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07-07-2017, 04:17 AM - 1 Like   #16
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AstroDave's original post is extremely thorough and is a must read as is the web sites he links to

please take the time to review them, it could save your equipment and your sight

no kidding

07-07-2017, 05:07 AM   #17
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Regarding ND filters. Two polarizers at an angle will make a variable ND filter (there are side effects but for photographing the Sun they won't be a bother). It might be more practical (maybe also more expensive).
07-08-2017, 07:28 PM - 1 Like   #18
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I've been practicing and trying different techniques. This is about my best so far, about a 50% crop. It really is annoying when you're subject won't hold still! Definitely still need to do more work. There won't be time to work out anything on the day it happens.


07-09-2017, 09:24 PM   #19
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This is probably my final solar eclipse set up.


Pentax HD PENTAX D FA 150-450mm f/4.5-5.6 DC AW mounted on a Zeikos 77" 3-Section Heavy-Duty Aluminum Tripod with 3-Way Pan Head. On the front of the lens is Cokin Z-Pro Series 100mm Filter Holder with the LEE Filters 100x100mm Solar Eclipse Filter. The camera is a Pentax K5 attached via the HDMI port out to a Lilliput 7" Field Monitor mounted on a Sirui T-025x Travel Tripod positioned near the lens tripod. 2-foot cable release and shake reduction turned off. I did not use mirror lockup as it seemed to be steady enough without it and would be one more thing to screw up when I switched in totality to bracket exposures.

I experimented with multiple different setups before I came to this final set up. The following are some of the things Iíve tried:

Crossed polarizers. Crossed polarizers can be used as a variable (kind of like a neutral density) filter. The problems that led to this being rejected were, not nearly enough stops of filtering and a blue tint that was almost impossible to get rid of.

Stacked neutral density filters. With my 3 darkest neutral density filters I could get up to about 16 stops. This was minimally adequate but still, has several significant limitations. The 1st being 16 stops is near the minimum needed. It still makes it very hard to not only focus but totally washes out live view. This is also not adequate (as in not safe) to use the optical viewfinder. Stacking the filters also resulted in image degradation.

Trying to use the live view on the back of the camera was very difficult as you are facing into the sun. Even if you had an articulated screen it would still be very difficult as you want the tripod to be lower and it is still very awkward to view. Additionally, live view from the screen on the back of the camera eats up battery power extremely quickly.

Trying to mount the field monitor any place on the tripod that the lens was mounted on was very awkward and difficult. Essentially wherever I would try to mount it would always seem to get in the way. Mounting the field monitor onto the camera no matter which method I seem to use (tried several from mounting on top of the camera to using an additional bracket) was also awkward and caused additional problems that every time I would move the lens would also require a change in the field monitor. Also, the field monitor was too close to really view it while trying to move the lens-camera combination. Mounting the field monitor on a small tripod near the larger tripod worked much better and also reduced any wind sail affects/vibrations that the field monitor would produce onto the lens tripod.


Using the LEE Filters 100x100mm Solar Eclipse Filter was nearly ideal. This filter produces 20 stops of filtering. This allowed the lens to be stopped down to only f/5.6 at 450 mm with a shutter speed of 1/180 and ISO of 80. This produced an excellent exposure. I was able to photograph very small sunspots that were clear enough to make out and were approaching only a few pixels across.

Using the Cokin Z-Pro Series Filter Holder allows the filter pack to be taken off quickly and smoothly during totality. It can also be placed back on just as quickly and easily. The Lee solar filter also had an additional feature to the filter that helped with this. Around the backside of the filter on the edges is a little black foam gasket. This not only keeps out any stray light from the edges but also helps act like a little bit of a spring. The Cokin Filter Holder has a little bit of a spring action to it but this is mainly to hold the various filters snugly. Once you tighten up the screws there is very little additional spring action.

Some observations:

The Lee solar filter will get quite warm to the touch even in the anemic Northwest morning sun. I do not believe this will in and of itself hurt the filter but if youíre not aware you could be surprised and accidentally drop the filter when you pull it out of the filter holder pack. Additionally, it would probably not be wise to set it on a very cool surface until it has a chance to cool off.

