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Messages - jrista

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Animal Kingdom / Re: Show your Bird Portraits
« on: May 05, 2014, 06:05:38 PM »
Eldar, funny I was just thinking of buying hip waders for shooting but wondered how safe they are for gear if you stumble??!  Any good stories?

He he, the advantage of being a flyfisher is that you are used to balance on slippery rocks. Best advice is probably to have a wading stick. That way you always have an extra support on the bottom. I try to not go in too deep though. Luckily I have no fun stories to tell, meaning all my equipment have survived so far ;)

I would strongly recommend wading pants though. You can get fairly good ones fairly cheap.

I wish I could wade in the waters around me. Most of our lakes are part of wetlands, which means they don't have rocky shores or rock covered's all decaying plant matter, which ultimately results in this soft black muck that is several feet deep. Step in it, and at the very least your going to lose your shoe...try to actually walk through it, and you might actually lose yourself as well, and certainly your gear. :\

Animal Kingdom / Re: Show your Bird Portraits
« on: May 05, 2014, 04:56:30 PM »
Beautiful shots, Eldar! That 1D X is a creamy background, what I would give to have that kind of SNR.

EOS Bodies / Re: More Sensor Technology Talk [CR1]
« on: May 05, 2014, 04:54:22 PM »
(f-ratio doesn't usually matter for planetary, as you image planets by taking videos with thousands of frames for anywhere from a couple minutes to as long as a half hour...then filter, register, and stack the best frames of the video, which is basically performing a superresolution integration...that eliminates blurring from seeing, and effectively allows you to image well beyond the diffraction limit.)

This is very interesting, and news to me. Dare I ask how that is possible? I assumed stacking would take the image to the theoretical best the setup can produce - how does it deal with diffraction? I was using my 500L with extenders to photograph planets using stacking recently, and assumed softness due to diffraction (I was at 4000mm f/40 for Jupiter and 5600mm f/56 for Mars).

There are different ways to stack. The most common is averaging, either basic averaging, weighted-averaging, or sigma-kappa clipping averaging. Those forms of stacking are usually used on star field images, for nebula, galaxies, clusters, to reduce noise (noise is reduced by a factor of SQRT(stackCount) stacking 100 frames reduces noise by a factor of 10.)

You can also use "drizzle" stacking and other forms of superresolution stacking. The purpose of these methods is less to reduce noise (although they do help reduce noise), and more to increase detail. Stacking for superresolution aims to chose the best version or versions of any given pixel out of thousands of frames, and sample each pixel in each frame and across frames multiple times with alternate "rotation" factors or something similar. That allows the algorithm to extract the maximum amount of information for each point of your subject.

While diffraction certainly limits your resolution when doing planetary imaging, seeing limits it to a FAR greater degree. The vast majority of blurrieness when doing planetary imaging is due to atmospheric turbulence and poor transparency, by about an order of magnitude compared to diffraction. Stacking thousands of frames with a superresolution algorithm easily cuts through both, assuming you get enough high quality frames. Because these algorithms pick the best version of a pixel and multisample each pixel, you can end up with surprisingly high detail images, despite the effects of seeing and diffraction.

Good timing in Copenhagen

Photo shot with: Canon 6D and Canon 70-200 2.8

Wow. I think we need to redefine what "good" means now...

Software & Accessories / Re: Microfibre Cloths for Lens Cleaning
« on: May 05, 2014, 01:34:05 PM »
Thanks for all the feedback and terrific suggestions. I had no idea this was going to turn into such an interesting topic. I have always just used a microfiber cloth to clean my lenses but am now considering some of the suggestions above.

Btw - what's wrong with putting the microfibre cloth in the washing machine? What happens to it?

When I was collecting crystal whisky glasses I was advised not to dry them with a cloth that had been washed with softener as it, and other chemicals we tend to put in washing machines, can cloud the glass. How this correlates to the glass found on camera lenses I do not know, but I tend to just get new cloths rather than wash them. That said, the guy I was chatting to has never had a problem washing his, in fact he wishes the company were still producing them.

