*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Hi David,

Thank you for your input. That is reassuring. However, a colaborator of
ours has had the unfortunate experience of damaging irreperably a Nikon
1.49 100x lens. Twice! For his experiments he had been pumping all 4 lasers
(in the range of a few hundred milliwats each) for several minutes. We are
considering getting a 1W 488 laser since it's supposed to afford extra
flexibility on the choice of fluorophores. It's CW and not pulsed, but
still makes us wonder if there isn't an extra risk of damage. Thus, looking
into Leica's lens. As an added bonus it seems to have the highest
transmission in the IR of most lenses I've seen (80% @ 900nm). Also, they
have a new 160x model which Nikon lacks.

Best,
Pedro


On 30 May 2013 16:02, David Baddeley <[log in to unmask]> wrote:

> It would be interesting to know how it's been optimised, rat
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi Pedro,
>
> It would be interesting to know how it's been optimised, rather than just
> that it's been optimised. We use the Nikon 60x 1.49 NA TIRF lens for
> dSTORM, and it generally works well (it's significantly better than the
> standard 100x 1.4). We haven't had any issues with laser induced lens
> damage with over 4 years of use. That said, it's not perfect (there is
> significant field curvature, the correction is only any good on axis, and
> the lens autofluorescence is higher than it could be). I guess the question
> of whether the leica objective is usable would come down to which
> corrections they've spread. If it's just chromatic abberation then you're
> going to need to correct that in software regardless of what objective you
> choose, so it might not be a big deal if the initial abberations are bigger
> (within reason - you want the axial CA to be sufficiently small that
> both/all colour channels are within ~ 300nm, although depending on where in
> the spectrum you use it
>  this might not even be the case for the Nikon objectives). If the
> spherical abberation correction is spread however, you have a much bigger
> problem as there's no real way to correct this in software. In general I'd
> be worried about the lack of a spherical abberation correction collar on
> the GSD objective as it's almost essential once you get to those NAs.
>
> If you are worried about laser damage, which the 'handling
> large amounts of laser power' comment might imply, objectives are
> surprisingly hardy. I have seen a couple of very expensive Leica objectives
> with the characteristic 'black spot of death', but this was caused by
> focussing a ~1W TiSa beam to a 1-2 um spot in the back focal plane. CW
> exposures of a few hundred mW don't seem to be problematic. Problems
> typically occur when you inadvertently focus your beam on a cement layer
> within the objective. It's probably worth noting that dSTORM (and all the
> other variants) is insensitive to beam collimation in the sample, so you
> have a lot of flexibility about where the beam focuses behind the lens.
> Also because you're typically only illuminating a smallish ROI to achieve
> high illumination intensities the spot in the back focal plane is
> correspondingly larger and less likely to damage the optics.
>
> cheers,
> David
>
> ________________________________
>  From: Pedro Almada <[log in to unmask]>
> To: [log in to unmask]
> Sent: Monday, 27 May 2013 1:19 PM
> Subject: Re: Objective Corrections by Maker
>
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Dear Justin,
>
> Yes, you're right. Testing really would be ideal. The problem is that we're
> looking into Leica's special 160x GSD lens (refered to as the GSD Optics
> Kit on the lens list). It's supposed to be especially manufactured to
> handle the massive amounts of laser light used in GSD and dSTORM
> microscopy. Since we want to build a dSTORM microscope it sounds perfect,
> but the Leica body is not very good for inhouse applications compared to a
> Nikon or ASI RAMM. But apparently, for a demo of the objective, we'd need
> to request a demo of the whole GSD system which is not really our
> purpose...
>
> Maybe I can find someone with a GSD and a Nikon microscope and go do some
> PSF's!
>
> Best regards,
> Pedro
>
>
> On 27 May 2013 17:53, Justin Price <[log in to unmask]> wrote:
>
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > *****
> >
> > Dear Pedro,
> >