Even with 20 stops of filtering the sun is so bright that there is still detectable reflective flair. This could be from 2 possible sources. The 1st being reflection of the front of the lens to the back of the solar filter and back in. As Pentax has put some of their best coatings on this lens I do not believe that this is the most likely source of the flair.


The next likely source for this a reflection is off the sensor to the back of the lens and back into the sensor. As even with these 20 stops the live view is still overexposed, I believe this is most likely the source of the flair. What this means is that it is best (in my opinion) to not shoot absolutely center of the frame. If all of the sun circle is off to the side of the center then the reflection will appear on the opposite side. This means that it will not only not interfere with the direct exposure but being off to the side can be dealt easily in PP if necessary.

With 20 stops of filtering, you may feel that you could use the optical viewfinder. Lee recommends against this and I concur. You might be able to get away with this for a few seconds but you wonít be doing this for just a few seconds. You will have to do this repeatedly for upwards of an hour. 20 stops are just not enough for this. Additionally, there still might be some leakage of ultraviolet light which you wouldnít detect until it has damaged your eyes.

With this set up with shutter speeds of 1/180 or 1/250 exposures appear to be very good. Exposures of 1/125 and 1/90 also appeared to be good and did not give any blinking warnings in the live view. Reviewing these later on the computer I could see that they had at least one blown color channel. Even one blown color channel will make it next to impossible to set your white balance lie for white. Additionally, you want a little bit of head room for later PP adjustments of things like contrast and brightness. So itís definitely better (if not imperative) to be a little underexposed.

I did consider going with a longer focal length than 450 mm. Early on I did experiment with an X1.4 and a 500 mm lens but concluded that the field-of-view was just too narrow on APS-C. It is too hard to keep the sun in the frame all the time and more difficult to have it off to the side and still in the frame (see above). Additionally, in totality, you probably will want to see much more around the sun so 450 mm appears to be about ideal.

When I mounted the lens on the tripod I found it worked much better to have the elevation handle forward. This not only kept it out of coming in contact with the center pole (in fact I didnít have to raise the center pole thus increasing stability) but I found I had much more leverage. Having a three-way pan head was also much better than a ball head. I could much easier control one thing at a time instead of having to control all of them simultaneously. This was very important as you needed to continuously track the sun.

Having the field monitor on its own tripod allowed both tripods to be set very much lower and more stable. They were also easier to handle and you could sit in your chair and watch the monitor. One word about this. Is probably best not only from the point of view of batteries (for both the field monitor and the camera) to stay in live view continuously. Normally there is a limit of approximately 10 to 15 minutes before the sensor starts to heat up in the camera wants to shut itself down. Even though most of the heat is attenuated by the solar filter is probably getting more heat than normal which probably exasperates this problem. I do not believe that this will necessarily harm the sensor but you might be stuck having to wait for the camera to cool down at a critical time. With this in mind, it is probably better to set yourself up on a schedule of on and off (say 5 minutes on 5 minutes off for example).

LEE Filters 100x100mm Solar Eclipse Filter
Pentax HD PENTAX D FA 150-450mm f/4.5-5.6 DC AW
Pentax K5.
Zeikos 77" 3-Section Heavy-Duty Aluminum Photo & Video Tripod with 3-Way Pan Head
Sirui T-025x Travel Tripod
Cokin Z-Pro Series Filter Holder
Lilliput 7" Field Monitor

Linked below is the camera set up and an example full frame full resolution sun photo. Seeing was fair to good. There were a few high thin clouds in the area that I had to wait to pass but there was also forming a thin overall layer. This is why the seeing was only fair to good.






DAZ

07-17-2017, 08:42 PM   #20
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Another excellent article, test, filters, weather

Excellent article here:
Jerry Lodriguss camera settings for 2017 Solar Eclipse

I made a test shot with my old K200D and a Baader ASBF70 solar filter. Used a 300mm Borg 67FL f/4.5 lens + Hotech flattener:


Pretty good for an old 10mp camera handheld (I added some color in post processing)! Nice to see the sunspot in the lower right is in focus. So, I did this because I did not know how easy or hard it will be. Totality will be dark, so I will use the K3 with a tripod head that has fine two axis control to bracket shots centered around 1/30 second (maybe).

The Baader filter can be gotten at my favorite astronomy shop - Agena Astro Baader Solar Filters
The size I ordered 5 days ago had 9 in stock, now out of stock! Get one now at the size you need before all gone!!

Yes, you can use the cardboard box that the flimsy filter came in as a transport case, just poke three holes in the top of the box and push the foam covered screw thingys through:



And plan on the weather. I have two hotel reservations about 400 miles apart. I might make a third one just in case. I will cancel the ones I don't need the day before the event.


Last edited by goldenarrow; 08-09-2017 at 06:25 PM.
07-18-2017, 05:18 AM   #21
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For those of you with experience, would making a graduated ND filter out of two polarizers work as well as a solar filter? Such a filter is, in essence, a strong ND filter, right?
07-18-2017, 11:58 AM   #22
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Shade helps

I bought a square yard of black velvet material From JoAnn's fabric, and drape it over my scope, camera and my head. I found when taking photos of the sun especially around noon everything is so bright it hinders the ability to focus, see your results and once your head starts sweating your eyes start burning. I use black "velvet" because there are no pin holes of light coming through to distract you. Its like a small shelter that really helps.
Hank
07-18-2017, 07:04 PM   #23
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QuoteOriginally posted by oneeyedhawk Quote
I bought a square yard of black velvet material From JoAnn's fabric, and drape it over my scope, camera and my head. I found when taking photos of the sun especially around noon everything is so bright it hinders the ability to focus, see your results and once your head starts sweating your eyes start burning. I use black "velvet" because there are no pin holes of light coming through to distract you. Its like a small shelter that really helps.
Hank
Excellent idea! I have some lying around not doing anything, will have to take it with me.


---------- Post added 07-18-17 at 09:06 PM ----------

QuoteOriginally posted by bdery Quote
For those of you with experience, would making a graduated ND filter out of two polarizers work as well as a solar filter? Such a filter is, in essence, a strong ND filter, right?
Dont know but what little I read says to just get a proper solar filter, not worth the risk to your eyes! You can't "unsee" any damage that might happen!!


07-19-2017, 02:59 AM   #24
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my personal decision making about the solar eclipse

1 at all costs protect your eyes, you don't get replacements

2 protect your equipment, it isn't cheap

3 consider the experience, how much would you miss by attempting to record the event for history

I will enjoy it greatly when I view the excellent photos posted by those who choose to take photographs of the eclipse

I will enjoy the experience without doing so


please, please remember # 1

disclaimer:

I am not a Doctor, nor have I ever played one on screen or stage, large or small

BUT I have read enough to be very, very wary of trying to photograph this eclipse

Last edited by aslyfox; 07-20-2017 at 07:00 AM.
07-19-2017, 05:21 AM   #25
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QuoteOriginally posted by goldenarrow Quote
Dont know but what little I read says to just get a proper solar filter, not worth the risk to your eyes! You can't "unsee" any damage that might happen!!
I would not look through the viewfinder but use the screen anyway.

We all have hundreds of pictures with the sun in it, and it is not more powerful during the eclipse, so there won't be any damage to the camera.
07-19-2017, 05:26 PM   #26
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QuoteOriginally posted by bdery Quote
I would not look through the viewfinder but use the screen anyway.

We all have hundreds of pictures with the sun in it, and it is not more powerful during the eclipse, so there won't be any damage to the camera.
It does get really hot, you may consider covering the lens with a lens cap when not looking through the viewfinder. And UV may still get to your eye through the pentaprism (not as much of course).
07-20-2017, 05:14 AM   #27
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QuoteOriginally posted by goldenarrow Quote
It does get really hot
No more than shooting with the sun ni the frame at noon on a summer day.

QuoteOriginally posted by goldenarrow Quote
And UV may still get to your eye through the pentaprism
Using live view I wouldn't look through the viewfinder, and UV is absorbed by the glass inside the lens anyway.
07-20-2017, 05:14 AM   #28
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QuoteOriginally posted by goldenarrow Quote
It does get really hot
No more than shooting with the sun ni the frame at noon on a summer day.

