Telegizmos Cover Review: Hot Stuff

[@bobpitney9023]

The outside sensor was kept in the shade. The scope/cover were tested in full sun. As such, the comparison between the sensors is not an accurate representation of how the cover works because the ambient environments were different. The radiant aspect of the cover works on the same principle as an attic radiant barrier...same science. And it does reduce temps inside the cover as compared with a cover that does not have a radiant barrier. As noted on this report, when the outside sensor was hit by direct sun light like the scope/cover, it's temps increased significantly. So there will be no miss-representation on my part, my company is TeleGizmos. I appreciate the reviewer's effort that was put into this review. However, while the review supports the test method, the method does not accurately represent the how the cover functions.

[@Aero19612]

I appreciate your comments, Bob. I will certainly leave them posted here so that all viewers will have access to them. By the way, I like the cover--very good quality. That said. I stand by the data and the conclusions. As the owner of the (expensive) equipment, I want to know what temperature that equipment sees during the heat of the day under the cover VS in a shaded area with freely moving air. I believe the data show this and suggest a lightweight portable pavilion would provide lower temperatures (just gotta think about the wind resistance--no small factor). I still use the cover, but I do bring the scope and camera indoors on hot days. Thank you for watching and for your thoughtful reply.

[@Aero19612]

Thanks Bob and thanks for watching! This is a very well-made cover. Very sturdy. After I made these measurements, I decided not to leave my scope and camera outside during the day; however, I do leave my mount outside under the cover. If you live in a cooler climate, then the trapped warmth is a bonus. I also have the Orion cover. It is thinner, has a silver outer layer to reflect sun and a red vinyl inner layer. I made similar temperature measurements during several 100-deg days but haven't made a video about it. For rain protection, I'd go with the cover in this video. Good luck.

[@michaeltshue5489]

@@Aero19612 I'd have to agree with Bob. I've no dog in the fight (other than researching solutions for my own use), but your test was flawed. You'd need to test 3 temps. 1) The under the Telescope cover. 2) directly outside the cover so that it receives more or less the same amount of sunlight. and 3) under a similar cover without the radiant barrier. You need #3 to see what effect the radiant barrier is having. The data set you have doesn't provide any useful information on the effectiveness of the radiant barrier, but more of what would happen it you moved your telescope into the shade.

[@Aero19612]

Hey Michael. I understand what you are saying. This test was not intended as a study on the radiant barrier. My only objective was to determine if I thought it was too hot under the cover to leave my camera and/or telescope outside. I concluded it gets too hot, so I bring them in in the morning and take them back out before the next imaging session. I do leave the mount outside under a cover. Thanks for watching! By the way, this is a well-made cover-no issue there. And if you live in a cooler climate, the hear is a good thing. Not so much when it's 106F outside. I also use a less-well-made, but larger, cover made by Orion that covers the whole mount.

[@tomcroskey8994]

Awesome review...this review is extremely helpful as I try to determine which cover to buy.

[@karcoms]

James. I also bought the 365 cover and tripod cover too. I like the build quality of it. What I observed with my test is this: If the ground under the cover is left open like in your setup heat will travel upwards into the set up since it is not an airtight setup. Not sure if you are using the elastic band that came with the cover to tie the cover around the scope to make sure it is wrapped nicely inside. I do agree with Rob's reasoning that the science of this is similar to how a house gets warmed up even with the inner liners but would probably get even hotter without one. But try your tests with wrapping the cover fully and possibly covering the ground underneath to not let the sun fall on the ground that could send the heat upwards since hot air rises anywhere.

[@karcoms]

James, take a look at the data from my temp and humidity sensor placed inside the cover on the mount (no camera/scope) and it does build up during the day and drop at night with corresponding humidity drop/rise. For me the tripod cover does not fully fit the mount I have hence one part of the triangle is left open but I have put a shade umbrella to reduce it but hot air does go inside. I have kept a small humidifer running through the day and turn it off in the evening when temp drops. photos.app.goo.gl/aw7QwAFGTyZJjezr8

[@Aero19612]

Interesting, Karthik! I think the shade umbrella will be a great help by avoiding direct sunlight on the cover. It would be interesting to try and seal the scope/mount. I've always assumed that having an opening allows air flow and a path for the heat to get pulled out of space near the scope. Thanks for watching!

