Ed Galea
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Hi Everyone. I'm a beginner so have a beginner question, which may have been previously answered, so hope you will forgive me if that is the case. I'm trying to determine which would be better for DSO astrophotography, a telephoto/zoom lens or a telescope? I'm just interested in the optics, not other issues such as cost (other issues will mitigate cost issues) or weight. I simply would like to know, for a given focal length and aperture size (hence f number), which would be better, a telephoto lens or a telescope, or is there no difference (forgetting price and weight)? By better, I mean which would, (a) produce the better-quality images and (b) require the least amount of time to produce a given quality image. The reason I ask is that a telephoto/zoom lens will have lots of lenses in the OT, for example 11 lenses in 7 groups, while a telescope would have perhaps 4 lenses in 3 groups. With the light going through so much more glass in the telephoto/zoom lens, does this effectively slow-down the lens compared to an equivalent telescope i.e., require longer exposure times, even though the same f number, and at the same time, does it potentially improve the quality of the image? For arugments sake, compare a quality 200mm F/2 telephoto/zoom lens with a quality 200mm F/2 telescope. -
Onikkinen many thanks, in particular for your last sentence. Thanks also to happy-kat. This is precisely what I was looking for. Those are precisely the DSO targets I was hoping to image in my Step 1. It sound like I won't really benefit (or need) any filters in Step 1 of my adventure. So in my merry-go-round of purchase decisions I think I'm back to the possiblity of a FujiFilm X T3 and Samyang 135 and possibly a yet to be decided Canon and Samyang 135 on a solid tripod of some kind. I will continue to search for a suitable Canon camera (currently thinking of a Canon EOS T7i or better) before I finalise my decision, but as I have said previously, I will want the camera to also function as a terristerial camera too which is way I fancy the XT3.
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Hi Onikkinen, many thanks again for the great information and for the words of encouragement. When you say 'a filter is never a necessity' are you suggesting that I don't need a filter or that it is not essential? Also, I 'm not clear if for the short duration exposures I will be taking initially (without a tracker) if a filter will make any descernable difference at all. But it is good to know that there are clip in filters for the fujifilm cameras.
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Nigella, yes indeed, but it is a learning process and we learn something with each step of the way. Also opens up new problems. For example, while the Canon provides a clip in filter solution, I don't think that is very practical as when you move onto a dedicated astro camera you will need to repurchase all your filters again. So I'd like to find a more practical solution that will allow me to reuse expensive filters when I change camera type. Any thoughts on this?
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Happy-kat, many thanks for the link, I will have a look at this - there are a huge number of posts on that thread so hopefully will find something relevant to my immediate issues, but interesting stuff never the less.
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Happy-kat, yes I guess that would be a reasonable, but my Step 2 will see me progress to a tracking mount. If I can't use filters on my selected camera/lens combination I'll have to change the camera. This looks like it could force me down the Canon route after all!
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Thanks Happy-kat, but doesn't that stopper the lens down? Won't I be losing aperture?
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Many thanks Andrew_B, you are a star (pun intended). One last question, as I am in Bortle 8 I understand that I will need to be imaging with filters, probably a broadband light pollution filter like the Optolong L-enhance or similar. My question is, how are these used/installed when using the X-T3? For example, if I was using the Samyang 135mm lens or a 200mm lens, how would I install the filter? Do I need to purchase some kind of cassette that takes the filter that sits between the back of the lens and the camera? The filter is either 1.25'' or 2.0'' so won't screw onto the lens. Optolong also do plug in versions, but I assume that is just for Canon? So if I go down the X-T3 route, does that mean I can't use filters to tame the light pollution? Thanks again for your patience.
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Hi Andrew_B, Thanks again for the insight. I heard about the issue you describe concerning the Fujifilm X-T3, but from what I understand, and you confirm, it is not as pronounced as the Sony 'star eater' problem. So I'm still thinking about the Fujifilm X-T3 as a possible contender. As you suggest, it would be a pretty good 'all around camera' and so will satisfy my terrestrial photography needs. Another camera I've been thinking about is the Pentax K-1 Mark 1. I understand that Pentax is fairly unique in that it has the built in astrotracer mode that is suitable for relatively 'short' 'long' exposures of around 60s to 90s. This could be quite useful. The camera is also full frame which has its attactions for AP. I think the disadvantage of this camera for me is that it is very heavy, there are not so many lenses and they are more expensive (the Samyang 135 mm comes in a K mount but is more expensive then options with more common mounts). While the Pentax K1 Mark 1 uses the Sony sensor, I believe it does not suffer from the dreaded 'star-eater' problem. I just had a look at a video by Cuiv, The Lazy Geek using this camera in Tokyo (similar Bortle to London) for DSO and it was pretty good. So the XT3 is better than the K1 for my terrestrial needs, but the K1 may be better than the XT3 for my AP needs? Any thoughts on these two or a better camera to meet both needs?
