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Showing results for tags 'focus'.
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Having searched for a while I managed to acquire the legendary Pentax Asahi SMC Takumar 6 element 135mm f2.5 m42 lens to use for wide-ish images, I've also got a 200mm f4 to try. I'm using it with a modded Canon 600D. I'm wondering if there is a way to improve the infinity focus, the below was shot at roughly f5.5 with the 135mm to reduce star bloat (around a 10 image stack of 30s each, no calibration frames), but the focus is still off despite the lens being at it's infinity focus stop with the focusing ring. It could be the m42 to ef adaptor I have maybe too thick/thin (though I don't really see how much thinner/thicker it can be to make a difference), the lens is fully home against the front face of the ring and the ring is fully connected to the DSLR body. Any suggestions or is this the best I can expect from such an old and wide-ish lens? The image has been level stretched around 3 times, and the red channel brought down in line with the green and blue. -
Hi, been trying a few times to image with a Coronado PST and cannot get focus. With the ZWO 224MC I tried printing a "low profile nosepiece" found on the internet and that didn't work - the camera looks like it needs to go further into the eyepiece holder - some people have managed to get it to work I don't know how. So I modelled another low profile nosepiece which has a 4mm depth groove around the bottom of the nosepiece face so it can sink into the Coronado eyepiece holder 4mm more - nope still no focus. People have suggested unscrewing the lens part of a barlow out and using that with the camera nosepiece, tried a 2x Meade telenegative and a generic 5x - nope makes it worse. So today I tried a DSLR connected to a t nosepiece extension tube and ran into the same issues. I don't know how people are managing to image with this scope - I know it's not designed to be imaged with but it is something I wish to do considering others have managed it. On another note, how clear is surface detail visually on a PST, I can manage to see sunspots but no light/dark granular structure, with the focus ring dialled all the way to the left I can see prominances, sunspots with the ring dialled more to the right though most of the time its all a red blur - checked the ITF and that's clear (it's the newer type PST).
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Hi All, new user here and proud new owner of an RC6 telescope Im am trying for a couple of days to get the new scope working correctly and I think I’m close. My biggest issue is collimating, witch I managed to get close yesterday while looking at a defocused star. My problem is that I can see a “shadow” of the secondary mirror in my images even though I have good focus. Can someone help me Figur this out? i also added o picture of my focus on a bright star and a picture where the spider veins of the secondary are visible. Thanks for the support and clear skies! -
Hi all! Since there is cloudy outside I tried getting a photo of a false star, i.e. a led-lamp that I put behind some alumina foils with a needle point in the foils. Distance is 7 meters. I cannot get anything resemling a star, I just see the secondary mirror holder in (or not in) focus... My equipment follows below... Here are some photos of parts that I have, but I have no clue how to assemble them to get focus. At one point I managed to get pritty decent focus on stars the other night, but I have no memory of how I did If you could help a lost soul figuring this pussle out I owe you a beer or three! The distances below are approximate in mm, disregarding the "mounting joint screw-thing".. Thank you! Peter W If you This is my equipment: Orion Mount Atlas EQ-G Orion 10'' Newton Astrograph Orion AccuFocus Electronic Telescope Focuser Orion LaserMate Deluxe II Telescope Laser Collimator Orion Collimating Telescope Eyepiece Orion 2" 2x Barlow Lens 6mm Orion Expanse Telescope Eyepiece 12.5mm Orion Sirius Plossl Telescope Eyepiece Orion 2" to 1.25" Precision Centering Adapter Baader MPCC Mark III Multi-Purpose Coma Corrector SBIG STF-8300 SBIG Filter Wheel FW-8 Baader filter 36mm LRGB Set Baader filter 36mm H-alpha Baader filter 36mm O III Baader filter 36mm S-II Baader filter 36mm UV/IR-Cut/L 2" Orion SkyGlow Astrophotography Filter Orion Magnificent Mini Deluxe AutoGuider Package -
Last night started off so clear (an unexpected according to CO) so managed to drag the rig out onto the patio. Nebula targets that are above houses and trees are few and far between at moment for me but ad a go at Horsehead initially then Heart. But I was not happy with the images I was getting and a close look showed the focus was not precise, in fact far from it. So using the auto focuser in EKOS I tried tuning it in. But each time I tried it failed. I did look on line for suggested parameters and that was not too useful as there were suggestions to use just about every combination possible. Now, maybe there is a wide range of parameters being used and which you find best may depend on camera and FL of the scope setup, I think I do not understand the mechanism of auto focusing enough, I sort of assumed it just moved the focusser in and out to get the star it had chosen as small as it would go. One thing I did find is that even after trying many different parameters already suggested as the best on-line if the stars had halos due to being a fair way out of focus it never achieved focus at all and basically I ended up manually focusing inwards for a while to see if the image got better, then if not move it outwards, until the stars were pretty much in focus and then an auto focus did pretty well and got the stars pin point. So is that what other people find ? Is that pretty normal for most auto focus algorithms ? Also I thought this might be a good place for people to maybe say what parameters they use in EKOS and mention the scope and camera if that is relevant ? If there is somewhere with this info I apologize profusely Steve -
Hello all, I’m a newbie...that will become very apparent in the next few sentences! I have a Celestron Nexstar 130 SLT and have a desire to take up astrophotography, I started with a few reasonable shots of the moon with my iPhone and have bought a Skyris 236C with no success. I would be greatful for any tips or advise on how to focus the moon for a start, I have uploaded a couple of photos one with the iPhone and one with the Skyris taken at the same time. TIA, Tony.
