Hi Toshihiko, Andrea, I don't see any strong reason why we should cut off the red side of the z' band (I believe the reason PanSTARRS make this cut is because they also have a y filter which covers the wavelength range redward of z'). I think we should have a combined i'+z' filter with the following cuts: blue cut off: the same as SDSS-i' (i.e. RG695) red cut off: the same as SDSS-z' (i.e. no cut off - it is a long-pass filter) So, we simply want a combined SDSS i'+z' filter. Hope this is clear. Regards, Vik. Vik Dhillon phone: +44 114 222 4528 Dept of Physics & Astronomy fax: +44 114 222 3555 University of Sheffield email: vik.dhillon@sheffield.ac.uk Sheffield S3 7RH, UK web: www.shef.ac.uk/physics/people/vdhillon On 6 March 2012 06:49, Toshihiko Kimura wrote: > Dear Dr.Richichi, > > Yes, we recently supplied Sloan filters for ULTRASPEC to University of > Sheffield. > > >> -transmission equivalent to combined i'+z' > > > Please check the attached transmission data. > Basically, the blue side of Sloan i'-passband is defined by RG695 (4mm), > and Sloan z' is defined as *longpass*, not broad bandpass such as Pan- > STARRS z. > So I may understand the spectral response of just RG695 is equivalent to > "combined i'+z'" ? > > If e.g. the sharper slope is preferable for you, or you want to cut off the > red side of passband, please let me know. > We can arrange the spectral performance as you request. > > Regarding the calculation about the parfocal, we simulated many times > for ULTRACAM and ULTRASPEC. We don't have any issues. > > Sincerely, > > ------------------------------------------------------------ > Toshihiko Kimura, Overseas Sales Manager > Asahi Spectra Co., Ltd. > Gardenia Bldg. 4F, 2-13-1 Kamijujo, Kita-ku, > Tokyo 114-0034 Japan > Phone : +81-3-3909-1151 Facsimile : +81-3-3909-1152 > e-mail : t-kimura@asahi-spectra.co.jp > ------------------------------------------------------------ > > -----Original Message----- From: Vik Dhillon > Sent: Monday, March 05, 2012 7:32 PM > To: Andrea Richichi ; Toshihiko Kimura > Subject: Re: CV project > > > Hi Andrea, > > Sorry for my delayed response. > The draft email looks good. > My contact at Asahi is Toshihiko Kimura (t-kimura@asahi-spectra.co.jp) > - he should be able to send you a quote quite quickly. > > Regards, > > Vik. > > Vik Dhillon phone: +44 114 222 4528 > Dept of Physics & Astronomy fax: +44 114 222 3555 > University of Sheffield email: vik.dhillon@sheffield.ac.uk > Sheffield S3 7RH, UK web: > www.shef.ac.uk/physics/people/vdhillon > > > > On 29 February 2012 03:09, Andrea Richichi wrote: >> >> Thanks Vik. >> I agree with you that i+z is good... atm and QE will do >> the rest. I have drafted an email for the company, >> pls check. Can you give me a contact at Asahi please? >> (there seem to be various companies with a simple >> google search). >> Assuming they can make in a few months, I'd probably >> wait a little for the actual order. But I'd like to know >> the price early for some planning here. >> cheers >> Andrea >> >> Dear >> I have received your contact from Prof V. Dhillon of >> Sheffield University, for whom you manufactured >> already several filters for the ULTRACAM and ULTRASPEC >> instruments. >> I would be interested in a preliminary quotation on >> feasibility, delivery time and price for an additional >> filter to be mounted inside ULTRASPEC, with the following >> characteristics: >> -size 50mm square >> -AR coating >> -parfocal with the other ULTRASPEC filters >> -transmission equivalent to combined i'+z' >> (or approx 7000A cut-on, >11000A cut-off) >> >> Also mention please terms for payment. >> The shipment would be to Thailand. >> >> with best regards >> >> >> >> On 28/02/2012 11:51, Vik Dhillon wrote: >>> >>> >>> Hi Andrea, >>> >>>> yes, a filter for occultations would be good (and I could actually >>>> charge it on another budget). In this case, I'd go as red as >>>> possible, without starting to hit the response of your detector. >>>> How far in the red does it go? >>> >>> >>> I attach the AR coatings that will be applied to our lenses. I also >>> attach a plot showing the CCD QE and atmospheric cut-off (along with >>> our SDSS filter profiles). For the red cut-off, I'd recommend you do >>> like the z' filter does in the attached plot, and allow the CCD >>> response to make the red cut-off (i.e. make the filter have 100% >>> transmission well beyond 1000nm). >>> >>>> You mention a possible use also for exoplanet eclipses >>>> with