Temperature ranges for optics

[Swissboy]

In another thread
http://www.birdforum.net/showthread.php?p=830085#post830085
the question arose about the temperature ranges optics are made for. As this important topic seems hidden in that thread, I am starting a new thread here. I am truly concerned about the information that Zeiss only tests their gear to +40C, if the information in that other thread is correct. Even the quoted +55C for Leica seem low, considering the fact that many optics stay out in the sun for hours. And the exposure must be worse for scopes than it is for binoculars.

[NWBirder]

In another thread
http://www.birdforum.net/showthread.php?p=830085#post830085
the question arose about the temperature ranges optics are made for. As this important topic seems hidden in that thread, I am starting a new thread here. I am truly concerned about the information that Zeiss only tests their gear to +40C, if the information in that other thread is correct. Even the quoted +55C for Leica seem low, considering the fact that many optics stay out in the sun for hours. And the exposure must be worse for scopes than it is for binoculars.

Interesting thought! I never bother thinking about the operating temperature range for optics. I guess for civilian use, the binoculars will survive as long as I am still kicking.

I use a pair of Zen-Ray SUMMIT 10x42. The place I live rains a lot and we occasionally have tempature dropped down near freezing. It is holding up pretty well so far even after soaked in the rain for several hours. I think I will dig in the internet to see if there is any standard for binocular temperature ratings.

[Mike Penfold]

No one here seems to leave their optics in a closed car (windows up, not running, and no people in it) in full sun for any length of time. In Panama, guides kept the drinks in a cooler with a gelpak or ice (didn't notice which). We started using a cooler, because they're cheap, effective, convenient, and keep the optics out of sight. There isn't always a spot in the shade.

That being said, for birding in warmer climates, if it's OK for humans, is it safe to assume it's OK for optics?

Mike

[Petesot]

Since I raised the issue in the first place, I will make it very explicit for the forum user community, without naming names at Zeiss, by reproducing in full, the e-mail chain I received (from info@zeiss.co.uk). I’m sure they would stand by their statements if asked again.


Me:

Hello

I would like to ask a question about the operating and storage temperature ranges of the Victory T* FL series of binoculars. The sales literature states a range of -20C to +40C. I assume this to be the operating range. I would like to know what consequences there would be if a binocular from this series were to be used at say +50C (in Death Valley, California for instance). Parked cars in the desert frequently heat up to well over +50C. Would the internal seals hold up? Does use outside of the temperature range have any consequences regarding the product warranty?
I look forward to your response.

Best Regards

Zeiss:

Good morning Peter

Our binoculars are tested to +40c and I am unable to say what, if anything, would happen in temperatures of +50c.

I have asked our service engineer and unfortunately we are unable to answer your question.

Kind Regards

Me:

Very many thanks for your swift response.

Maybe my question regarding the warranty could still be resolved - does the warranty cover use of the product outside of the specification? I'm guessing that it does not.

I look forward to hearing from you.

Best regards

Zeiss:

Hi Peter

I would say that if any damage occurred outside of the specification that this would not be covered by warranty seeing that it states that they are tested at +40.

Kind Regards

Me:

OK

I think (that) answers my questions, again many thanks.


So there you have it. The same goes for the Conquest line by the way. The e-mail chain took place over 8th to 9th March 2007.

This topic has been an interest of mine for a while since I’ve been comparing many different roof prism binoculars in my search for the ‘ultimate best purchase’, starting cheap and gradually talking my way round to the more expensive models.

The best temperature information I’ve found is provided by Swarovski. For the EL’s and SLC’s, the operating temperature range is -25C to +55C, the storage temperature range is broader at -30C to +70C.

No other manufacturer that I’ve come across, and I’ve checked many makes and models, explicitly quote a storage temperature range. The operating temperature ranges I’m aware of and to the best of my knowledge (for approx. 8x42 configuration binoculars) are:

Minox BD 8.5x42 BR A.L.T. -10 to +45
Minox BD 8x42 BL -10 to +50
Minox HG 8.5x43 BR A.L.T. -10 to +50
Leica 8x42 BR -25 to +55
Leica 8x42 BN -25 to +55
Swarovski EL 8.5x42 WB -25 to +55
Steiner Wildlife Pro 8x42 -40 to +80
Zeiss Victory 8x42 T* FL -20 to +40
Zeiss Conquest 8x40 T* -20 to +40
Nikon 8x42 HG L -20 to ?
Kahles 8x42 -20 to +50
Opticron 8x42 DBA Oasis -20 to +50
Opticron BGA Classic 8x42 -20 to +50
Opticron Imagic BGA Oasis 8x42 -20 to +50
Pentax DCF SP 8x43 -20 to +50
Kowa Genesis 8.5x44 -10 to +50
Meopta Meostar 8x42 -25 to +55
Swarovski Pocket 10x25 B -25 to +55

You can easily check these for yourselves by examining websites, sales brochures or e-mailing the manufacturers. I’ve had to convert to C from F in several instances.

I have not been successful in tracking down operating temperature ranges for the following:

Steiner SkyHawk 8x42
Steiner Wildlife Pro 8x44 XP
Nikon Monarch 8x42 DCF
Bushnell Elite 8x43
Bushnell Legend 8x42
Brunton Epoch 8.5x43 WP
Vixen Apex Pro 8x42
Fujinon CD 8x42
Leupold 8x42 Golden Ring HD
Leupold 8x42 Golden Ring
Leupold Wind River Pinnacle 8x42
Vortex 8x42 Stokes DLS
Vortex 8x42 Razor
Opticron Verano BGA PC 8x42
RSPB 8x42 HG PC
RSPB 8x42 BG PC
Avian 8x42 DCF
Minolta Activa 8x42 D WP
Delta 8x42 PC AG
Kowa BD42-8
Eagle Ranger Platinum 8x42
Alpen Apex 8x42
Swift HHS Audubon 8x42 828
Swift Ultralite 8x42
Pyser Falcon 8.4x45
Luger 8x42 DX
Burris Signature Select 8x42
Docter 8x42 B/CF

I have been advised that the Opticron Verano should not be used at extreme temperatures; the other Opticrons are listed above. I have yet to research the new Pentax DCF ED line, the new Minox BV or BL 8x56 / 13x56 BR lines or the new Vortex 50mm Razor line (I assume this to be the same as the smaller Razors, if only I knew what it was).

Yes it is obsessive and this is not the only specification I have lists for (!): mass, height, close focus distance, FoV, eye relief, etc. for 7x42 (11 models), 8x50 (21 models), 10x42 (50 models, including ‘zooms’), 10x50 (26 models) and 15x (5 models) as well as the above listed 8x42 configuration (total of 45 models). I can hear you all laughing already. Me too in fact, but what else to do of an evening when your wife is studying at University?

I hope this adds substance to the debate.

[Surveyor]

Petesot;

Something else to consider. What is the testing profile? What is the starting temperture (do they start at min.)? Do they bring bins to temperture quickly or slowly, how long do they hold them at max. and then how long is the cooling cycle. Are the cycles repeated? Quick cylcles are a lot harder on bins. Some bins may be mil speced for continuous duty. I have not ran across any bin manufacturers that are willing to share spec. tolerences or procedures.

It would be great if they published there specs. and tolerances.

Ron

[Petesot]

I couldn't agree more Ron.

I've never seen any procedures. Even if they didn't give it all away it would be nice to know roughly what they do. I'd hate to hand in binoculars for repair and they pulled out the old 'it's outside the warranty as you used it outside the spec' gambit, when most folk don't really appreciate what the spec is, especially if the item was relatively expensive.

Nitrogen/argon filling is another one: I've got good information on (and impressive spec) for some makes/models (e.g. argon filled to 5m immersion) and simply 'nitrogen filled' for the others. I sometimes really wish I had sufficient information to be able to rank what otherwise look like similar binoculars, especially if the cost is similar.

Normally, if there's not the information I desire, I simply put the model on the bottom in that category. Brutal, but effective. Just some information might lift a binocular considerably in my regard, even if the spec is not that impressive relatively speaking - after all, I don't mind if I'm not paying top dollar. I'm sure that temperature and immersion depth information exists for most models; manufacturers ought to provide it in the context of how to use the binocular best.

I find it anomalous that the Zeiss specification in terms of operating temperature range is not that competitive against the other top binoculars. Perhaps it's related to the construction material - light and strong but not ideal for keeping the optical system/focusing within tight tolerances. There is endless debate on this topic in photographic circles. Leica for instance still insist on using lots of metal in camera lens construction. The focus movement in some of their lenses, from close up to infinity, relies on a lens movement within the optical system of less than 1mm! To guarantee this over wide operating conditions, only certain materials cut the mustard. These need not be exotic but a trade off must be made somewhere, e.g dense metal v light polymer composites. As in all things, the more more impressive the spec, the higher the QA/QC there must be to achieve this, the higher the price. For me, I'm not sure the cost of Zeiss optics is something I'm willing to accept if I anticipate being in an extreme environment, regardless of whether the optics are considered as industry leading (for some at least).

[andrew_s]

Are the operating temperature ranges quoted the temperature of the binocular itself, or the air temperature at the time of use?

Cycling in Spain or the south of France when the shade temperature is about +35, my cycle computer would read +45 to +50 if I didn't shade it whilst riding (equivalent to an in-use birding temperature?) and up to at least +60 if I parked the bike in the sun outside a cafe (equivalent to telescope use on a calm day, though probably heat shimmer would discourage much use)

The quoted minimum temperatures also seem to be well inside the range of likely use, at least in Scandanavia and the US/Canada. Do people use their bins in these temperatures much, or are there problems with moisture from the eyeballs frosting the oculars that discourage use? My time in the Antarctic was a long time ago, and I can't remember the details any more.

[Surveyor]

Petesot;

Zeiss bins appear as they may conform to ISO 9022. ISO 9022-2:2002 relates to humidity, heat and cold testing.

I do not have those sections and 9022 consists of 20+ sections at $35 to $48 each. I am not that curious. Someone may have access to an ISO CD and find out what it says.

Ron

[mak]

Pete.

I have just looked at the ZEISS catalogue.

Functional temperature range for:
All FL's.-30c - +63c.
Victory & Conquest Compacts -20c -+ 40c.
Conquest -20c - +55c

mak

[Petesot]

mak

Very interesting! I have the Zeiss binocular brochure for 2006 and all it talks about is -20C to +40C. The information you provided flies in the face of the e-mail chain I detailed earlier in this thread. I'll have to dig around the web a bit more, the Zeiss Germany web site appears to be silent on the topic. The other thing missing in the brochure was eye relief data!

Since Steiner Wildlife Pro binoculars use a Makrolon synthetic housing and rate their binoculars for use in extreme temperatures, then maybe the Zeiss binoculars are also fine from a technical standpoint (supported by the figures you quoted), I'm just not certain that the warranty covers it. I wonder why different data appears to be available from Zeiss? Maybe it's aimed at different markets? I had the UK brochure.

Perhaps Zeiss users could comment on what their warranty/user manual states?

[Petesot]

I just re-read the 2006 Zeiss binocular/spotting scope brochure I have and it states for the binoculars:

“All models are nitrogen-filled to prevent internal lens misting in the case of major temperature fluctuations and climate-proof from -20 to +40 °C.”

In the context of Paul’s figures, I think that this statement may mean that the minimum spec for all of their binoculars is -20C to +40C with a better spec for some of their product lines. Annoyingly, the brochure I have does not give the operating temperature ranges for the different binocular lines, leading one to think that -20C to +40C was universal.

Perhaps we’re now getting to the bottom of the confusion; it still does not explain the e-mail thread I received from Zeiss. Perhaps the response didn’t ultimately come from an appropriate authority.

My suggestion to Zeiss would be to improve their sales literature and also make the brochures easily available for download.

[mak]

Perhaps we’re now getting to the bottom of the confusion; it still does not explain the e-mail thread I received from Zeiss. Perhaps the response didn’t ultimately come from an appropriate authority.

My suggestion to Zeiss would be to improve their sales literature and also make the brochures easily available for download.


The info given is from the latest Zeiss brochure (picked up at IWA). Looking at your contact e-mail address, I would have tried the Sports Optics division maybe they would have had the same information to hand as myself.

[ThoLa]

"My suggestion to Zeiss would be to improve their sales literature and also make the brochures easily available for download."[/QUOTE]



As easy to download as any on the web:

http://www.zeiss.de/C12567A80033F8E4/?Open

[Petesot]

Ah!

That's where it is, just didn't see it. You can see though how poor the temperature range information is in this brochure.

[ThoLa]

Hello!

An extensive comparative test of binoculars has been done last year. I has been carried out by a state-funded, independent consumer organisation. They buy anonymously in shops, so there is no bias due to pre-selected items from companies.

Durability was tested according to ISO 10109-4 and ISO 9022, respectively.
In terms of temperature this means: -25 C for 10 hours; dry heat, +85 C, relative humidity 40 % for 10 hours; moist heat, cyclic (+23 C, 83 % rel. humidity + 40 C at 92 % rel. humidity), six cycles altogether.
Other conditions: Rain 01 without wind.
Shock (impact) according to DIN 58390-3/09.94,
etc.

Results:
Leica Ultravid 8x32 very good (1,3)
Zeiss Conquest 8x30 good (2,4)
Swarovski SLC 10x42neu very good (1,3)
Zeiss Victory 10x42 T*FL very good (1,1) (!)
Pentax DCF HR II 10x42 very good (1,3)
Nikon HGL 8x32 DCF WP good (1,6)

Canon 10x30 IS sufficient (3,8) (for comparative reasons)

This is the most substantial and most objective test I have come across so far.
A similar, comparable test has been done in 2004 for pocket binoculars.

The bottom line here is: There is very little difference between zeiss and other quality brands with respect to durability (thermal or otherwise).

The binos all survived 85 deg C for 10 hours. That ought to be sufficient if you leave it in the car and park the car in Death Valley while you go out hiking over the week-end.

The companies tend to play safe with the recommended values they give, but safety margins are usually generous.

I can send a pdf of the article to interested parties.

Regards,
Thomas

[mak]

mak
The other thing missing in the brochure was eye relief data!
Since Steiner Wildlife Pro binoculars use a Makrolon synthetic housing and rate their binoculars for use in extreme temperatures, then maybe the Zeiss binoculars are also fine from a technical standpoint (supported by the figures you quoted), I'm just not certain that the warranty covers it. I wonder why different data appears to be available from Zeiss? Maybe it's aimed at different markets? I had the UK brochure.


The latest brochure, which was available at the IWA show does show the eye relief and prism system used and lens type and water resistant mbar data. Maybe the information available to me is different to yours.

[Curtis Croulet]

In another thread
http://www.birdforum.net/showthread.php?p=830085#post830085
the question arose about the temperature ranges optics are made for. As this important topic seems hidden in that thread, I am starting a new thread here. I am truly concerned about the information that Zeiss only tests their gear to +40C, if the information in that other thread is correct. Even the quoted +55C for Leica seem low, considering the fact that many optics stay out in the sun for hours. And the exposure must be worse for scopes than it is for binoculars.

Thank you for bringing this to my attention. I have the 8x42 FL. In my usage, it is far more likely that it will be exposed to temperatures over 40C, even exceeding 50C, than under -20C.

[Mike Penfold]

In a study completed at McMaster University in Hamilton, Ontario, supported by the Canada Safety Council and General Motors of Canada, it was found that on a 35C/95F day, the temperature inside a previously air-conditioned car reached 50C/122F within 20 minutes. Within 40 minutes the temperature inside a car was 65.5C/150F. Opening the windows a crack didn't make a difference.

BTW, it's nice to know that Zeiss reads BirdForum.

Mike

[usedtobe]

Hello!

An extensive comparative test of binoculars has been done last year. I has been carried out by a state-funded, independent consumer organisation. They buy anonymously in shops, so there is no bias due to pre-selected items from companies.

Durability was tested according to ISO 10109-4 and ISO 9022, respectively.
In terms of temperature this means: -25 C for 10 hours; dry heat, +85 C, relative humidity 40 % for 10 hours; moist heat, cyclic (+23 C, 83 % rel. humidity + 40 C at 92 % rel. humidity), six cycles altogether.
Other conditions: Rain 01 without wind.
Shock (impact) according to DIN 58390-3/09.94,
etc.

Results:
Leica Ultravid 8x32 very good (1,3)
Zeiss Conquest 8x30 good (2,4)
Swarovski SLC 10x42neu very good (1,3)
Zeiss Victory 10x42 T*FL very good (1,1) (!)
Pentax DCF HR II 10x42 very good (1,3)
Nikon HGL 8x32 DCF WP good (1,6)

Canon 10x30 IS sufficient (3,8) (for comparative reasons)

This is the most substantial and most objective test I have come across so far.
A similar, comparable test has been done in 2004 for pocket binoculars.

The bottom line here is: There is very little difference between zeiss and other quality brands with respect to durability (thermal or otherwise).

The binos all survived 85 deg C for 10 hours. That ought to be sufficient if you leave it in the car and park the car in Death Valley while you go out hiking over the week-end.

The companies tend to play safe with the recommended values they give, but safety margins are usually generous.

I can send a pdf of the article to interested parties.

Regards,
Thomas
HI ，Thomas，

Could u please send me the PDF of article?. look forward to reading all the detail in it.

Thanks

[Petesot]

Thomas

I'd appreciate a copy of the .pdf too. Many thanks.

[ThoLa]

Thomas

I'd appreciate a copy of the .pdf too. Many thanks.



Hi again!

No problem.
Ehh, yes there is. I am not sure how to make an attachment here.

If you care to drop me a line to my e-mail accout at

tlazar@web.de

I'll buzz it out at once.

Cheers,
Thomas


PS: I've just come back from wasting half an afternoon in a shop comparing Zeiss Victories to Conquests. The Victories are better ..... moan.

[Mike Penfold]

In a study of the effect of volatile organic compounds in new cars referred to in The Toronto Star, April 7, 2007, scientists at Miunich's Technical University, "...placed [cars] under halogen lamps inside a lab so the interior temperature reached 65C [149F], to simulate a car being parked in direct sunshine." BTW, according to the Canada Safety Council, human skin burns in 1-5 seconds in water at 60C/140F.

Mike