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Hi i own Celestron 130EQ which comes with 20mm erect EP and 10mm EP.... i bought a GSO ED 3x Barlow... The focus is not very sharp while using Barlow... Is it the EP at fault ???? Is it worth upgrading to Kelner or a Plossl ????
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Hi I’ve recently got some shiny new kit, and last night was the first clear skies here when I had the opportunity to try it all out. This is not my first time observing, so I’m well prepared for unexpected issues, but it is my first time ccd imaging. There was lots of learning, including; cable management needs to be better, I (still) never have the right USB cable, and the focus tube needs some mechanical refining to address slippage. But the problem I’m not sure how to solve is one of focus. I bought the SW Trius 814 kit (Trius 814, mini usb filter wheel with OAG, and Lodestar X2) and naively thought that perhaps if it was sold together it would all work together. And maybe it does, I’m not immune to stupidity I could achieve focus with the 814 relatively easily, and even captured a test image and solved it in Ekos, all very heart warming. But I couldn’t then get focus with the Lodestar X2 (attached to the integrated OAG in the mini wheel) without pulling the focus tube out considerably further (approx. 50-80mm I didn’t measure). This obviously isn’t ideal. Am I missing something? The setup is: ED80 -> Field flattener -> filterwheel with OAG -> Trius 814 with the Lodestar attaches directly to the OAG. All advice appreciated, and please don’t imagine that I won’t have missed something ‘obvious’ Thanks Justin
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I'm brand new to this site, but I'm having an issue with my Celestron Powerseeker 127eq telescope. It's brand new right out of the box today. I have another telescope, Zhummel Z10, but the celestron just won't focus. It gets so close to focusing and just needs a little more. Any my help is appreciated thank! -
Two questions if I may. 1. Can the three screws marked by yellow arrows in the picture below be used to mount a second finder shoe on the C11 EDGE HD scope, permitting both a straight through and a right angle finder to be fitted? 2. The EDGE has field flattening optics inside; is the distance from the visual back to the chip critical, or by making adjustments to the position of the mirror to achieve focus on a chip say 250mm away from the visual back mean the field will still be flat at that distance? Thanks. James
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I have yet to be entirely happy with the focus on my pictures. When cropping them quite heavily (I use a DSLR, so smaller DSOs need a bit of cropping) the stars always feel a bit bloaty and look out of focus - much more than the image from the full frame. I have been using the focus aid in APT, checking out the FWHM tool. I don't know much about the science behind it, but my understanding is that the number needs to be as low as possible. Last night I was focussing and tweaked it down to around 1 to 1.5 - obviously it was fluctuating with the atmosphere/interference, but I thought that it was a pretty good score. I locked the focus very carefully, making sure that I didn't change the figure - I usually tighten half-way, check the value and then re-do it (if needed) before locking it down completely. I only twigged tonight that DSS shows a FWHM maximum on the light frames after it has checked them and, when I looked for the images I took last night, the FWHM figures were coming out at over 4.5. I am presuming that this is far from ideal focus, but is also a long way from what I thought it was. Is there any relation between the FWHM measurements in APT and DSS? Is there a reason for the discrepancy or am I just going to need to be even more careful with focussing? Are there vital settings in APT that I need to set? Will check for more scope related settings next time I get out. Might also need to get the Bhatinov mask out rather than relying on just APT Focus Aid. Thanks, as ever, for any thoughts
