issue with taking photos with Rebel T7 & EF 75-300mm Lens

[bmdush]

I recently purchased a additional lens for my Rebel T7, the EF 75-300mm. When I first got it, I was able to take a few photos. I then tested a wide angle converter with it and now it won't take photos without it at all using AF. It kind of works with MF turned on. But they still won't focus quite right. The camera works perfectly normal when I put my EF-S 18-55mm lens on. Any suggestions on how to solve the problem?

[bmdush]

Being honest here. I’m not entirely sure what you mean by focal length. I’m a newbie to photography and am still understanding all of the terminology. 

So hopefully more detail can help you. I have been using the 18-55mm EF-S lens that came with my camera. But it’s no where close to being what I need. I have to be too close to the front and have to use the 55mm. Everything would be too far away. My sanctuary also has bad lighting so you are right. Flash is not an option. It is still somewhat too dark on Sunday morning with the sunshine outside. When we have special services like a candlelight service, lighting goes completely out of the window. 

[Tronhard]

OK, to help us help you, and for you to get a good handle on the terminology and advice,  it is important for to get some basic photographic knowledge under your belt.  So, invest about 2 1/2 hours and watch this introduction to photography by Chris Bray, a National Geographic Pro.  His course will give you the basics in an easy to digest format.

Learn Photography [Full Course] by Australian Geographic Photographer Chris Bray - YouTube

After watching the Intro and Basics sections, I suggest you go to timestamp 1:53:40 to get the low-down on lenses, but whatch the rest of the video at a later date.

[Tronhard]

There are two things that will improve your photography.

First learning more about photography.  Right now, as you admit, your knowledge is very limited.   That will hamper you in engaging with other photographers and making the best use of advice offered by others - including how relevant it is to you.  So, as I already suggested, you need to get some knowledge under your belt.  The video I referred to is a start. 

The other part is the gear issue that brought you to us to begin with. If you were going to stick with your existing Canon body, then you can seek to improve the optics.  Sticking a wide-angle lens adapter on a poor-quality telephoto zoom is not a viable solution.  Right now, you have an 18-55 lens that may work for the wider view stuff like the images of the sanctuary.  The issue of getting close-up images of your worship ceremonies requires quite  a different solution from the one you tried (with the best will in the world!). 

But you have other issues here.  You need to be able to function in low-light situations without a tripod or a flash.  That indicates what we call a 'fast' lens - and the 'speed' of a lens is indicated by the f-number.  The smaller the number the 'faster' it is and more tolerant of low light conditions.  One thing your current 75-300 lens does not offer is Image Stabilization (IS) - this is a feature of lenses (and some bodies, but not yours) to make the lens less likely to show movement from shaking when you are dealing with low-light situations.  This feature would be hugely beneficial to you.

There are two solutions to these issues.

1. Keep the 18-55 lens as your wide-angle lens for sanctuary shots if it has a wide enough view. That leaves us with a lens to cover the longer range shots. The numbers xx-xxx indicate the degree of magnification and isolation you can get with a lens - the bigger the numbers the better a lens is at isolating distant objects. 
So, in summary: keep your 18-55 for wide shots, get an image-stabilized lens in the EF 70-200  or EF 70-300 range that has a fairly small f-value.

As I mentioned, the Canon EF 70-300 lenses are good (all versions) and you can pick up some bargains there - used or refurbished.  There are also Canon EF 70-200 IS USM lenses that will work better in low light - but these are professional-grade lenses and expensive.  All of these are image stabilized, so you are winning already with any of these.  There are some third-party options (i.e. not made by Canon, but still good lenses):  
In the same range, Tamron make a SP 70-300mm f/4-5.6 Di VC USD lens that is highly regarded and considered excellent value.  The VR indicates stands for Vibration Control, the same thing as Canon's IS.

2. Another option is to go for one lens that covers the whole range in one unit.  These are usually called 'super zooms' because you can go from a wide view to a very close-up view all in one unit.  This has some advantages - no changing of lenses means you can react fast to different situations, where necessary; and every time you change lenses you increase the risk of getting dust into your camera that will show up as marks on the photos.  The down side is that the lenses usually don't have quite the same image quality as the more modest ranges - but likely not as bad as your 75-300!
There is a Sigma option: 18-300mm F3.5-6.3 DC MACRO OS HSM | Contemporary | Lenses | SIGMA Corporation (sigma-global.com)  in this case the OS indicates Optical Stabilization - the same thing as IS for Canon lenses.

I know you are getting bombarded with a lot of information here from me, and others and likely suffering overload.  So, I would suggest going to someone you trust as a knowledgeable photographer (maybe a parishioner?), a local photographic society, or a camera store and talking to them.

But we are always here to help if we can, so feel free to ask more questions!!

[normadel]

Do you have another lens you can test the body with? Any EF-S or EF lens will do.

If the camera works with a known-good lens, you should get yourself a lens with wide-angle range. A good inexpensive option would be an EF-S 18-55 or an EF-S 18-135.  They are readily available used (warranteed from a used equipment dealer) or possibly cheaper on eBay. Dealers I recommend are KEH.com, MPB.com, UsedPhotoPro.com.

A 75-300 lens on a crop-sensor camera is equivalent to a 120-480mm focal length on a full-size sensor camera. Definitely less-than-useful indoors.

[Tronhard]

Look on the top right of the screen by your avatar.  There is an envelope icon there - click on it to see a personal message I have sent to you.

[Waddizzle]

The sample photo that you posted of an outdoor shot looks like someone forgot to remove the lens cap.  I am beginning to wonder if your lens has an aperture issue.  However, a bad or stuck aperture would not necessarily stop the camera/lens combo for autofocusing.  It could if the aperture were stuck in a fully stopped down position.

As others have pointed out, this lens is not one of Canon’s best efforts.  I think the design goal for this common kit lens was to teach beginners about photography, not capturing magazine cover quality mages.  

If this lens is bad, which it seems to be, then I recommend replacing it with an EF-S 55-250mm IS STM from Canon.  This lens is a replacement for the range of focal lengths of your current lens.  It is not my first choice for indoor photography of almost any kind.  

For indoor photography with a Rebel, I would look into the Canon EF-S 24mm f/2.8 STM.  This lens is a pretty good match for Rebel bodies and new users.

[rs-eos · Accepted solution]

It sounds like at least two focal lengths are needed.  One to get a wider shot to fit in more of the environment/subjects.  The second, to get closeup details.  If so, you'll find it difficult to have just a single lens for that, especially one that will help with the low-light.

I strongly recommend renting some lenses to see what may work best in your particular situation, then purchasing later.

Just a complete guess here, and quite expensive, but perhaps the EF 24mm f/1.4 would work well for your wide shots.   Also thinking perhaps of the EF 135mm f/2.0 if you need a telephoto lens with more light-gathering capability than an f/2.8 lens.    You can then trade some light-gathering performance with flexibility by looking at perhaps two zooms: EF 16-35mm f/2.8 and EF 70-200mm f/2.8 (or EF 24-70mm f/2.8)

[Tronhard]

As always, when we offer assistance, not having any idea of budget constraints will mean that we are challenged to find the best solutions that are cost-effective for you.  Ernie has suggested the EF-S 55-250, which is a good lens, and it may well work - but we have no idea of how far away your subjects are for the long shots.  Ricky's suggestion of renting a couple of lenses - perhaps the 55-250 STM or USM, and the 70-300 MkII USM could give you a chance to test the waters.