> > Yes, the tubelenses between each if the major four commercial vendors
> vary
> > with Zeiss and Olympus I believe both being 180 (someone please correct
> me
> > if I'm wrong), but vary in correction schemes.
> >
> > If you have your heart set on a particular objective that you have in
> hand
> > for an available scope you should just test it out.  If the barrel of the
> > objective and the threads on the nosepiece are compatible I would then
> > suggest to scan 100nm beads and collect multicolor PSFs.
> >
> > The information collected from the experiment will allow you to asses the
> > performance with the mismatch and allow you to compensate for final
> > processing and analysis.
> >
> > If you do decide to try this experiment please share what you find. I'd
> be
> > interested to see what pops.
> >
> > Best regards,
> > Justin
> >
> >
> >
> > On May 27, 2013, at 6:37 AM, Zdenek Svindrych <[log in to unmask]> wrote:
> >
> > > *****
> > > To join, leave or search the confocal microscopy listserv, go to:
> > > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > > *****
> > >
> > > Hi there,
> > >
> > > unfortunately, even the same vendor changes the compensation scheme
> from
> > > time to time. I remember that for our new confocal the old objectives
> > from
> > > SP2 were not ideal, as the tube lens had changed... (maybe they just
> > wanted
> > > to sell more objectives, I'm sure the images would be fine; we didn't
> buy
> > > the new lenses nor the new fonfocal yet :-).
> > > See e.g. this document (page 10):
> > http://www.mikrol.ru/fileadmin/downloads/
> > > Other/Publications/Leica_STI_CDR1_Schade_et_al_eng.PDF
> > >
> > > I believe that the new Olympus objectives are fully corrected. We often
> > use
> > > them with a simple achromatic doublet tubelens and the image is fine
> > > (although we are not doing confocal imaging, which is more sensitive).
> > >
> > > Cheers,
> > >
> > > zdenek
> > >
> > >
> > > ---------- Původní zpráva ----------
> > > Od: Pedro Almada <[log in to unmask]>
> > > Datum: 27. 5. 2013
> > > Předmět: Re: Objective Corrections by Maker
> > >
> > > "*****
> > > To join, leave or search the confocal microscopy listserv, go to:
> > > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > > *****
> > >
> > > Dear Listers and Guy,
> > >
> > > Yes, you are right. Their original answer was just that the tubelens
> was
> > > achromat so I was hoping someone knew more specifically. On your
> > > suggestion, I pressed more and he said this:
> > > "Our Product Manager has confirmed that the correction are made on
> both:
> > > objective and tube lens."
> > >
> > > So I guess their lenses aren't exchangeable with Nikon! Sad to hear.
> > >
> > > Thank you,
> > > Pedro Almada
> > >
> > >
> > > On 24 May 2013 10:45, Guy Cox <[log in to unmask]> wrote:
> > >
> > >> Demand a definitive answer from Leica. You are spending big money here
> > >> and obviously back at Wetzlar there is someone who can answer your
> > >> question. From what I have heard, only Nikon state definitively that
> all
> > >> corrections are done in the objective, but I would be very interested
> to
> > >> hear any further information.
> > >>
> > >> Guy
> > >>
> > >> -----Original Message-----
> > >> From: Confocal Microscopy List [mailto:
> [log in to unmask]
> > ]
> > >> On Behalf Of Pedro Almada
> > >> Sent: Friday, 24 May 2013 6:45 PM
> > >> To: [log in to unmask]
> > >> Subject: Objective Corrections by Maker
> > >>
> > >> *****
> > >> To join, leave or search the confocal microscopy listserv, go to:
> > >> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > >> *****
> > >>
> > >> Dear list members,
> > >>
> > >> This another non confocal question but I believe it fits the interests
> > of
> > >> the list. We're trying to find out if Leica does any of the
> corrections
> > > for
> > >> it's objectives on the tube lens. We've heard that Olympus and Nikon
> do
> > > all
> > >> corrections on the objective itself but Zeiss requires the correct
> tube
> > >> lens. Is this accurate? I've asked our Leica rep but he couldn't
> answer.
> > >>
> > >> The reason we're asking is that we have a Nikon body but we're very
> > >> interested in a specific Leica lens. They use the same thread and tube
> > >> focal distance, only the parfocal distance is different and we can
> live
> > >> with that...
> > >>
> > >> Any insight is appreciated!
> > >>
> > >> Best,
> > >> Pedro Almada
> > >> "
> >
>