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Can I reach focus with a DSLR and a focal reducer like with a barlow because my telescope does not have enough inward focus . -
Hi all, I've been dabbling for about a year and am having a lot of fun. Nothing too serious and I don't have mega expectations but I'm starting to wonder if my images could be sharper and there's something I'm missing. I'm attaching a picture which is the best 10% of a 3 minute video with 500d 'bolted' straight to the 200p f5 scope. No filters...no barlows...just camera straight on. It's sharpened and saturated after the fact so in every way this is the sharpest I can get it. I've always had the same issue whether it's with a single shot, stacks of shots, or stacked video. Views through the eyepieces (circle-T 12.5/25) are mega sharp! I'm happy that collimation is very good and it was a remarkably clear night tonight. All in all I'd be pretty happy with this image (maybe over exposed a bit...) if the craters with shadows didn't make me want to rub my eyes. Thanks in advance for any thoughts or advice! -
I spent the full night out last night and got 6 hours of Ha lights on the Bubble and the Horsehead. Reasonably pleased with the results, but even though I followed my usual process and got good focus statistics in APT, I am slightly out of focus with roundy stars and some are even slightly donutty. Samples are attached below. Problem: - After getting close to spot-on focus, the APT Bahtinov Aid showed a focus distance oscillating from -0.02 to +0.02. Seeing seemed good to the inexpert eye. Not so sure about transparency as there was some thin, wispy cloud throughout the night. So, I started the night's imaging with focus 'Close' rather than 'On' focus. - Different subs show different quality stars, ranging from small donuts to circles. Background information: - HEQ5 Pro Rowan; SW Esprit 80 with field flattener, SW stock manual Crayford focuser; ZWO EFW Mini; Baader 1.25" 3.5nm Ha filter; ZWO ASI1600MM Pro binned 1x1 @ -20c. - AA Starwave 50mm guidescope with ZWO ASI290mm Mini guidecam binned 2x2. - All subs are 300s, gain 139, offset 10. - Polar alignment with Sharpcap to 17 arcsec ("Excellent"); capture with APT; guiding with Phd2. Focus with Bahtinov mask and APT Bahtinov Aid. Stacked in DSS with Darks, Flats and Dark Flats. - Mount is well balanced in RA, but is very camera-heavy in Dec. - PHD2 guiding was around 2"/px. Imaging pixel scale is 1.9"/px. Questions: - Do I put the round stars down to seeing, given that the Bahtinov Aid focus distance was bouncing equally above and below zero? - Can poor seeing cause the donut stars? - Would an electronic auto-focuser do any better in this situation? - Would the Seeing Monitor in Sharpcap give useful information? I didn't think to use it last night. - Could my guiding performance, and possibly the Dec balance, have affected the image quality in this way? - What are my options in future - abandon imaging for the night? Bin all images in software 2x2 or 4x4 to sharpen the stars at the expense of lower resolution? - Other suggestions? Sample 1: Detail from a single 5-min sub of Bubble nebula at 100% showing round stars, and a blurred bubble. Sample 2: Detail from a different sub of the Bubble nebula at 400% showing donuts Sample 3: Detail from a 5-min sub of the Horsehead nebula at 100%, showing both round and donut stars Finally, both images stacked, calibrated and stretched, scaled to 4x4 in Gimp. 28x300s Ha on bubble, 22*300s Ha on horsehead.
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Good night, I have a Shoestring Astronomy automatic focuser. But it does not memorize the absolute position... Will it be necessary to add encoders in order to use it on a full robotic setup? I'll use SGP. Thanks so much, Aleix
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I have been researching Radio-Astronomy and have not been able to determine information on antenna directionality. Do RT mounts require axis motors to keep the object in it's focus area? What are the resolution ranges and factors that determine the discrimination of say one star from another which have very small degrees of separation?
