Fotodiox adapter and it will allow me to adjust the aperture?

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Last edited by Piotrek K; 05-30-2014 at 03:33 AM. Reason: Spelling

[Na Horuk]

Wouldn't it be simpler and ultimately less expensive to get an old macro lens like Pentax M 50mm f4 macro or Pentax A 50mm f2.8 macro? You get aperture ring and everything and you can expect the lens to hold its value. Real macro lenses have many advantages, they are very sharp and have a flat field of focus, they have aperture ring with DoF scales and magnification ratio.. they go to at least 1:2 to begin with and with extension tubes (or on some adapted cameras) even beyond

[lytrytyr]

Real macro lenses have many advantages, they are very sharp and have a flat field of focus

Flatness of the focus field shouldn't be an issue with the tiny Q crop.

they have aperture ring

Are you suggesting that the D FA 100/2.8 WR is not a real macro lens?

SMC Pentax-D FA 100mm F2.8 Macro WR Reviews - D FA Prime Lenses - Pentax Lens Reviews & Lens Database

[Piotrek K]

Thanks for the replies so far. Well, I have five or six 50 mm lenses, so buying another one... I already have DA 40 XS, so it seems more logical to "invest" in a new cheap adapter. But I'm not 100% sure if the setup will work - maybe someone could clear this for me.

[Na Horuk]

Are you suggesting that the D FA 100/2.8 WR is not a real macro lens? SMC Pentax-D FA 100mm F2.8 Macro WR Reviews - D FA Prime Lenses - Pentax Lens Reviews & Lens Database

Ha! Caught me! I have that lens, and I think its only downsides are lack of aperture ring and focus limiter!
And sorry, I don't know about the tube and lens specifically

[lytrytyr]

Am I right in thinking that I can use DA 40XS with a small extension tube (tube without A contacts) with Fotodiox adapter

OK, if I'm understanding correctly, your setup will be:

Q, then Q2K adapter, then a "dumb" tube, then the DA 40 XS.

This would mean that your DA 40 XS will be wide open at f/2.8,
where it will be prone to CAs that will show up
on the ruthlessly unforgiving Q sensor.

it will allow me to adjust the aperture?

I don't think this will let you stop down the aperture
on a lens like the DA 40 XS that doesn't have an aperture ring.

As previous posters suggested,
you'd be better with a cheap old macro, like an M series,
which does have its own aperture ring,
or one of your current fifties.

[CFWhitman]

OK, if I'm understanding correctly, your setup will be:

Q, then Q2K adapter, then a "dumb" tube, then the DA 40 XS.

This would mean that your DA 40 XS will be wide open at f/2.8,
where it will be prone to CAs that will show up
on the ruthlessly unforgiving Q sensor.

I don't think this will let you stop down the aperture
on a lens like the DA 40 XS that doesn't have an aperture ring.

I thought that the point of the Fotodiox adapter with aperture control was to provide aperture control to lenses which would not otherwise have it, which should make the DA 40 XS work (although focusing it probably wouldn't be all that easy). Can you confirm that this is not the case?

@Piotrek K
If you can't make the 40mm work, then I suggest going with a macro of a different focal length than 50mm. I'd lean toward a 90mm since there were a lot of good quality ones made. Of course you should choose whatever focal length you can find at a reasonable price and you think would be good for you.

[lytrytyr]

I thought that the point of the Fotodiox adapter with aperture control was to provide aperture control to lenses which would not otherwise have it, which should make the DA 40 XS work (although focusing it probably wouldn't be all that easy). Can you confirm that this is not the case?

If OP is using a "dumb" tube between the adapter and the lens,
there'll be no way for the adapter to get control of the aperture in the lens.

Am I right in thinking that I can use DA 40XS with a small extension tube (tube without A contacts) with Fotodiox adapter and it will allow me to adjust the aperture?

I've used my Pentax adapter directly on my DA 40 XS,
and then, of course, you do get full aperture control.

And with the focus peaking, focusing isn't too bad, either.

[Piotrek K]

To clarify: the extension tbe I have has functionality equivalent to M series lenses. So on DSLR's it can stop down M lenses normally, but has no "A" contacts. I suppose it doesn't matter and in this case (for Q and adapter which can control the aperture) it functions exactly like "A" tube, but I'm not 100% sure - that's why I'm asking if such a setup will allow me to control the aperture.

[lytrytyr]

To clarify: the extension tbe I have has functionality equivalent to M series lenses. So on DSLR's it can stop down M lenses normally, but has no "A" contacts. I suppose it doesn't matter and in this case (for Q and adapter which can control the aperture) it functions exactly like "A" tube, but I'm not 100% sure - that's why I'm asking if such a setup will allow me to control the aperture.

OK, I just tried it with the Pentax adapter,
a Pentax extension ring whose functionality
should be the same as what you have,
and the DA 40 XS.

The lens does stop down as the aperture is changed on the adapter.
So if your Fotodiox is similar, you should be good to go!

[crewl1]

I thought that the point of the Fotodiox adapter with aperture control was to provide aperture control to lenses which would not otherwise have it, which should make the DA 40 XS work (although focusing it probably wouldn't be all that easy). Can you confirm that this is not the case?

It depends on the tubes.
Some dumb tubes like I have do not have any facility for moving the aperture lever, they are just empty tubes with bayonet mount.
In this example the fotodiox mechanism for aperture cannot reach the lens at the other end of the tube as there is no coupling.

[lytrytyr]

Larry, OP says his tube can stop down an M lens, so I'm thinking he should be good.

[CFWhitman]

It depends on the tubes.
Some dumb tubes like I have do not have any facility for moving the aperture lever, they are just empty tubes with bayonet mount.
In this example the fotodiox mechanism for aperture cannot reach the lens at the other end of the tube as there is no coupling.

I do realize that. I had the impression he had a tube with the aperture control lever. It occurred to me after I had posted, however, that there could be some problems related to the way they changed the aperture coupling between the original K-mount and the KA-mount from being proportional to the diameter of the aperture to being proportional to the area of it. I'm pretty sure that the tube, though, being "dumb," would just move the lever on the lens the same amount as the lever on the adapter, so I think it should be alright since the adapter is designed for the newer lenses that have no aperture control of their own. The adapter's design should be the only thing that matters as long as the tube does have an aperture lever. This would be a problem with using the tube on a new K mount body (well, KAF2, technically) with a new DA lens. The tube would appear to the camera as an old K or M lens and the aperture would open err, close the wrong amount.

[crewl1]

Thanks for the clarification folks, didn't see the post describing the tubes.

[Piotrek K]

...I finally ended with some different setup that seems to work really good. This consists of EL-Nikkor 50/2,8 (enlarger lens in M39) plus M39 - M 42 adapter plus M42 chinese variable extension tube.This is small, so good for the Q and significantly sharper then my standard 50's.