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Thanks for the info Happy-Kat, I just joined.
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Thanks Nigella, it is difficult to take that first step. But my additional constraint in STEP 1 is that I also want a camera for terristrial photography too! So my initial investment won't be wasted if I decide AP is not for me! So, I want to find a good camera (and lens) that will get demonstrate to me the joys of AP, allow me to develop some skills in post processing, be a great camera/lens for terirsterial photography and then rapidly move onto the latter steps where I will invest in a telescope and dedicated astro camera. That is why I'm happy to invest quite a bit of £££ in the initial camera/lens combo, it will have other uses and it will be stepping stone onto other things!
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Thanks Onikkinen, I totally understand where you're coming from. The Samyank 135 does come with an X mount, so will be compatible with the Fujifilm XT3. I just heard from Happy-kat that the Fujifilm RAW mode was not compatible with some stacker software. I imagine it will be a pain to have to convert all your RAW images each time you need to stack them. Just another step in the work flow! Another camera I've been thinking about is the Pentax K-1 Mark 1. I understand that Pentax is fairly unique in that it has an astrotracer mode which is like a built in tracker - suitable for relatively 'short' 'long' exposrues. It enables you to take images of 60s to 90s depending on the focal length of the lens. That could be quite useful. It is also a full frame sensor. I think the disadvantages of this camera is that it is very heavy, there are not so many lenses and they are more expensive (Samyang 135mm appears to be a bit more expensive with the K mount). While the Pentax K1 uses the Sony sensor, I believe it does not suffer from the 'star-eater' problem that the Sony A6400 does and which put me off the Sony camera. Any thoughts?
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Thanks for the advice Happy-kat. I wasn't aware that the Fujifilm RAW mode was not compatible with some stackers. I imagine it will be a pain to have to convert all your RAW images each time you need to stack them. Just another step in the work flow! What about the Pentax K-1 Mark 1 as a camera. I understand it has an astrotracer mode which is like a built in tracker. It enable you to take images of 60s to 90s. That could be quite useful. It is also a full frame sensor. I think the disadvantages of this camera is that it is very heavy, there are not so many lenses and they are more expensive (Samyang 135 appears to be quite a bit more expensive with the K mount). While the Pentax K1 uses the Sony sensor, I believe it does not suffer from the 'star-eater' problem that the Sony A6400 does. Thanks again.
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Hi Nigella, thanks for your comments and nice images! I'd love to be able to achieve something as good with a camera and lens and simple tripod. Right now I trying to take my first step and get a suitable camera and lens and suitable mount for this kit. My camera search has led me to the Fujiflim X-T3 or possibly the newer X-T4. I believe the X-T4 has better video capabilities which may be useful for planetary photography and I think I read somewhere that it is better in low light?. What do you and the community think about these cameras for AP? Would the X-T3 be appropriate or should I go for the X-T4, is it worth the extra £££ for AP? Also, by going the Fujiflims route, will I be limiting myself in terms of the scope of lenses I can use and other accessories? Hopefully, the Samyang 135 has an X mount adapter as this is ONE of the lenses I'm thinking about getting for AP. Any advice welcome.
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Thanks Onikkinen, I hear what you are saying and appreciate the advice. But given that I am in Bortle 8 I'm not sure what I will be able to achieve or if I'll be happy with what I can achieve. So I want to approach this is a gradual way, taking small steps. I know this will cost more in the long run, but in the short run, I think it is the most sensible way to approach this. Especially as I'm also after a good setup for terristerial photography. I'm totally with you on the mount, when I puchase a tracking mount it will be something substantial that I can grow into and HEQ5 is something I'll consider. Right now (my Step 1) its the camera and lens and suitable mount for this kit. I hear you about the astro camera, but that is my Step 4. But I'm also looking for a camera that can be used for terrestrial photography as well as AP. So my camera search has led me to the Fujiflim X-T3 or possibly the newer X-T4. I believe the X-T4 has better video capabilities which may be useful for planetary photography and I think I read somewhere that it is better in low light?. What do you and the community think about these cameras for AP? Would the X-T3 be appropriate or should I go for the X-T4, is it worth the extra £££ for AP? Also, by going the Fujiflims route, will I be limiting myself in terms of the scope of lenses I can use and other accessories? Hopefully, the Samyang 135 has an X mount adapter as this is ONE of the lenses I'm thinking about getting for AP. Any advice welcome.