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I recently acquired a Meade Lightbridge 16" scope (f 4.5), and realized that I'm unable to focus with my barlow attached ( the barlow is a Celestron X-Cel LX 3x barlow). After some experimentation, I found that it's because the focal plane of the primary is too short - it's just at the end of the focuser when it's fully retracted. By removing the 2"-1.25" adapter, I found that I'm able to focus with the barlow if it can go about 6 mm further in. Other than cutting my truss tubes to shorten them, or buying a lower profile focuser, is there any cheap, DIY method by which I can achieve focus? An astronomer friend of mine suggested fully tightening all the primary collimation knobs, so that the primary mirror moves up a little inside the OTA, thus bringing the focus further out of the focuser, but that didn't help ( it probably moved upwards only by a couple of millimeters) -
Hey guys I'm new to telescopes and well I have tried reading up on possible fixes, nothing works. First day I used it I was able to get a clear image on the lowest power inserting a 20mm eye piece and it would focus. Attempted my first night to look at Mars. Well it was a big blur and nothing worked. Next day I was attempting to look at a mountain and no matter what I did or try it remained blurry. Focus dial is free moving but the image stay as a massive blur. With no eyepiece it's still all a blur. If I look through it backwards there is a clear image however looking from the eyepiece it remains blurry. Im not sure what to do now. Any ideas? -
Hey ? I took delivery of a Skywatcher 200p last night and got it set up ok I think. I got a good view of Jupiter with the 25mm lens but when I put the Barlow lens in I couldn't focus it. I also tried the 10mm lens but it made everything grey, no real light comes in at all. It came with a thing that might be called a focuser extension, not sure, but it didn't help. What rookie mistakes am I making? -
Hi, I bought some Williams Optics Binoviewers. They appear very nice quality but I cannot achieve foucus with them on a 5" Celestron Newtonian, FL = 650MM fr = f5. I have not used binoviwers before today and I bought them primarily for my new telescope which hasn't arrived yet, a Celestron 9.25 CST. I wanted to try the binoviwers out on the 5" today but could not achieve focus. I also tried using the 1.5 x Barlow that came with them. Is there a reason they won't focus? Do you think they will be OK on my bigger scope? Thanks. -
Hello, I'm getting desperate over this hobby (but I refuse to give up); with every change new problems set in. I purchased a SVBONY SV106 (60mm - 240mm) guide scope to replace a 80mm - 400mm scope, I was using as a guide scope which was installed on the Orion 8 tube rings. I replaced the finder scope with the guide scope. First issue balancing but that one I sorted out. Then I tried to focus the ASI120MM with the new guide scope. For the old one (80x400) , I needed 2 extensions (in fact the extensions are low cost barlows from which I removed the plastic lens) to get focus. To align the new guide scope, I used a 17mm eyepiece and that went ok while pointing at some far away trees. But I could not get the ASI120MM focused on the same trees, not with PHD2 nor with Firecapture; I turned the gain way down, but with or without extensions, no focus. As bad weather is (again) setting in and the scope is permanently outside I had to stop trying. So I take on this break to get some assistance. Anybody any advice on this, for AstroRookie -
Hey there! So if you have a telescope as mentioned in the title, you probably noticed that the focus wheel stops working after a bit. Well If you look under the focuser you can see a small metal piece with 4 screws on it. You need a Philips head screwdriver to unscrew these, WARNING there's a lot of superglue(which actually isn't needed at all) so wear gloves!after you've unscrewed the metal piece a small black 2 ended piece should fall out. If it didn't fall, take it out. Now place your focusing wheels back without that small piece that fell out and screw everything back in. The remaining black piece that fell out should probably be thrown away. Now just don't focus out to the max and everything should work just fine! I hope this helped(btw I'm new here so i might've butchered the terminology) *just let me know -
Hi all. after receiving my scope yesterday I went outside for about half an hour with it and was quite impressed on how easy everything is to set up and use. However I have two questions that I would like answered. When viewing at the moon using my 25mm eyepiece I could see a blue and orange haze around the left and right side of the moon. Was this because I didn’t have eyepeice focused probably or is there another reason? And also while focusing I had a lot of vibration is there a way to reduce it. Today I tried to get my red dot focused aligned with my telescope and I think I’ve managed o do it correctly but was concerned that my target was to close. My target was the Ariel on the roof top as I didn’t have any clear targets that were far away I had to choose that. I managed to get it aligned probably but heard that the targets were supposed to me further away? Man Thanks
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I’ve just acquired the above (birthday prezzie!). It’s a nice finder, and a definite boost from the 7x30 bundled with the scope! However, I’m struggling to get anywhere near focus with my Pentax K50 on the end of it... anyone know why? There’s no focus mechanism to speak of, other than the objective lens’ mounting thread... -
Hi, i just wanna share a in depth review that i made on how the Primalucelab Sesto Senso works, and how i actually runs an autofocus routine with it. you can watch the whole review on my youtube channel here:
