Letus Extreme and...

[Tom Burt]

Sounds like something is seriously flawed... Perhaps you should go after that refund.

In my experience, the adapter is not an easy piece of equipment to work with when it comes to adjusting and then maintaining back focus - and especially not for the average person without any experience with collimation and shimming. I have been far from impressed with Letus's build quality and some of their oversights... Of course these problems are no different than those I've found in other inexpensive adapters – inexpensive when compared to the P+S or MovieTube adapters.

However for me… Despite being a pain, it does make a nice image… And as long as it doesn't compromise my work in the process, the nice image is what counts. I bought it to use on the same specs and low budget projects that I used to use the P+S on... My feeling is that optically, it blows the P+S away... And I'm willing to put up with a little extra work if it get's me a better image... I'm not crazy about the extra hassle, but nothing is free.

[Piotr Wozniacki]

I have taken some pictures (with my mobile - sorry for the very poor quality; I was in haste), showing what happens to the front tube alignment with the front bracket after I turn the adapter on its thread ring in my EX1, so that the GG rectangle is level in the viefinder.

In spite of the poor pictures quality, it's obvious that - with the camera and the adapter on rails - I can either have the front bracket aligned and the screw tightened but the GG twisted as per the pictures I posted earlier in this thread, or have the GG level, but the front tube unable to rest on the bracket and the two connected with the screw.

I hope Aaron will address this obvious machining error...

[George Kroonder]

Originally Posted by Piotr Wozniacki

Couple of days ago, Aaron has offered issuing RMA to me as well - does anyone know how it works from Europe? When first importing my LEX bundle, it spent 2 weeks at the customes, and I had to pay the duty and VAT an the total price (Fedex rate included !!!)

Hi Piotr,

This should be fine as long as Letus marks it apropriately (as 'no value' repair/exchange) as I'm sure they will. Be sure to keep your reciept for returning the 'old' unit; customs may ask for it (but I've never had them do so).

George/

[Piotr Wozniacki]

Thanks George for reassuring - do you know if the RMA number as provided by Letus (in the form of just passing its value with e-mail) is of any meaning to the way customs may handle it? I'm asking, because a customs officer told me on the phone today that if I have it printed on paper, it will suffice to clear it hassle-free both directions - but I understood it's supposed to be a document, not just a number per se...

Apart from the customs procedures, what still holds me from sending my LEX back not being certain that what I'll get back will be completely flawless. Is it possible that all other units are OK, and I was unlucky enough to get mine plagued with all kinds of possible flaws?

[George Kroonder]

Hi Piotr,

Just include a copy of the e-mail in the box (always good) and you could attach another one to the FedEx form. Usually I find it enough to mark it as "warranty repair" on the customs documents/shipping label. Letus will do something similar, and you should be fine.

You seem to have more than your fair dose of 'bad luck', but I believe you can expect to get the unit back fixed. The crooked GG seems really bad. I'd include a checklist of everything you believe is amis with the unit when you send it back.

George/

[Piotr Wozniacki]

Not having any support from Letus, and with a very important project coming soon - I managed to make my Letus usable (far from perfect - the GG' stands pushed back in order to stop the whining, but at the cost of infinity softness; the GG not level but at least being able to fix the front tube on the rails, etc).

Now I am facing another problem: when setting the critical focus of my EX1, with GG stationary (and of course without lens), I cannot get the peaking to be even close to uniform over the whole frame. When it's on in the middle (only possible near the upper edge), it disappears at both sides; slightly turn the focus ring and it appears on the right side, but vanishes from the middle; it never appears on the left side!

Now, is this how the new, "improved" EX1 achromat is supposed to behave? I don't think so; in fact I have serious doubts whether mine is indeed the improved version (it came fixed to the main adapter body, not as a separate screw-on part). What do you think?

Another reason for non-uniform focus might be the GG is not planar; given the nature of push/pull actions involved in back-focus adjustment, and how crude and unstable that is - it almost seems impossible to ensure it's 100% planar!

And indeed - after I set it to peaking near the GG's middle area and put a lens on, my test shots exhibit considerable softness near the edges (particularly the right one - funny, because the left edge area has been impossible to achieve peaking at all, and yet it's much sharper with the lens on)...

Any comment welcome!

[Sean Donnelly]

I'd be willing to bet that the GG position is the source of your focus problems. If rolling through the focus causes the peaking to move left/right, I'd say it is very likely the GG is shifted. These are very minute changes, and I'm honestly a little surprised about the crudeness of the adjustment. For some reason I remember Steve Cahill saying the improved Nikon mount has a depth adjustment?

-Sean

[Jeremy Hughes]

It does, kinda. You can push and pull it out slightly before you lock it down with the alen wrench