I don't think it's a huge issue but I can see the potential for problems depending on what the cloth is exposed to in the laundry process.  I agree that cloth can retain various chemicals or compounds from a wash process.  If I were to wash an important item like a lens cloth, I would probably just hand wash it so I can control what is introduced to the cloth in the form of dirt or other contaminants from other dirty items, soaps, grit, etc.  All you are trying to do is remove some light oils, dust and light dirt from the cloth anyway.  Woolite or some other delicate detergent would probably work great, then simply hang dry the cloth.  If you've ever held a dryer softener sheet, you will get an idea what is left on clean clothes in the dryer.  Nice for skin maybe but not for leaving smudges on lens glass.

Yeah that's a good point I don't want left over detergent / softner or lint on it plus our washing machine isn't the best at completely removing all that junk! I think I'll just hand wash them from now on. Thanks for the tip!

Washing your cleaning cloths the same way you wash your clothes is a bad idea. Most cloths washing detergents and softeners are explicitly designed to leave behind sent molecules to "freshen" up your clothing. Not all detergent gets rinsed out either, unless you use a doubly-long extended rinse cycle, and even then, your still going to have soap residues in the fabric.

Washing your cleaning cloths with your cloths, or in the same way as your cloths, is a sure way to ruin them. You want very clean cloths, without any residues or detergents or other molecules of any kind.

One of the best ways to clean cleaning cloths is to use activated water. This is water that's been sent through electrolysis, which slightly changes the pH and also created "charge bubbles", electrically charged nodules of water molecules that bond to dirt in a similar way to detergent. Since it's really just water, there is nothing to be left behind.

Diving for Fish

Cherry Creek, a state park, wetland, and nature reserve only a few minutes from my home, has really started to heat up with a whole ton of bird arrivals. Last night, I had a Black-crowned Night Heron practically pose for me, and at one point, he dove off his branch in an attempt to catch a fish. Sadly, the fishcapade was a failure, but I did capture a rather awesome flight shot.

Black-crowned Night Heron
Cottonwood Creek Wetland
Cherry Creek, Colorado

Canon EOS 7D
Canon EF 600mm f/4 L II
Gitzo GT3532LS + Jobu Pro 2

EOS Bodies / Re: More Sensor Technology Talk [CR1]
« on: May 05, 2014, 01:20:46 PM »
Very dangerous, jrista, very dangerous. Astrophotography is like boating - you start out with a $300.00 (slow) toy kayak, you end up wanting an America Cup yacht. I am at the toy kayak stage, and likely to stay there. A combination of living in the center of a "white" zone (central city to the rest of you), having a day job, no longer having the ability to easily adapt to swing schedules, and living in an often cloudy location (St. Louis MO) make serious application to astrophotography difficult. I can learn a bit at our local astronomy park, 45 minutes away in an "orange-soon-to-be-red" zone. High quality darkness is about 2.5 to 3 hours away at minimum.

I know a lot of imagers who shoot under red and white zones. Have you ever looked into a Light Pollution Reduction/Suppression filter? There are a number of them. I'm in a yellow zone myself, but I still use the Astronomik CLS filter myself (I prefer shooting nebula, if you shoot galaxies, lp filters are a mixed bag). You could also look into doing Narrow Band imaging...with NB, you block out a ton of light except the one (or three) very narrow bands your interested in. You need longer exposures, but NB works extremely well under red and white zones, and I've seen some stellar work from people in some of the most heavily populated places in the eastern half of America.

Hats off to you for taking on PixInsight.

PI isn't so bad once you get used to it. It has a funky way of doing things until you learn why...then you realize how incredibly awesome it is. ;) I also recommend it if you image under light polluted skies. It's DBE or Dynamic Background Extraction script can help you extract light pollution from your background skies and flatten it, and can do so if you use LPR filters or not.

I am still drinking the Sigma DP#M koolaid because the color subtlety is very suitable for landscape, and the camera weighs ~300 grams including an aluminum L bracket/grip and can be well supported by a 1600 gram tripod/head/QR kit. Pop some extra batteries, filters, and "nodal" slide in my pocket, and I have a great fast-hiking compatible landscape kit.

For those who understand what Sigma Foveon cameras offer, I say more power to 'em! There is no question the color fidelity is extremely high with Foveon sensors. The light weight is also pretty nice for when you gotta hike to your vistas. That's one of the reasons I like the idea of an A7r for landscape photography...but the camera overall is just...not general purpose enough to justify the cost.

Landscape / Re: hide and seek with the moon
« on: May 05, 2014, 12:15:39 PM »
Ok, I'm sticking to the sticker shock theory ;D. I see what you mean about the non-periodic error that would be an problem. I'll keep looking at my options. This is a very expensive habit hobby >.<.

You have no idea how expensive. :P I have some fairly big aspirations. Just check out the prices on these pieces of equipment:

10Micron GM2000HPS UP
PlaneWave 20" CDK
FLI ProLine PL16803 Mono CCD

That's a semi-pro setup. It's what will allow me to get magazine-quality results, assuming I can find appropriately dark skies and some land to build an observatory under. Those pieces of gear are also on the lower-midrange end of the "high end" market....there are even better mounts, larger telescopes, and even better imagers that cost three to five times more.

So yeah, ridiculously expensive, if you get really really serious. :P

Landscape / Re: hide and seek with the moon
« on: May 05, 2014, 11:58:03 AM »
Yay! more data! Hmm your view on Celestron greatly differs from those at the local astronomy club  :-\. They tend to hold the Advanced VX and CGEM mounts to a pretty high standard. I think it's sticker shock, photographers have already come to terms with $1k tripods and $2k+ lenses. The astronomers in the club haven't quite crossed that bridge yet ;).

Celestron equipment has a very strong religious following. I was hooked on getting a CGEM DX until I started researching, asking questions. Turns out that the CGEM and CGEM DX both have a flawed gearbox that causes what is called the 8/3 error, a non-periodic, non-integer error that is extremely difficult to guide out. I spent over two solid months researching mounts. In the grand scheme of things, my "real" mount will ultimately be the 10Micron GM2000HPS UP, a $24,000 mount which uses in-mount sky modeling and absolute encoding to allow for 20 minutes unguided exposures, and can hold up to 132lb of instrument capacity. :P

In my travels around internet forums during my research, though, I found one very glaring fact: Pretty much NO ONE, EVER, complains about the Orion Atlas or EQ6 mounts. They have about as pristine a reputation as I have ever seen. They are very well loved mounts. This is in great contrast to the fact that you can find dozens, if not hundreds, of complaint threads about the CGEM mounts on astronomy forums all over the net. Mostly about gearbox issues, but not solely. Some Celestron fans and objective mount reviewers will tell you the complaints are not warranted, and perhaps not...but that does not change the fact that the CGEM mounts are widely complained about buy a LOT of people. Statistically, that has to indicate some fundamental issue.

Personally, I LOVE Celestron OTAs. Their EdgeHD scopes are amazing, although they do suffer a bit from the standard SCT problems. If you want an excellent large-aperture OTA, an EdgeHD is definitely a worth while investment. Just...put it on an Atlas, instead of a CGEM. :P

The scope according to the website is about 12lb (I threw it on a scale and it's about right). The 23lb you see includes the metal case it comes with. I know it doesn't change the P2P error, but in terms of load, 120ED + 5D should be ok on the AVX?

If the weight is only 12lb, then it should be OK. I'm not sure what imager your using, if it's a DSLR that could add another pound or so. The guiding setup will add another pound or so, plus don't forget to count the weight of the various cables that you'll need to control everything (cable from the camera to laptop, cable from the guidecam to the mount, cable from the guidecam to laptop, cable from mount to laptop). You might also have additional weight from an extra vixen dovetail and telescope rings (to mount the guidescope to the telescope), which also adds a couple of pounds. Even assuming the scope is 12lb, 50% capacity is only 15lb, and all these accessories are going to put you over that limit.

The AVX is generally not considered a great mount for doing astrophotography. It's great for visual observing, but you have to understand the tolerances involved in astrophotography...if your tracking is off by arcSECONDS, your going to have problems. The AVX is the rock-bottom mount you could possibly get for AP, and it really is insufficient. That assumes that you never, ever plan to use a larger scope in the future...if you do, the $1000 on the AVX is just a waste, as you'll need a larger mount for a larger scope in the future anyway. (You will also quickly find that you'll want a longer scope, much longer, for doing anything other than nebula wide field something like the 8" EdgeHD or 8" AT8RC, both very cost effective OTAs that produce superb results, would work on an Atlas, they definitely would not work on an AVX.) You would be surprised how much better the Atlas/EQ6 is. Some astrophotographers have loaded it up with 30, 35 pounds of weight and been able to image would never be able to do that with an AVX.

The price of the Atlas is $1500, so it's $700 more than the AVX. I know that sounds like a lot...but I honestly cannot stress enough how important the mount is for astrophotography. The difference between what is acceptable for visual observing (which is probably what most of your local astronomy club members are doing), and what is acceptable for astrophotography is quite large. You can deal with stars and nebula and planets bouncing around a bit for visual work...even the smallest amount of that is completely unacceptable for astrophotography. If you don't eventually plan on getting a really large OTA that weighs over 50lb, then the Orion Atlas or SkyWatcher EQ6 would probably be the only mount you would ever it once, never need to replace it or buy a bigger one. The same is not true of the AVX. Your already pushing it's capabilities with your ProED 120.

I guess the cost difference of 900 vs 1500 is peanuts compared to everything else >.<

It really is. The mount is the centerpiece. If your mount isn't up to snuff, then it really doesn't matter what your mounting onto it...your already screwed. :P Big thing to keep in mind, visual is very different, in terms of requirements and what's acceptable, from astrophotography. Local astronomy clubs tend to be based on visual observing, and less on astrophotography, so their advice is likely to be a bit biased.

Animal Kingdom / Re: Show your Bird Portraits
« on: May 05, 2014, 11:50:48 AM »
Long-billed Dowitcher

The Cottonwood Creek area is really starting to heat up. A number of duck species are still hanging around, at this point I suspect for the whole summer. The shorebirds are starting to show up in larger numbers as well. One of my favorites is the Dowitcher, the long-billed dowitcher to be specific. They are one of the more colorful shorebirds, with colorful golden-fringed back feathers and buffy breats, and beautiful streaks around their faces.

Managed to capture a few shots of a trio of dowitchers just at sunset. My vantage point allowed the fresh new greens of spring and the old dried browns of last years growth to produce colorful OOF reflections and blurs, which nicely complimented and contrasted with the bird's own colors.

Long-billed Dowitcher
Cottonwood Creek Wetland

Canon EOS 7D
Canon EF 600mm f/4 L II
Gitzo GT3532LS + Jobu Pro 2

Animal Kingdom / Re: Show your Bird Portraits
« on: May 05, 2014, 11:45:54 AM »
Maiaibing, LOVE the color in those shots! So rich!

Radagast, phenomenal detail! Such a beautiful bird.

EOS Bodies / Re: More Sensor Technology Talk [CR1]
« on: May 05, 2014, 11:32:36 AM »
Glancing at his gear wish list, it looks like he's more into action than astro. An A7R is 2500 less in the budget (camera + EF adapter). Personally I would love one for portrait and landscape work, but I can not justify the expense. I suspect I'd get more use from that tamron 150-600 and a new tripod.

So, while I'd like an A7r for my landscape photography, it is actually one of the worst possible choices for astrophotography. I do landscapes sometimes, wildlife and birds most of the time, and astrophotography every time there is a clear night.

I was looking at the A7R with adapter for landscapes, but then I read on Thom Hogan's site that Sony uses lossy compression on their RAWs (unless I misread him), and you can't switch it off!

Why would they do that?   :( :(

On that basis, it may have amazing DR but then it surely will just smudge out some of the detail for err, actually I'm not sure for what benefit...

Hmm, I hadn't heard of that. If they do, it's foolish, and you really no longer have a RAW image. I am a bit skeptical of doesn't seem logical, but who knows.

Had a look at that astro link - it's a whole new language there  :) If I understood correctly, then it's a 2000mm lens? And optically is it better than your 600mm lens with a 1.4x and 2.x attached? Just curious as to the benefits. Thanks.

Reflecting light tends to produce superior spots at the sensor plane in comparison to refracting light. Reflecting light can warp star diffraction spots due to coma and astigmatism, but that's about it. Refracting light, on the other hand, suffers from all forms of optical aberrations...which also includes chromatic aberrations, spherical aberration, etc. The RC, or Ritchey-Chretien, telescope design is one of the more superior designs. It's the same design used in all the major earth-bound telescopes...the huge ones, up to 10 meters in size. It tends to produce superior results, although it does suffer from some coma and astigmatism in the corners.

There is a better telescope design than even the RC, called a CDK or Corrected Dall-Kirkham. The CDK uses a mirror and built in corrector to get one of the best spot shapes, center to corner, of any telescope design I've ever seen. PlaneWave makes CDK scopes, but they are pretty pricey. From what I've read and seen, a CDK is about the best telescope design in the world today.

As good as my lens is, and it is very good with a very flat field corner to corner, it is no RC and certainly no CDK. If I throw on teleconverters, that gets me more focal length (which is not necessarily the best thing...a LOT of nebula are even larger than I can fit in my field with the 600mm, let alone a 2000mm scope), but  it also increases the optical aberrations. For galaxies, clusters, and getting close up on parts of nebula, a longer, better scope like the Astro-Tech 10" RC is better. The larger aperture, ten inches vs. six inches, also means I can resolve smaller magnitude stars, galaxies, and other details. Most scopes work with focal reducers, so while it is 2000mm natively, I can use a 0.63x reducer to make it an f/5 1260mm telescope. That is relatively fast with a moderately wide field. For planetary work, I can also throw on a 2x or 3x barlow lens, and get a 400mm f/16 or 6000mm f/24 scope, which is much better for planetary imaging (f-ratio doesn't usually matter for planetary, as you image planets by taking videos with thousands of frames for anywhere from a couple minutes to as long as a half hour...then filter, register, and stack the best frames of the video, which is basically performing a superresolution integration...that eliminates blurring from seeing, and effectively allows you to image well beyond the diffraction limit.)

Landscape / Re: hide and seek with the moon
« on: May 05, 2014, 11:16:12 AM »
Thanks for the pointers. I already ordered the reducer/field flattener that goes with this scope.  I think that should help the vignetting I'm seeing right now with my 2" to 1.25" adapter + t-mount adapter + t-mount to EOS adapter.

Reducers/flatteners definitely help with corner performance. They do reduce focal length,, if you have an f/7.5 scope, and use a 0.85x reducer, your going to end up with a 765mm scope. Wider scopes are great for nebula and imaging larger regions of the sky, they are a lot harder to use for galaxies, clusters, planetary work, etc. For those, you want something much longer, at least 1600mm, and for planetary, it's really best to have as much focal length as you can muster (regardless of the f-ratio...3000mm, 5000mm, even 9000mm is best for planetary work.)

I'm looking to get the Celestron Advanced VX mount to go with this. Any thoughts on that? Any accessories I should also pick up in one shipment? I heard the GPS unit is nifty, as is a polar axis scope. Anything else I should look into?

Celestron is not really my first choice for mounts. They make some excellent scopes, and are they only source of hyperstar capable scopes, but their mounts are generally a bit wanting, and you pretty much always have to go to Celestron for any support. The EQ5/EQ6 range of mounts are actually better mounts, and the support community for them is truly vast. The Orion Sirius is an EQ5 type mount, where as the Orion Atlas is an EQ6 type mount. The Sirius is a step above the Celestron AVX, but closer to it in price. The Atlas is one of the most popular and best supported lower end mounts in the world. It's $1400, vs. the $1000 for the Sirius, but it is really the lowest entry mount you probably want to go with for astrophotography.

Mounts like the AVX are just too low end to really do a good job for astrophotography. Mount capacity is a critical factor, as is the intrinsic periodic error. The AVX has a max capacity of 30lb, and it's periodic error (PE) is around 30-50" peak-to-peak (P2P). The Orion Atlas, on the other hand, has a capacity of 40lb and a (PE) of around 15" P2P. The periodic error is what is going to determine the minimum size of your stars as you track across the sky for long exposures. At 30" or more, the AVX is just not going to handle exposures of more than about a minute or so without really good guiding. The Atlas can handle unguided exposures of a few minutes, and is easier to guide than the AVX.

Capacity is the next most important point. It's best not to load up a mount with more than about half it's capacity if you are doing astrophotography, unless your using a real high end mount. At 30lb, your 23lb scope is already over 2/3rds the weight capacity, where as it is barely over half for the Atlas. At 2/3rds capacity (and even more, once you throw on a camera, and even more once you throw on a guide scope and guide camera, which are really going to be essential for tight stars with any lower end mount), the AVX is going to be extremely difficult to control and guide out errors for. For the size and weight of your scope, especially with a camera and guider setup, you want a mount that is at the very least capable of handling 40lb. A mount capable of handling 60lb would be best...but that gets you into the territory of midrange mounts, which cost around $2500-3500.

So, I very highly recommend the Orion Atlas. It's a very capable mount, with a phenomenal support community. It also works with EQMOD, which is a full open source, free total replacement software driver package that lets you ditch the hand controller and control your mount entirely from a laptop (once you really get into imaging, you'll learn you also need computer control software, such as BackyardEOS if your using a Canon DSLR for imaging, PHD2 for guiding, etc.) EQMOD is more capable and more flexible than the SynScan hand controller that comes with EQ5/EQ6 type mounts. The use of EQMOD also opens up the door for improving the Atlas, which is another somewhat unique feature...there is a hypertuning mod available (which cleans up the mount and gets rid of manufacturing crap left behind in the gears, which makes the PE worse, and regreases everything with high quality synthetic grease), as well as a number of belt and worm mods. Belt and worm mods can eliminate gears, reduce backlash issues, and otherwise greatly improve the performance of your mount to midrange levels for far less cost. (NOTE: To use EQMOD, you will need to get an EQDIR cable. They are about $45, but a standard USB to Serial cable costs almost that much anyway, so it is a very worth while investment.)

You really can't go wrong with the Orion Atlas (or any other EQ6 mount, like the SkyWatcher EQ6 SynScan, which is basically the same thing, just different seller.) Either way, the Atlas/EQ6 is a much better fit given that your scope already weighs 23lb, and that you are guaranteed to need to do guiding. You can pick up the Orion 50mm mini guidescope and SSAG guider for relatively cheap, and the weight of that setup is about as small as you can get for guiding. Without guiding, even with an Atlas, the 15" p2p periodic error is going to kill your chances for doing exposures longer than a couple minutes. Average seeing is 2-3", average star size is 1.5-1.8"...without guiding, your stars will eventually be around 10-15" in size...far too large.

Landscape / Re: hide and seek with the moon
« on: May 05, 2014, 02:06:54 AM »
After mulling about for a bit, I finally decided to bite the bullet and get a telescope. After much thinking and searching I decided to get a Sky-Watcher ProED 120mm Doublet APO Refractor. I saw it as a poor man's EF 800mm. Sure, it doesn't have AF, or sharpest of corners... but, I now have a 900mm lens ;D.

I have only started this new part of my habit hobby. There's no equatorial mount... no GOTO tracker... they'll (likely) appear in due time. I just got the scope last Thursday and am struggling with the Astrophotographer's curse, 30 days and 30 nights of rain (living in the Pacific NW isn't helping). Today was the first night I had any opportunity and for a 5 minute window, I had a break in the clouds!

I present to you a "moonscape". Image taken with a Canon EF 2x Tele + EOS 5D3 mounted on a Arca-Swiss Z1 + Gitzo 2541 at 1/320 sec & ISO 6400.  The photo has been touched up but uncropped in Lightroom 5.

For the seasoned astrophotographers lurking around, any advice? I know the ISO is a tad high for this, but I didn't have a lot of time and had to make sure I got the shot in less than 5 photos.

First, congrats on the purchase. Good to see others getting into astrophotography. :) Once you get an equatorial mount, a very wide new world will open up to you. Just make sure you get s good mount...they are the most important piece of any astrophotographers kit.

As for bit is to definitely use a lower ISO. I pretty much always use ISO 100 or 200 for the moon. It moves, but not fast enough that a 1/4 second exposure will cause blurring. You REALLY want the DR that a lower ISO offers when shooting the's an exceptionally high DR subject.

I have lots more advice to offer...but I'll let you settle in first. ;P

Animal Kingdom / Re: Show your Bird Portraits
« on: May 04, 2014, 10:37:44 PM »
Great shots, everyone! Some really good work is showing up on here these days. Alan, love that last shot with the Greenfinch...the way his head is cocked is great!

Click, thanks! I like that first Killdeer shot, too. Hopefully I'll be able to get some better ones as spring rolls on...those were my first shorebird shots of the year, and killdeer...well, sometimes they kinda make you wanna kill a deer...just because you gotta kill something...with their antics. :P

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