r'i'z' combined... meaning 600 to 950 nm? >>>> If we made it narrower, such as 700 to 950, would it be a >>>> problem for exoplanets? For occultations, I am worried about >>>> scattering in the atmosphere, and also most of the interesting >>>> stars would be very cool. >>> >>> >>> I think a blue cut off of 700nm for the exoplanet work will be fine. >>> Basically, what we're asking for here is a i'+z' filter combined, >>> which would be a nice easy way of specifying it to Asahi. You would >>> also want to tell them to make it parfocal with the other SDSS filters >>> that they have just made for us. >>> >>>> I remember that in order to actually achieve very fast response >>>> with ULTRASPEC you would need to "hire" a specialist... what >>>> is the likelihood of that happening? And what would be the >>>> (realistic) fastest frame rate? I'd be happy with a ~ 5x5" field. >>> >>> >>> I think this is very likely to happen now, as I have just received new >>> grant funding to cover this kind of work. >>> >>> I've not simulated the resulting speeds that we will be able to >>> obtain, but I guess the maximum will be something like 100 Hz. >>> I'll let you know when I have calculated an accurate value. >>> >>> Cheers, >>> >>> Vik. >>> >>>> On 23/02/2012 13:21, Vik Dhillon wrote: >>>>> >>>>> >>>>> Hi Andrea, >>>>> >>>>> Thanks for the email and sorry for my slow response, due to the start >>>>> of the new teaching term here. >>>>> >>>>> 330kB ~ £7000, so a fraction of this would indeed be enough to filters >>>>> for ULTRASPEC. For your information, here are the filters we will have >>>>> on day 1 of ULTRASPEC operations on the TNT: >>>>> >>>>> SDSS u'g'r'i'z' >>>>> Clear filter (i.e. 300-1000nm) >>>>> Halpha (narrow, ~50A) >>>>> Halpha (broad, ~100A) >>>>> CIII/NIII+HeII (around 4686A, isolating a well known emission line in >>>>> accreting NS, WD and BH binaries) >>>>> red continuum (a largely line-free region around 6000A) >>>>> blue continuum (a largely line-free region around 5150A) >>>>> NaI (D lines, broad, 300A) >>>>> >>>>> We have 2 x 6-position interchangeable filter wheels, by the way. >>>>> >>>>> Can you think of any other filters that might be useful for your >>>>> occultation work? >>>>> >>>>> One good filter for exoplanet work, for example, would be a red one >>>>> that combines r', i' and z', which would be optimum for finding the >>>>> eclipses (not transits) of exoplanets. >>>>> >>>>> Note that all our filters are custom-made 50mm square and are designed >>>>> to be par-focal with each other, so that they should not require a >>>>> telescope focus change. This makes them reasonably expensive. I >>>>> normally order filters from Asahi in Japan (who made the original >>>>> sloan filters for the SDSS project). They are an excellent company, >>>>> and are well used to working with our ULTRACAM/ULTRASPEC requirements. >>>>> They typically charge US$ 1000-2000 for a custom filter (you normally >>>>> get two for this price, which is the minimum order number). >>>>> >>>>> Cheers, >>>>> >>>>> Vik. >>>>> >>>>> Vik Dhillon phone: +44 114 222 4528 >>>>> Dept of Physics& Astronomy fax: +44 114 222 3555 >>>>> >>>>> University of Sheffield email: >>>>> vik.dhillon@sheffield.ac.uk >>>>> Sheffield S3 7RH, UK web: >>>>> www.shef.ac.uk/physics/people/vdhillon >>>>> >>>>> >>>>> >>>>> On 20 February 2012 02:59, Andrea Richichi >>>>> wrote: >>>>>> >>>>>> >>>>>> Dear Ira and Amornrat, >>>>>> just to let you know that, effective March 1 for 12 months, >>>>>> some small budget is available at NARIT for the project on >>>>>> Cataclysmic Variables. It amounts to 330kB, so not a lot >>>>>> to splurge on but perhaps sufficient for some >>>>>> observation or conference trip, publication, or small expenses. >>>>>> If you have suggestions on how to use this money please >>>>>> let me know soon. >>>>>> As far as I know, there should be a parallel request to the >>>>>> National Research Council still under consideration. >>>>>> >>>>>> FYI Vik, >>>>>> this money could be used also to make small contributions >>>>>> to ULTRASPEC such as for example extra filters etc - although >>>>>> I can't really say what would be the burocratical burden of >>>>>> ordering from here. Let me know if something occurs to you. >>>>>> >>>>>> regards >>>>>> Andrea >>>>>> >>>> -- >>>> ----------------------------------------------------- >>>> Andrea Richichi >>>> NARIT >>>> National Astronomical Research Institute of Thailand >>>> 191 Siriphanich Bldg., Huay Kaew Rd., Suthep, Muang >>>> Chiang Mai 50200 >>>> Thailand >>>> Tel +66 (0)53 225569 ext 402 >>>> Fax +66 (0)53 225524 >>>> http://www.narit.or.th/en/ >>>> >> >> -- >> ----------------------------------------------------- >> Andrea Richichi >> NARIT >> National Astronomical Research Institute of Thailand >> 191 Siriphanich Bldg., Huay Kaew Rd., Suthep, Muang >> Chiang Mai 50200 >> Thailand >> Tel +66 (0)53 225569 ext 402 >> Fax +66 (0)53 225524 >> http://www.narit.or.th/en/ Dear Dr.Richichi, By the message from Prof.Dhillon yesterday, I understand just RG695 will be equivalent to i' + z'. I would be interested in a preliminary quotation on feasibility, delivery time and price for an additional filter to be mounted inside ULTRASPEC, with the following characteristics: Please check the attached file. -size 50mm square -AR coating -parfocal with the other ULTRASPEC filters Sure, we will meet the requirements as above including the parfocal. AR film should be coated on both surfaces of RG695. We will polish the substrates with round shape, and then cut it with square to keep the good surface quality. Also mention please terms for payment. The shipment would be to Thailand. When you will confirm the arrival of carton, please remit to our bank account. And if you have the preferable shipping method, please let me know. Total amount is less than USD1,000, so I suppose EMS might be OK. The fee costs USD30. Sincerely, Toshihiko Vik Dhillon vik.dhillon@sheffield.ac.uk 22 Mar to Toshihiko, Andrea Hi Toshihiko, Sorry for my slow response to your email. $550 for each filter sounds like a reasonable price. We would like to place two separate orders, if that's ok, with one order for Andrea in Thailand and the other for me in the UK. Would you be able to send each of us a new quotation, including delivery? Thanks for your help, Vik. Vik Dhillon phone: +44 114 222 4528 Dept of Physics & Astronomy fax: +44 114 222 3555 University of Sheffield email: vik.dhillon@sheffield.ac.uk Sheffield S3 7RH, UK web: www.shef.ac.uk/physics/people/vdhillon On 9 March 2012 07:57, Toshihiko Kimura wrote: > Dear Prof.Dhillon, > > >> So you will have to add approximately 1mm >> of fused silica to make this filter parfocal with the ULTRASPEC > > > Absolutely, we must do so. > Our engineer calculated the physical thickness in consideration > of CWL of ULTRASPEC i'. > But speaking correctly, the CWL of i'+z' should be around 830nm > this time. > I suppose it would be close to ULTRASPEC i' in consideration of > f ratio, but anyway I'll ask our expert when we get the order. > > >> Is the quote for 1 filter or 2? (If the quote is for 1 filter, >> could you tell me how much more it would cost to make 2?) > > > How about the USD550 x 2 pcs ? > > We are very sorry for the small discount. > Perhaps only filter-vendors know this fact, the quality of Schott > colored glass is very poor. > Main issue is small bubble inside. We must use the colored glass > with keeping the bubble away !! > > Schott is the big company. > We complied and requested to improve the quality many times, > however they never minded because the colored glass is not the > main business for Schott any more. > > Eventually, we must prepare many pieces of Schott glass. > > Furthermore, the colored glass filter is still regarded as "cheap" > from the user. This is also the problem for us. > > We don't want to use Schott glass any more, but most of astronomers > prefer to use. We must live with Schott poor quality. > > Thanks, > > > Toshihiko > > -----Original Message----- From: Vik Dhillon > Sent: Friday, March 09, 2012 4:08 PM > > To: Toshihiko Kimura > Cc: Andrea Richichi > Subject: Re: RG695(CV project) > > > Hi Toshihiko, > > Thanks for the data file - that looks perfect! > > I have two questions: > > 1. You say the thickness of RG695 is 3.9mm, but the ULTRASPEC filters > are approximately 5mm thick. So you will have to add approximately 1mm > of fused silica to make this filter parfocal with the ULTRASPEC SDSS > set? > > 2. Is the quote for 1 filter or 2? (If the quote is for 1 filter, > could you tell me how much more it would cost to make 2?) > > Regards, > > Vik. > > Vik Dhillon phone: +44 114 222 4528 > Dept of Physics & Astronomy fax: +44 114 222 3555 > University of Sheffield email: vik.dhillon@sheffield.ac.uk > Sheffield S3 7RH, UK web: > www.shef.ac.uk/physics/people/vdhillon > > > > On 9 March 2012 05:46, Toshihiko Kimura > wrote: >> >> Dear Prof.Dhillon, >> >> Please check the attached file. >> We calculated the internal transmission of RG695(3.9mm) >> on the basis of Schott catalogue. >> 3.9mm is the same thickness as ULTRASPEC i' filter. >> According to Schott catalogue, +/-6nm is the tolerance for >> cut-on wavelength in RG695. >> >> Dear Dr.Richichi, >> >>> Can you please mention how long it might take from order to delivery? >> >> >> >> Please regard 8 weeks as *shipping schedule* (not delivery) >> from our plant. >> DHL costs a little higher than EMS, but we can expect the faster >> delivery. >> >> Best regards, >> >> Toshihiko >> >> -----Original Message----- From: Vik Dhillon >> Sent: Wednesday, March 07, 2012 5:57 PM >> To: Toshihiko Kimura >> Cc: Andrea Richichi >> Subject: Re: CV project >> >> Hi Toshihiko, >> >> Could you send us a data file showing the theoretical bandpass of the >> proposed SDSS i'+z' filter, just so that we can be 100% sure we >> understand each other? >> >> Thanks, >> >> Vik. >> >> Vik Dhillon phone: +44 114 222 4528 >> Dept of Physics & Astronomy fax: +44 114 222 3555 >> University of Sheffield email: vik.dhillon@sheffield.ac.uk >> Sheffield S3 7RH, UK web: >> www.shef.ac.uk/physics/people/vdhillon >> >> >> >> On 7 March 2012 08:51, Toshihiko Kimura >> wrote: >>> >>> >>> Dear Dr.Richichi, >>> >>> By the message from Prof.Dhillon yesterday, I understand just RG695 >>> will be equivalent to i' + z'. >>> >>> >>>> I would be interested in a preliminary quotation on >>>> feasibility, delivery time and price for an additional >>>> filter to be mounted inside ULTRASPEC, with the following >>>> characteristics: >>> >>> >>> >>> >>> Please check the attached file. >>> >>> >>>>> -size 50mm square >>>>> -AR coating >>>>> -parfocal with the other ULTRASPEC filters >>> >>> >>> >>> >>> Sure, we will meet the requirements as above including the parfocal. >>> AR film should be coated on both surfaces of RG695. >>> We will polish the substrates with round shape, and then cut it with >>> square to keep the good surface quality. >>> >>> >>>> Also mention please terms for payment. >>>> The shipment would be to Thailand. >>> >>> >>> >>> >>> When you will confirm the arrival of carton, please remit to our bank >>> account. >>> And if you have the preferable shipping method, please let me know. >>> Total amount is less than USD1,000, so I suppose EMS might be OK. >>> The fee costs USD30. >>> >>> Sincerely, >>> >>> Toshihiko >>> >>> >>> -----Original Message----- From: Vik Dhillon >>> Sent: Tuesday, March 06, 2012 5:37 PM >>> To: Toshihiko Kimura >>> Cc: Andrea Richichi >>> Subject: Re: CV project >>> >>> Hi Toshihiko, Andrea, >>> >>> I don't see any strong reason why we should cut off the red side of >>> the z' band (I believe the reason PanSTARRS make this cut is because >>> they also have a y filter which covers the wavelength range redward of >>> z'). >>> >>> I think we should have a combined i'+z' filter with the following cuts: >>> blue cut off: the same as SDSS-i' (i.e. RG695) >>> red cut off: the same as SDSS-z' (i.e. no cut off - it is a long-pass >>> filter) >>> >>> So, we simply want a combined SDSS i'+z' filter. Hope this is clear. >>> >>> Regards, >>> >>> Vik. >>> >>> Vik Dhillon phone: +44 114 222 4528 >>> Dept of Physics & Astronomy fax: +44 114 222 3555 >>> University of Sheffield email: vik.dhillon@sheffield.ac.uk >>> Sheffield S3 7RH, UK web: >>> www.shef.ac.uk/physics/people/vdhillon > > Andrea Richichi andrea@narit.or.th via sheffield.ac.uk 9 Mar to Vik Dear Vik the transmission looks fine to me (I am glad to see that Halpha is mostly excluded, just). Given that the time from order to shipment is ~2 months, I'd wait a little longer to order until we are closer to the completion of ULTRASPEC. I suppose it's ok to install the filter here? Or did you plan to test it in UK? I have just seen your additional questions to Toshihiko. I'll let you continue as you know better what is needed keeping in mind that purchasing one filter is ok for us and we can place the order from here. cheers Andrea Dear Prof. Dhillon, Dr. Richichi, Dr. Aukkaravittayapun, We will ship the parfocal SDSS i'+z' filter for ULTRASPEC to Prof. Dhillon (Univ. of Sheffield) and Dr. Richichi (NARIT) respectively tomorrow. Each EMS tracking no. is as follows: EJ150249181JP to Univ. of Sheffield EJ150249204JP to NARIT Filter prescription: AR*RG695(3.9mm +0.05, -0mm) + fused silica(1.05mm +0.05, -0mm)*AR I will send the actual transmission data by electronic file and invoice later. Best regards, Toshihiko