QuoteOriginally posted by goldenarrow Quote
And UV may still get to your eye through the pentaprism
Using live view I wouldn't look through the viewfinder, and UV is absorbed by the glass inside the lens anyway.
07-20-2017, 06:04 AM   #29
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QuoteOriginally posted by bdery Quote
No more than shooting with the sun ni the frame at noon on a summer day.



Using live view I wouldn't look through the viewfinder, and UV is absorbed by the glass inside the lens anyway.
That's very dangerous and misleading! There's a huge difference between having the sun in the frame in a landscape image and steadily pointing a long telephoto lens directly at the sun.

A 300 mm f/5.6 lens, for example, creates a spot of sunlight that is 300 times brighter than ambient sunlight. The longer the lens and the bigger the aperture, the greater the total destructive energy.

Filtering the UV from the sunlight will do nothing to stop you from burning your retina or the sensor which is main risk. Even if you filter all the IR from the sunlight, you are still exposing yourself to 50% of the total thermal energy of the sun. You'll still burn your eyes and overheat any spot on the sensor if the point a long lens at the sun. (BTW, the IR issue is why using exposed color negative film to filter sunlight is such a bad idea -- although color negative film might block almost all the visible light to seem safe, it lets IR through that will cook your retina.)
07-20-2017, 06:30 AM   #30
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by all means do your research

ask an astronomer or a professional photographer who takes pictures of the sun

form your own opinion

this was cited by a fellow poster

QuoteOriginally posted by goldenarrow Quote

Observing and Photographing the 2017 Total Solar Eclipse

here is a selection from it:

Photographic Filters

You will need a good safe solar filter both to view and photograph the partial phases of the eclipse.

Even after the eclipse starts, the Moon is not blocking out the entire photosphere of the Sun. The photosphere puts out so much light and radiation, it can blind you if you look directly at it, especially through binoculars or a telescope. Be careful!

It is only after the Moon completely block the Sun, and totality starts, that it is safe to take off your filters and look at the Sun with your naked eyes. You can look at the eclipse with binocular and a telescope without a filter ONLY during totality.

WARNING! Solar filters must be placed in front of the lens. That is where they will filter out most of the light before it reaches the objective of the lens or telescope. The lenses in a lens or telescope or binoculars gather light based on their aperture, or diameter. They gather and concentrate this light. That's why we use them to make faint things more visible and to magnify them. When you use these on the Sun, which is already incredibly dangerous to look at, you gather and magnify even more light, which makes it extremely dangerous. You have to filter out most of this light before it enters your lens or binoculars or telescope. You can NOT place any kind of filter behind the objective, say between the lens and camera, or telescope and eyepiece. It is extremely dangerous! Your solar filter belongs on the front end of the lens or telescope, facing the sky. . . . Some other photographers may think they can use a polarizing filter to cut down on the intensity of the Sun's light. While polarizing filters may darken a normal scene to some extent, they are not going to come anywhere near enough reduction to use on the Sun.

WARNING! Almost all regular photographic neutral density filters and polarizing filters are NOT SAFE for VISUAL USE even if they seem to cut down the intensity of the Sun to a level usable for photography. This is because while they block a lot of visible light, they allow harmful radiation to pass through that is invisible. So if you try to use one of these for photography, which is not a good idea, you can NOT look through the camera while it is pointed at the Sun, even with the filter in place. Don't even try it!

Some solar filters are threaded to screw into the front of camera lenses. It is highly recommended not to use these for this total eclipse. Make sure your filter is easy to remove just before totality because the last thing you want to be doing 15 seconds before totality is struggling to remove a filter.

please read the full article

the author's bona fides

http://www.learn.usa.canon.com/resources/contributors/contributors/lodriguss_bio.shtml

" Lodriguss' astronomical photography of objects such as nebulae and galaxies has appeared in books and magazines all over the world. He is recognized as an expert in the field of DSLR astrophotography and the digital enhancement and correction of deep-sky color astrophotographs. "

___________________________________________________

" hey, lets be careful out there "


Last edited by aslyfox; 07-20-2017 at 06:57 AM.
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