[@gary5051]

Thanks Jim. I just did a very similar test with two Bluetooth sensors used in commercial greenhouses and similar. I found the same result as you - that the interior, where the things I care about were, was 12-15F higher that directly outside the scope as measured by an identical sensor. So far the temps here in Boston are not even at their peak so things will get worse as the summer moves in. I brought the scope and cameras inside but, so far, am leaving the mount under the cover. I emailed telegizmos twice to see if they had a suggestion or an idea how to add some kind of vent flap to let hot air out. They have not responded so I guess that tells the story of 1) the lack of heat protection by their product and 2) Telegizmos lack of concern for their customers. As soon as I can design and build a solid, vent-able enclosure for the mount and scope, I’ll be parting ways with the cover. Thanks for reinforcing my resolve to move to a better solution.

[@Aero19612]

It's a well-built cover, but I just don't feel comfortable leaving my scope and camera outside in the elevated heat. I, too, will leave the mount outside. Mine has been outside since last September. Thanks for watching, Gary!

[@HollomanUFOLanding]

I've been experimenting with OTA temperature issues for a long time now and the best thing I have found? Large white towels. Wrap 2 white towels around your OTA, placed 90 degrees to each other. I place some large white leastic strips over the towels to help keep them in place. Keeps the OTA dry and amazingly cool. Then place your (waterproof) cover of choice over the towels. The twoels not only keep things dry and reflect any heat back, but also, because of their construction, are very very resistant to holding / retaining heat. Hope that is of some help.

[@Aero19612]

That's a good suggestion. The heat an issue for sure in Texas. Bugs are too! While I'd love the convenience of leaving everything hooked up, it won't take long for crawly things to take up residence in the camera. Thanks for watching!

[@enriquebechet1]

Thanks for the review. I just bought one for my cem 70/ edge800 . I just put it on my scope and altogether inside my shed. Lol I bought it not move my scope every day from shed 10 feet to my imaging spot . When is raining. I haven’t test it, but I am scared to leave it under the rain . I live in California the days are not too hot my only concern is the rain

[@Aero19612]

This is a very robust cover and will hold up well to rain. Heat is my issue, so you’re ok. For my system, it leaves quite a bit of clear space at the bottom so rain could work it’s way under the cover. I have the mount outside under the cover for long periods (months). I also put an larger and more flimsy Orion cover over the TG360 cover to get full coverage. Good luck, and thanks for watching!

[@piertechinc]

Hello James. Thanks for the review. Regarding the dew, you can use a light bulb under the cover to stabilize the temperature at night to eliminate the dew.

[@Aero19612]

Good idea, Vito. Thanks!

[@leewolfson1]

Thanks for the info. I'd like to hear what the manufacturer would say. I had an opposite problem that was not helped by my wishful thinking. My C-11 is out on my deck with the tripod legs seated in modified wood furniture glides that are bolted to the deck. This provides a semi-permanent orientation for the mount. I do not have any really easy way of bringing the scope inside, so it sits outside covered by the Telegizmo cover from April to ? The cover was advertised as protecting the scope all year, including the winter months, but I began to get nervous when the temperature began to get into the single numbers (Fº) by late November. I contacted both Celestron and the person who sold me the the OTA a year ago. Both of them (for different reasons) said DO NOT LEAVE IT OUT over the winter. Celestron was concerned about the optics and my friend (an engineer) was concerned about the mechanical parts. I immediately brought everything inside. By the way, I am in Minnesota, and we just had about 3 weeks of well-below-zero nighttime temperatures. I think the cover does an adequate job from preventing a downpour from soaking everything, but I have come out on a humid summer morning and found everything under the cover dripping with condensation. It obvously cant prevent that. It also cannot really seal up the scope to keep everything dust free. Now I learn from your video that the cover doesnt do much to control heat. On a positive note: I have had both frogs and bees make themselves at home underneath it. It is a well-made durable product and does provide some protection, but my wishful thinking that it would substitute for an observatory was absurd.

[@Aero19612]

Thanks for watching, Lee. The cover is well-made, but I won't leave my equipment outside more than a few days at a time. Be careful of high winds. I accidentally left my scope out and a very fast moving thunderstorm passed over (there was 10% chance of rain--so much for weather forecasts). The wind overpowered the clutch and RA rotated turning the cover into a "sail". The wind blew the cover off and my mount, OTA, and camera got totally soaked before I could get it inside. In our hot summers, I won't leave the mount outside without a USB-powered fan blowing on the camera and to circulate air. The tendency to trap heat under the cover might help you a little bit during your winters--maybe it'll be 5 to 10 deg warmer under the cover, but I agree with those who have advised not to leave the scope outside 24/7 with just this cover.

[@zirconzircon8861]

Wish I had seen this earlier, James. I ordered the Telegizmos 365 T3G2 yesterday and it just shipped out of Garland Texas this morning. Just a thought ... but it would seem to make sense that a foil type radiant barrier would be on the outside ... not inside. Any heat that gets in there is not going to be able to get out. Anyway, thanks for taking the time to do this. There's certainly a couple of things I learned here. By the way, where did you purchase the USB fan?

[@Aero19612]

Wow. Sorry I missed your question here. I agree: put the foil on the outside. I'm sure I got the fan off of Amazon. Good luck and thanks for watching!

[@roberthodgson1866]

@@Aero19612 k,

[@dayjeremy]

Have you tried turning the cover inside out and doing this test with the reflective layer on the outside? As for the dew you can just put some large desiccant packs under the cover to deal with that.

[@Aero19612]

No, I haven't tried that. The highly reflective interior fabric might reflect a lot of the heat away. Might also blind aircraft landing at DFW ;-) Thanks for watching, Jeremy

[@abhijitjuvekar]

The problem with all shrouds or covers is they don't stop radiating heat coming off the concrete floor. If the tripod legs get hot it reach all the way up to the mount head. I have tried multiple layers of cloths, plastic bag cover, plastic bucket kept upsidedown on the mount head etc. methods but none is efficient. Perhaps covering each tripod leg with separate cloth/cover might help ?

[@Aero19612]

I agree. These covers seem to be better suited for cooler climates where extra heat can be beneficial. In hot climates, it just makes the heat load worse. Thanks for watching, Abhijit!

[@MexximusUK]

I have just bought one of these and love it! Nice neutral colour as well

[@Aero19612]

Yep, it's a very sturdy cover. Should last a long time.

[@garyrear]

Thanks for doing this review James. Since it's been more than 3 years now since you've reviewed this cover what are your thoughts on it now? Are you still using it? I Live in Canada and just ordered the Telegizmos 365 cover from Woodland Hills in hopes I could leave my William Optics Z73 refractor outside for long periods of time during the harsh Canadian winters. Our temperatures can drop well below 0 f or -18c . Do you think the outer material crack with the cold temperature?

[@Aero19612]

Thanks for watching, Gary! Yes, I still have and use the cover but not on a daily basis. I will leave the mount/tripod outside under the cover for consecutive clear sky days, but I bring the scope in every morning. It is very well made and should stand up to your climate quite well. I had reservations leaving my scope/camera outside in the Texas heat and the increase in temperature under the cover. For you, that will be a benefit. One thing to think about (maybe too late): I bought the cover for my C9.25 and it covers the scope (with guide scope on top) fine but not much of the tripod.

[@garyrear]

@@Aero19612 Thanks for the reply. I do have a concern about having snow blowing up underneath the cover so I thought I would ask one of my friends who is handy with a sewing machine to make some kind of a triangle cloth/fabric type think that I could attach just below the spreader. Hoping that would block most wind and snow from going up into the equipment.

[@hypersphereengineering6015]

Good video, but why don't you have a Dew Strap Heater on that Corrector Plate??

[@Aero19612]

That video is from my "early" days when I played dice with dew. I frequently lost. Look through more recent videos and you'll see a whole study on dew strap heating and dew shield length. I've got an arrangement now that works quite well. Clear Skies!

[@hypersphereengineering6015]

@@Aero19612 fair enough

[@zoriastr]

Nice review, thank you!

[@RoyceDavis]

Can anyone comment as to if the bottom of the cover gets sealed off or can water get in there? I can’t seem to find a picture from the bottom but all the photos I’ve seen digest that only the top of the telescope is covered so if it rained you’re equipment would not be protected.

[@Aero19612]

Hi Royce, The cover is not sealed at the bottom, although there is a draw string to tighten the bottom. If left out in a “ gentle” rain, the scope would not get wet, but the tripod legs would. In Texas, we get very short duration high winds and torrential rain. I didn’t anticipate that and the cover acted like a sail, allowing the wind to overpower the RA clutch. The scope rotated, then the cover really acted like a sail and shot off the scope letting it get soaked. Not good. Also, not the cover’s fault. All me. Just be careful leaving your scope out in the weather.

[@RoyceDavis]

Thanks that’s the info I was looking for. I also live in TX and the occasional storms we get are what worries me. I realize it should be considered common sense to take the scope in before a storm but the Telegismo website is adamant about 24/7 365 so I thought hey it’s worth a shot. Thanks again!

[@dandadrumman]

This is pretty disappointing, I had suspected some mount issues due to it getting too hot, causing expansion and gear binding. I do remove my telescope and camera, but I leave the mount under the cover 24/7.

[@Aero19612]

Thanks for watching, Dan. Of course, the elevated temperatures only occur when the cover is on the scope during the hot day, so it doesn't affect the gears since they are not operating. Even so, there is grease/lubricant in the gears--not sure if the high temps break down the grease. That would be bad. I am going to follow your approach and bring the scope and camera in during the day from now on.